1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995-2023 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/event-loop.h"
25 #include "gdbsupport/event-pipe.h"
26 #include "gdbsupport/rsp-low.h"
27 #include "gdbsupport/signals-state-save-restore.h"
28 #include "nat/linux-nat.h"
29 #include "nat/linux-waitpid.h"
30 #include "gdbsupport/gdb_wait.h"
31 #include "nat/gdb_ptrace.h"
32 #include "nat/linux-ptrace.h"
33 #include "nat/linux-procfs.h"
34 #include "nat/linux-personality.h"
36 #include <sys/ioctl.h>
39 #include <sys/syscall.h>
43 #include <sys/types.h>
48 #include "gdbsupport/filestuff.h"
49 #include "tracepoint.h"
51 #include "gdbsupport/common-inferior.h"
52 #include "nat/fork-inferior.h"
53 #include "gdbsupport/environ.h"
54 #include "gdbsupport/gdb-sigmask.h"
55 #include "gdbsupport/scoped_restore.h"
57 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
58 then ELFMAG0 will have been defined. If it didn't get included by
59 gdb_proc_service.h then including it will likely introduce a duplicate
60 definition of elf_fpregset_t. */
63 #include "nat/linux-namespaces.h"
73 /* Some targets did not define these ptrace constants from the start,
74 so gdbserver defines them locally here. In the future, these may
75 be removed after they are added to asm/ptrace.h. */
76 #if !(defined(PT_TEXT_ADDR) \
77 || defined(PT_DATA_ADDR) \
78 || defined(PT_TEXT_END_ADDR))
79 #if defined(__mcoldfire__)
80 /* These are still undefined in 3.10 kernels. */
81 #define PT_TEXT_ADDR 49*4
82 #define PT_DATA_ADDR 50*4
83 #define PT_TEXT_END_ADDR 51*4
84 /* These are still undefined in 3.10 kernels. */
85 #elif defined(__TMS320C6X__)
86 #define PT_TEXT_ADDR (0x10000*4)
87 #define PT_DATA_ADDR (0x10004*4)
88 #define PT_TEXT_END_ADDR (0x10008*4)
92 #if (defined(__UCLIBC__) \
93 && defined(HAS_NOMMU) \
94 && defined(PT_TEXT_ADDR) \
95 && defined(PT_DATA_ADDR) \
96 && defined(PT_TEXT_END_ADDR))
97 #define SUPPORTS_READ_OFFSETS
100 #ifdef HAVE_LINUX_BTRACE
101 # include "nat/linux-btrace.h"
102 # include "gdbsupport/btrace-common.h"
105 #ifndef HAVE_ELF32_AUXV_T
106 /* Copied from glibc's elf.h. */
109 uint32_t a_type
; /* Entry type */
112 uint32_t a_val
; /* Integer value */
113 /* We use to have pointer elements added here. We cannot do that,
114 though, since it does not work when using 32-bit definitions
115 on 64-bit platforms and vice versa. */
120 #ifndef HAVE_ELF64_AUXV_T
121 /* Copied from glibc's elf.h. */
124 uint64_t a_type
; /* Entry type */
127 uint64_t a_val
; /* Integer value */
128 /* We use to have pointer elements added here. We cannot do that,
129 though, since it does not work when using 32-bit definitions
130 on 64-bit platforms and vice versa. */
135 /* Does the current host support PTRACE_GETREGSET? */
136 int have_ptrace_getregset
= -1;
138 /* Return TRUE if THREAD is the leader thread of the process. */
141 is_leader (thread_info
*thread
)
143 ptid_t ptid
= ptid_of (thread
);
144 return ptid
.pid () == ptid
.lwp ();
149 /* See nat/linux-nat.h. */
152 ptid_of_lwp (struct lwp_info
*lwp
)
154 return ptid_of (get_lwp_thread (lwp
));
157 /* See nat/linux-nat.h. */
160 lwp_set_arch_private_info (struct lwp_info
*lwp
,
161 struct arch_lwp_info
*info
)
163 lwp
->arch_private
= info
;
166 /* See nat/linux-nat.h. */
168 struct arch_lwp_info
*
169 lwp_arch_private_info (struct lwp_info
*lwp
)
171 return lwp
->arch_private
;
174 /* See nat/linux-nat.h. */
177 lwp_is_stopped (struct lwp_info
*lwp
)
182 /* See nat/linux-nat.h. */
184 enum target_stop_reason
185 lwp_stop_reason (struct lwp_info
*lwp
)
187 return lwp
->stop_reason
;
190 /* See nat/linux-nat.h. */
193 lwp_is_stepping (struct lwp_info
*lwp
)
195 return lwp
->stepping
;
198 /* A list of all unknown processes which receive stop signals. Some
199 other process will presumably claim each of these as forked
200 children momentarily. */
202 struct simple_pid_list
204 /* The process ID. */
207 /* The status as reported by waitpid. */
211 struct simple_pid_list
*next
;
213 static struct simple_pid_list
*stopped_pids
;
215 /* Trivial list manipulation functions to keep track of a list of new
216 stopped processes. */
219 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
221 struct simple_pid_list
*new_pid
= XNEW (struct simple_pid_list
);
224 new_pid
->status
= status
;
225 new_pid
->next
= *listp
;
230 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
232 struct simple_pid_list
**p
;
234 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
235 if ((*p
)->pid
== pid
)
237 struct simple_pid_list
*next
= (*p
)->next
;
239 *statusp
= (*p
)->status
;
247 enum stopping_threads_kind
249 /* Not stopping threads presently. */
250 NOT_STOPPING_THREADS
,
252 /* Stopping threads. */
255 /* Stopping and suspending threads. */
256 STOPPING_AND_SUSPENDING_THREADS
259 /* This is set while stop_all_lwps is in effect. */
260 static stopping_threads_kind stopping_threads
= NOT_STOPPING_THREADS
;
262 /* FIXME make into a target method? */
263 int using_threads
= 1;
265 /* True if we're presently stabilizing threads (moving them out of
267 static int stabilizing_threads
;
269 static void unsuspend_all_lwps (struct lwp_info
*except
);
270 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
271 static int lwp_is_marked_dead (struct lwp_info
*lwp
);
272 static int kill_lwp (unsigned long lwpid
, int signo
);
273 static void enqueue_pending_signal (struct lwp_info
*lwp
, int signal
, siginfo_t
*info
);
274 static int linux_low_ptrace_options (int attached
);
275 static int check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
);
277 /* When the event-loop is doing a step-over, this points at the thread
279 static ptid_t step_over_bkpt
;
282 linux_process_target::low_supports_breakpoints ()
288 linux_process_target::low_get_pc (regcache
*regcache
)
294 linux_process_target::low_set_pc (regcache
*regcache
, CORE_ADDR newpc
)
296 gdb_assert_not_reached ("linux target op low_set_pc is not implemented");
299 std::vector
<CORE_ADDR
>
300 linux_process_target::low_get_next_pcs (regcache
*regcache
)
302 gdb_assert_not_reached ("linux target op low_get_next_pcs is not "
307 linux_process_target::low_decr_pc_after_break ()
312 /* True if LWP is stopped in its stepping range. */
315 lwp_in_step_range (struct lwp_info
*lwp
)
317 CORE_ADDR pc
= lwp
->stop_pc
;
319 return (pc
>= lwp
->step_range_start
&& pc
< lwp
->step_range_end
);
322 /* The event pipe registered as a waitable file in the event loop. */
323 static event_pipe linux_event_pipe
;
325 /* True if we're currently in async mode. */
326 #define target_is_async_p() (linux_event_pipe.is_open ())
328 static void send_sigstop (struct lwp_info
*lwp
);
330 /* Return non-zero if HEADER is a 64-bit ELF file. */
333 elf_64_header_p (const Elf64_Ehdr
*header
, unsigned int *machine
)
335 if (header
->e_ident
[EI_MAG0
] == ELFMAG0
336 && header
->e_ident
[EI_MAG1
] == ELFMAG1
337 && header
->e_ident
[EI_MAG2
] == ELFMAG2
338 && header
->e_ident
[EI_MAG3
] == ELFMAG3
)
340 *machine
= header
->e_machine
;
341 return header
->e_ident
[EI_CLASS
] == ELFCLASS64
;
348 /* Return non-zero if FILE is a 64-bit ELF file,
349 zero if the file is not a 64-bit ELF file,
350 and -1 if the file is not accessible or doesn't exist. */
353 elf_64_file_p (const char *file
, unsigned int *machine
)
358 fd
= open (file
, O_RDONLY
);
362 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
369 return elf_64_header_p (&header
, machine
);
372 /* Accepts an integer PID; Returns true if the executable PID is
373 running is a 64-bit ELF file.. */
376 linux_pid_exe_is_elf_64_file (int pid
, unsigned int *machine
)
380 sprintf (file
, "/proc/%d/exe", pid
);
381 return elf_64_file_p (file
, machine
);
385 linux_process_target::delete_lwp (lwp_info
*lwp
)
387 struct thread_info
*thr
= get_lwp_thread (lwp
);
389 threads_debug_printf ("deleting %ld", lwpid_of (thr
));
393 low_delete_thread (lwp
->arch_private
);
399 linux_process_target::low_delete_thread (arch_lwp_info
*info
)
401 /* Default implementation should be overridden if architecture-specific
402 info is being used. */
403 gdb_assert (info
== nullptr);
406 /* Open the /proc/PID/mem file for PROC. */
409 open_proc_mem_file (process_info
*proc
)
411 gdb_assert (proc
->priv
->mem_fd
== -1);
414 xsnprintf (filename
, sizeof filename
, "/proc/%d/mem", proc
->pid
);
417 = gdb_open_cloexec (filename
, O_RDWR
| O_LARGEFILE
, 0).release ();
421 linux_process_target::add_linux_process_no_mem_file (int pid
, int attached
)
423 struct process_info
*proc
;
425 proc
= add_process (pid
, attached
);
426 proc
->priv
= XCNEW (struct process_info_private
);
428 proc
->priv
->arch_private
= low_new_process ();
429 proc
->priv
->mem_fd
= -1;
436 linux_process_target::add_linux_process (int pid
, int attached
)
438 process_info
*proc
= add_linux_process_no_mem_file (pid
, attached
);
439 open_proc_mem_file (proc
);
444 linux_process_target::remove_linux_process (process_info
*proc
)
446 if (proc
->priv
->mem_fd
>= 0)
447 close (proc
->priv
->mem_fd
);
449 this->low_delete_process (proc
->priv
->arch_private
);
452 proc
->priv
= nullptr;
454 remove_process (proc
);
458 linux_process_target::low_new_process ()
464 linux_process_target::low_delete_process (arch_process_info
*info
)
466 /* Default implementation must be overridden if architecture-specific
468 gdb_assert (info
== nullptr);
472 linux_process_target::low_new_fork (process_info
*parent
, process_info
*child
)
478 linux_process_target::arch_setup_thread (thread_info
*thread
)
480 scoped_restore_current_thread restore_thread
;
481 switch_to_thread (thread
);
487 linux_process_target::handle_extended_wait (lwp_info
**orig_event_lwp
,
490 client_state
&cs
= get_client_state ();
491 struct lwp_info
*event_lwp
= *orig_event_lwp
;
492 int event
= linux_ptrace_get_extended_event (wstat
);
493 struct thread_info
*event_thr
= get_lwp_thread (event_lwp
);
494 struct lwp_info
*new_lwp
;
496 gdb_assert (event_lwp
->waitstatus
.kind () == TARGET_WAITKIND_IGNORE
);
498 /* All extended events we currently use are mid-syscall. Only
499 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
500 you have to be using PTRACE_SEIZE to get that. */
501 event_lwp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
503 if ((event
== PTRACE_EVENT_FORK
) || (event
== PTRACE_EVENT_VFORK
)
504 || (event
== PTRACE_EVENT_CLONE
))
507 unsigned long new_pid
;
510 /* Get the pid of the new lwp. */
511 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_thr
), (PTRACE_TYPE_ARG3
) 0,
514 /* If we haven't already seen the new PID stop, wait for it now. */
515 if (!pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
517 /* The new child has a pending SIGSTOP. We can't affect it until it
518 hits the SIGSTOP, but we're already attached. */
520 ret
= my_waitpid (new_pid
, &status
, __WALL
);
523 perror_with_name ("waiting for new child");
524 else if (ret
!= new_pid
)
525 warning ("wait returned unexpected PID %d", ret
);
526 else if (!WIFSTOPPED (status
))
527 warning ("wait returned unexpected status 0x%x", status
);
530 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
532 struct process_info
*parent_proc
;
533 struct process_info
*child_proc
;
534 struct lwp_info
*child_lwp
;
535 struct thread_info
*child_thr
;
537 ptid
= ptid_t (new_pid
, new_pid
);
539 threads_debug_printf ("Got fork event from LWP %ld, "
541 ptid_of (event_thr
).lwp (),
544 /* Add the new process to the tables and clone the breakpoint
545 lists of the parent. We need to do this even if the new process
546 will be detached, since we will need the process object and the
547 breakpoints to remove any breakpoints from memory when we
548 detach, and the client side will access registers. */
549 child_proc
= add_linux_process (new_pid
, 0);
550 gdb_assert (child_proc
!= NULL
);
551 child_lwp
= add_lwp (ptid
);
552 gdb_assert (child_lwp
!= NULL
);
553 child_lwp
->stopped
= 1;
554 child_lwp
->must_set_ptrace_flags
= 1;
555 child_lwp
->status_pending_p
= 0;
556 child_thr
= get_lwp_thread (child_lwp
);
557 child_thr
->last_resume_kind
= resume_stop
;
558 child_thr
->last_status
.set_stopped (GDB_SIGNAL_0
);
560 /* If we're suspending all threads, leave this one suspended
561 too. If the fork/clone parent is stepping over a breakpoint,
562 all other threads have been suspended already. Leave the
563 child suspended too. */
564 if (stopping_threads
== STOPPING_AND_SUSPENDING_THREADS
565 || event_lwp
->bp_reinsert
!= 0)
567 threads_debug_printf ("leaving child suspended");
568 child_lwp
->suspended
= 1;
571 parent_proc
= get_thread_process (event_thr
);
572 child_proc
->attached
= parent_proc
->attached
;
574 if (event_lwp
->bp_reinsert
!= 0
575 && supports_software_single_step ()
576 && event
== PTRACE_EVENT_VFORK
)
578 /* If we leave single-step breakpoints there, child will
579 hit it, so uninsert single-step breakpoints from parent
580 (and child). Once vfork child is done, reinsert
581 them back to parent. */
582 uninsert_single_step_breakpoints (event_thr
);
585 clone_all_breakpoints (child_thr
, event_thr
);
587 target_desc_up tdesc
= allocate_target_description ();
588 copy_target_description (tdesc
.get (), parent_proc
->tdesc
);
589 child_proc
->tdesc
= tdesc
.release ();
591 /* Clone arch-specific process data. */
592 low_new_fork (parent_proc
, child_proc
);
594 /* Save fork info in the parent thread. */
595 if (event
== PTRACE_EVENT_FORK
)
596 event_lwp
->waitstatus
.set_forked (ptid
);
597 else if (event
== PTRACE_EVENT_VFORK
)
598 event_lwp
->waitstatus
.set_vforked (ptid
);
600 /* The status_pending field contains bits denoting the
601 extended event, so when the pending event is handled,
602 the handler will look at lwp->waitstatus. */
603 event_lwp
->status_pending_p
= 1;
604 event_lwp
->status_pending
= wstat
;
606 /* Link the threads until the parent event is passed on to
608 event_lwp
->fork_relative
= child_lwp
;
609 child_lwp
->fork_relative
= event_lwp
;
611 /* If the parent thread is doing step-over with single-step
612 breakpoints, the list of single-step breakpoints are cloned
613 from the parent's. Remove them from the child process.
614 In case of vfork, we'll reinsert them back once vforked
616 if (event_lwp
->bp_reinsert
!= 0
617 && supports_software_single_step ())
619 /* The child process is forked and stopped, so it is safe
620 to access its memory without stopping all other threads
621 from other processes. */
622 delete_single_step_breakpoints (child_thr
);
624 gdb_assert (has_single_step_breakpoints (event_thr
));
625 gdb_assert (!has_single_step_breakpoints (child_thr
));
628 /* Report the event. */
633 ("Got clone event from LWP %ld, new child is LWP %ld",
634 lwpid_of (event_thr
), new_pid
);
636 ptid
= ptid_t (pid_of (event_thr
), new_pid
);
637 new_lwp
= add_lwp (ptid
);
639 /* Either we're going to immediately resume the new thread
640 or leave it stopped. resume_one_lwp is a nop if it
641 thinks the thread is currently running, so set this first
642 before calling resume_one_lwp. */
643 new_lwp
->stopped
= 1;
645 /* If we're suspending all threads, leave this one suspended
646 too. If the fork/clone parent is stepping over a breakpoint,
647 all other threads have been suspended already. Leave the
648 child suspended too. */
649 if (stopping_threads
== STOPPING_AND_SUSPENDING_THREADS
650 || event_lwp
->bp_reinsert
!= 0)
651 new_lwp
->suspended
= 1;
653 /* Normally we will get the pending SIGSTOP. But in some cases
654 we might get another signal delivered to the group first.
655 If we do get another signal, be sure not to lose it. */
656 if (WSTOPSIG (status
) != SIGSTOP
)
658 new_lwp
->stop_expected
= 1;
659 new_lwp
->status_pending_p
= 1;
660 new_lwp
->status_pending
= status
;
662 else if (cs
.report_thread_events
)
664 new_lwp
->waitstatus
.set_thread_created ();
665 new_lwp
->status_pending_p
= 1;
666 new_lwp
->status_pending
= status
;
670 thread_db_notice_clone (event_thr
, ptid
);
673 /* Don't report the event. */
676 else if (event
== PTRACE_EVENT_VFORK_DONE
)
678 event_lwp
->waitstatus
.set_vfork_done ();
680 if (event_lwp
->bp_reinsert
!= 0 && supports_software_single_step ())
682 reinsert_single_step_breakpoints (event_thr
);
684 gdb_assert (has_single_step_breakpoints (event_thr
));
687 /* Report the event. */
690 else if (event
== PTRACE_EVENT_EXEC
&& cs
.report_exec_events
)
692 struct process_info
*proc
;
693 std::vector
<int> syscalls_to_catch
;
697 threads_debug_printf ("Got exec event from LWP %ld",
698 lwpid_of (event_thr
));
700 /* Get the event ptid. */
701 event_ptid
= ptid_of (event_thr
);
702 event_pid
= event_ptid
.pid ();
704 /* Save the syscall list from the execing process. */
705 proc
= get_thread_process (event_thr
);
706 syscalls_to_catch
= std::move (proc
->syscalls_to_catch
);
708 /* Delete the execing process and all its threads. */
710 switch_to_thread (nullptr);
712 /* Create a new process/lwp/thread. */
713 proc
= add_linux_process (event_pid
, 0);
714 event_lwp
= add_lwp (event_ptid
);
715 event_thr
= get_lwp_thread (event_lwp
);
716 gdb_assert (current_thread
== event_thr
);
717 arch_setup_thread (event_thr
);
719 /* Set the event status. */
720 event_lwp
->waitstatus
.set_execd
722 (linux_proc_pid_to_exec_file (lwpid_of (event_thr
))));
724 /* Mark the exec status as pending. */
725 event_lwp
->stopped
= 1;
726 event_lwp
->status_pending_p
= 1;
727 event_lwp
->status_pending
= wstat
;
728 event_thr
->last_resume_kind
= resume_continue
;
729 event_thr
->last_status
.set_ignore ();
731 /* Update syscall state in the new lwp, effectively mid-syscall too. */
732 event_lwp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
734 /* Restore the list to catch. Don't rely on the client, which is free
735 to avoid sending a new list when the architecture doesn't change.
736 Also, for ANY_SYSCALL, the architecture doesn't really matter. */
737 proc
->syscalls_to_catch
= std::move (syscalls_to_catch
);
739 /* Report the event. */
740 *orig_event_lwp
= event_lwp
;
744 internal_error (_("unknown ptrace event %d"), event
);
748 linux_process_target::get_pc (lwp_info
*lwp
)
750 process_info
*proc
= get_thread_process (get_lwp_thread (lwp
));
751 gdb_assert (!proc
->starting_up
);
753 if (!low_supports_breakpoints ())
756 scoped_restore_current_thread restore_thread
;
757 switch_to_thread (get_lwp_thread (lwp
));
759 struct regcache
*regcache
= get_thread_regcache (current_thread
, 1);
760 CORE_ADDR pc
= low_get_pc (regcache
);
762 threads_debug_printf ("pc is 0x%lx", (long) pc
);
768 linux_process_target::get_syscall_trapinfo (lwp_info
*lwp
, int *sysno
)
770 struct regcache
*regcache
;
772 scoped_restore_current_thread restore_thread
;
773 switch_to_thread (get_lwp_thread (lwp
));
775 regcache
= get_thread_regcache (current_thread
, 1);
776 low_get_syscall_trapinfo (regcache
, sysno
);
778 threads_debug_printf ("get_syscall_trapinfo sysno %d", *sysno
);
782 linux_process_target::low_get_syscall_trapinfo (regcache
*regcache
, int *sysno
)
784 /* By default, report an unknown system call number. */
785 *sysno
= UNKNOWN_SYSCALL
;
789 linux_process_target::save_stop_reason (lwp_info
*lwp
)
792 CORE_ADDR sw_breakpoint_pc
;
793 #if USE_SIGTRAP_SIGINFO
797 if (!low_supports_breakpoints ())
800 process_info
*proc
= get_thread_process (get_lwp_thread (lwp
));
801 if (proc
->starting_up
)
803 /* Claim we have the stop PC so that the caller doesn't try to
809 sw_breakpoint_pc
= pc
- low_decr_pc_after_break ();
811 /* breakpoint_at reads from the current thread. */
812 scoped_restore_current_thread restore_thread
;
813 switch_to_thread (get_lwp_thread (lwp
));
815 #if USE_SIGTRAP_SIGINFO
816 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
817 (PTRACE_TYPE_ARG3
) 0, &siginfo
) == 0)
819 if (siginfo
.si_signo
== SIGTRAP
)
821 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
)
822 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
824 /* The si_code is ambiguous on this arch -- check debug
826 if (!check_stopped_by_watchpoint (lwp
))
827 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
829 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
))
831 /* If we determine the LWP stopped for a SW breakpoint,
832 trust it. Particularly don't check watchpoint
833 registers, because at least on s390, we'd find
834 stopped-by-watchpoint as long as there's a watchpoint
836 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
838 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
840 /* This can indicate either a hardware breakpoint or
841 hardware watchpoint. Check debug registers. */
842 if (!check_stopped_by_watchpoint (lwp
))
843 lwp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
845 else if (siginfo
.si_code
== TRAP_TRACE
)
847 /* We may have single stepped an instruction that
848 triggered a watchpoint. In that case, on some
849 architectures (such as x86), instead of TRAP_HWBKPT,
850 si_code indicates TRAP_TRACE, and we need to check
851 the debug registers separately. */
852 if (!check_stopped_by_watchpoint (lwp
))
853 lwp
->stop_reason
= TARGET_STOPPED_BY_SINGLE_STEP
;
858 /* We may have just stepped a breakpoint instruction. E.g., in
859 non-stop mode, GDB first tells the thread A to step a range, and
860 then the user inserts a breakpoint inside the range. In that
861 case we need to report the breakpoint PC. */
862 if ((!lwp
->stepping
|| lwp
->stop_pc
== sw_breakpoint_pc
)
863 && low_breakpoint_at (sw_breakpoint_pc
))
864 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
866 if (hardware_breakpoint_inserted_here (pc
))
867 lwp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
869 if (lwp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
)
870 check_stopped_by_watchpoint (lwp
);
873 if (lwp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
)
876 ("%s stopped by software breakpoint",
877 target_pid_to_str (ptid_of (get_lwp_thread (lwp
))).c_str ());
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
)
892 ("%s stopped by hardware breakpoint",
893 target_pid_to_str (ptid_of (get_lwp_thread (lwp
))).c_str ());
894 else if (lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
896 ("%s stopped by hardware watchpoint",
897 target_pid_to_str (ptid_of (get_lwp_thread (lwp
))).c_str ());
898 else if (lwp
->stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
900 ("%s stopped by trace",
901 target_pid_to_str (ptid_of (get_lwp_thread (lwp
))).c_str ());
908 linux_process_target::add_lwp (ptid_t ptid
)
910 lwp_info
*lwp
= new lwp_info
;
912 lwp
->thread
= add_thread (ptid
, lwp
);
914 low_new_thread (lwp
);
920 linux_process_target::low_new_thread (lwp_info
*info
)
925 /* Callback to be used when calling fork_inferior, responsible for
926 actually initiating the tracing of the inferior. */
931 if (ptrace (PTRACE_TRACEME
, 0, (PTRACE_TYPE_ARG3
) 0,
932 (PTRACE_TYPE_ARG4
) 0) < 0)
933 trace_start_error_with_name ("ptrace");
935 if (setpgid (0, 0) < 0)
936 trace_start_error_with_name ("setpgid");
938 /* If GDBserver is connected to gdb via stdio, redirect the inferior's
939 stdout to stderr so that inferior i/o doesn't corrupt the connection.
940 Also, redirect stdin to /dev/null. */
941 if (remote_connection_is_stdio ())
944 trace_start_error_with_name ("close");
945 if (open ("/dev/null", O_RDONLY
) < 0)
946 trace_start_error_with_name ("open");
948 trace_start_error_with_name ("dup2");
949 if (write (2, "stdin/stdout redirected\n",
950 sizeof ("stdin/stdout redirected\n") - 1) < 0)
952 /* Errors ignored. */;
957 /* Start an inferior process and returns its pid.
958 PROGRAM is the name of the program to be started, and PROGRAM_ARGS
959 are its arguments. */
962 linux_process_target::create_inferior (const char *program
,
963 const std::vector
<char *> &program_args
)
965 client_state
&cs
= get_client_state ();
966 struct lwp_info
*new_lwp
;
971 maybe_disable_address_space_randomization restore_personality
972 (cs
.disable_randomization
);
973 std::string str_program_args
= construct_inferior_arguments (program_args
);
975 pid
= fork_inferior (program
,
976 str_program_args
.c_str (),
977 get_environ ()->envp (), linux_ptrace_fun
,
978 NULL
, NULL
, NULL
, NULL
);
981 /* When spawning a new process, we can't open the mem file yet. We
982 still have to nurse the process through the shell, and that execs
983 a couple times. The address space a /proc/PID/mem file is
984 accessing is destroyed on exec. */
985 process_info
*proc
= add_linux_process_no_mem_file (pid
, 0);
987 ptid
= ptid_t (pid
, pid
);
988 new_lwp
= add_lwp (ptid
);
989 new_lwp
->must_set_ptrace_flags
= 1;
991 post_fork_inferior (pid
, program
);
993 /* PROC is now past the shell running the program we want, so we can
994 open the /proc/PID/mem file. */
995 open_proc_mem_file (proc
);
1000 /* Implement the post_create_inferior target_ops method. */
1003 linux_process_target::post_create_inferior ()
1005 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
1009 if (lwp
->must_set_ptrace_flags
)
1011 struct process_info
*proc
= current_process ();
1012 int options
= linux_low_ptrace_options (proc
->attached
);
1014 linux_enable_event_reporting (lwpid_of (current_thread
), options
);
1015 lwp
->must_set_ptrace_flags
= 0;
1020 linux_process_target::attach_lwp (ptid_t ptid
)
1022 struct lwp_info
*new_lwp
;
1023 int lwpid
= ptid
.lwp ();
1025 if (ptrace (PTRACE_ATTACH
, lwpid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0)
1029 new_lwp
= add_lwp (ptid
);
1031 /* We need to wait for SIGSTOP before being able to make the next
1032 ptrace call on this LWP. */
1033 new_lwp
->must_set_ptrace_flags
= 1;
1035 if (linux_proc_pid_is_stopped (lwpid
))
1037 threads_debug_printf ("Attached to a stopped process");
1039 /* The process is definitely stopped. It is in a job control
1040 stop, unless the kernel predates the TASK_STOPPED /
1041 TASK_TRACED distinction, in which case it might be in a
1042 ptrace stop. Make sure it is in a ptrace stop; from there we
1043 can kill it, signal it, et cetera.
1045 First make sure there is a pending SIGSTOP. Since we are
1046 already attached, the process can not transition from stopped
1047 to running without a PTRACE_CONT; so we know this signal will
1048 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1049 probably already in the queue (unless this kernel is old
1050 enough to use TASK_STOPPED for ptrace stops); but since
1051 SIGSTOP is not an RT signal, it can only be queued once. */
1052 kill_lwp (lwpid
, SIGSTOP
);
1054 /* Finally, resume the stopped process. This will deliver the
1055 SIGSTOP (or a higher priority signal, just like normal
1056 PTRACE_ATTACH), which we'll catch later on. */
1057 ptrace (PTRACE_CONT
, lwpid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0);
1060 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
1061 brings it to a halt.
1063 There are several cases to consider here:
1065 1) gdbserver has already attached to the process and is being notified
1066 of a new thread that is being created.
1067 In this case we should ignore that SIGSTOP and resume the
1068 process. This is handled below by setting stop_expected = 1,
1069 and the fact that add_thread sets last_resume_kind ==
1072 2) This is the first thread (the process thread), and we're attaching
1073 to it via attach_inferior.
1074 In this case we want the process thread to stop.
1075 This is handled by having linux_attach set last_resume_kind ==
1076 resume_stop after we return.
1078 If the pid we are attaching to is also the tgid, we attach to and
1079 stop all the existing threads. Otherwise, we attach to pid and
1080 ignore any other threads in the same group as this pid.
1082 3) GDB is connecting to gdbserver and is requesting an enumeration of all
1084 In this case we want the thread to stop.
1085 FIXME: This case is currently not properly handled.
1086 We should wait for the SIGSTOP but don't. Things work apparently
1087 because enough time passes between when we ptrace (ATTACH) and when
1088 gdb makes the next ptrace call on the thread.
1090 On the other hand, if we are currently trying to stop all threads, we
1091 should treat the new thread as if we had sent it a SIGSTOP. This works
1092 because we are guaranteed that the add_lwp call above added us to the
1093 end of the list, and so the new thread has not yet reached
1094 wait_for_sigstop (but will). */
1095 new_lwp
->stop_expected
= 1;
1100 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1101 already attached. Returns true if a new LWP is found, false
1105 attach_proc_task_lwp_callback (ptid_t ptid
)
1107 /* Is this a new thread? */
1108 if (find_thread_ptid (ptid
) == NULL
)
1110 int lwpid
= ptid
.lwp ();
1113 threads_debug_printf ("Found new lwp %d", lwpid
);
1115 err
= the_linux_target
->attach_lwp (ptid
);
1117 /* Be quiet if we simply raced with the thread exiting. EPERM
1118 is returned if the thread's task still exists, and is marked
1119 as exited or zombie, as well as other conditions, so in that
1120 case, confirm the status in /proc/PID/status. */
1122 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1123 threads_debug_printf
1124 ("Cannot attach to lwp %d: thread is gone (%d: %s)",
1125 lwpid
, err
, safe_strerror (err
));
1129 = linux_ptrace_attach_fail_reason_string (ptid
, err
);
1131 warning (_("Cannot attach to lwp %d: %s"), lwpid
, reason
.c_str ());
1139 static void async_file_mark (void);
1141 /* Attach to PID. If PID is the tgid, attach to it and all
1145 linux_process_target::attach (unsigned long pid
)
1147 struct process_info
*proc
;
1148 struct thread_info
*initial_thread
;
1149 ptid_t ptid
= ptid_t (pid
, pid
);
1152 /* Delay opening the /proc/PID/mem file until we've successfully
1154 proc
= add_linux_process_no_mem_file (pid
, 1);
1156 /* Attach to PID. We will check for other threads
1158 err
= attach_lwp (ptid
);
1161 this->remove_linux_process (proc
);
1163 std::string reason
= linux_ptrace_attach_fail_reason_string (ptid
, err
);
1164 error ("Cannot attach to process %ld: %s", pid
, reason
.c_str ());
1167 open_proc_mem_file (proc
);
1169 /* Don't ignore the initial SIGSTOP if we just attached to this
1170 process. It will be collected by wait shortly. */
1171 initial_thread
= find_thread_ptid (ptid_t (pid
, pid
));
1172 initial_thread
->last_resume_kind
= resume_stop
;
1174 /* We must attach to every LWP. If /proc is mounted, use that to
1175 find them now. On the one hand, the inferior may be using raw
1176 clone instead of using pthreads. On the other hand, even if it
1177 is using pthreads, GDB may not be connected yet (thread_db needs
1178 to do symbol lookups, through qSymbol). Also, thread_db walks
1179 structures in the inferior's address space to find the list of
1180 threads/LWPs, and those structures may well be corrupted. Note
1181 that once thread_db is loaded, we'll still use it to list threads
1182 and associate pthread info with each LWP. */
1183 linux_proc_attach_tgid_threads (pid
, attach_proc_task_lwp_callback
);
1185 /* GDB will shortly read the xml target description for this
1186 process, to figure out the process' architecture. But the target
1187 description is only filled in when the first process/thread in
1188 the thread group reports its initial PTRACE_ATTACH SIGSTOP. Do
1189 that now, otherwise, if GDB is fast enough, it could read the
1190 target description _before_ that initial stop. */
1193 struct lwp_info
*lwp
;
1195 ptid_t pid_ptid
= ptid_t (pid
);
1197 lwpid
= wait_for_event_filtered (pid_ptid
, pid_ptid
, &wstat
, __WALL
);
1198 gdb_assert (lwpid
> 0);
1200 lwp
= find_lwp_pid (ptid_t (lwpid
));
1202 if (!WIFSTOPPED (wstat
) || WSTOPSIG (wstat
) != SIGSTOP
)
1204 lwp
->status_pending_p
= 1;
1205 lwp
->status_pending
= wstat
;
1208 initial_thread
->last_resume_kind
= resume_continue
;
1212 gdb_assert (proc
->tdesc
!= NULL
);
1219 last_thread_of_process_p (int pid
)
1221 bool seen_one
= false;
1223 thread_info
*thread
= find_thread (pid
, [&] (thread_info
*thr_arg
)
1227 /* This is the first thread of this process we see. */
1233 /* This is the second thread of this process we see. */
1238 return thread
== NULL
;
1244 linux_kill_one_lwp (struct lwp_info
*lwp
)
1246 struct thread_info
*thr
= get_lwp_thread (lwp
);
1247 int pid
= lwpid_of (thr
);
1249 /* PTRACE_KILL is unreliable. After stepping into a signal handler,
1250 there is no signal context, and ptrace(PTRACE_KILL) (or
1251 ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
1252 ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
1253 alternative is to kill with SIGKILL. We only need one SIGKILL
1254 per process, not one for each thread. But since we still support
1255 support debugging programs using raw clone without CLONE_THREAD,
1256 we send one for each thread. For years, we used PTRACE_KILL
1257 only, so we're being a bit paranoid about some old kernels where
1258 PTRACE_KILL might work better (dubious if there are any such, but
1259 that's why it's paranoia), so we try SIGKILL first, PTRACE_KILL
1260 second, and so we're fine everywhere. */
1263 kill_lwp (pid
, SIGKILL
);
1266 int save_errno
= errno
;
1268 threads_debug_printf ("kill_lwp (SIGKILL) %s, 0, 0 (%s)",
1269 target_pid_to_str (ptid_of (thr
)).c_str (),
1270 save_errno
? safe_strerror (save_errno
) : "OK");
1274 ptrace (PTRACE_KILL
, pid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0);
1277 int save_errno
= errno
;
1279 threads_debug_printf ("PTRACE_KILL %s, 0, 0 (%s)",
1280 target_pid_to_str (ptid_of (thr
)).c_str (),
1281 save_errno
? safe_strerror (save_errno
) : "OK");
1285 /* Kill LWP and wait for it to die. */
1288 kill_wait_lwp (struct lwp_info
*lwp
)
1290 struct thread_info
*thr
= get_lwp_thread (lwp
);
1291 int pid
= ptid_of (thr
).pid ();
1292 int lwpid
= ptid_of (thr
).lwp ();
1296 threads_debug_printf ("killing lwp %d, for pid: %d", lwpid
, pid
);
1300 linux_kill_one_lwp (lwp
);
1302 /* Make sure it died. Notes:
1304 - The loop is most likely unnecessary.
1306 - We don't use wait_for_event as that could delete lwps
1307 while we're iterating over them. We're not interested in
1308 any pending status at this point, only in making sure all
1309 wait status on the kernel side are collected until the
1312 - We don't use __WALL here as the __WALL emulation relies on
1313 SIGCHLD, and killing a stopped process doesn't generate
1314 one, nor an exit status.
1316 res
= my_waitpid (lwpid
, &wstat
, 0);
1317 if (res
== -1 && errno
== ECHILD
)
1318 res
= my_waitpid (lwpid
, &wstat
, __WCLONE
);
1319 } while (res
> 0 && WIFSTOPPED (wstat
));
1321 /* Even if it was stopped, the child may have already disappeared.
1322 E.g., if it was killed by SIGKILL. */
1323 if (res
< 0 && errno
!= ECHILD
)
1324 perror_with_name ("kill_wait_lwp");
1327 /* Callback for `for_each_thread'. Kills an lwp of a given process,
1328 except the leader. */
1331 kill_one_lwp_callback (thread_info
*thread
, int pid
)
1333 struct lwp_info
*lwp
= get_thread_lwp (thread
);
1335 /* We avoid killing the first thread here, because of a Linux kernel (at
1336 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
1337 the children get a chance to be reaped, it will remain a zombie
1340 if (lwpid_of (thread
) == pid
)
1342 threads_debug_printf ("is last of process %s",
1343 target_pid_to_str (thread
->id
).c_str ());
1347 kill_wait_lwp (lwp
);
1351 linux_process_target::kill (process_info
*process
)
1353 int pid
= process
->pid
;
1355 /* If we're killing a running inferior, make sure it is stopped
1356 first, as PTRACE_KILL will not work otherwise. */
1357 stop_all_lwps (0, NULL
);
1359 for_each_thread (pid
, [&] (thread_info
*thread
)
1361 kill_one_lwp_callback (thread
, pid
);
1364 /* See the comment in linux_kill_one_lwp. We did not kill the first
1365 thread in the list, so do so now. */
1366 lwp_info
*lwp
= find_lwp_pid (ptid_t (pid
));
1369 threads_debug_printf ("cannot find lwp for pid: %d", pid
);
1371 kill_wait_lwp (lwp
);
1375 /* Since we presently can only stop all lwps of all processes, we
1376 need to unstop lwps of other processes. */
1377 unstop_all_lwps (0, NULL
);
1381 /* Get pending signal of THREAD, for detaching purposes. This is the
1382 signal the thread last stopped for, which we need to deliver to the
1383 thread when detaching, otherwise, it'd be suppressed/lost. */
1386 get_detach_signal (struct thread_info
*thread
)
1388 client_state
&cs
= get_client_state ();
1389 enum gdb_signal signo
= GDB_SIGNAL_0
;
1391 struct lwp_info
*lp
= get_thread_lwp (thread
);
1393 if (lp
->status_pending_p
)
1394 status
= lp
->status_pending
;
1397 /* If the thread had been suspended by gdbserver, and it stopped
1398 cleanly, then it'll have stopped with SIGSTOP. But we don't
1399 want to deliver that SIGSTOP. */
1400 if (thread
->last_status
.kind () != TARGET_WAITKIND_STOPPED
1401 || thread
->last_status
.sig () == GDB_SIGNAL_0
)
1404 /* Otherwise, we may need to deliver the signal we
1406 status
= lp
->last_status
;
1409 if (!WIFSTOPPED (status
))
1411 threads_debug_printf ("lwp %s hasn't stopped: no pending signal",
1412 target_pid_to_str (ptid_of (thread
)).c_str ());
1416 /* Extended wait statuses aren't real SIGTRAPs. */
1417 if (WSTOPSIG (status
) == SIGTRAP
&& linux_is_extended_waitstatus (status
))
1419 threads_debug_printf ("lwp %s had stopped with extended "
1420 "status: no pending signal",
1421 target_pid_to_str (ptid_of (thread
)).c_str ());
1425 signo
= gdb_signal_from_host (WSTOPSIG (status
));
1427 if (cs
.program_signals_p
&& !cs
.program_signals
[signo
])
1429 threads_debug_printf ("lwp %s had signal %s, but it is in nopass state",
1430 target_pid_to_str (ptid_of (thread
)).c_str (),
1431 gdb_signal_to_string (signo
));
1434 else if (!cs
.program_signals_p
1435 /* If we have no way to know which signals GDB does not
1436 want to have passed to the program, assume
1437 SIGTRAP/SIGINT, which is GDB's default. */
1438 && (signo
== GDB_SIGNAL_TRAP
|| signo
== GDB_SIGNAL_INT
))
1440 threads_debug_printf ("lwp %s had signal %s, "
1441 "but we don't know if we should pass it. "
1443 target_pid_to_str (ptid_of (thread
)).c_str (),
1444 gdb_signal_to_string (signo
));
1449 threads_debug_printf ("lwp %s has pending signal %s: delivering it",
1450 target_pid_to_str (ptid_of (thread
)).c_str (),
1451 gdb_signal_to_string (signo
));
1453 return WSTOPSIG (status
);
1458 linux_process_target::detach_one_lwp (lwp_info
*lwp
)
1460 struct thread_info
*thread
= get_lwp_thread (lwp
);
1464 /* If there is a pending SIGSTOP, get rid of it. */
1465 if (lwp
->stop_expected
)
1467 threads_debug_printf ("Sending SIGCONT to %s",
1468 target_pid_to_str (ptid_of (thread
)).c_str ());
1470 kill_lwp (lwpid_of (thread
), SIGCONT
);
1471 lwp
->stop_expected
= 0;
1474 /* Pass on any pending signal for this thread. */
1475 sig
= get_detach_signal (thread
);
1477 /* Preparing to resume may try to write registers, and fail if the
1478 lwp is zombie. If that happens, ignore the error. We'll handle
1479 it below, when detach fails with ESRCH. */
1482 /* Flush any pending changes to the process's registers. */
1483 regcache_invalidate_thread (thread
);
1485 /* Finally, let it resume. */
1486 low_prepare_to_resume (lwp
);
1488 catch (const gdb_exception_error
&ex
)
1490 if (!check_ptrace_stopped_lwp_gone (lwp
))
1494 lwpid
= lwpid_of (thread
);
1495 if (ptrace (PTRACE_DETACH
, lwpid
, (PTRACE_TYPE_ARG3
) 0,
1496 (PTRACE_TYPE_ARG4
) (long) sig
) < 0)
1498 int save_errno
= errno
;
1500 /* We know the thread exists, so ESRCH must mean the lwp is
1501 zombie. This can happen if one of the already-detached
1502 threads exits the whole thread group. In that case we're
1503 still attached, and must reap the lwp. */
1504 if (save_errno
== ESRCH
)
1508 ret
= my_waitpid (lwpid
, &status
, __WALL
);
1511 warning (_("Couldn't reap LWP %d while detaching: %s"),
1512 lwpid
, safe_strerror (errno
));
1514 else if (!WIFEXITED (status
) && !WIFSIGNALED (status
))
1516 warning (_("Reaping LWP %d while detaching "
1517 "returned unexpected status 0x%x"),
1523 error (_("Can't detach %s: %s"),
1524 target_pid_to_str (ptid_of (thread
)).c_str (),
1525 safe_strerror (save_errno
));
1529 threads_debug_printf ("PTRACE_DETACH (%s, %s, 0) (OK)",
1530 target_pid_to_str (ptid_of (thread
)).c_str (),
1537 linux_process_target::detach (process_info
*process
)
1539 struct lwp_info
*main_lwp
;
1541 /* As there's a step over already in progress, let it finish first,
1542 otherwise nesting a stabilize_threads operation on top gets real
1544 complete_ongoing_step_over ();
1546 /* Stop all threads before detaching. First, ptrace requires that
1547 the thread is stopped to successfully detach. Second, thread_db
1548 may need to uninstall thread event breakpoints from memory, which
1549 only works with a stopped process anyway. */
1550 stop_all_lwps (0, NULL
);
1552 #ifdef USE_THREAD_DB
1553 thread_db_detach (process
);
1556 /* Stabilize threads (move out of jump pads). */
1557 target_stabilize_threads ();
1559 /* Detach from the clone lwps first. If the thread group exits just
1560 while we're detaching, we must reap the clone lwps before we're
1561 able to reap the leader. */
1562 for_each_thread (process
->pid
, [this] (thread_info
*thread
)
1564 /* We don't actually detach from the thread group leader just yet.
1565 If the thread group exits, we must reap the zombie clone lwps
1566 before we're able to reap the leader. */
1567 if (thread
->id
.pid () == thread
->id
.lwp ())
1570 lwp_info
*lwp
= get_thread_lwp (thread
);
1571 detach_one_lwp (lwp
);
1574 main_lwp
= find_lwp_pid (ptid_t (process
->pid
));
1575 detach_one_lwp (main_lwp
);
1579 /* Since we presently can only stop all lwps of all processes, we
1580 need to unstop lwps of other processes. */
1581 unstop_all_lwps (0, NULL
);
1585 /* Remove all LWPs that belong to process PROC from the lwp list. */
1588 linux_process_target::mourn (process_info
*process
)
1590 #ifdef USE_THREAD_DB
1591 thread_db_mourn (process
);
1594 for_each_thread (process
->pid
, [this] (thread_info
*thread
)
1596 delete_lwp (get_thread_lwp (thread
));
1599 this->remove_linux_process (process
);
1603 linux_process_target::join (int pid
)
1608 ret
= my_waitpid (pid
, &status
, 0);
1609 if (WIFEXITED (status
) || WIFSIGNALED (status
))
1611 } while (ret
!= -1 || errno
!= ECHILD
);
1614 /* Return true if the given thread is still alive. */
1617 linux_process_target::thread_alive (ptid_t ptid
)
1619 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
1621 /* We assume we always know if a thread exits. If a whole process
1622 exited but we still haven't been able to report it to GDB, we'll
1623 hold on to the last lwp of the dead process. */
1625 return !lwp_is_marked_dead (lwp
);
1631 linux_process_target::thread_still_has_status_pending (thread_info
*thread
)
1633 struct lwp_info
*lp
= get_thread_lwp (thread
);
1635 if (!lp
->status_pending_p
)
1638 if (thread
->last_resume_kind
!= resume_stop
1639 && (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
1640 || lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
1645 gdb_assert (lp
->last_status
!= 0);
1649 scoped_restore_current_thread restore_thread
;
1650 switch_to_thread (thread
);
1652 if (pc
!= lp
->stop_pc
)
1654 threads_debug_printf ("PC of %ld changed",
1659 #if !USE_SIGTRAP_SIGINFO
1660 else if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
1661 && !low_breakpoint_at (pc
))
1663 threads_debug_printf ("previous SW breakpoint of %ld gone",
1667 else if (lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
1668 && !hardware_breakpoint_inserted_here (pc
))
1670 threads_debug_printf ("previous HW breakpoint of %ld gone",
1678 threads_debug_printf ("discarding pending breakpoint status");
1679 lp
->status_pending_p
= 0;
1687 /* Returns true if LWP is resumed from the client's perspective. */
1690 lwp_resumed (struct lwp_info
*lwp
)
1692 struct thread_info
*thread
= get_lwp_thread (lwp
);
1694 if (thread
->last_resume_kind
!= resume_stop
)
1697 /* Did gdb send us a `vCont;t', but we haven't reported the
1698 corresponding stop to gdb yet? If so, the thread is still
1699 resumed/running from gdb's perspective. */
1700 if (thread
->last_resume_kind
== resume_stop
1701 && thread
->last_status
.kind () == TARGET_WAITKIND_IGNORE
)
1708 linux_process_target::status_pending_p_callback (thread_info
*thread
,
1711 struct lwp_info
*lp
= get_thread_lwp (thread
);
1713 /* Check if we're only interested in events from a specific process
1714 or a specific LWP. */
1715 if (!thread
->id
.matches (ptid
))
1718 if (!lwp_resumed (lp
))
1721 if (lp
->status_pending_p
1722 && !thread_still_has_status_pending (thread
))
1724 resume_one_lwp (lp
, lp
->stepping
, GDB_SIGNAL_0
, NULL
);
1728 return lp
->status_pending_p
;
1732 find_lwp_pid (ptid_t ptid
)
1734 long lwp
= ptid
.lwp () != 0 ? ptid
.lwp () : ptid
.pid ();
1735 thread_info
*thread
= find_thread ([lwp
] (thread_info
*thr_arg
)
1737 return thr_arg
->id
.lwp () == lwp
;
1743 return get_thread_lwp (thread
);
1746 /* Return the number of known LWPs in the tgid given by PID. */
1753 for_each_thread (pid
, [&] (thread_info
*thread
)
1761 /* See nat/linux-nat.h. */
1764 iterate_over_lwps (ptid_t filter
,
1765 gdb::function_view
<iterate_over_lwps_ftype
> callback
)
1767 thread_info
*thread
= find_thread (filter
, [&] (thread_info
*thr_arg
)
1769 lwp_info
*lwp
= get_thread_lwp (thr_arg
);
1771 return callback (lwp
);
1777 return get_thread_lwp (thread
);
1781 linux_process_target::check_zombie_leaders ()
1783 for_each_process ([this] (process_info
*proc
)
1785 pid_t leader_pid
= pid_of (proc
);
1786 lwp_info
*leader_lp
= find_lwp_pid (ptid_t (leader_pid
));
1788 threads_debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, "
1789 "num_lwps=%d, zombie=%d",
1790 leader_pid
, leader_lp
!= NULL
, num_lwps (leader_pid
),
1791 linux_proc_pid_is_zombie (leader_pid
));
1793 if (leader_lp
!= NULL
&& !leader_lp
->stopped
1794 /* Check if there are other threads in the group, as we may
1795 have raced with the inferior simply exiting. Note this
1796 isn't a watertight check. If the inferior is
1797 multi-threaded and is exiting, it may be we see the
1798 leader as zombie before we reap all the non-leader
1799 threads. See comments below. */
1800 && !last_thread_of_process_p (leader_pid
)
1801 && linux_proc_pid_is_zombie (leader_pid
))
1803 /* A zombie leader in a multi-threaded program can mean one
1806 #1 - Only the leader exited, not the whole program, e.g.,
1807 with pthread_exit. Since we can't reap the leader's exit
1808 status until all other threads are gone and reaped too,
1809 we want to delete the zombie leader right away, as it
1810 can't be debugged, we can't read its registers, etc.
1811 This is the main reason we check for zombie leaders
1814 #2 - The whole thread-group/process exited (a group exit,
1815 via e.g. exit(3), and there is (or will be shortly) an
1816 exit reported for each thread in the process, and then
1817 finally an exit for the leader once the non-leaders are
1820 #3 - There are 3 or more threads in the group, and a
1821 thread other than the leader exec'd. See comments on
1822 exec events at the top of the file.
1824 Ideally we would never delete the leader for case #2.
1825 Instead, we want to collect the exit status of each
1826 non-leader thread, and then finally collect the exit
1827 status of the leader as normal and use its exit code as
1828 whole-process exit code. Unfortunately, there's no
1829 race-free way to distinguish cases #1 and #2. We can't
1830 assume the exit events for the non-leaders threads are
1831 already pending in the kernel, nor can we assume the
1832 non-leader threads are in zombie state already. Between
1833 the leader becoming zombie and the non-leaders exiting
1834 and becoming zombie themselves, there's a small time
1835 window, so such a check would be racy. Temporarily
1836 pausing all threads and checking to see if all threads
1837 exit or not before re-resuming them would work in the
1838 case that all threads are running right now, but it
1839 wouldn't work if some thread is currently already
1840 ptrace-stopped, e.g., due to scheduler-locking.
1842 So what we do is we delete the leader anyhow, and then
1843 later on when we see its exit status, we re-add it back.
1844 We also make sure that we only report a whole-process
1845 exit when we see the leader exiting, as opposed to when
1846 the last LWP in the LWP list exits, which can be a
1847 non-leader if we deleted the leader here. */
1848 threads_debug_printf ("Thread group leader %d zombie "
1849 "(it exited, or another thread execd), "
1852 delete_lwp (leader_lp
);
1857 /* Callback for `find_thread'. Returns the first LWP that is not
1861 not_stopped_callback (thread_info
*thread
, ptid_t filter
)
1863 if (!thread
->id
.matches (filter
))
1866 lwp_info
*lwp
= get_thread_lwp (thread
);
1868 return !lwp
->stopped
;
1871 /* Increment LWP's suspend count. */
1874 lwp_suspended_inc (struct lwp_info
*lwp
)
1878 if (lwp
->suspended
> 4)
1879 threads_debug_printf
1880 ("LWP %ld has a suspiciously high suspend count, suspended=%d",
1881 lwpid_of (get_lwp_thread (lwp
)), lwp
->suspended
);
1884 /* Decrement LWP's suspend count. */
1887 lwp_suspended_decr (struct lwp_info
*lwp
)
1891 if (lwp
->suspended
< 0)
1893 struct thread_info
*thread
= get_lwp_thread (lwp
);
1895 internal_error ("unsuspend LWP %ld, suspended=%d\n", lwpid_of (thread
),
1900 /* This function should only be called if the LWP got a SIGTRAP.
1902 Handle any tracepoint steps or hits. Return true if a tracepoint
1903 event was handled, 0 otherwise. */
1906 handle_tracepoints (struct lwp_info
*lwp
)
1908 struct thread_info
*tinfo
= get_lwp_thread (lwp
);
1909 int tpoint_related_event
= 0;
1911 gdb_assert (lwp
->suspended
== 0);
1913 /* If this tracepoint hit causes a tracing stop, we'll immediately
1914 uninsert tracepoints. To do this, we temporarily pause all
1915 threads, unpatch away, and then unpause threads. We need to make
1916 sure the unpausing doesn't resume LWP too. */
1917 lwp_suspended_inc (lwp
);
1919 /* And we need to be sure that any all-threads-stopping doesn't try
1920 to move threads out of the jump pads, as it could deadlock the
1921 inferior (LWP could be in the jump pad, maybe even holding the
1924 /* Do any necessary step collect actions. */
1925 tpoint_related_event
|= tracepoint_finished_step (tinfo
, lwp
->stop_pc
);
1927 tpoint_related_event
|= handle_tracepoint_bkpts (tinfo
, lwp
->stop_pc
);
1929 /* See if we just hit a tracepoint and do its main collect
1931 tpoint_related_event
|= tracepoint_was_hit (tinfo
, lwp
->stop_pc
);
1933 lwp_suspended_decr (lwp
);
1935 gdb_assert (lwp
->suspended
== 0);
1936 gdb_assert (!stabilizing_threads
1937 || (lwp
->collecting_fast_tracepoint
1938 != fast_tpoint_collect_result::not_collecting
));
1940 if (tpoint_related_event
)
1942 threads_debug_printf ("got a tracepoint event");
1949 fast_tpoint_collect_result
1950 linux_process_target::linux_fast_tracepoint_collecting
1951 (lwp_info
*lwp
, fast_tpoint_collect_status
*status
)
1953 CORE_ADDR thread_area
;
1954 struct thread_info
*thread
= get_lwp_thread (lwp
);
1956 /* Get the thread area address. This is used to recognize which
1957 thread is which when tracing with the in-process agent library.
1958 We don't read anything from the address, and treat it as opaque;
1959 it's the address itself that we assume is unique per-thread. */
1960 if (low_get_thread_area (lwpid_of (thread
), &thread_area
) == -1)
1961 return fast_tpoint_collect_result::not_collecting
;
1963 return fast_tracepoint_collecting (thread_area
, lwp
->stop_pc
, status
);
1967 linux_process_target::low_get_thread_area (int lwpid
, CORE_ADDR
*addrp
)
1973 linux_process_target::maybe_move_out_of_jump_pad (lwp_info
*lwp
, int *wstat
)
1975 scoped_restore_current_thread restore_thread
;
1976 switch_to_thread (get_lwp_thread (lwp
));
1979 || (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) != SIGTRAP
))
1980 && supports_fast_tracepoints ()
1981 && agent_loaded_p ())
1983 struct fast_tpoint_collect_status status
;
1985 threads_debug_printf
1986 ("Checking whether LWP %ld needs to move out of the jump pad.",
1987 lwpid_of (current_thread
));
1989 fast_tpoint_collect_result r
1990 = linux_fast_tracepoint_collecting (lwp
, &status
);
1993 || (WSTOPSIG (*wstat
) != SIGILL
1994 && WSTOPSIG (*wstat
) != SIGFPE
1995 && WSTOPSIG (*wstat
) != SIGSEGV
1996 && WSTOPSIG (*wstat
) != SIGBUS
))
1998 lwp
->collecting_fast_tracepoint
= r
;
2000 if (r
!= fast_tpoint_collect_result::not_collecting
)
2002 if (r
== fast_tpoint_collect_result::before_insn
2003 && lwp
->exit_jump_pad_bkpt
== NULL
)
2005 /* Haven't executed the original instruction yet.
2006 Set breakpoint there, and wait till it's hit,
2007 then single-step until exiting the jump pad. */
2008 lwp
->exit_jump_pad_bkpt
2009 = set_breakpoint_at (status
.adjusted_insn_addr
, NULL
);
2012 threads_debug_printf
2013 ("Checking whether LWP %ld needs to move out of the jump pad..."
2014 " it does", lwpid_of (current_thread
));
2021 /* If we get a synchronous signal while collecting, *and*
2022 while executing the (relocated) original instruction,
2023 reset the PC to point at the tpoint address, before
2024 reporting to GDB. Otherwise, it's an IPA lib bug: just
2025 report the signal to GDB, and pray for the best. */
2027 lwp
->collecting_fast_tracepoint
2028 = fast_tpoint_collect_result::not_collecting
;
2030 if (r
!= fast_tpoint_collect_result::not_collecting
2031 && (status
.adjusted_insn_addr
<= lwp
->stop_pc
2032 && lwp
->stop_pc
< status
.adjusted_insn_addr_end
))
2035 struct regcache
*regcache
;
2037 /* The si_addr on a few signals references the address
2038 of the faulting instruction. Adjust that as
2040 if ((WSTOPSIG (*wstat
) == SIGILL
2041 || WSTOPSIG (*wstat
) == SIGFPE
2042 || WSTOPSIG (*wstat
) == SIGBUS
2043 || WSTOPSIG (*wstat
) == SIGSEGV
)
2044 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
2045 (PTRACE_TYPE_ARG3
) 0, &info
) == 0
2046 /* Final check just to make sure we don't clobber
2047 the siginfo of non-kernel-sent signals. */
2048 && (uintptr_t) info
.si_addr
== lwp
->stop_pc
)
2050 info
.si_addr
= (void *) (uintptr_t) status
.tpoint_addr
;
2051 ptrace (PTRACE_SETSIGINFO
, lwpid_of (current_thread
),
2052 (PTRACE_TYPE_ARG3
) 0, &info
);
2055 regcache
= get_thread_regcache (current_thread
, 1);
2056 low_set_pc (regcache
, status
.tpoint_addr
);
2057 lwp
->stop_pc
= status
.tpoint_addr
;
2059 /* Cancel any fast tracepoint lock this thread was
2061 force_unlock_trace_buffer ();
2064 if (lwp
->exit_jump_pad_bkpt
!= NULL
)
2066 threads_debug_printf
2067 ("Cancelling fast exit-jump-pad: removing bkpt."
2068 "stopping all threads momentarily.");
2070 stop_all_lwps (1, lwp
);
2072 delete_breakpoint (lwp
->exit_jump_pad_bkpt
);
2073 lwp
->exit_jump_pad_bkpt
= NULL
;
2075 unstop_all_lwps (1, lwp
);
2077 gdb_assert (lwp
->suspended
>= 0);
2082 threads_debug_printf
2083 ("Checking whether LWP %ld needs to move out of the jump pad... no",
2084 lwpid_of (current_thread
));
2089 /* Enqueue one signal in the "signals to report later when out of the
2093 enqueue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
2095 struct thread_info
*thread
= get_lwp_thread (lwp
);
2097 threads_debug_printf ("Deferring signal %d for LWP %ld.",
2098 WSTOPSIG (*wstat
), lwpid_of (thread
));
2102 for (const auto &sig
: lwp
->pending_signals_to_report
)
2103 threads_debug_printf (" Already queued %d", sig
.signal
);
2105 threads_debug_printf (" (no more currently queued signals)");
2108 /* Don't enqueue non-RT signals if they are already in the deferred
2109 queue. (SIGSTOP being the easiest signal to see ending up here
2111 if (WSTOPSIG (*wstat
) < __SIGRTMIN
)
2113 for (const auto &sig
: lwp
->pending_signals_to_report
)
2115 if (sig
.signal
== WSTOPSIG (*wstat
))
2117 threads_debug_printf
2118 ("Not requeuing already queued non-RT signal %d for LWP %ld",
2119 sig
.signal
, lwpid_of (thread
));
2125 lwp
->pending_signals_to_report
.emplace_back (WSTOPSIG (*wstat
));
2127 ptrace (PTRACE_GETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
2128 &lwp
->pending_signals_to_report
.back ().info
);
2131 /* Dequeue one signal from the "signals to report later when out of
2132 the jump pad" list. */
2135 dequeue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
2137 struct thread_info
*thread
= get_lwp_thread (lwp
);
2139 if (!lwp
->pending_signals_to_report
.empty ())
2141 const pending_signal
&p_sig
= lwp
->pending_signals_to_report
.front ();
2143 *wstat
= W_STOPCODE (p_sig
.signal
);
2144 if (p_sig
.info
.si_signo
!= 0)
2145 ptrace (PTRACE_SETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
2148 lwp
->pending_signals_to_report
.pop_front ();
2150 threads_debug_printf ("Reporting deferred signal %d for LWP %ld.",
2151 WSTOPSIG (*wstat
), lwpid_of (thread
));
2155 for (const auto &sig
: lwp
->pending_signals_to_report
)
2156 threads_debug_printf (" Still queued %d", sig
.signal
);
2158 threads_debug_printf (" (no more queued signals)");
2168 linux_process_target::check_stopped_by_watchpoint (lwp_info
*child
)
2170 scoped_restore_current_thread restore_thread
;
2171 switch_to_thread (get_lwp_thread (child
));
2173 if (low_stopped_by_watchpoint ())
2175 child
->stop_reason
= TARGET_STOPPED_BY_WATCHPOINT
;
2176 child
->stopped_data_address
= low_stopped_data_address ();
2179 return child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2183 linux_process_target::low_stopped_by_watchpoint ()
2189 linux_process_target::low_stopped_data_address ()
2194 /* Return the ptrace options that we want to try to enable. */
2197 linux_low_ptrace_options (int attached
)
2199 client_state
&cs
= get_client_state ();
2203 options
|= PTRACE_O_EXITKILL
;
2205 if (cs
.report_fork_events
)
2206 options
|= PTRACE_O_TRACEFORK
;
2208 if (cs
.report_vfork_events
)
2209 options
|= (PTRACE_O_TRACEVFORK
| PTRACE_O_TRACEVFORKDONE
);
2211 if (cs
.report_exec_events
)
2212 options
|= PTRACE_O_TRACEEXEC
;
2214 options
|= PTRACE_O_TRACESYSGOOD
;
2220 linux_process_target::filter_event (int lwpid
, int wstat
)
2222 client_state
&cs
= get_client_state ();
2223 struct lwp_info
*child
;
2224 struct thread_info
*thread
;
2225 int have_stop_pc
= 0;
2227 child
= find_lwp_pid (ptid_t (lwpid
));
2229 /* Check for events reported by anything not in our LWP list. */
2230 if (child
== nullptr)
2232 if (WIFSTOPPED (wstat
))
2234 if (WSTOPSIG (wstat
) == SIGTRAP
2235 && linux_ptrace_get_extended_event (wstat
) == PTRACE_EVENT_EXEC
)
2237 /* A non-leader thread exec'ed after we've seen the
2238 leader zombie, and removed it from our lists (in
2239 check_zombie_leaders). The non-leader thread changes
2240 its tid to the tgid. */
2241 threads_debug_printf
2242 ("Re-adding thread group leader LWP %d after exec.",
2245 child
= add_lwp (ptid_t (lwpid
, lwpid
));
2247 switch_to_thread (child
->thread
);
2251 /* A process we are controlling has forked and the new
2252 child's stop was reported to us by the kernel. Save
2253 its PID and go back to waiting for the fork event to
2254 be reported - the stopped process might be returned
2255 from waitpid before or after the fork event is. */
2256 threads_debug_printf
2257 ("Saving LWP %d status %s in stopped_pids list",
2258 lwpid
, status_to_str (wstat
).c_str ());
2259 add_to_pid_list (&stopped_pids
, lwpid
, wstat
);
2264 /* Don't report an event for the exit of an LWP not in our
2265 list, i.e. not part of any inferior we're debugging.
2266 This can happen if we detach from a program we originally
2267 forked and then it exits. However, note that we may have
2268 earlier deleted a leader of an inferior we're debugging,
2269 in check_zombie_leaders. Re-add it back here if so. */
2270 find_process ([&] (process_info
*proc
)
2272 if (proc
->pid
== lwpid
)
2274 threads_debug_printf
2275 ("Re-adding thread group leader LWP %d after exit.",
2278 child
= add_lwp (ptid_t (lwpid
, lwpid
));
2285 if (child
== nullptr)
2289 thread
= get_lwp_thread (child
);
2293 child
->last_status
= wstat
;
2295 /* Check if the thread has exited. */
2296 if ((WIFEXITED (wstat
) || WIFSIGNALED (wstat
)))
2298 threads_debug_printf ("%d exited", lwpid
);
2300 if (finish_step_over (child
))
2302 /* Unsuspend all other LWPs, and set them back running again. */
2303 unsuspend_all_lwps (child
);
2306 /* If this is not the leader LWP, then the exit signal was not
2307 the end of the debugged application and should be ignored,
2308 unless GDB wants to hear about thread exits. */
2309 if (cs
.report_thread_events
|| is_leader (thread
))
2311 /* Since events are serialized to GDB core, and we can't
2312 report this one right now. Leave the status pending for
2313 the next time we're able to report it. */
2314 mark_lwp_dead (child
, wstat
);
2324 gdb_assert (WIFSTOPPED (wstat
));
2326 if (WIFSTOPPED (wstat
))
2328 struct process_info
*proc
;
2330 /* Architecture-specific setup after inferior is running. */
2331 proc
= find_process_pid (pid_of (thread
));
2332 if (proc
->tdesc
== NULL
)
2336 /* This needs to happen after we have attached to the
2337 inferior and it is stopped for the first time, but
2338 before we access any inferior registers. */
2339 arch_setup_thread (thread
);
2343 /* The process is started, but GDBserver will do
2344 architecture-specific setup after the program stops at
2345 the first instruction. */
2346 child
->status_pending_p
= 1;
2347 child
->status_pending
= wstat
;
2353 if (WIFSTOPPED (wstat
) && child
->must_set_ptrace_flags
)
2355 struct process_info
*proc
= find_process_pid (pid_of (thread
));
2356 int options
= linux_low_ptrace_options (proc
->attached
);
2358 linux_enable_event_reporting (lwpid
, options
);
2359 child
->must_set_ptrace_flags
= 0;
2362 /* Always update syscall_state, even if it will be filtered later. */
2363 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SYSCALL_SIGTRAP
)
2365 child
->syscall_state
2366 = (child
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
2367 ? TARGET_WAITKIND_SYSCALL_RETURN
2368 : TARGET_WAITKIND_SYSCALL_ENTRY
);
2372 /* Almost all other ptrace-stops are known to be outside of system
2373 calls, with further exceptions in handle_extended_wait. */
2374 child
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2377 /* Be careful to not overwrite stop_pc until save_stop_reason is
2379 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGTRAP
2380 && linux_is_extended_waitstatus (wstat
))
2382 child
->stop_pc
= get_pc (child
);
2383 if (handle_extended_wait (&child
, wstat
))
2385 /* The event has been handled, so just return without
2391 if (linux_wstatus_maybe_breakpoint (wstat
))
2393 if (save_stop_reason (child
))
2398 child
->stop_pc
= get_pc (child
);
2400 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGSTOP
2401 && child
->stop_expected
)
2403 threads_debug_printf ("Expected stop.");
2405 child
->stop_expected
= 0;
2407 if (thread
->last_resume_kind
== resume_stop
)
2409 /* We want to report the stop to the core. Treat the
2410 SIGSTOP as a normal event. */
2411 threads_debug_printf ("resume_stop SIGSTOP caught for %s.",
2412 target_pid_to_str (ptid_of (thread
)).c_str ());
2414 else if (stopping_threads
!= NOT_STOPPING_THREADS
)
2416 /* Stopping threads. We don't want this SIGSTOP to end up
2418 threads_debug_printf ("SIGSTOP caught for %s while stopping threads.",
2419 target_pid_to_str (ptid_of (thread
)).c_str ());
2424 /* This is a delayed SIGSTOP. Filter out the event. */
2425 threads_debug_printf ("%s %s, 0, 0 (discard delayed SIGSTOP)",
2426 child
->stepping
? "step" : "continue",
2427 target_pid_to_str (ptid_of (thread
)).c_str ());
2429 resume_one_lwp (child
, child
->stepping
, 0, NULL
);
2434 child
->status_pending_p
= 1;
2435 child
->status_pending
= wstat
;
2440 linux_process_target::maybe_hw_step (thread_info
*thread
)
2442 if (supports_hardware_single_step ())
2446 /* GDBserver must insert single-step breakpoint for software
2448 gdb_assert (has_single_step_breakpoints (thread
));
2454 linux_process_target::resume_stopped_resumed_lwps (thread_info
*thread
)
2456 struct lwp_info
*lp
= get_thread_lwp (thread
);
2460 && !lp
->status_pending_p
2461 && thread
->last_status
.kind () == TARGET_WAITKIND_IGNORE
)
2465 if (thread
->last_resume_kind
== resume_step
)
2467 if (supports_software_single_step ())
2468 install_software_single_step_breakpoints (lp
);
2470 step
= maybe_hw_step (thread
);
2473 threads_debug_printf ("resuming stopped-resumed LWP %s at %s: step=%d",
2474 target_pid_to_str (ptid_of (thread
)).c_str (),
2475 paddress (lp
->stop_pc
), step
);
2477 resume_one_lwp (lp
, step
, GDB_SIGNAL_0
, NULL
);
2482 linux_process_target::wait_for_event_filtered (ptid_t wait_ptid
,
2484 int *wstatp
, int options
)
2486 struct thread_info
*event_thread
;
2487 struct lwp_info
*event_child
, *requested_child
;
2488 sigset_t block_mask
, prev_mask
;
2491 /* N.B. event_thread points to the thread_info struct that contains
2492 event_child. Keep them in sync. */
2493 event_thread
= NULL
;
2495 requested_child
= NULL
;
2497 /* Check for a lwp with a pending status. */
2499 if (filter_ptid
== minus_one_ptid
|| filter_ptid
.is_pid ())
2501 event_thread
= find_thread_in_random ([&] (thread_info
*thread
)
2503 return status_pending_p_callback (thread
, filter_ptid
);
2506 if (event_thread
!= NULL
)
2508 event_child
= get_thread_lwp (event_thread
);
2509 threads_debug_printf ("Got a pending child %ld", lwpid_of (event_thread
));
2512 else if (filter_ptid
!= null_ptid
)
2514 requested_child
= find_lwp_pid (filter_ptid
);
2516 if (stopping_threads
== NOT_STOPPING_THREADS
2517 && requested_child
->status_pending_p
2518 && (requested_child
->collecting_fast_tracepoint
2519 != fast_tpoint_collect_result::not_collecting
))
2521 enqueue_one_deferred_signal (requested_child
,
2522 &requested_child
->status_pending
);
2523 requested_child
->status_pending_p
= 0;
2524 requested_child
->status_pending
= 0;
2525 resume_one_lwp (requested_child
, 0, 0, NULL
);
2528 if (requested_child
->suspended
2529 && requested_child
->status_pending_p
)
2531 internal_error ("requesting an event out of a"
2532 " suspended child?");
2535 if (requested_child
->status_pending_p
)
2537 event_child
= requested_child
;
2538 event_thread
= get_lwp_thread (event_child
);
2542 if (event_child
!= NULL
)
2544 threads_debug_printf ("Got an event from pending child %ld (%04x)",
2545 lwpid_of (event_thread
),
2546 event_child
->status_pending
);
2548 *wstatp
= event_child
->status_pending
;
2549 event_child
->status_pending_p
= 0;
2550 event_child
->status_pending
= 0;
2551 switch_to_thread (event_thread
);
2552 return lwpid_of (event_thread
);
2555 /* But if we don't find a pending event, we'll have to wait.
2557 We only enter this loop if no process has a pending wait status.
2558 Thus any action taken in response to a wait status inside this
2559 loop is responding as soon as we detect the status, not after any
2562 /* Make sure SIGCHLD is blocked until the sigsuspend below. Block
2563 all signals while here. */
2564 sigfillset (&block_mask
);
2565 gdb_sigmask (SIG_BLOCK
, &block_mask
, &prev_mask
);
2567 /* Always pull all events out of the kernel. We'll randomly select
2568 an event LWP out of all that have events, to prevent
2570 while (event_child
== NULL
)
2574 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
2577 - If the thread group leader exits while other threads in the
2578 thread group still exist, waitpid(TGID, ...) hangs. That
2579 waitpid won't return an exit status until the other threads
2580 in the group are reaped.
2582 - When a non-leader thread execs, that thread just vanishes
2583 without reporting an exit (so we'd hang if we waited for it
2584 explicitly in that case). The exec event is reported to
2587 ret
= my_waitpid (-1, wstatp
, options
| WNOHANG
);
2589 threads_debug_printf ("waitpid(-1, ...) returned %d, %s",
2590 ret
, errno
? safe_strerror (errno
) : "ERRNO-OK");
2594 threads_debug_printf ("waitpid %ld received %s",
2595 (long) ret
, status_to_str (*wstatp
).c_str ());
2597 /* Filter all events. IOW, leave all events pending. We'll
2598 randomly select an event LWP out of all that have events
2600 filter_event (ret
, *wstatp
);
2601 /* Retry until nothing comes out of waitpid. A single
2602 SIGCHLD can indicate more than one child stopped. */
2606 /* Now that we've pulled all events out of the kernel, resume
2607 LWPs that don't have an interesting event to report. */
2608 if (stopping_threads
== NOT_STOPPING_THREADS
)
2609 for_each_thread ([this] (thread_info
*thread
)
2611 resume_stopped_resumed_lwps (thread
);
2614 /* ... and find an LWP with a status to report to the core, if
2616 event_thread
= find_thread_in_random ([&] (thread_info
*thread
)
2618 return status_pending_p_callback (thread
, filter_ptid
);
2621 if (event_thread
!= NULL
)
2623 event_child
= get_thread_lwp (event_thread
);
2624 *wstatp
= event_child
->status_pending
;
2625 event_child
->status_pending_p
= 0;
2626 event_child
->status_pending
= 0;
2630 /* Check for zombie thread group leaders. Those can't be reaped
2631 until all other threads in the thread group are. */
2632 check_zombie_leaders ();
2634 auto not_stopped
= [&] (thread_info
*thread
)
2636 return not_stopped_callback (thread
, wait_ptid
);
2639 /* If there are no resumed children left in the set of LWPs we
2640 want to wait for, bail. We can't just block in
2641 waitpid/sigsuspend, because lwps might have been left stopped
2642 in trace-stop state, and we'd be stuck forever waiting for
2643 their status to change (which would only happen if we resumed
2644 them). Even if WNOHANG is set, this return code is preferred
2645 over 0 (below), as it is more detailed. */
2646 if (find_thread (not_stopped
) == NULL
)
2648 threads_debug_printf ("exit (no unwaited-for LWP)");
2650 gdb_sigmask (SIG_SETMASK
, &prev_mask
, NULL
);
2654 /* No interesting event to report to the caller. */
2655 if ((options
& WNOHANG
))
2657 threads_debug_printf ("WNOHANG set, no event found");
2659 gdb_sigmask (SIG_SETMASK
, &prev_mask
, NULL
);
2663 /* Block until we get an event reported with SIGCHLD. */
2664 threads_debug_printf ("sigsuspend'ing");
2666 sigsuspend (&prev_mask
);
2667 gdb_sigmask (SIG_SETMASK
, &prev_mask
, NULL
);
2671 gdb_sigmask (SIG_SETMASK
, &prev_mask
, NULL
);
2673 switch_to_thread (event_thread
);
2675 return lwpid_of (event_thread
);
2679 linux_process_target::wait_for_event (ptid_t ptid
, int *wstatp
, int options
)
2681 return wait_for_event_filtered (ptid
, ptid
, wstatp
, options
);
2684 /* Select one LWP out of those that have events pending. */
2687 select_event_lwp (struct lwp_info
**orig_lp
)
2689 struct thread_info
*event_thread
= NULL
;
2691 /* In all-stop, give preference to the LWP that is being
2692 single-stepped. There will be at most one, and it's the LWP that
2693 the core is most interested in. If we didn't do this, then we'd
2694 have to handle pending step SIGTRAPs somehow in case the core
2695 later continues the previously-stepped thread, otherwise we'd
2696 report the pending SIGTRAP, and the core, not having stepped the
2697 thread, wouldn't understand what the trap was for, and therefore
2698 would report it to the user as a random signal. */
2701 event_thread
= find_thread ([] (thread_info
*thread
)
2703 lwp_info
*lp
= get_thread_lwp (thread
);
2705 return (thread
->last_status
.kind () == TARGET_WAITKIND_IGNORE
2706 && thread
->last_resume_kind
== resume_step
2707 && lp
->status_pending_p
);
2710 if (event_thread
!= NULL
)
2711 threads_debug_printf
2712 ("Select single-step %s",
2713 target_pid_to_str (ptid_of (event_thread
)).c_str ());
2715 if (event_thread
== NULL
)
2717 /* No single-stepping LWP. Select one at random, out of those
2718 which have had events. */
2720 event_thread
= find_thread_in_random ([&] (thread_info
*thread
)
2722 lwp_info
*lp
= get_thread_lwp (thread
);
2724 /* Only resumed LWPs that have an event pending. */
2725 return (thread
->last_status
.kind () == TARGET_WAITKIND_IGNORE
2726 && lp
->status_pending_p
);
2730 if (event_thread
!= NULL
)
2732 struct lwp_info
*event_lp
= get_thread_lwp (event_thread
);
2734 /* Switch the event LWP. */
2735 *orig_lp
= event_lp
;
2739 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
2743 unsuspend_all_lwps (struct lwp_info
*except
)
2745 for_each_thread ([&] (thread_info
*thread
)
2747 lwp_info
*lwp
= get_thread_lwp (thread
);
2750 lwp_suspended_decr (lwp
);
2754 static bool lwp_running (thread_info
*thread
);
2756 /* Stabilize threads (move out of jump pads).
2758 If a thread is midway collecting a fast tracepoint, we need to
2759 finish the collection and move it out of the jump pad before
2760 reporting the signal.
2762 This avoids recursion while collecting (when a signal arrives
2763 midway, and the signal handler itself collects), which would trash
2764 the trace buffer. In case the user set a breakpoint in a signal
2765 handler, this avoids the backtrace showing the jump pad, etc..
2766 Most importantly, there are certain things we can't do safely if
2767 threads are stopped in a jump pad (or in its callee's). For
2770 - starting a new trace run. A thread still collecting the
2771 previous run, could trash the trace buffer when resumed. The trace
2772 buffer control structures would have been reset but the thread had
2773 no way to tell. The thread could even midway memcpy'ing to the
2774 buffer, which would mean that when resumed, it would clobber the
2775 trace buffer that had been set for a new run.
2777 - we can't rewrite/reuse the jump pads for new tracepoints
2778 safely. Say you do tstart while a thread is stopped midway while
2779 collecting. When the thread is later resumed, it finishes the
2780 collection, and returns to the jump pad, to execute the original
2781 instruction that was under the tracepoint jump at the time the
2782 older run had been started. If the jump pad had been rewritten
2783 since for something else in the new run, the thread would now
2784 execute the wrong / random instructions. */
2787 linux_process_target::stabilize_threads ()
2789 thread_info
*thread_stuck
= find_thread ([this] (thread_info
*thread
)
2791 return stuck_in_jump_pad (thread
);
2794 if (thread_stuck
!= NULL
)
2796 threads_debug_printf ("can't stabilize, LWP %ld is stuck in jump pad",
2797 lwpid_of (thread_stuck
));
2801 scoped_restore_current_thread restore_thread
;
2803 stabilizing_threads
= 1;
2806 for_each_thread ([this] (thread_info
*thread
)
2808 move_out_of_jump_pad (thread
);
2811 /* Loop until all are stopped out of the jump pads. */
2812 while (find_thread (lwp_running
) != NULL
)
2814 struct target_waitstatus ourstatus
;
2815 struct lwp_info
*lwp
;
2818 /* Note that we go through the full wait even loop. While
2819 moving threads out of jump pad, we need to be able to step
2820 over internal breakpoints and such. */
2821 wait_1 (minus_one_ptid
, &ourstatus
, 0);
2823 if (ourstatus
.kind () == TARGET_WAITKIND_STOPPED
)
2825 lwp
= get_thread_lwp (current_thread
);
2828 lwp_suspended_inc (lwp
);
2830 if (ourstatus
.sig () != GDB_SIGNAL_0
2831 || current_thread
->last_resume_kind
== resume_stop
)
2833 wstat
= W_STOPCODE (gdb_signal_to_host (ourstatus
.sig ()));
2834 enqueue_one_deferred_signal (lwp
, &wstat
);
2839 unsuspend_all_lwps (NULL
);
2841 stabilizing_threads
= 0;
2845 thread_stuck
= find_thread ([this] (thread_info
*thread
)
2847 return stuck_in_jump_pad (thread
);
2850 if (thread_stuck
!= NULL
)
2851 threads_debug_printf
2852 ("couldn't stabilize, LWP %ld got stuck in jump pad",
2853 lwpid_of (thread_stuck
));
2857 /* Convenience function that is called when the kernel reports an
2858 event that is not passed out to GDB. */
2861 ignore_event (struct target_waitstatus
*ourstatus
)
2863 /* If we got an event, there may still be others, as a single
2864 SIGCHLD can indicate more than one child stopped. This forces
2865 another target_wait call. */
2868 ourstatus
->set_ignore ();
2873 linux_process_target::filter_exit_event (lwp_info
*event_child
,
2874 target_waitstatus
*ourstatus
)
2876 client_state
&cs
= get_client_state ();
2877 struct thread_info
*thread
= get_lwp_thread (event_child
);
2878 ptid_t ptid
= ptid_of (thread
);
2880 if (!is_leader (thread
))
2882 if (cs
.report_thread_events
)
2883 ourstatus
->set_thread_exited (0);
2885 ourstatus
->set_ignore ();
2887 delete_lwp (event_child
);
2892 /* Returns 1 if GDB is interested in any event_child syscalls. */
2895 gdb_catching_syscalls_p (struct lwp_info
*event_child
)
2897 struct thread_info
*thread
= get_lwp_thread (event_child
);
2898 struct process_info
*proc
= get_thread_process (thread
);
2900 return !proc
->syscalls_to_catch
.empty ();
2904 linux_process_target::gdb_catch_this_syscall (lwp_info
*event_child
)
2907 struct thread_info
*thread
= get_lwp_thread (event_child
);
2908 struct process_info
*proc
= get_thread_process (thread
);
2910 if (proc
->syscalls_to_catch
.empty ())
2913 if (proc
->syscalls_to_catch
[0] == ANY_SYSCALL
)
2916 get_syscall_trapinfo (event_child
, &sysno
);
2918 for (int iter
: proc
->syscalls_to_catch
)
2926 linux_process_target::wait_1 (ptid_t ptid
, target_waitstatus
*ourstatus
,
2927 target_wait_flags target_options
)
2929 THREADS_SCOPED_DEBUG_ENTER_EXIT
;
2931 client_state
&cs
= get_client_state ();
2933 struct lwp_info
*event_child
;
2936 int step_over_finished
;
2937 int bp_explains_trap
;
2938 int maybe_internal_trap
;
2944 threads_debug_printf ("[%s]", target_pid_to_str (ptid
).c_str ());
2946 /* Translate generic target options into linux options. */
2948 if (target_options
& TARGET_WNOHANG
)
2951 bp_explains_trap
= 0;
2954 ourstatus
->set_ignore ();
2956 auto status_pending_p_any
= [&] (thread_info
*thread
)
2958 return status_pending_p_callback (thread
, minus_one_ptid
);
2961 auto not_stopped
= [&] (thread_info
*thread
)
2963 return not_stopped_callback (thread
, minus_one_ptid
);
2966 /* Find a resumed LWP, if any. */
2967 if (find_thread (status_pending_p_any
) != NULL
)
2969 else if (find_thread (not_stopped
) != NULL
)
2974 if (step_over_bkpt
== null_ptid
)
2975 pid
= wait_for_event (ptid
, &w
, options
);
2978 threads_debug_printf ("step_over_bkpt set [%s], doing a blocking wait",
2979 target_pid_to_str (step_over_bkpt
).c_str ());
2980 pid
= wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
2983 if (pid
== 0 || (pid
== -1 && !any_resumed
))
2985 gdb_assert (target_options
& TARGET_WNOHANG
);
2987 threads_debug_printf ("ret = null_ptid, TARGET_WAITKIND_IGNORE");
2989 ourstatus
->set_ignore ();
2994 threads_debug_printf ("ret = null_ptid, TARGET_WAITKIND_NO_RESUMED");
2996 ourstatus
->set_no_resumed ();
3000 event_child
= get_thread_lwp (current_thread
);
3002 /* wait_for_event only returns an exit status for the last
3003 child of a process. Report it. */
3004 if (WIFEXITED (w
) || WIFSIGNALED (w
))
3008 ourstatus
->set_exited (WEXITSTATUS (w
));
3010 threads_debug_printf
3011 ("ret = %s, exited with retcode %d",
3012 target_pid_to_str (ptid_of (current_thread
)).c_str (),
3017 ourstatus
->set_signalled (gdb_signal_from_host (WTERMSIG (w
)));
3019 threads_debug_printf
3020 ("ret = %s, terminated with signal %d",
3021 target_pid_to_str (ptid_of (current_thread
)).c_str (),
3025 if (ourstatus
->kind () == TARGET_WAITKIND_EXITED
)
3026 return filter_exit_event (event_child
, ourstatus
);
3028 return ptid_of (current_thread
);
3031 /* If step-over executes a breakpoint instruction, in the case of a
3032 hardware single step it means a gdb/gdbserver breakpoint had been
3033 planted on top of a permanent breakpoint, in the case of a software
3034 single step it may just mean that gdbserver hit the reinsert breakpoint.
3035 The PC has been adjusted by save_stop_reason to point at
3036 the breakpoint address.
3037 So in the case of the hardware single step advance the PC manually
3038 past the breakpoint and in the case of software single step advance only
3039 if it's not the single_step_breakpoint we are hitting.
3040 This avoids that a program would keep trapping a permanent breakpoint
3042 if (step_over_bkpt
!= null_ptid
3043 && event_child
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3044 && (event_child
->stepping
3045 || !single_step_breakpoint_inserted_here (event_child
->stop_pc
)))
3047 int increment_pc
= 0;
3048 int breakpoint_kind
= 0;
3049 CORE_ADDR stop_pc
= event_child
->stop_pc
;
3051 breakpoint_kind
= breakpoint_kind_from_current_state (&stop_pc
);
3052 sw_breakpoint_from_kind (breakpoint_kind
, &increment_pc
);
3054 threads_debug_printf
3055 ("step-over for %s executed software breakpoint",
3056 target_pid_to_str (ptid_of (current_thread
)).c_str ());
3058 if (increment_pc
!= 0)
3060 struct regcache
*regcache
3061 = get_thread_regcache (current_thread
, 1);
3063 event_child
->stop_pc
+= increment_pc
;
3064 low_set_pc (regcache
, event_child
->stop_pc
);
3066 if (!low_breakpoint_at (event_child
->stop_pc
))
3067 event_child
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3071 /* If this event was not handled before, and is not a SIGTRAP, we
3072 report it. SIGILL and SIGSEGV are also treated as traps in case
3073 a breakpoint is inserted at the current PC. If this target does
3074 not support internal breakpoints at all, we also report the
3075 SIGTRAP without further processing; it's of no concern to us. */
3077 = (low_supports_breakpoints ()
3078 && (WSTOPSIG (w
) == SIGTRAP
3079 || ((WSTOPSIG (w
) == SIGILL
3080 || WSTOPSIG (w
) == SIGSEGV
)
3081 && low_breakpoint_at (event_child
->stop_pc
))));
3083 if (maybe_internal_trap
)
3085 /* Handle anything that requires bookkeeping before deciding to
3086 report the event or continue waiting. */
3088 /* First check if we can explain the SIGTRAP with an internal
3089 breakpoint, or if we should possibly report the event to GDB.
3090 Do this before anything that may remove or insert a
3092 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
3094 /* We have a SIGTRAP, possibly a step-over dance has just
3095 finished. If so, tweak the state machine accordingly,
3096 reinsert breakpoints and delete any single-step
3098 step_over_finished
= finish_step_over (event_child
);
3100 /* Now invoke the callbacks of any internal breakpoints there. */
3101 check_breakpoints (event_child
->stop_pc
);
3103 /* Handle tracepoint data collecting. This may overflow the
3104 trace buffer, and cause a tracing stop, removing
3106 trace_event
= handle_tracepoints (event_child
);
3108 if (bp_explains_trap
)
3109 threads_debug_printf ("Hit a gdbserver breakpoint.");
3113 /* We have some other signal, possibly a step-over dance was in
3114 progress, and it should be cancelled too. */
3115 step_over_finished
= finish_step_over (event_child
);
3118 /* We have all the data we need. Either report the event to GDB, or
3119 resume threads and keep waiting for more. */
3121 /* If we're collecting a fast tracepoint, finish the collection and
3122 move out of the jump pad before delivering a signal. See
3123 linux_stabilize_threads. */
3126 && WSTOPSIG (w
) != SIGTRAP
3127 && supports_fast_tracepoints ()
3128 && agent_loaded_p ())
3130 threads_debug_printf ("Got signal %d for LWP %ld. Check if we need "
3131 "to defer or adjust it.",
3132 WSTOPSIG (w
), lwpid_of (current_thread
));
3134 /* Allow debugging the jump pad itself. */
3135 if (current_thread
->last_resume_kind
!= resume_step
3136 && maybe_move_out_of_jump_pad (event_child
, &w
))
3138 enqueue_one_deferred_signal (event_child
, &w
);
3140 threads_debug_printf ("Signal %d for LWP %ld deferred (in jump pad)",
3141 WSTOPSIG (w
), lwpid_of (current_thread
));
3143 resume_one_lwp (event_child
, 0, 0, NULL
);
3145 return ignore_event (ourstatus
);
3149 if (event_child
->collecting_fast_tracepoint
3150 != fast_tpoint_collect_result::not_collecting
)
3152 threads_debug_printf
3153 ("LWP %ld was trying to move out of the jump pad (%d). "
3154 "Check if we're already there.",
3155 lwpid_of (current_thread
),
3156 (int) event_child
->collecting_fast_tracepoint
);
3160 event_child
->collecting_fast_tracepoint
3161 = linux_fast_tracepoint_collecting (event_child
, NULL
);
3163 if (event_child
->collecting_fast_tracepoint
3164 != fast_tpoint_collect_result::before_insn
)
3166 /* No longer need this breakpoint. */
3167 if (event_child
->exit_jump_pad_bkpt
!= NULL
)
3169 threads_debug_printf
3170 ("No longer need exit-jump-pad bkpt; removing it."
3171 "stopping all threads momentarily.");
3173 /* Other running threads could hit this breakpoint.
3174 We don't handle moribund locations like GDB does,
3175 instead we always pause all threads when removing
3176 breakpoints, so that any step-over or
3177 decr_pc_after_break adjustment is always taken
3178 care of while the breakpoint is still
3180 stop_all_lwps (1, event_child
);
3182 delete_breakpoint (event_child
->exit_jump_pad_bkpt
);
3183 event_child
->exit_jump_pad_bkpt
= NULL
;
3185 unstop_all_lwps (1, event_child
);
3187 gdb_assert (event_child
->suspended
>= 0);
3191 if (event_child
->collecting_fast_tracepoint
3192 == fast_tpoint_collect_result::not_collecting
)
3194 threads_debug_printf
3195 ("fast tracepoint finished collecting successfully.");
3197 /* We may have a deferred signal to report. */
3198 if (dequeue_one_deferred_signal (event_child
, &w
))
3199 threads_debug_printf ("dequeued one signal.");
3202 threads_debug_printf ("no deferred signals.");
3204 if (stabilizing_threads
)
3206 ourstatus
->set_stopped (GDB_SIGNAL_0
);
3208 threads_debug_printf
3209 ("ret = %s, stopped while stabilizing threads",
3210 target_pid_to_str (ptid_of (current_thread
)).c_str ());
3212 return ptid_of (current_thread
);
3218 /* Check whether GDB would be interested in this event. */
3220 /* Check if GDB is interested in this syscall. */
3222 && WSTOPSIG (w
) == SYSCALL_SIGTRAP
3223 && !gdb_catch_this_syscall (event_child
))
3225 threads_debug_printf ("Ignored syscall for LWP %ld.",
3226 lwpid_of (current_thread
));
3228 resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
3230 return ignore_event (ourstatus
);
3233 /* If GDB is not interested in this signal, don't stop other
3234 threads, and don't report it to GDB. Just resume the inferior
3235 right away. We do this for threading-related signals as well as
3236 any that GDB specifically requested we ignore. But never ignore
3237 SIGSTOP if we sent it ourselves, and do not ignore signals when
3238 stepping - they may require special handling to skip the signal
3239 handler. Also never ignore signals that could be caused by a
3242 && current_thread
->last_resume_kind
!= resume_step
3244 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
3245 (current_process ()->priv
->thread_db
!= NULL
3246 && (WSTOPSIG (w
) == __SIGRTMIN
3247 || WSTOPSIG (w
) == __SIGRTMIN
+ 1))
3250 (cs
.pass_signals
[gdb_signal_from_host (WSTOPSIG (w
))]
3251 && !(WSTOPSIG (w
) == SIGSTOP
3252 && current_thread
->last_resume_kind
== resume_stop
)
3253 && !linux_wstatus_maybe_breakpoint (w
))))
3255 siginfo_t info
, *info_p
;
3257 threads_debug_printf ("Ignored signal %d for LWP %ld.",
3258 WSTOPSIG (w
), lwpid_of (current_thread
));
3260 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
3261 (PTRACE_TYPE_ARG3
) 0, &info
) == 0)
3266 if (step_over_finished
)
3268 /* We cancelled this thread's step-over above. We still
3269 need to unsuspend all other LWPs, and set them back
3270 running again while the signal handler runs. */
3271 unsuspend_all_lwps (event_child
);
3273 /* Enqueue the pending signal info so that proceed_all_lwps
3275 enqueue_pending_signal (event_child
, WSTOPSIG (w
), info_p
);
3277 proceed_all_lwps ();
3281 resume_one_lwp (event_child
, event_child
->stepping
,
3282 WSTOPSIG (w
), info_p
);
3285 return ignore_event (ourstatus
);
3288 /* Note that all addresses are always "out of the step range" when
3289 there's no range to begin with. */
3290 in_step_range
= lwp_in_step_range (event_child
);
3292 /* If GDB wanted this thread to single step, and the thread is out
3293 of the step range, we always want to report the SIGTRAP, and let
3294 GDB handle it. Watchpoints should always be reported. So should
3295 signals we can't explain. A SIGTRAP we can't explain could be a
3296 GDB breakpoint --- we may or not support Z0 breakpoints. If we
3297 do, we're be able to handle GDB breakpoints on top of internal
3298 breakpoints, by handling the internal breakpoint and still
3299 reporting the event to GDB. If we don't, we're out of luck, GDB
3300 won't see the breakpoint hit. If we see a single-step event but
3301 the thread should be continuing, don't pass the trap to gdb.
3302 That indicates that we had previously finished a single-step but
3303 left the single-step pending -- see
3304 complete_ongoing_step_over. */
3305 report_to_gdb
= (!maybe_internal_trap
3306 || (current_thread
->last_resume_kind
== resume_step
3308 || event_child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
3310 && !bp_explains_trap
3312 && !step_over_finished
3313 && !(current_thread
->last_resume_kind
== resume_continue
3314 && event_child
->stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
))
3315 || (gdb_breakpoint_here (event_child
->stop_pc
)
3316 && gdb_condition_true_at_breakpoint (event_child
->stop_pc
)
3317 && gdb_no_commands_at_breakpoint (event_child
->stop_pc
))
3318 || event_child
->waitstatus
.kind () != TARGET_WAITKIND_IGNORE
);
3320 run_breakpoint_commands (event_child
->stop_pc
);
3322 /* We found no reason GDB would want us to stop. We either hit one
3323 of our own breakpoints, or finished an internal step GDB
3324 shouldn't know about. */
3327 if (bp_explains_trap
)
3328 threads_debug_printf ("Hit a gdbserver breakpoint.");
3330 if (step_over_finished
)
3331 threads_debug_printf ("Step-over finished.");
3334 threads_debug_printf ("Tracepoint event.");
3336 if (lwp_in_step_range (event_child
))
3337 threads_debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).",
3338 paddress (event_child
->stop_pc
),
3339 paddress (event_child
->step_range_start
),
3340 paddress (event_child
->step_range_end
));
3342 /* We're not reporting this breakpoint to GDB, so apply the
3343 decr_pc_after_break adjustment to the inferior's regcache
3346 if (low_supports_breakpoints ())
3348 struct regcache
*regcache
3349 = get_thread_regcache (current_thread
, 1);
3350 low_set_pc (regcache
, event_child
->stop_pc
);
3353 if (step_over_finished
)
3355 /* If we have finished stepping over a breakpoint, we've
3356 stopped and suspended all LWPs momentarily except the
3357 stepping one. This is where we resume them all again.
3358 We're going to keep waiting, so use proceed, which
3359 handles stepping over the next breakpoint. */
3360 unsuspend_all_lwps (event_child
);
3364 /* Remove the single-step breakpoints if any. Note that
3365 there isn't single-step breakpoint if we finished stepping
3367 if (supports_software_single_step ()
3368 && has_single_step_breakpoints (current_thread
))
3370 stop_all_lwps (0, event_child
);
3371 delete_single_step_breakpoints (current_thread
);
3372 unstop_all_lwps (0, event_child
);
3376 threads_debug_printf ("proceeding all threads.");
3378 proceed_all_lwps ();
3380 return ignore_event (ourstatus
);
3385 if (event_child
->waitstatus
.kind () != TARGET_WAITKIND_IGNORE
)
3386 threads_debug_printf ("LWP %ld: extended event with waitstatus %s",
3387 lwpid_of (get_lwp_thread (event_child
)),
3388 event_child
->waitstatus
.to_string ().c_str ());
3390 if (current_thread
->last_resume_kind
== resume_step
)
3392 if (event_child
->step_range_start
== event_child
->step_range_end
)
3393 threads_debug_printf
3394 ("GDB wanted to single-step, reporting event.");
3395 else if (!lwp_in_step_range (event_child
))
3396 threads_debug_printf ("Out of step range, reporting event.");
3399 if (event_child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
3400 threads_debug_printf ("Stopped by watchpoint.");
3401 else if (gdb_breakpoint_here (event_child
->stop_pc
))
3402 threads_debug_printf ("Stopped by GDB breakpoint.");
3405 threads_debug_printf ("Hit a non-gdbserver trap event.");
3407 /* Alright, we're going to report a stop. */
3409 /* Remove single-step breakpoints. */
3410 if (supports_software_single_step ())
3412 /* Remove single-step breakpoints or not. It it is true, stop all
3413 lwps, so that other threads won't hit the breakpoint in the
3415 int remove_single_step_breakpoints_p
= 0;
3419 remove_single_step_breakpoints_p
3420 = has_single_step_breakpoints (current_thread
);
3424 /* In all-stop, a stop reply cancels all previous resume
3425 requests. Delete all single-step breakpoints. */
3427 find_thread ([&] (thread_info
*thread
) {
3428 if (has_single_step_breakpoints (thread
))
3430 remove_single_step_breakpoints_p
= 1;
3438 if (remove_single_step_breakpoints_p
)
3440 /* If we remove single-step breakpoints from memory, stop all lwps,
3441 so that other threads won't hit the breakpoint in the staled
3443 stop_all_lwps (0, event_child
);
3447 gdb_assert (has_single_step_breakpoints (current_thread
));
3448 delete_single_step_breakpoints (current_thread
);
3452 for_each_thread ([] (thread_info
*thread
){
3453 if (has_single_step_breakpoints (thread
))
3454 delete_single_step_breakpoints (thread
);
3458 unstop_all_lwps (0, event_child
);
3462 if (!stabilizing_threads
)
3464 /* In all-stop, stop all threads. */
3466 stop_all_lwps (0, NULL
);
3468 if (step_over_finished
)
3472 /* If we were doing a step-over, all other threads but
3473 the stepping one had been paused in start_step_over,
3474 with their suspend counts incremented. We don't want
3475 to do a full unstop/unpause, because we're in
3476 all-stop mode (so we want threads stopped), but we
3477 still need to unsuspend the other threads, to
3478 decrement their `suspended' count back. */
3479 unsuspend_all_lwps (event_child
);
3483 /* If we just finished a step-over, then all threads had
3484 been momentarily paused. In all-stop, that's fine,
3485 we want threads stopped by now anyway. In non-stop,
3486 we need to re-resume threads that GDB wanted to be
3488 unstop_all_lwps (1, event_child
);
3492 /* If we're not waiting for a specific LWP, choose an event LWP
3493 from among those that have had events. Giving equal priority
3494 to all LWPs that have had events helps prevent
3496 if (ptid
== minus_one_ptid
)
3498 event_child
->status_pending_p
= 1;
3499 event_child
->status_pending
= w
;
3501 select_event_lwp (&event_child
);
3503 /* current_thread and event_child must stay in sync. */
3504 switch_to_thread (get_lwp_thread (event_child
));
3506 event_child
->status_pending_p
= 0;
3507 w
= event_child
->status_pending
;
3511 /* Stabilize threads (move out of jump pads). */
3513 target_stabilize_threads ();
3517 /* If we just finished a step-over, then all threads had been
3518 momentarily paused. In all-stop, that's fine, we want
3519 threads stopped by now anyway. In non-stop, we need to
3520 re-resume threads that GDB wanted to be running. */
3521 if (step_over_finished
)
3522 unstop_all_lwps (1, event_child
);
3525 /* At this point, we haven't set OURSTATUS. This is where we do it. */
3526 gdb_assert (ourstatus
->kind () == TARGET_WAITKIND_IGNORE
);
3528 if (event_child
->waitstatus
.kind () != TARGET_WAITKIND_IGNORE
)
3530 /* If the reported event is an exit, fork, vfork or exec, let
3533 /* Break the unreported fork relationship chain. */
3534 if (event_child
->waitstatus
.kind () == TARGET_WAITKIND_FORKED
3535 || event_child
->waitstatus
.kind () == TARGET_WAITKIND_VFORKED
)
3537 event_child
->fork_relative
->fork_relative
= NULL
;
3538 event_child
->fork_relative
= NULL
;
3541 *ourstatus
= event_child
->waitstatus
;
3542 /* Clear the event lwp's waitstatus since we handled it already. */
3543 event_child
->waitstatus
.set_ignore ();
3547 /* The LWP stopped due to a plain signal or a syscall signal. Either way,
3548 event_child->waitstatus wasn't filled in with the details, so look at
3549 the wait status W. */
3550 if (WSTOPSIG (w
) == SYSCALL_SIGTRAP
)
3554 get_syscall_trapinfo (event_child
, &syscall_number
);
3555 if (event_child
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
)
3556 ourstatus
->set_syscall_entry (syscall_number
);
3557 else if (event_child
->syscall_state
== TARGET_WAITKIND_SYSCALL_RETURN
)
3558 ourstatus
->set_syscall_return (syscall_number
);
3560 gdb_assert_not_reached ("unexpected syscall state");
3562 else if (current_thread
->last_resume_kind
== resume_stop
3563 && WSTOPSIG (w
) == SIGSTOP
)
3565 /* A thread that has been requested to stop by GDB with vCont;t,
3566 and it stopped cleanly, so report as SIG0. The use of
3567 SIGSTOP is an implementation detail. */
3568 ourstatus
->set_stopped (GDB_SIGNAL_0
);
3571 ourstatus
->set_stopped (gdb_signal_from_host (WSTOPSIG (w
)));
3574 /* Now that we've selected our final event LWP, un-adjust its PC if
3575 it was a software breakpoint, and the client doesn't know we can
3576 adjust the breakpoint ourselves. */
3577 if (event_child
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3578 && !cs
.swbreak_feature
)
3580 int decr_pc
= low_decr_pc_after_break ();
3584 struct regcache
*regcache
3585 = get_thread_regcache (current_thread
, 1);
3586 low_set_pc (regcache
, event_child
->stop_pc
+ decr_pc
);
3590 gdb_assert (step_over_bkpt
== null_ptid
);
3592 threads_debug_printf ("ret = %s, %s",
3593 target_pid_to_str (ptid_of (current_thread
)).c_str (),
3594 ourstatus
->to_string ().c_str ());
3596 if (ourstatus
->kind () == TARGET_WAITKIND_EXITED
)
3597 return filter_exit_event (event_child
, ourstatus
);
3599 return ptid_of (current_thread
);
3602 /* Get rid of any pending event in the pipe. */
3604 async_file_flush (void)
3606 linux_event_pipe
.flush ();
3609 /* Put something in the pipe, so the event loop wakes up. */
3611 async_file_mark (void)
3613 linux_event_pipe
.mark ();
3617 linux_process_target::wait (ptid_t ptid
,
3618 target_waitstatus
*ourstatus
,
3619 target_wait_flags target_options
)
3623 /* Flush the async file first. */
3624 if (target_is_async_p ())
3625 async_file_flush ();
3629 event_ptid
= wait_1 (ptid
, ourstatus
, target_options
);
3631 while ((target_options
& TARGET_WNOHANG
) == 0
3632 && event_ptid
== null_ptid
3633 && ourstatus
->kind () == TARGET_WAITKIND_IGNORE
);
3635 /* If at least one stop was reported, there may be more. A single
3636 SIGCHLD can signal more than one child stop. */
3637 if (target_is_async_p ()
3638 && (target_options
& TARGET_WNOHANG
) != 0
3639 && event_ptid
!= null_ptid
)
3645 /* Send a signal to an LWP. */
3648 kill_lwp (unsigned long lwpid
, int signo
)
3653 ret
= syscall (__NR_tkill
, lwpid
, signo
);
3654 if (errno
== ENOSYS
)
3656 /* If tkill fails, then we are not using nptl threads, a
3657 configuration we no longer support. */
3658 perror_with_name (("tkill"));
3664 linux_stop_lwp (struct lwp_info
*lwp
)
3670 send_sigstop (struct lwp_info
*lwp
)
3674 pid
= lwpid_of (get_lwp_thread (lwp
));
3676 /* If we already have a pending stop signal for this process, don't
3678 if (lwp
->stop_expected
)
3680 threads_debug_printf ("Have pending sigstop for lwp %d", pid
);
3685 threads_debug_printf ("Sending sigstop to lwp %d", pid
);
3687 lwp
->stop_expected
= 1;
3688 kill_lwp (pid
, SIGSTOP
);
3692 send_sigstop (thread_info
*thread
, lwp_info
*except
)
3694 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3696 /* Ignore EXCEPT. */
3706 /* Increment the suspend count of an LWP, and stop it, if not stopped
3709 suspend_and_send_sigstop (thread_info
*thread
, lwp_info
*except
)
3711 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3713 /* Ignore EXCEPT. */
3717 lwp_suspended_inc (lwp
);
3719 send_sigstop (thread
, except
);
3723 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
3725 /* Store the exit status for later. */
3726 lwp
->status_pending_p
= 1;
3727 lwp
->status_pending
= wstat
;
3729 /* Store in waitstatus as well, as there's nothing else to process
3731 if (WIFEXITED (wstat
))
3732 lwp
->waitstatus
.set_exited (WEXITSTATUS (wstat
));
3733 else if (WIFSIGNALED (wstat
))
3734 lwp
->waitstatus
.set_signalled (gdb_signal_from_host (WTERMSIG (wstat
)));
3736 /* Prevent trying to stop it. */
3739 /* No further stops are expected from a dead lwp. */
3740 lwp
->stop_expected
= 0;
3743 /* Return true if LWP has exited already, and has a pending exit event
3744 to report to GDB. */
3747 lwp_is_marked_dead (struct lwp_info
*lwp
)
3749 return (lwp
->status_pending_p
3750 && (WIFEXITED (lwp
->status_pending
)
3751 || WIFSIGNALED (lwp
->status_pending
)));
3755 linux_process_target::wait_for_sigstop ()
3757 struct thread_info
*saved_thread
;
3762 saved_thread
= current_thread
;
3763 if (saved_thread
!= NULL
)
3764 saved_tid
= saved_thread
->id
;
3766 saved_tid
= null_ptid
; /* avoid bogus unused warning */
3768 scoped_restore_current_thread restore_thread
;
3770 threads_debug_printf ("pulling events");
3772 /* Passing NULL_PTID as filter indicates we want all events to be
3773 left pending. Eventually this returns when there are no
3774 unwaited-for children left. */
3775 ret
= wait_for_event_filtered (minus_one_ptid
, null_ptid
, &wstat
, __WALL
);
3776 gdb_assert (ret
== -1);
3778 if (saved_thread
== NULL
|| mythread_alive (saved_tid
))
3782 threads_debug_printf ("Previously current thread died.");
3784 /* We can't change the current inferior behind GDB's back,
3785 otherwise, a subsequent command may apply to the wrong
3787 restore_thread
.dont_restore ();
3788 switch_to_thread (nullptr);
3793 linux_process_target::stuck_in_jump_pad (thread_info
*thread
)
3795 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3797 if (lwp
->suspended
!= 0)
3799 internal_error ("LWP %ld is suspended, suspended=%d\n",
3800 lwpid_of (thread
), lwp
->suspended
);
3802 gdb_assert (lwp
->stopped
);
3804 /* Allow debugging the jump pad, gdb_collect, etc.. */
3805 return (supports_fast_tracepoints ()
3806 && agent_loaded_p ()
3807 && (gdb_breakpoint_here (lwp
->stop_pc
)
3808 || lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
3809 || thread
->last_resume_kind
== resume_step
)
3810 && (linux_fast_tracepoint_collecting (lwp
, NULL
)
3811 != fast_tpoint_collect_result::not_collecting
));
3815 linux_process_target::move_out_of_jump_pad (thread_info
*thread
)
3817 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3820 if (lwp
->suspended
!= 0)
3822 internal_error ("LWP %ld is suspended, suspended=%d\n",
3823 lwpid_of (thread
), lwp
->suspended
);
3825 gdb_assert (lwp
->stopped
);
3827 /* For gdb_breakpoint_here. */
3828 scoped_restore_current_thread restore_thread
;
3829 switch_to_thread (thread
);
3831 wstat
= lwp
->status_pending_p
? &lwp
->status_pending
: NULL
;
3833 /* Allow debugging the jump pad, gdb_collect, etc. */
3834 if (!gdb_breakpoint_here (lwp
->stop_pc
)
3835 && lwp
->stop_reason
!= TARGET_STOPPED_BY_WATCHPOINT
3836 && thread
->last_resume_kind
!= resume_step
3837 && maybe_move_out_of_jump_pad (lwp
, wstat
))
3839 threads_debug_printf ("LWP %ld needs stabilizing (in jump pad)",
3844 lwp
->status_pending_p
= 0;
3845 enqueue_one_deferred_signal (lwp
, wstat
);
3847 threads_debug_printf ("Signal %d for LWP %ld deferred (in jump pad",
3848 WSTOPSIG (*wstat
), lwpid_of (thread
));
3851 resume_one_lwp (lwp
, 0, 0, NULL
);
3854 lwp_suspended_inc (lwp
);
3858 lwp_running (thread_info
*thread
)
3860 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3862 if (lwp_is_marked_dead (lwp
))
3865 return !lwp
->stopped
;
3869 linux_process_target::stop_all_lwps (int suspend
, lwp_info
*except
)
3871 /* Should not be called recursively. */
3872 gdb_assert (stopping_threads
== NOT_STOPPING_THREADS
);
3874 THREADS_SCOPED_DEBUG_ENTER_EXIT
;
3876 threads_debug_printf
3877 ("%s, except=%s", suspend
? "stop-and-suspend" : "stop",
3879 ? target_pid_to_str (ptid_of (get_lwp_thread (except
))).c_str ()
3882 stopping_threads
= (suspend
3883 ? STOPPING_AND_SUSPENDING_THREADS
3884 : STOPPING_THREADS
);
3887 for_each_thread ([&] (thread_info
*thread
)
3889 suspend_and_send_sigstop (thread
, except
);
3892 for_each_thread ([&] (thread_info
*thread
)
3894 send_sigstop (thread
, except
);
3897 wait_for_sigstop ();
3898 stopping_threads
= NOT_STOPPING_THREADS
;
3900 threads_debug_printf ("setting stopping_threads back to !stopping");
3903 /* Enqueue one signal in the chain of signals which need to be
3904 delivered to this process on next resume. */
3907 enqueue_pending_signal (struct lwp_info
*lwp
, int signal
, siginfo_t
*info
)
3909 lwp
->pending_signals
.emplace_back (signal
);
3910 if (info
== nullptr)
3911 memset (&lwp
->pending_signals
.back ().info
, 0, sizeof (siginfo_t
));
3913 lwp
->pending_signals
.back ().info
= *info
;
3917 linux_process_target::install_software_single_step_breakpoints (lwp_info
*lwp
)
3919 struct thread_info
*thread
= get_lwp_thread (lwp
);
3920 struct regcache
*regcache
= get_thread_regcache (thread
, 1);
3922 scoped_restore_current_thread restore_thread
;
3924 switch_to_thread (thread
);
3925 std::vector
<CORE_ADDR
> next_pcs
= low_get_next_pcs (regcache
);
3927 for (CORE_ADDR pc
: next_pcs
)
3928 set_single_step_breakpoint (pc
, current_ptid
);
3932 linux_process_target::single_step (lwp_info
* lwp
)
3936 if (supports_hardware_single_step ())
3940 else if (supports_software_single_step ())
3942 install_software_single_step_breakpoints (lwp
);
3946 threads_debug_printf ("stepping is not implemented on this target");
3951 /* The signal can be delivered to the inferior if we are not trying to
3952 finish a fast tracepoint collect. Since signal can be delivered in
3953 the step-over, the program may go to signal handler and trap again
3954 after return from the signal handler. We can live with the spurious
3958 lwp_signal_can_be_delivered (struct lwp_info
*lwp
)
3960 return (lwp
->collecting_fast_tracepoint
3961 == fast_tpoint_collect_result::not_collecting
);
3965 linux_process_target::resume_one_lwp_throw (lwp_info
*lwp
, int step
,
3966 int signal
, siginfo_t
*info
)
3968 struct thread_info
*thread
= get_lwp_thread (lwp
);
3970 struct process_info
*proc
= get_thread_process (thread
);
3972 /* Note that target description may not be initialised
3973 (proc->tdesc == NULL) at this point because the program hasn't
3974 stopped at the first instruction yet. It means GDBserver skips
3975 the extra traps from the wrapper program (see option --wrapper).
3976 Code in this function that requires register access should be
3977 guarded by proc->tdesc == NULL or something else. */
3979 if (lwp
->stopped
== 0)
3982 gdb_assert (lwp
->waitstatus
.kind () == TARGET_WAITKIND_IGNORE
);
3984 fast_tpoint_collect_result fast_tp_collecting
3985 = lwp
->collecting_fast_tracepoint
;
3987 gdb_assert (!stabilizing_threads
3988 || (fast_tp_collecting
3989 != fast_tpoint_collect_result::not_collecting
));
3991 /* Cancel actions that rely on GDB not changing the PC (e.g., the
3992 user used the "jump" command, or "set $pc = foo"). */
3993 if (thread
->while_stepping
!= NULL
&& lwp
->stop_pc
!= get_pc (lwp
))
3995 /* Collecting 'while-stepping' actions doesn't make sense
3997 release_while_stepping_state_list (thread
);
4000 /* If we have pending signals or status, and a new signal, enqueue the
4001 signal. Also enqueue the signal if it can't be delivered to the
4002 inferior right now. */
4004 && (lwp
->status_pending_p
4005 || !lwp
->pending_signals
.empty ()
4006 || !lwp_signal_can_be_delivered (lwp
)))
4008 enqueue_pending_signal (lwp
, signal
, info
);
4010 /* Postpone any pending signal. It was enqueued above. */
4014 if (lwp
->status_pending_p
)
4016 threads_debug_printf
4017 ("Not resuming lwp %ld (%s, stop %s); has pending status",
4018 lwpid_of (thread
), step
? "step" : "continue",
4019 lwp
->stop_expected
? "expected" : "not expected");
4023 scoped_restore_current_thread restore_thread
;
4024 switch_to_thread (thread
);
4026 /* This bit needs some thinking about. If we get a signal that
4027 we must report while a single-step reinsert is still pending,
4028 we often end up resuming the thread. It might be better to
4029 (ew) allow a stack of pending events; then we could be sure that
4030 the reinsert happened right away and not lose any signals.
4032 Making this stack would also shrink the window in which breakpoints are
4033 uninserted (see comment in linux_wait_for_lwp) but not enough for
4034 complete correctness, so it won't solve that problem. It may be
4035 worthwhile just to solve this one, however. */
4036 if (lwp
->bp_reinsert
!= 0)
4038 threads_debug_printf (" pending reinsert at 0x%s",
4039 paddress (lwp
->bp_reinsert
));
4041 if (supports_hardware_single_step ())
4043 if (fast_tp_collecting
== fast_tpoint_collect_result::not_collecting
)
4046 warning ("BAD - reinserting but not stepping.");
4048 warning ("BAD - reinserting and suspended(%d).",
4053 step
= maybe_hw_step (thread
);
4056 if (fast_tp_collecting
== fast_tpoint_collect_result::before_insn
)
4057 threads_debug_printf
4058 ("lwp %ld wants to get out of fast tracepoint jump pad "
4059 "(exit-jump-pad-bkpt)", lwpid_of (thread
));
4061 else if (fast_tp_collecting
== fast_tpoint_collect_result::at_insn
)
4063 threads_debug_printf
4064 ("lwp %ld wants to get out of fast tracepoint jump pad single-stepping",
4067 if (supports_hardware_single_step ())
4071 internal_error ("moving out of jump pad single-stepping"
4072 " not implemented on this target");
4076 /* If we have while-stepping actions in this thread set it stepping.
4077 If we have a signal to deliver, it may or may not be set to
4078 SIG_IGN, we don't know. Assume so, and allow collecting
4079 while-stepping into a signal handler. A possible smart thing to
4080 do would be to set an internal breakpoint at the signal return
4081 address, continue, and carry on catching this while-stepping
4082 action only when that breakpoint is hit. A future
4084 if (thread
->while_stepping
!= NULL
)
4086 threads_debug_printf
4087 ("lwp %ld has a while-stepping action -> forcing step.",
4090 step
= single_step (lwp
);
4093 if (proc
->tdesc
!= NULL
&& low_supports_breakpoints ())
4095 struct regcache
*regcache
= get_thread_regcache (current_thread
, 1);
4097 lwp
->stop_pc
= low_get_pc (regcache
);
4099 threads_debug_printf (" %s from pc 0x%lx", step
? "step" : "continue",
4100 (long) lwp
->stop_pc
);
4103 /* If we have pending signals, consume one if it can be delivered to
4105 if (!lwp
->pending_signals
.empty () && lwp_signal_can_be_delivered (lwp
))
4107 const pending_signal
&p_sig
= lwp
->pending_signals
.front ();
4109 signal
= p_sig
.signal
;
4110 if (p_sig
.info
.si_signo
!= 0)
4111 ptrace (PTRACE_SETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
4114 lwp
->pending_signals
.pop_front ();
4117 threads_debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)",
4118 lwpid_of (thread
), step
? "step" : "continue", signal
,
4119 lwp
->stop_expected
? "expected" : "not expected");
4121 low_prepare_to_resume (lwp
);
4123 regcache_invalidate_thread (thread
);
4125 lwp
->stepping
= step
;
4127 ptrace_request
= PTRACE_SINGLESTEP
;
4128 else if (gdb_catching_syscalls_p (lwp
))
4129 ptrace_request
= PTRACE_SYSCALL
;
4131 ptrace_request
= PTRACE_CONT
;
4132 ptrace (ptrace_request
,
4134 (PTRACE_TYPE_ARG3
) 0,
4135 /* Coerce to a uintptr_t first to avoid potential gcc warning
4136 of coercing an 8 byte integer to a 4 byte pointer. */
4137 (PTRACE_TYPE_ARG4
) (uintptr_t) signal
);
4141 int saved_errno
= errno
;
4143 threads_debug_printf ("ptrace errno = %d (%s)",
4144 saved_errno
, strerror (saved_errno
));
4146 errno
= saved_errno
;
4147 perror_with_name ("resuming thread");
4150 /* Successfully resumed. Clear state that no longer makes sense,
4151 and mark the LWP as running. Must not do this before resuming
4152 otherwise if that fails other code will be confused. E.g., we'd
4153 later try to stop the LWP and hang forever waiting for a stop
4154 status. Note that we must not throw after this is cleared,
4155 otherwise handle_zombie_lwp_error would get confused. */
4157 lwp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
4161 linux_process_target::low_prepare_to_resume (lwp_info
*lwp
)
4166 /* Called when we try to resume a stopped LWP and that errors out. If
4167 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
4168 or about to become), discard the error, clear any pending status
4169 the LWP may have, and return true (we'll collect the exit status
4170 soon enough). Otherwise, return false. */
4173 check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
)
4175 struct thread_info
*thread
= get_lwp_thread (lp
);
4177 /* If we get an error after resuming the LWP successfully, we'd
4178 confuse !T state for the LWP being gone. */
4179 gdb_assert (lp
->stopped
);
4181 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
4182 because even if ptrace failed with ESRCH, the tracee may be "not
4183 yet fully dead", but already refusing ptrace requests. In that
4184 case the tracee has 'R (Running)' state for a little bit
4185 (observed in Linux 3.18). See also the note on ESRCH in the
4186 ptrace(2) man page. Instead, check whether the LWP has any state
4187 other than ptrace-stopped. */
4189 /* Don't assume anything if /proc/PID/status can't be read. */
4190 if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread
)) == 0)
4192 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
4193 lp
->status_pending_p
= 0;
4200 linux_process_target::resume_one_lwp (lwp_info
*lwp
, int step
, int signal
,
4205 resume_one_lwp_throw (lwp
, step
, signal
, info
);
4207 catch (const gdb_exception_error
&ex
)
4209 if (check_ptrace_stopped_lwp_gone (lwp
))
4211 /* This could because we tried to resume an LWP after its leader
4212 exited. Mark it as resumed, so we can collect an exit event
4215 lwp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
4222 /* This function is called once per thread via for_each_thread.
4223 We look up which resume request applies to THREAD and mark it with a
4224 pointer to the appropriate resume request.
4226 This algorithm is O(threads * resume elements), but resume elements
4227 is small (and will remain small at least until GDB supports thread
4231 linux_set_resume_request (thread_info
*thread
, thread_resume
*resume
, size_t n
)
4233 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4235 for (int ndx
= 0; ndx
< n
; ndx
++)
4237 ptid_t ptid
= resume
[ndx
].thread
;
4238 if (ptid
== minus_one_ptid
4239 || ptid
== thread
->id
4240 /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads
4242 || (ptid
.pid () == pid_of (thread
)
4244 || ptid
.lwp () == -1)))
4246 if (resume
[ndx
].kind
== resume_stop
4247 && thread
->last_resume_kind
== resume_stop
)
4249 threads_debug_printf
4250 ("already %s LWP %ld at GDB's request",
4251 (thread
->last_status
.kind () == TARGET_WAITKIND_STOPPED
4252 ? "stopped" : "stopping"),
4258 /* Ignore (wildcard) resume requests for already-resumed
4260 if (resume
[ndx
].kind
!= resume_stop
4261 && thread
->last_resume_kind
!= resume_stop
)
4263 threads_debug_printf
4264 ("already %s LWP %ld at GDB's request",
4265 (thread
->last_resume_kind
== resume_step
4266 ? "stepping" : "continuing"),
4271 /* Don't let wildcard resumes resume fork children that GDB
4272 does not yet know are new fork children. */
4273 if (lwp
->fork_relative
!= NULL
)
4275 struct lwp_info
*rel
= lwp
->fork_relative
;
4277 if (rel
->status_pending_p
4278 && (rel
->waitstatus
.kind () == TARGET_WAITKIND_FORKED
4279 || rel
->waitstatus
.kind () == TARGET_WAITKIND_VFORKED
))
4281 threads_debug_printf
4282 ("not resuming LWP %ld: has queued stop reply",
4288 /* If the thread has a pending event that has already been
4289 reported to GDBserver core, but GDB has not pulled the
4290 event out of the vStopped queue yet, likewise, ignore the
4291 (wildcard) resume request. */
4292 if (in_queued_stop_replies (thread
->id
))
4294 threads_debug_printf
4295 ("not resuming LWP %ld: has queued stop reply",
4300 lwp
->resume
= &resume
[ndx
];
4301 thread
->last_resume_kind
= lwp
->resume
->kind
;
4303 lwp
->step_range_start
= lwp
->resume
->step_range_start
;
4304 lwp
->step_range_end
= lwp
->resume
->step_range_end
;
4306 /* If we had a deferred signal to report, dequeue one now.
4307 This can happen if LWP gets more than one signal while
4308 trying to get out of a jump pad. */
4310 && !lwp
->status_pending_p
4311 && dequeue_one_deferred_signal (lwp
, &lwp
->status_pending
))
4313 lwp
->status_pending_p
= 1;
4315 threads_debug_printf
4316 ("Dequeueing deferred signal %d for LWP %ld, "
4317 "leaving status pending.",
4318 WSTOPSIG (lwp
->status_pending
),
4326 /* No resume action for this thread. */
4331 linux_process_target::resume_status_pending (thread_info
*thread
)
4333 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4335 /* LWPs which will not be resumed are not interesting, because
4336 we might not wait for them next time through linux_wait. */
4337 if (lwp
->resume
== NULL
)
4340 return thread_still_has_status_pending (thread
);
4344 linux_process_target::thread_needs_step_over (thread_info
*thread
)
4346 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4348 struct process_info
*proc
= get_thread_process (thread
);
4350 /* GDBserver is skipping the extra traps from the wrapper program,
4351 don't have to do step over. */
4352 if (proc
->tdesc
== NULL
)
4355 /* LWPs which will not be resumed are not interesting, because we
4356 might not wait for them next time through linux_wait. */
4360 threads_debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped",
4365 if (thread
->last_resume_kind
== resume_stop
)
4367 threads_debug_printf
4368 ("Need step over [LWP %ld]? Ignoring, should remain stopped",
4373 gdb_assert (lwp
->suspended
>= 0);
4377 threads_debug_printf ("Need step over [LWP %ld]? Ignoring, suspended",
4382 if (lwp
->status_pending_p
)
4384 threads_debug_printf
4385 ("Need step over [LWP %ld]? Ignoring, has pending status.",
4390 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
4394 /* If the PC has changed since we stopped, then don't do anything,
4395 and let the breakpoint/tracepoint be hit. This happens if, for
4396 instance, GDB handled the decr_pc_after_break subtraction itself,
4397 GDB is OOL stepping this thread, or the user has issued a "jump"
4398 command, or poked thread's registers herself. */
4399 if (pc
!= lwp
->stop_pc
)
4401 threads_debug_printf
4402 ("Need step over [LWP %ld]? Cancelling, PC was changed. "
4403 "Old stop_pc was 0x%s, PC is now 0x%s", lwpid_of (thread
),
4404 paddress (lwp
->stop_pc
), paddress (pc
));
4408 /* On software single step target, resume the inferior with signal
4409 rather than stepping over. */
4410 if (supports_software_single_step ()
4411 && !lwp
->pending_signals
.empty ()
4412 && lwp_signal_can_be_delivered (lwp
))
4414 threads_debug_printf
4415 ("Need step over [LWP %ld]? Ignoring, has pending signals.",
4421 scoped_restore_current_thread restore_thread
;
4422 switch_to_thread (thread
);
4424 /* We can only step over breakpoints we know about. */
4425 if (breakpoint_here (pc
) || fast_tracepoint_jump_here (pc
))
4427 /* Don't step over a breakpoint that GDB expects to hit
4428 though. If the condition is being evaluated on the target's side
4429 and it evaluate to false, step over this breakpoint as well. */
4430 if (gdb_breakpoint_here (pc
)
4431 && gdb_condition_true_at_breakpoint (pc
)
4432 && gdb_no_commands_at_breakpoint (pc
))
4434 threads_debug_printf ("Need step over [LWP %ld]? yes, but found"
4435 " GDB breakpoint at 0x%s; skipping step over",
4436 lwpid_of (thread
), paddress (pc
));
4442 threads_debug_printf ("Need step over [LWP %ld]? yes, "
4443 "found breakpoint at 0x%s",
4444 lwpid_of (thread
), paddress (pc
));
4446 /* We've found an lwp that needs stepping over --- return 1 so
4447 that find_thread stops looking. */
4452 threads_debug_printf
4453 ("Need step over [LWP %ld]? No, no breakpoint found at 0x%s",
4454 lwpid_of (thread
), paddress (pc
));
4460 linux_process_target::start_step_over (lwp_info
*lwp
)
4462 struct thread_info
*thread
= get_lwp_thread (lwp
);
4465 threads_debug_printf ("Starting step-over on LWP %ld. Stopping all threads",
4468 stop_all_lwps (1, lwp
);
4470 if (lwp
->suspended
!= 0)
4472 internal_error ("LWP %ld suspended=%d\n", lwpid_of (thread
),
4476 threads_debug_printf ("Done stopping all threads for step-over.");
4478 /* Note, we should always reach here with an already adjusted PC,
4479 either by GDB (if we're resuming due to GDB's request), or by our
4480 caller, if we just finished handling an internal breakpoint GDB
4481 shouldn't care about. */
4486 scoped_restore_current_thread restore_thread
;
4487 switch_to_thread (thread
);
4489 lwp
->bp_reinsert
= pc
;
4490 uninsert_breakpoints_at (pc
);
4491 uninsert_fast_tracepoint_jumps_at (pc
);
4493 step
= single_step (lwp
);
4496 resume_one_lwp (lwp
, step
, 0, NULL
);
4498 /* Require next event from this LWP. */
4499 step_over_bkpt
= thread
->id
;
4503 linux_process_target::finish_step_over (lwp_info
*lwp
)
4505 if (lwp
->bp_reinsert
!= 0)
4507 scoped_restore_current_thread restore_thread
;
4509 threads_debug_printf ("Finished step over.");
4511 switch_to_thread (get_lwp_thread (lwp
));
4513 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
4514 may be no breakpoint to reinsert there by now. */
4515 reinsert_breakpoints_at (lwp
->bp_reinsert
);
4516 reinsert_fast_tracepoint_jumps_at (lwp
->bp_reinsert
);
4518 lwp
->bp_reinsert
= 0;
4520 /* Delete any single-step breakpoints. No longer needed. We
4521 don't have to worry about other threads hitting this trap,
4522 and later not being able to explain it, because we were
4523 stepping over a breakpoint, and we hold all threads but
4524 LWP stopped while doing that. */
4525 if (!supports_hardware_single_step ())
4527 gdb_assert (has_single_step_breakpoints (current_thread
));
4528 delete_single_step_breakpoints (current_thread
);
4531 step_over_bkpt
= null_ptid
;
4539 linux_process_target::complete_ongoing_step_over ()
4541 if (step_over_bkpt
!= null_ptid
)
4543 struct lwp_info
*lwp
;
4547 threads_debug_printf ("detach: step over in progress, finish it first");
4549 /* Passing NULL_PTID as filter indicates we want all events to
4550 be left pending. Eventually this returns when there are no
4551 unwaited-for children left. */
4552 ret
= wait_for_event_filtered (minus_one_ptid
, null_ptid
, &wstat
,
4554 gdb_assert (ret
== -1);
4556 lwp
= find_lwp_pid (step_over_bkpt
);
4559 finish_step_over (lwp
);
4561 /* If we got our step SIGTRAP, don't leave it pending,
4562 otherwise we would report it to GDB as a spurious
4564 gdb_assert (lwp
->status_pending_p
);
4565 if (WIFSTOPPED (lwp
->status_pending
)
4566 && WSTOPSIG (lwp
->status_pending
) == SIGTRAP
)
4568 thread_info
*thread
= get_lwp_thread (lwp
);
4569 if (thread
->last_resume_kind
!= resume_step
)
4571 threads_debug_printf ("detach: discard step-over SIGTRAP");
4573 lwp
->status_pending_p
= 0;
4574 lwp
->status_pending
= 0;
4575 resume_one_lwp (lwp
, lwp
->stepping
, 0, NULL
);
4578 threads_debug_printf
4579 ("detach: resume_step, not discarding step-over SIGTRAP");
4582 step_over_bkpt
= null_ptid
;
4583 unsuspend_all_lwps (lwp
);
4588 linux_process_target::resume_one_thread (thread_info
*thread
,
4589 bool leave_all_stopped
)
4591 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4594 if (lwp
->resume
== NULL
)
4597 if (lwp
->resume
->kind
== resume_stop
)
4599 threads_debug_printf ("resume_stop request for LWP %ld",
4604 threads_debug_printf ("stopping LWP %ld", lwpid_of (thread
));
4606 /* Stop the thread, and wait for the event asynchronously,
4607 through the event loop. */
4612 threads_debug_printf ("already stopped LWP %ld", lwpid_of (thread
));
4614 /* The LWP may have been stopped in an internal event that
4615 was not meant to be notified back to GDB (e.g., gdbserver
4616 breakpoint), so we should be reporting a stop event in
4619 /* If the thread already has a pending SIGSTOP, this is a
4620 no-op. Otherwise, something later will presumably resume
4621 the thread and this will cause it to cancel any pending
4622 operation, due to last_resume_kind == resume_stop. If
4623 the thread already has a pending status to report, we
4624 will still report it the next time we wait - see
4625 status_pending_p_callback. */
4627 /* If we already have a pending signal to report, then
4628 there's no need to queue a SIGSTOP, as this means we're
4629 midway through moving the LWP out of the jumppad, and we
4630 will report the pending signal as soon as that is
4632 if (lwp
->pending_signals_to_report
.empty ())
4636 /* For stop requests, we're done. */
4638 thread
->last_status
.set_ignore ();
4642 /* If this thread which is about to be resumed has a pending status,
4643 then don't resume it - we can just report the pending status.
4644 Likewise if it is suspended, because e.g., another thread is
4645 stepping past a breakpoint. Make sure to queue any signals that
4646 would otherwise be sent. In all-stop mode, we do this decision
4647 based on if *any* thread has a pending status. If there's a
4648 thread that needs the step-over-breakpoint dance, then don't
4649 resume any other thread but that particular one. */
4650 leave_pending
= (lwp
->suspended
4651 || lwp
->status_pending_p
4652 || leave_all_stopped
);
4654 /* If we have a new signal, enqueue the signal. */
4655 if (lwp
->resume
->sig
!= 0)
4657 siginfo_t info
, *info_p
;
4659 /* If this is the same signal we were previously stopped by,
4660 make sure to queue its siginfo. */
4661 if (WIFSTOPPED (lwp
->last_status
)
4662 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
4663 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (thread
),
4664 (PTRACE_TYPE_ARG3
) 0, &info
) == 0)
4669 enqueue_pending_signal (lwp
, lwp
->resume
->sig
, info_p
);
4674 threads_debug_printf ("resuming LWP %ld", lwpid_of (thread
));
4676 proceed_one_lwp (thread
, NULL
);
4679 threads_debug_printf ("leaving LWP %ld stopped", lwpid_of (thread
));
4681 thread
->last_status
.set_ignore ();
4686 linux_process_target::resume (thread_resume
*resume_info
, size_t n
)
4688 struct thread_info
*need_step_over
= NULL
;
4690 THREADS_SCOPED_DEBUG_ENTER_EXIT
;
4692 for_each_thread ([&] (thread_info
*thread
)
4694 linux_set_resume_request (thread
, resume_info
, n
);
4697 /* If there is a thread which would otherwise be resumed, which has
4698 a pending status, then don't resume any threads - we can just
4699 report the pending status. Make sure to queue any signals that
4700 would otherwise be sent. In non-stop mode, we'll apply this
4701 logic to each thread individually. We consume all pending events
4702 before considering to start a step-over (in all-stop). */
4703 bool any_pending
= false;
4705 any_pending
= find_thread ([this] (thread_info
*thread
)
4707 return resume_status_pending (thread
);
4710 /* If there is a thread which would otherwise be resumed, which is
4711 stopped at a breakpoint that needs stepping over, then don't
4712 resume any threads - have it step over the breakpoint with all
4713 other threads stopped, then resume all threads again. Make sure
4714 to queue any signals that would otherwise be delivered or
4716 if (!any_pending
&& low_supports_breakpoints ())
4717 need_step_over
= find_thread ([this] (thread_info
*thread
)
4719 return thread_needs_step_over (thread
);
4722 bool leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
4724 if (need_step_over
!= NULL
)
4725 threads_debug_printf ("Not resuming all, need step over");
4726 else if (any_pending
)
4727 threads_debug_printf ("Not resuming, all-stop and found "
4728 "an LWP with pending status");
4730 threads_debug_printf ("Resuming, no pending status or step over needed");
4732 /* Even if we're leaving threads stopped, queue all signals we'd
4733 otherwise deliver. */
4734 for_each_thread ([&] (thread_info
*thread
)
4736 resume_one_thread (thread
, leave_all_stopped
);
4740 start_step_over (get_thread_lwp (need_step_over
));
4742 /* We may have events that were pending that can/should be sent to
4743 the client now. Trigger a linux_wait call. */
4744 if (target_is_async_p ())
4749 linux_process_target::proceed_one_lwp (thread_info
*thread
, lwp_info
*except
)
4751 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4757 threads_debug_printf ("lwp %ld", lwpid_of (thread
));
4761 threads_debug_printf (" LWP %ld already running", lwpid_of (thread
));
4765 if (thread
->last_resume_kind
== resume_stop
4766 && thread
->last_status
.kind () != TARGET_WAITKIND_IGNORE
)
4768 threads_debug_printf (" client wants LWP to remain %ld stopped",
4773 if (lwp
->status_pending_p
)
4775 threads_debug_printf (" LWP %ld has pending status, leaving stopped",
4780 gdb_assert (lwp
->suspended
>= 0);
4784 threads_debug_printf (" LWP %ld is suspended", lwpid_of (thread
));
4788 if (thread
->last_resume_kind
== resume_stop
4789 && lwp
->pending_signals_to_report
.empty ()
4790 && (lwp
->collecting_fast_tracepoint
4791 == fast_tpoint_collect_result::not_collecting
))
4793 /* We haven't reported this LWP as stopped yet (otherwise, the
4794 last_status.kind check above would catch it, and we wouldn't
4795 reach here. This LWP may have been momentarily paused by a
4796 stop_all_lwps call while handling for example, another LWP's
4797 step-over. In that case, the pending expected SIGSTOP signal
4798 that was queued at vCont;t handling time will have already
4799 been consumed by wait_for_sigstop, and so we need to requeue
4800 another one here. Note that if the LWP already has a SIGSTOP
4801 pending, this is a no-op. */
4803 threads_debug_printf
4804 ("Client wants LWP %ld to stop. Making sure it has a SIGSTOP pending",
4810 if (thread
->last_resume_kind
== resume_step
)
4812 threads_debug_printf (" stepping LWP %ld, client wants it stepping",
4815 /* If resume_step is requested by GDB, install single-step
4816 breakpoints when the thread is about to be actually resumed if
4817 the single-step breakpoints weren't removed. */
4818 if (supports_software_single_step ()
4819 && !has_single_step_breakpoints (thread
))
4820 install_software_single_step_breakpoints (lwp
);
4822 step
= maybe_hw_step (thread
);
4824 else if (lwp
->bp_reinsert
!= 0)
4826 threads_debug_printf (" stepping LWP %ld, reinsert set",
4829 step
= maybe_hw_step (thread
);
4834 resume_one_lwp (lwp
, step
, 0, NULL
);
4838 linux_process_target::unsuspend_and_proceed_one_lwp (thread_info
*thread
,
4841 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4846 lwp_suspended_decr (lwp
);
4848 proceed_one_lwp (thread
, except
);
4852 linux_process_target::proceed_all_lwps ()
4854 struct thread_info
*need_step_over
;
4856 /* If there is a thread which would otherwise be resumed, which is
4857 stopped at a breakpoint that needs stepping over, then don't
4858 resume any threads - have it step over the breakpoint with all
4859 other threads stopped, then resume all threads again. */
4861 if (low_supports_breakpoints ())
4863 need_step_over
= find_thread ([this] (thread_info
*thread
)
4865 return thread_needs_step_over (thread
);
4868 if (need_step_over
!= NULL
)
4870 threads_debug_printf ("found thread %ld needing a step-over",
4871 lwpid_of (need_step_over
));
4873 start_step_over (get_thread_lwp (need_step_over
));
4878 threads_debug_printf ("Proceeding, no step-over needed");
4880 for_each_thread ([this] (thread_info
*thread
)
4882 proceed_one_lwp (thread
, NULL
);
4887 linux_process_target::unstop_all_lwps (int unsuspend
, lwp_info
*except
)
4889 THREADS_SCOPED_DEBUG_ENTER_EXIT
;
4892 threads_debug_printf ("except=(LWP %ld)",
4893 lwpid_of (get_lwp_thread (except
)));
4895 threads_debug_printf ("except=nullptr");
4898 for_each_thread ([&] (thread_info
*thread
)
4900 unsuspend_and_proceed_one_lwp (thread
, except
);
4903 for_each_thread ([&] (thread_info
*thread
)
4905 proceed_one_lwp (thread
, except
);
4910 #ifdef HAVE_LINUX_REGSETS
4912 #define use_linux_regsets 1
4914 /* Returns true if REGSET has been disabled. */
4917 regset_disabled (struct regsets_info
*info
, struct regset_info
*regset
)
4919 return (info
->disabled_regsets
!= NULL
4920 && info
->disabled_regsets
[regset
- info
->regsets
]);
4923 /* Disable REGSET. */
4926 disable_regset (struct regsets_info
*info
, struct regset_info
*regset
)
4930 dr_offset
= regset
- info
->regsets
;
4931 if (info
->disabled_regsets
== NULL
)
4932 info
->disabled_regsets
= (char *) xcalloc (1, info
->num_regsets
);
4933 info
->disabled_regsets
[dr_offset
] = 1;
4937 regsets_fetch_inferior_registers (struct regsets_info
*regsets_info
,
4938 struct regcache
*regcache
)
4940 struct regset_info
*regset
;
4941 int saw_general_regs
= 0;
4945 pid
= lwpid_of (current_thread
);
4946 for (regset
= regsets_info
->regsets
; regset
->size
>= 0; regset
++)
4951 if (regset
->size
== 0 || regset_disabled (regsets_info
, regset
))
4954 buf
= xmalloc (regset
->size
);
4956 nt_type
= regset
->nt_type
;
4960 iov
.iov_len
= regset
->size
;
4961 data
= (void *) &iov
;
4967 res
= ptrace (regset
->get_request
, pid
,
4968 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
4970 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
4975 || (errno
== EINVAL
&& regset
->type
== OPTIONAL_REGS
))
4977 /* If we get EIO on a regset, or an EINVAL and the regset is
4978 optional, do not try it again for this process mode. */
4979 disable_regset (regsets_info
, regset
);
4981 else if (errno
== ENODATA
)
4983 /* ENODATA may be returned if the regset is currently
4984 not "active". This can happen in normal operation,
4985 so suppress the warning in this case. */
4987 else if (errno
== ESRCH
)
4989 /* At this point, ESRCH should mean the process is
4990 already gone, in which case we simply ignore attempts
4991 to read its registers. */
4996 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
5003 if (regset
->type
== GENERAL_REGS
)
5004 saw_general_regs
= 1;
5005 regset
->store_function (regcache
, buf
);
5009 if (saw_general_regs
)
5016 regsets_store_inferior_registers (struct regsets_info
*regsets_info
,
5017 struct regcache
*regcache
)
5019 struct regset_info
*regset
;
5020 int saw_general_regs
= 0;
5024 pid
= lwpid_of (current_thread
);
5025 for (regset
= regsets_info
->regsets
; regset
->size
>= 0; regset
++)
5030 if (regset
->size
== 0 || regset_disabled (regsets_info
, regset
)
5031 || regset
->fill_function
== NULL
)
5034 buf
= xmalloc (regset
->size
);
5036 /* First fill the buffer with the current register set contents,
5037 in case there are any items in the kernel's regset that are
5038 not in gdbserver's regcache. */
5040 nt_type
= regset
->nt_type
;
5044 iov
.iov_len
= regset
->size
;
5045 data
= (void *) &iov
;
5051 res
= ptrace (regset
->get_request
, pid
,
5052 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
5054 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
5059 /* Then overlay our cached registers on that. */
5060 regset
->fill_function (regcache
, buf
);
5062 /* Only now do we write the register set. */
5064 res
= ptrace (regset
->set_request
, pid
,
5065 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
5067 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
5074 || (errno
== EINVAL
&& regset
->type
== OPTIONAL_REGS
))
5076 /* If we get EIO on a regset, or an EINVAL and the regset is
5077 optional, do not try it again for this process mode. */
5078 disable_regset (regsets_info
, regset
);
5080 else if (errno
== ESRCH
)
5082 /* At this point, ESRCH should mean the process is
5083 already gone, in which case we simply ignore attempts
5084 to change its registers. See also the related
5085 comment in resume_one_lwp. */
5091 perror ("Warning: ptrace(regsets_store_inferior_registers)");
5094 else if (regset
->type
== GENERAL_REGS
)
5095 saw_general_regs
= 1;
5098 if (saw_general_regs
)
5104 #else /* !HAVE_LINUX_REGSETS */
5106 #define use_linux_regsets 0
5107 #define regsets_fetch_inferior_registers(regsets_info, regcache) 1
5108 #define regsets_store_inferior_registers(regsets_info, regcache) 1
5112 /* Return 1 if register REGNO is supported by one of the regset ptrace
5113 calls or 0 if it has to be transferred individually. */
5116 linux_register_in_regsets (const struct regs_info
*regs_info
, int regno
)
5118 unsigned char mask
= 1 << (regno
% 8);
5119 size_t index
= regno
/ 8;
5121 return (use_linux_regsets
5122 && (regs_info
->regset_bitmap
== NULL
5123 || (regs_info
->regset_bitmap
[index
] & mask
) != 0));
5126 #ifdef HAVE_LINUX_USRREGS
5129 register_addr (const struct usrregs_info
*usrregs
, int regnum
)
5133 if (regnum
< 0 || regnum
>= usrregs
->num_regs
)
5134 error ("Invalid register number %d.", regnum
);
5136 addr
= usrregs
->regmap
[regnum
];
5143 linux_process_target::fetch_register (const usrregs_info
*usrregs
,
5144 regcache
*regcache
, int regno
)
5151 if (regno
>= usrregs
->num_regs
)
5153 if (low_cannot_fetch_register (regno
))
5156 regaddr
= register_addr (usrregs
, regno
);
5160 size
= ((register_size (regcache
->tdesc
, regno
)
5161 + sizeof (PTRACE_XFER_TYPE
) - 1)
5162 & -sizeof (PTRACE_XFER_TYPE
));
5163 buf
= (char *) alloca (size
);
5165 pid
= lwpid_of (current_thread
);
5166 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
5169 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
5170 ptrace (PTRACE_PEEKUSER
, pid
,
5171 /* Coerce to a uintptr_t first to avoid potential gcc warning
5172 of coercing an 8 byte integer to a 4 byte pointer. */
5173 (PTRACE_TYPE_ARG3
) (uintptr_t) regaddr
, (PTRACE_TYPE_ARG4
) 0);
5174 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
5177 /* Mark register REGNO unavailable. */
5178 supply_register (regcache
, regno
, NULL
);
5183 low_supply_ptrace_register (regcache
, regno
, buf
);
5187 linux_process_target::store_register (const usrregs_info
*usrregs
,
5188 regcache
*regcache
, int regno
)
5195 if (regno
>= usrregs
->num_regs
)
5197 if (low_cannot_store_register (regno
))
5200 regaddr
= register_addr (usrregs
, regno
);
5204 size
= ((register_size (regcache
->tdesc
, regno
)
5205 + sizeof (PTRACE_XFER_TYPE
) - 1)
5206 & -sizeof (PTRACE_XFER_TYPE
));
5207 buf
= (char *) alloca (size
);
5208 memset (buf
, 0, size
);
5210 low_collect_ptrace_register (regcache
, regno
, buf
);
5212 pid
= lwpid_of (current_thread
);
5213 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
5216 ptrace (PTRACE_POKEUSER
, pid
,
5217 /* Coerce to a uintptr_t first to avoid potential gcc warning
5218 about coercing an 8 byte integer to a 4 byte pointer. */
5219 (PTRACE_TYPE_ARG3
) (uintptr_t) regaddr
,
5220 (PTRACE_TYPE_ARG4
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
5223 /* At this point, ESRCH should mean the process is
5224 already gone, in which case we simply ignore attempts
5225 to change its registers. See also the related
5226 comment in resume_one_lwp. */
5231 if (!low_cannot_store_register (regno
))
5232 error ("writing register %d: %s", regno
, safe_strerror (errno
));
5234 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
5237 #endif /* HAVE_LINUX_USRREGS */
5240 linux_process_target::low_collect_ptrace_register (regcache
*regcache
,
5241 int regno
, char *buf
)
5243 collect_register (regcache
, regno
, buf
);
5247 linux_process_target::low_supply_ptrace_register (regcache
*regcache
,
5248 int regno
, const char *buf
)
5250 supply_register (regcache
, regno
, buf
);
5254 linux_process_target::usr_fetch_inferior_registers (const regs_info
*regs_info
,
5258 #ifdef HAVE_LINUX_USRREGS
5259 struct usrregs_info
*usr
= regs_info
->usrregs
;
5263 for (regno
= 0; regno
< usr
->num_regs
; regno
++)
5264 if (all
|| !linux_register_in_regsets (regs_info
, regno
))
5265 fetch_register (usr
, regcache
, regno
);
5268 fetch_register (usr
, regcache
, regno
);
5273 linux_process_target::usr_store_inferior_registers (const regs_info
*regs_info
,
5277 #ifdef HAVE_LINUX_USRREGS
5278 struct usrregs_info
*usr
= regs_info
->usrregs
;
5282 for (regno
= 0; regno
< usr
->num_regs
; regno
++)
5283 if (all
|| !linux_register_in_regsets (regs_info
, regno
))
5284 store_register (usr
, regcache
, regno
);
5287 store_register (usr
, regcache
, regno
);
5292 linux_process_target::fetch_registers (regcache
*regcache
, int regno
)
5296 const regs_info
*regs_info
= get_regs_info ();
5300 if (regs_info
->usrregs
!= NULL
)
5301 for (regno
= 0; regno
< regs_info
->usrregs
->num_regs
; regno
++)
5302 low_fetch_register (regcache
, regno
);
5304 all
= regsets_fetch_inferior_registers (regs_info
->regsets_info
, regcache
);
5305 if (regs_info
->usrregs
!= NULL
)
5306 usr_fetch_inferior_registers (regs_info
, regcache
, -1, all
);
5310 if (low_fetch_register (regcache
, regno
))
5313 use_regsets
= linux_register_in_regsets (regs_info
, regno
);
5315 all
= regsets_fetch_inferior_registers (regs_info
->regsets_info
,
5317 if ((!use_regsets
|| all
) && regs_info
->usrregs
!= NULL
)
5318 usr_fetch_inferior_registers (regs_info
, regcache
, regno
, 1);
5323 linux_process_target::store_registers (regcache
*regcache
, int regno
)
5327 const regs_info
*regs_info
= get_regs_info ();
5331 all
= regsets_store_inferior_registers (regs_info
->regsets_info
,
5333 if (regs_info
->usrregs
!= NULL
)
5334 usr_store_inferior_registers (regs_info
, regcache
, regno
, all
);
5338 use_regsets
= linux_register_in_regsets (regs_info
, regno
);
5340 all
= regsets_store_inferior_registers (regs_info
->regsets_info
,
5342 if ((!use_regsets
|| all
) && regs_info
->usrregs
!= NULL
)
5343 usr_store_inferior_registers (regs_info
, regcache
, regno
, 1);
5348 linux_process_target::low_fetch_register (regcache
*regcache
, int regno
)
5353 /* A wrapper for the read_memory target op. */
5356 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
5358 return the_target
->read_memory (memaddr
, myaddr
, len
);
5362 /* Helper for read_memory/write_memory using /proc/PID/mem. Because
5363 we can use a single read/write call, this can be much more
5364 efficient than banging away at PTRACE_PEEKTEXT. Also, unlike
5365 PTRACE_PEEKTEXT/PTRACE_POKETEXT, this works with running threads.
5366 One an only one of READBUF and WRITEBUF is non-null. If READBUF is
5367 not null, then we're reading, otherwise we're writing. */
5370 proc_xfer_memory (CORE_ADDR memaddr
, unsigned char *readbuf
,
5371 const gdb_byte
*writebuf
, int len
)
5373 gdb_assert ((readbuf
== nullptr) != (writebuf
== nullptr));
5375 process_info
*proc
= current_process ();
5377 int fd
= proc
->priv
->mem_fd
;
5385 /* Use pread64/pwrite64 if available, since they save a syscall
5386 and can handle 64-bit offsets even on 32-bit platforms (for
5387 instance, SPARC debugging a SPARC64 application). But only
5388 use them if the offset isn't so high that when cast to off_t
5389 it'd be negative, as seen on SPARC64. pread64/pwrite64
5390 outright reject such offsets. lseek does not. */
5392 if ((off_t
) memaddr
>= 0)
5393 bytes
= (readbuf
!= nullptr
5394 ? pread64 (fd
, readbuf
, len
, memaddr
)
5395 : pwrite64 (fd
, writebuf
, len
, memaddr
));
5400 if (lseek (fd
, memaddr
, SEEK_SET
) != -1)
5401 bytes
= (readbuf
!= nullptr
5402 ? read (fd
, readbuf
, len
)
5403 : write (fd
, writebuf
, len
));
5408 else if (bytes
== 0)
5410 /* EOF means the address space is gone, the whole process
5411 exited or execed. */
5416 if (readbuf
!= nullptr)
5427 linux_process_target::read_memory (CORE_ADDR memaddr
,
5428 unsigned char *myaddr
, int len
)
5430 return proc_xfer_memory (memaddr
, myaddr
, nullptr, len
);
5433 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
5434 memory at MEMADDR. On failure (cannot write to the inferior)
5435 returns the value of errno. Always succeeds if LEN is zero. */
5438 linux_process_target::write_memory (CORE_ADDR memaddr
,
5439 const unsigned char *myaddr
, int len
)
5443 /* Dump up to four bytes. */
5444 char str
[4 * 2 + 1];
5446 int dump
= len
< 4 ? len
: 4;
5448 for (int i
= 0; i
< dump
; i
++)
5450 sprintf (p
, "%02x", myaddr
[i
]);
5455 threads_debug_printf ("Writing %s to 0x%08lx in process %d",
5456 str
, (long) memaddr
, current_process ()->pid
);
5459 return proc_xfer_memory (memaddr
, nullptr, myaddr
, len
);
5463 linux_process_target::look_up_symbols ()
5465 #ifdef USE_THREAD_DB
5466 struct process_info
*proc
= current_process ();
5468 if (proc
->priv
->thread_db
!= NULL
)
5476 linux_process_target::request_interrupt ()
5478 /* Send a SIGINT to the process group. This acts just like the user
5479 typed a ^C on the controlling terminal. */
5480 int res
= ::kill (-signal_pid
, SIGINT
);
5482 warning (_("Sending SIGINT to process group of pid %ld failed: %s"),
5483 signal_pid
, safe_strerror (errno
));
5487 linux_process_target::supports_read_auxv ()
5492 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
5493 to debugger memory starting at MYADDR. */
5496 linux_process_target::read_auxv (int pid
, CORE_ADDR offset
,
5497 unsigned char *myaddr
, unsigned int len
)
5499 char filename
[PATH_MAX
];
5502 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
5504 fd
= open (filename
, O_RDONLY
);
5508 if (offset
!= (CORE_ADDR
) 0
5509 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
5512 n
= read (fd
, myaddr
, len
);
5520 linux_process_target::insert_point (enum raw_bkpt_type type
, CORE_ADDR addr
,
5521 int size
, raw_breakpoint
*bp
)
5523 if (type
== raw_bkpt_type_sw
)
5524 return insert_memory_breakpoint (bp
);
5526 return low_insert_point (type
, addr
, size
, bp
);
5530 linux_process_target::low_insert_point (raw_bkpt_type type
, CORE_ADDR addr
,
5531 int size
, raw_breakpoint
*bp
)
5533 /* Unsupported (see target.h). */
5538 linux_process_target::remove_point (enum raw_bkpt_type type
, CORE_ADDR addr
,
5539 int size
, raw_breakpoint
*bp
)
5541 if (type
== raw_bkpt_type_sw
)
5542 return remove_memory_breakpoint (bp
);
5544 return low_remove_point (type
, addr
, size
, bp
);
5548 linux_process_target::low_remove_point (raw_bkpt_type type
, CORE_ADDR addr
,
5549 int size
, raw_breakpoint
*bp
)
5551 /* Unsupported (see target.h). */
5555 /* Implement the stopped_by_sw_breakpoint target_ops
5559 linux_process_target::stopped_by_sw_breakpoint ()
5561 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5563 return (lwp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
);
5566 /* Implement the supports_stopped_by_sw_breakpoint target_ops
5570 linux_process_target::supports_stopped_by_sw_breakpoint ()
5572 return USE_SIGTRAP_SIGINFO
;
5575 /* Implement the stopped_by_hw_breakpoint target_ops
5579 linux_process_target::stopped_by_hw_breakpoint ()
5581 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5583 return (lwp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
);
5586 /* Implement the supports_stopped_by_hw_breakpoint target_ops
5590 linux_process_target::supports_stopped_by_hw_breakpoint ()
5592 return USE_SIGTRAP_SIGINFO
;
5595 /* Implement the supports_hardware_single_step target_ops method. */
5598 linux_process_target::supports_hardware_single_step ()
5604 linux_process_target::stopped_by_watchpoint ()
5606 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5608 return lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
5612 linux_process_target::stopped_data_address ()
5614 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5616 return lwp
->stopped_data_address
;
5619 /* This is only used for targets that define PT_TEXT_ADDR,
5620 PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly
5621 the target has different ways of acquiring this information, like
5625 linux_process_target::supports_read_offsets ()
5627 #ifdef SUPPORTS_READ_OFFSETS
5634 /* Under uClinux, programs are loaded at non-zero offsets, which we need
5635 to tell gdb about. */
5638 linux_process_target::read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
5640 #ifdef SUPPORTS_READ_OFFSETS
5641 unsigned long text
, text_end
, data
;
5642 int pid
= lwpid_of (current_thread
);
5646 text
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_TEXT_ADDR
,
5647 (PTRACE_TYPE_ARG4
) 0);
5648 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_TEXT_END_ADDR
,
5649 (PTRACE_TYPE_ARG4
) 0);
5650 data
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_DATA_ADDR
,
5651 (PTRACE_TYPE_ARG4
) 0);
5655 /* Both text and data offsets produced at compile-time (and so
5656 used by gdb) are relative to the beginning of the program,
5657 with the data segment immediately following the text segment.
5658 However, the actual runtime layout in memory may put the data
5659 somewhere else, so when we send gdb a data base-address, we
5660 use the real data base address and subtract the compile-time
5661 data base-address from it (which is just the length of the
5662 text segment). BSS immediately follows data in both
5665 *data_p
= data
- (text_end
- text
);
5671 gdb_assert_not_reached ("target op read_offsets not supported");
5676 linux_process_target::supports_get_tls_address ()
5678 #ifdef USE_THREAD_DB
5686 linux_process_target::get_tls_address (thread_info
*thread
,
5688 CORE_ADDR load_module
,
5691 #ifdef USE_THREAD_DB
5692 return thread_db_get_tls_address (thread
, offset
, load_module
, address
);
5699 linux_process_target::supports_qxfer_osdata ()
5705 linux_process_target::qxfer_osdata (const char *annex
,
5706 unsigned char *readbuf
,
5707 unsigned const char *writebuf
,
5708 CORE_ADDR offset
, int len
)
5710 return linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
5714 linux_process_target::siginfo_fixup (siginfo_t
*siginfo
,
5715 gdb_byte
*inf_siginfo
, int direction
)
5717 bool done
= low_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
5719 /* If there was no callback, or the callback didn't do anything,
5720 then just do a straight memcpy. */
5724 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
5726 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
5731 linux_process_target::low_siginfo_fixup (siginfo_t
*native
, gdb_byte
*inf
,
5738 linux_process_target::supports_qxfer_siginfo ()
5744 linux_process_target::qxfer_siginfo (const char *annex
,
5745 unsigned char *readbuf
,
5746 unsigned const char *writebuf
,
5747 CORE_ADDR offset
, int len
)
5751 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
5753 if (current_thread
== NULL
)
5756 pid
= lwpid_of (current_thread
);
5758 threads_debug_printf ("%s siginfo for lwp %d.",
5759 readbuf
!= NULL
? "Reading" : "Writing",
5762 if (offset
>= sizeof (siginfo
))
5765 if (ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
) != 0)
5768 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
5769 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
5770 inferior with a 64-bit GDBSERVER should look the same as debugging it
5771 with a 32-bit GDBSERVER, we need to convert it. */
5772 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
5774 if (offset
+ len
> sizeof (siginfo
))
5775 len
= sizeof (siginfo
) - offset
;
5777 if (readbuf
!= NULL
)
5778 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
5781 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
5783 /* Convert back to ptrace layout before flushing it out. */
5784 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
5786 if (ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
) != 0)
5793 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
5794 so we notice when children change state; as the handler for the
5795 sigsuspend in my_waitpid. */
5798 sigchld_handler (int signo
)
5800 int old_errno
= errno
;
5806 /* Use the async signal safe debug function. */
5807 if (debug_write ("sigchld_handler\n",
5808 sizeof ("sigchld_handler\n") - 1) < 0)
5809 break; /* just ignore */
5813 if (target_is_async_p ())
5814 async_file_mark (); /* trigger a linux_wait */
5820 linux_process_target::supports_non_stop ()
5826 linux_process_target::async (bool enable
)
5828 bool previous
= target_is_async_p ();
5830 threads_debug_printf ("async (%d), previous=%d",
5833 if (previous
!= enable
)
5836 sigemptyset (&mask
);
5837 sigaddset (&mask
, SIGCHLD
);
5839 gdb_sigmask (SIG_BLOCK
, &mask
, NULL
);
5843 if (!linux_event_pipe
.open_pipe ())
5845 gdb_sigmask (SIG_UNBLOCK
, &mask
, NULL
);
5847 warning ("creating event pipe failed.");
5851 /* Register the event loop handler. */
5852 add_file_handler (linux_event_pipe
.event_fd (),
5853 handle_target_event
, NULL
,
5856 /* Always trigger a linux_wait. */
5861 delete_file_handler (linux_event_pipe
.event_fd ());
5863 linux_event_pipe
.close_pipe ();
5866 gdb_sigmask (SIG_UNBLOCK
, &mask
, NULL
);
5873 linux_process_target::start_non_stop (bool nonstop
)
5875 /* Register or unregister from event-loop accordingly. */
5876 target_async (nonstop
);
5878 if (target_is_async_p () != (nonstop
!= false))
5885 linux_process_target::supports_multi_process ()
5890 /* Check if fork events are supported. */
5893 linux_process_target::supports_fork_events ()
5898 /* Check if vfork events are supported. */
5901 linux_process_target::supports_vfork_events ()
5906 /* Check if exec events are supported. */
5909 linux_process_target::supports_exec_events ()
5914 /* Target hook for 'handle_new_gdb_connection'. Causes a reset of the
5915 ptrace flags for all inferiors. This is in case the new GDB connection
5916 doesn't support the same set of events that the previous one did. */
5919 linux_process_target::handle_new_gdb_connection ()
5921 /* Request that all the lwps reset their ptrace options. */
5922 for_each_thread ([] (thread_info
*thread
)
5924 struct lwp_info
*lwp
= get_thread_lwp (thread
);
5928 /* Stop the lwp so we can modify its ptrace options. */
5929 lwp
->must_set_ptrace_flags
= 1;
5930 linux_stop_lwp (lwp
);
5934 /* Already stopped; go ahead and set the ptrace options. */
5935 struct process_info
*proc
= find_process_pid (pid_of (thread
));
5936 int options
= linux_low_ptrace_options (proc
->attached
);
5938 linux_enable_event_reporting (lwpid_of (thread
), options
);
5939 lwp
->must_set_ptrace_flags
= 0;
5945 linux_process_target::handle_monitor_command (char *mon
)
5947 #ifdef USE_THREAD_DB
5948 return thread_db_handle_monitor_command (mon
);
5955 linux_process_target::core_of_thread (ptid_t ptid
)
5957 return linux_common_core_of_thread (ptid
);
5961 linux_process_target::supports_disable_randomization ()
5967 linux_process_target::supports_agent ()
5973 linux_process_target::supports_range_stepping ()
5975 if (supports_software_single_step ())
5978 return low_supports_range_stepping ();
5982 linux_process_target::low_supports_range_stepping ()
5988 linux_process_target::supports_pid_to_exec_file ()
5994 linux_process_target::pid_to_exec_file (int pid
)
5996 return linux_proc_pid_to_exec_file (pid
);
6000 linux_process_target::supports_multifs ()
6006 linux_process_target::multifs_open (int pid
, const char *filename
,
6007 int flags
, mode_t mode
)
6009 return linux_mntns_open_cloexec (pid
, filename
, flags
, mode
);
6013 linux_process_target::multifs_unlink (int pid
, const char *filename
)
6015 return linux_mntns_unlink (pid
, filename
);
6019 linux_process_target::multifs_readlink (int pid
, const char *filename
,
6020 char *buf
, size_t bufsiz
)
6022 return linux_mntns_readlink (pid
, filename
, buf
, bufsiz
);
6025 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
6026 struct target_loadseg
6028 /* Core address to which the segment is mapped. */
6030 /* VMA recorded in the program header. */
6032 /* Size of this segment in memory. */
6036 # if defined PT_GETDSBT
6037 struct target_loadmap
6039 /* Protocol version number, must be zero. */
6041 /* Pointer to the DSBT table, its size, and the DSBT index. */
6042 unsigned *dsbt_table
;
6043 unsigned dsbt_size
, dsbt_index
;
6044 /* Number of segments in this map. */
6046 /* The actual memory map. */
6047 struct target_loadseg segs
[/*nsegs*/];
6049 # define LINUX_LOADMAP PT_GETDSBT
6050 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
6051 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
6053 struct target_loadmap
6055 /* Protocol version number, must be zero. */
6057 /* Number of segments in this map. */
6059 /* The actual memory map. */
6060 struct target_loadseg segs
[/*nsegs*/];
6062 # define LINUX_LOADMAP PTRACE_GETFDPIC
6063 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
6064 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
6068 linux_process_target::supports_read_loadmap ()
6074 linux_process_target::read_loadmap (const char *annex
, CORE_ADDR offset
,
6075 unsigned char *myaddr
, unsigned int len
)
6077 int pid
= lwpid_of (current_thread
);
6079 struct target_loadmap
*data
= NULL
;
6080 unsigned int actual_length
, copy_length
;
6082 if (strcmp (annex
, "exec") == 0)
6083 addr
= (int) LINUX_LOADMAP_EXEC
;
6084 else if (strcmp (annex
, "interp") == 0)
6085 addr
= (int) LINUX_LOADMAP_INTERP
;
6089 if (ptrace (LINUX_LOADMAP
, pid
, addr
, &data
) != 0)
6095 actual_length
= sizeof (struct target_loadmap
)
6096 + sizeof (struct target_loadseg
) * data
->nsegs
;
6098 if (offset
< 0 || offset
> actual_length
)
6101 copy_length
= actual_length
- offset
< len
? actual_length
- offset
: len
;
6102 memcpy (myaddr
, (char *) data
+ offset
, copy_length
);
6105 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
6108 linux_process_target::supports_catch_syscall ()
6110 return low_supports_catch_syscall ();
6114 linux_process_target::low_supports_catch_syscall ()
6120 linux_process_target::read_pc (regcache
*regcache
)
6122 if (!low_supports_breakpoints ())
6125 return low_get_pc (regcache
);
6129 linux_process_target::write_pc (regcache
*regcache
, CORE_ADDR pc
)
6131 gdb_assert (low_supports_breakpoints ());
6133 low_set_pc (regcache
, pc
);
6137 linux_process_target::supports_thread_stopped ()
6143 linux_process_target::thread_stopped (thread_info
*thread
)
6145 return get_thread_lwp (thread
)->stopped
;
6148 /* This exposes stop-all-threads functionality to other modules. */
6151 linux_process_target::pause_all (bool freeze
)
6153 stop_all_lwps (freeze
, NULL
);
6156 /* This exposes unstop-all-threads functionality to other gdbserver
6160 linux_process_target::unpause_all (bool unfreeze
)
6162 unstop_all_lwps (unfreeze
, NULL
);
6165 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
6168 get_phdr_phnum_from_proc_auxv (const int pid
, const int is_elf64
,
6169 CORE_ADDR
*phdr_memaddr
, int *num_phdr
)
6171 char filename
[PATH_MAX
];
6173 const int auxv_size
= is_elf64
6174 ? sizeof (Elf64_auxv_t
) : sizeof (Elf32_auxv_t
);
6175 char buf
[sizeof (Elf64_auxv_t
)]; /* The larger of the two. */
6177 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
6179 fd
= open (filename
, O_RDONLY
);
6185 while (read (fd
, buf
, auxv_size
) == auxv_size
6186 && (*phdr_memaddr
== 0 || *num_phdr
== 0))
6190 Elf64_auxv_t
*const aux
= (Elf64_auxv_t
*) buf
;
6192 switch (aux
->a_type
)
6195 *phdr_memaddr
= aux
->a_un
.a_val
;
6198 *num_phdr
= aux
->a_un
.a_val
;
6204 Elf32_auxv_t
*const aux
= (Elf32_auxv_t
*) buf
;
6206 switch (aux
->a_type
)
6209 *phdr_memaddr
= aux
->a_un
.a_val
;
6212 *num_phdr
= aux
->a_un
.a_val
;
6220 if (*phdr_memaddr
== 0 || *num_phdr
== 0)
6222 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
6223 "phdr_memaddr = %ld, phdr_num = %d",
6224 (long) *phdr_memaddr
, *num_phdr
);
6231 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
6234 get_dynamic (const int pid
, const int is_elf64
)
6236 CORE_ADDR phdr_memaddr
, relocation
;
6238 unsigned char *phdr_buf
;
6239 const int phdr_size
= is_elf64
? sizeof (Elf64_Phdr
) : sizeof (Elf32_Phdr
);
6241 if (get_phdr_phnum_from_proc_auxv (pid
, is_elf64
, &phdr_memaddr
, &num_phdr
))
6244 gdb_assert (num_phdr
< 100); /* Basic sanity check. */
6245 phdr_buf
= (unsigned char *) alloca (num_phdr
* phdr_size
);
6247 if (linux_read_memory (phdr_memaddr
, phdr_buf
, num_phdr
* phdr_size
))
6250 /* Compute relocation: it is expected to be 0 for "regular" executables,
6251 non-zero for PIE ones. */
6253 for (i
= 0; relocation
== -1 && i
< num_phdr
; i
++)
6256 Elf64_Phdr
*const p
= (Elf64_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6258 if (p
->p_type
== PT_PHDR
)
6259 relocation
= phdr_memaddr
- p
->p_vaddr
;
6263 Elf32_Phdr
*const p
= (Elf32_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6265 if (p
->p_type
== PT_PHDR
)
6266 relocation
= phdr_memaddr
- p
->p_vaddr
;
6269 if (relocation
== -1)
6271 /* PT_PHDR is optional, but necessary for PIE in general. Fortunately
6272 any real world executables, including PIE executables, have always
6273 PT_PHDR present. PT_PHDR is not present in some shared libraries or
6274 in fpc (Free Pascal 2.4) binaries but neither of those have a need for
6275 or present DT_DEBUG anyway (fpc binaries are statically linked).
6277 Therefore if there exists DT_DEBUG there is always also PT_PHDR.
6279 GDB could find RELOCATION also from AT_ENTRY - e_entry. */
6284 for (i
= 0; i
< num_phdr
; i
++)
6288 Elf64_Phdr
*const p
= (Elf64_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6290 if (p
->p_type
== PT_DYNAMIC
)
6291 return p
->p_vaddr
+ relocation
;
6295 Elf32_Phdr
*const p
= (Elf32_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6297 if (p
->p_type
== PT_DYNAMIC
)
6298 return p
->p_vaddr
+ relocation
;
6305 /* Return &_r_debug in the inferior, or -1 if not present. Return value
6306 can be 0 if the inferior does not yet have the library list initialized.
6307 We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of
6308 DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */
6311 get_r_debug (const int pid
, const int is_elf64
)
6313 CORE_ADDR dynamic_memaddr
;
6314 const int dyn_size
= is_elf64
? sizeof (Elf64_Dyn
) : sizeof (Elf32_Dyn
);
6315 unsigned char buf
[sizeof (Elf64_Dyn
)]; /* The larger of the two. */
6318 dynamic_memaddr
= get_dynamic (pid
, is_elf64
);
6319 if (dynamic_memaddr
== 0)
6322 while (linux_read_memory (dynamic_memaddr
, buf
, dyn_size
) == 0)
6326 Elf64_Dyn
*const dyn
= (Elf64_Dyn
*) buf
;
6327 #if defined DT_MIPS_RLD_MAP || defined DT_MIPS_RLD_MAP_REL
6331 unsigned char buf
[sizeof (Elf64_Xword
)];
6335 #ifdef DT_MIPS_RLD_MAP
6336 if (dyn
->d_tag
== DT_MIPS_RLD_MAP
)
6338 if (linux_read_memory (dyn
->d_un
.d_val
,
6339 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6344 #endif /* DT_MIPS_RLD_MAP */
6345 #ifdef DT_MIPS_RLD_MAP_REL
6346 if (dyn
->d_tag
== DT_MIPS_RLD_MAP_REL
)
6348 if (linux_read_memory (dyn
->d_un
.d_val
+ dynamic_memaddr
,
6349 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6354 #endif /* DT_MIPS_RLD_MAP_REL */
6356 if (dyn
->d_tag
== DT_DEBUG
&& map
== -1)
6357 map
= dyn
->d_un
.d_val
;
6359 if (dyn
->d_tag
== DT_NULL
)
6364 Elf32_Dyn
*const dyn
= (Elf32_Dyn
*) buf
;
6365 #if defined DT_MIPS_RLD_MAP || defined DT_MIPS_RLD_MAP_REL
6369 unsigned char buf
[sizeof (Elf32_Word
)];
6373 #ifdef DT_MIPS_RLD_MAP
6374 if (dyn
->d_tag
== DT_MIPS_RLD_MAP
)
6376 if (linux_read_memory (dyn
->d_un
.d_val
,
6377 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6382 #endif /* DT_MIPS_RLD_MAP */
6383 #ifdef DT_MIPS_RLD_MAP_REL
6384 if (dyn
->d_tag
== DT_MIPS_RLD_MAP_REL
)
6386 if (linux_read_memory (dyn
->d_un
.d_val
+ dynamic_memaddr
,
6387 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6392 #endif /* DT_MIPS_RLD_MAP_REL */
6394 if (dyn
->d_tag
== DT_DEBUG
&& map
== -1)
6395 map
= dyn
->d_un
.d_val
;
6397 if (dyn
->d_tag
== DT_NULL
)
6401 dynamic_memaddr
+= dyn_size
;
6407 /* Read one pointer from MEMADDR in the inferior. */
6410 read_one_ptr (CORE_ADDR memaddr
, CORE_ADDR
*ptr
, int ptr_size
)
6414 /* Go through a union so this works on either big or little endian
6415 hosts, when the inferior's pointer size is smaller than the size
6416 of CORE_ADDR. It is assumed the inferior's endianness is the
6417 same of the superior's. */
6420 CORE_ADDR core_addr
;
6425 ret
= linux_read_memory (memaddr
, &addr
.uc
, ptr_size
);
6428 if (ptr_size
== sizeof (CORE_ADDR
))
6429 *ptr
= addr
.core_addr
;
6430 else if (ptr_size
== sizeof (unsigned int))
6433 gdb_assert_not_reached ("unhandled pointer size");
6439 linux_process_target::supports_qxfer_libraries_svr4 ()
6444 struct link_map_offsets
6446 /* Offset and size of r_debug.r_version. */
6447 int r_version_offset
;
6449 /* Offset and size of r_debug.r_map. */
6452 /* Offset of r_debug_extended.r_next. */
6455 /* Offset to l_addr field in struct link_map. */
6458 /* Offset to l_name field in struct link_map. */
6461 /* Offset to l_ld field in struct link_map. */
6464 /* Offset to l_next field in struct link_map. */
6467 /* Offset to l_prev field in struct link_map. */
6471 static const link_map_offsets lmo_32bit_offsets
=
6473 0, /* r_version offset. */
6474 4, /* r_debug.r_map offset. */
6475 20, /* r_debug_extended.r_next. */
6476 0, /* l_addr offset in link_map. */
6477 4, /* l_name offset in link_map. */
6478 8, /* l_ld offset in link_map. */
6479 12, /* l_next offset in link_map. */
6480 16 /* l_prev offset in link_map. */
6483 static const link_map_offsets lmo_64bit_offsets
=
6485 0, /* r_version offset. */
6486 8, /* r_debug.r_map offset. */
6487 40, /* r_debug_extended.r_next. */
6488 0, /* l_addr offset in link_map. */
6489 8, /* l_name offset in link_map. */
6490 16, /* l_ld offset in link_map. */
6491 24, /* l_next offset in link_map. */
6492 32 /* l_prev offset in link_map. */
6495 /* Get the loaded shared libraries from one namespace. */
6498 read_link_map (std::string
&document
, CORE_ADDR lmid
, CORE_ADDR lm_addr
,
6499 CORE_ADDR lm_prev
, int ptr_size
, const link_map_offsets
*lmo
)
6501 CORE_ADDR l_name
, l_addr
, l_ld
, l_next
, l_prev
;
6504 && read_one_ptr (lm_addr
+ lmo
->l_name_offset
,
6505 &l_name
, ptr_size
) == 0
6506 && read_one_ptr (lm_addr
+ lmo
->l_addr_offset
,
6507 &l_addr
, ptr_size
) == 0
6508 && read_one_ptr (lm_addr
+ lmo
->l_ld_offset
,
6509 &l_ld
, ptr_size
) == 0
6510 && read_one_ptr (lm_addr
+ lmo
->l_prev_offset
,
6511 &l_prev
, ptr_size
) == 0
6512 && read_one_ptr (lm_addr
+ lmo
->l_next_offset
,
6513 &l_next
, ptr_size
) == 0)
6515 unsigned char libname
[PATH_MAX
];
6517 if (lm_prev
!= l_prev
)
6519 warning ("Corrupted shared library list: 0x%s != 0x%s",
6520 paddress (lm_prev
), paddress (l_prev
));
6524 /* Not checking for error because reading may stop before we've got
6525 PATH_MAX worth of characters. */
6527 linux_read_memory (l_name
, libname
, sizeof (libname
) - 1);
6528 libname
[sizeof (libname
) - 1] = '\0';
6529 if (libname
[0] != '\0')
6531 string_appendf (document
, "<library name=\"");
6532 xml_escape_text_append (document
, (char *) libname
);
6533 string_appendf (document
, "\" lm=\"0x%s\" l_addr=\"0x%s\" "
6534 "l_ld=\"0x%s\" lmid=\"0x%s\"/>",
6535 paddress (lm_addr
), paddress (l_addr
),
6536 paddress (l_ld
), paddress (lmid
));
6544 /* Construct qXfer:libraries-svr4:read reply. */
6547 linux_process_target::qxfer_libraries_svr4 (const char *annex
,
6548 unsigned char *readbuf
,
6549 unsigned const char *writebuf
,
6550 CORE_ADDR offset
, int len
)
6552 struct process_info_private
*const priv
= current_process ()->priv
;
6553 char filename
[PATH_MAX
];
6555 unsigned int machine
;
6556 CORE_ADDR lmid
= 0, lm_addr
= 0, lm_prev
= 0;
6558 if (writebuf
!= NULL
)
6560 if (readbuf
== NULL
)
6563 pid
= lwpid_of (current_thread
);
6564 xsnprintf (filename
, sizeof filename
, "/proc/%d/exe", pid
);
6565 is_elf64
= elf_64_file_p (filename
, &machine
);
6566 const link_map_offsets
*lmo
;
6570 lmo
= &lmo_64bit_offsets
;
6575 lmo
= &lmo_32bit_offsets
;
6579 while (annex
[0] != '\0')
6585 sep
= strchr (annex
, '=');
6589 name_len
= sep
- annex
;
6590 if (name_len
== 4 && startswith (annex
, "lmid"))
6592 else if (name_len
== 5 && startswith (annex
, "start"))
6594 else if (name_len
== 4 && startswith (annex
, "prev"))
6598 annex
= strchr (sep
, ';');
6605 annex
= decode_address_to_semicolon (addrp
, sep
+ 1);
6608 std::string document
= "<library-list-svr4 version=\"1.0\"";
6610 /* When the starting LM_ADDR is passed in the annex, only traverse that
6611 namespace, which is assumed to be identified by LMID.
6613 Otherwise, start with R_DEBUG and traverse all namespaces we find. */
6617 read_link_map (document
, lmid
, lm_addr
, lm_prev
, ptr_size
, lmo
);
6622 warning ("ignoring prev=0x%s without start", paddress (lm_prev
));
6624 /* We could interpret LMID as 'provide only the libraries for this
6625 namespace' but GDB is currently only providing lmid, start, and
6626 prev, or nothing. */
6628 warning ("ignoring lmid=0x%s without start", paddress (lmid
));
6630 CORE_ADDR r_debug
= priv
->r_debug
;
6632 r_debug
= priv
->r_debug
= get_r_debug (pid
, is_elf64
);
6634 /* We failed to find DT_DEBUG. Such situation will not change
6635 for this inferior - do not retry it. Report it to GDB as
6636 E01, see for the reasons at the GDB solib-svr4.c side. */
6637 if (r_debug
== (CORE_ADDR
) -1)
6640 /* Terminate the header if we end up with an empty list. */
6644 while (r_debug
!= 0)
6647 if (linux_read_memory (r_debug
+ lmo
->r_version_offset
,
6648 (unsigned char *) &r_version
,
6649 sizeof (r_version
)) != 0)
6651 warning ("unable to read r_version from 0x%s",
6652 paddress (r_debug
+ lmo
->r_version_offset
));
6658 warning ("unexpected r_debug version %d", r_version
);
6662 if (read_one_ptr (r_debug
+ lmo
->r_map_offset
, &lm_addr
,
6665 warning ("unable to read r_map from 0x%s",
6666 paddress (r_debug
+ lmo
->r_map_offset
));
6670 /* We read the entire namespace. */
6673 /* The first entry corresponds to the main executable unless the
6674 dynamic loader was loaded late by a static executable. But
6675 in such case the main executable does not have PT_DYNAMIC
6676 present and we would not have gotten here. */
6677 if (r_debug
== priv
->r_debug
)
6680 string_appendf (document
, " main-lm=\"0x%s\">",
6681 paddress (lm_addr
));
6686 if (read_one_ptr (lm_addr
+ lmo
->l_next_offset
,
6687 &lm_addr
, ptr_size
) != 0)
6689 warning ("unable to read l_next from 0x%s",
6690 paddress (lm_addr
+ lmo
->l_next_offset
));
6695 read_link_map (document
, r_debug
, lm_addr
, lm_prev
, ptr_size
, lmo
);
6700 if (read_one_ptr (r_debug
+ lmo
->r_next_offset
, &r_debug
,
6703 warning ("unable to read r_next from 0x%s",
6704 paddress (r_debug
+ lmo
->r_next_offset
));
6710 document
+= "</library-list-svr4>";
6712 int document_len
= document
.length ();
6713 if (offset
< document_len
)
6714 document_len
-= offset
;
6717 if (len
> document_len
)
6720 memcpy (readbuf
, document
.data () + offset
, len
);
6725 #ifdef HAVE_LINUX_BTRACE
6728 linux_process_target::supports_btrace ()
6733 btrace_target_info
*
6734 linux_process_target::enable_btrace (thread_info
*tp
,
6735 const btrace_config
*conf
)
6737 return linux_enable_btrace (tp
->id
, conf
);
6740 /* See to_disable_btrace target method. */
6743 linux_process_target::disable_btrace (btrace_target_info
*tinfo
)
6745 enum btrace_error err
;
6747 err
= linux_disable_btrace (tinfo
);
6748 return (err
== BTRACE_ERR_NONE
? 0 : -1);
6751 /* Encode an Intel Processor Trace configuration. */
6754 linux_low_encode_pt_config (std::string
*buffer
,
6755 const struct btrace_data_pt_config
*config
)
6757 *buffer
+= "<pt-config>\n";
6759 switch (config
->cpu
.vendor
)
6762 string_xml_appendf (*buffer
, "<cpu vendor=\"GenuineIntel\" family=\"%u\" "
6763 "model=\"%u\" stepping=\"%u\"/>\n",
6764 config
->cpu
.family
, config
->cpu
.model
,
6765 config
->cpu
.stepping
);
6772 *buffer
+= "</pt-config>\n";
6775 /* Encode a raw buffer. */
6778 linux_low_encode_raw (std::string
*buffer
, const gdb_byte
*data
,
6784 /* We use hex encoding - see gdbsupport/rsp-low.h. */
6785 *buffer
+= "<raw>\n";
6791 elem
[0] = tohex ((*data
>> 4) & 0xf);
6792 elem
[1] = tohex (*data
++ & 0xf);
6794 buffer
->append (elem
, 2);
6797 *buffer
+= "</raw>\n";
6800 /* See to_read_btrace target method. */
6803 linux_process_target::read_btrace (btrace_target_info
*tinfo
,
6804 std::string
*buffer
,
6805 enum btrace_read_type type
)
6807 struct btrace_data btrace
;
6808 enum btrace_error err
;
6810 err
= linux_read_btrace (&btrace
, tinfo
, type
);
6811 if (err
!= BTRACE_ERR_NONE
)
6813 if (err
== BTRACE_ERR_OVERFLOW
)
6814 *buffer
+= "E.Overflow.";
6816 *buffer
+= "E.Generic Error.";
6821 switch (btrace
.format
)
6823 case BTRACE_FORMAT_NONE
:
6824 *buffer
+= "E.No Trace.";
6827 case BTRACE_FORMAT_BTS
:
6828 *buffer
+= "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n";
6829 *buffer
+= "<btrace version=\"1.0\">\n";
6831 for (const btrace_block
&block
: *btrace
.variant
.bts
.blocks
)
6832 string_xml_appendf (*buffer
, "<block begin=\"0x%s\" end=\"0x%s\"/>\n",
6833 paddress (block
.begin
), paddress (block
.end
));
6835 *buffer
+= "</btrace>\n";
6838 case BTRACE_FORMAT_PT
:
6839 *buffer
+= "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n";
6840 *buffer
+= "<btrace version=\"1.0\">\n";
6841 *buffer
+= "<pt>\n";
6843 linux_low_encode_pt_config (buffer
, &btrace
.variant
.pt
.config
);
6845 linux_low_encode_raw (buffer
, btrace
.variant
.pt
.data
,
6846 btrace
.variant
.pt
.size
);
6848 *buffer
+= "</pt>\n";
6849 *buffer
+= "</btrace>\n";
6853 *buffer
+= "E.Unsupported Trace Format.";
6860 /* See to_btrace_conf target method. */
6863 linux_process_target::read_btrace_conf (const btrace_target_info
*tinfo
,
6864 std::string
*buffer
)
6866 const struct btrace_config
*conf
;
6868 *buffer
+= "<!DOCTYPE btrace-conf SYSTEM \"btrace-conf.dtd\">\n";
6869 *buffer
+= "<btrace-conf version=\"1.0\">\n";
6871 conf
= linux_btrace_conf (tinfo
);
6874 switch (conf
->format
)
6876 case BTRACE_FORMAT_NONE
:
6879 case BTRACE_FORMAT_BTS
:
6880 string_xml_appendf (*buffer
, "<bts");
6881 string_xml_appendf (*buffer
, " size=\"0x%x\"", conf
->bts
.size
);
6882 string_xml_appendf (*buffer
, " />\n");
6885 case BTRACE_FORMAT_PT
:
6886 string_xml_appendf (*buffer
, "<pt");
6887 string_xml_appendf (*buffer
, " size=\"0x%x\"", conf
->pt
.size
);
6888 string_xml_appendf (*buffer
, "/>\n");
6893 *buffer
+= "</btrace-conf>\n";
6896 #endif /* HAVE_LINUX_BTRACE */
6898 /* See nat/linux-nat.h. */
6901 current_lwp_ptid (void)
6903 return ptid_of (current_thread
);
6907 linux_process_target::thread_name (ptid_t thread
)
6909 return linux_proc_tid_get_name (thread
);
6914 linux_process_target::thread_handle (ptid_t ptid
, gdb_byte
**handle
,
6917 return thread_db_thread_handle (ptid
, handle
, handle_len
);
6922 linux_process_target::thread_pending_parent (thread_info
*thread
)
6924 lwp_info
*parent
= get_thread_lwp (thread
)->pending_parent ();
6926 if (parent
== nullptr)
6929 return get_lwp_thread (parent
);
6933 linux_process_target::thread_pending_child (thread_info
*thread
)
6935 lwp_info
*child
= get_thread_lwp (thread
)->pending_child ();
6937 if (child
== nullptr)
6940 return get_lwp_thread (child
);
6943 /* Default implementation of linux_target_ops method "set_pc" for
6944 32-bit pc register which is literally named "pc". */
6947 linux_set_pc_32bit (struct regcache
*regcache
, CORE_ADDR pc
)
6949 uint32_t newpc
= pc
;
6951 supply_register_by_name (regcache
, "pc", &newpc
);
6954 /* Default implementation of linux_target_ops method "get_pc" for
6955 32-bit pc register which is literally named "pc". */
6958 linux_get_pc_32bit (struct regcache
*regcache
)
6962 collect_register_by_name (regcache
, "pc", &pc
);
6963 threads_debug_printf ("stop pc is 0x%" PRIx32
, pc
);
6967 /* Default implementation of linux_target_ops method "set_pc" for
6968 64-bit pc register which is literally named "pc". */
6971 linux_set_pc_64bit (struct regcache
*regcache
, CORE_ADDR pc
)
6973 uint64_t newpc
= pc
;
6975 supply_register_by_name (regcache
, "pc", &newpc
);
6978 /* Default implementation of linux_target_ops method "get_pc" for
6979 64-bit pc register which is literally named "pc". */
6982 linux_get_pc_64bit (struct regcache
*regcache
)
6986 collect_register_by_name (regcache
, "pc", &pc
);
6987 threads_debug_printf ("stop pc is 0x%" PRIx64
, pc
);
6991 /* See linux-low.h. */
6994 linux_get_auxv (int pid
, int wordsize
, CORE_ADDR match
, CORE_ADDR
*valp
)
6996 gdb_byte
*data
= (gdb_byte
*) alloca (2 * wordsize
);
6999 gdb_assert (wordsize
== 4 || wordsize
== 8);
7001 while (the_target
->read_auxv (pid
, offset
, data
, 2 * wordsize
)
7006 uint32_t *data_p
= (uint32_t *) data
;
7007 if (data_p
[0] == match
)
7015 uint64_t *data_p
= (uint64_t *) data
;
7016 if (data_p
[0] == match
)
7023 offset
+= 2 * wordsize
;
7029 /* See linux-low.h. */
7032 linux_get_hwcap (int pid
, int wordsize
)
7034 CORE_ADDR hwcap
= 0;
7035 linux_get_auxv (pid
, wordsize
, AT_HWCAP
, &hwcap
);
7039 /* See linux-low.h. */
7042 linux_get_hwcap2 (int pid
, int wordsize
)
7044 CORE_ADDR hwcap2
= 0;
7045 linux_get_auxv (pid
, wordsize
, AT_HWCAP2
, &hwcap2
);
7049 #ifdef HAVE_LINUX_REGSETS
7051 initialize_regsets_info (struct regsets_info
*info
)
7053 for (info
->num_regsets
= 0;
7054 info
->regsets
[info
->num_regsets
].size
>= 0;
7055 info
->num_regsets
++)
7061 initialize_low (void)
7063 struct sigaction sigchld_action
;
7065 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
7066 set_target_ops (the_linux_target
);
7068 linux_ptrace_init_warnings ();
7069 linux_proc_init_warnings ();
7071 sigchld_action
.sa_handler
= sigchld_handler
;
7072 sigemptyset (&sigchld_action
.sa_mask
);
7073 sigchld_action
.sa_flags
= SA_RESTART
;
7074 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
7076 initialize_low_arch ();
7078 linux_check_ptrace_features ();