1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995-2015 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 #include "linux-low.h"
21 #include "nat/linux-osdata.h"
25 #include "nat/linux-nat.h"
26 #include "nat/linux-waitpid.h"
28 #include <sys/ptrace.h>
29 #include "nat/linux-ptrace.h"
30 #include "nat/linux-procfs.h"
31 #include "nat/linux-personality.h"
33 #include <sys/ioctl.h>
36 #include <sys/syscall.h>
40 #include <sys/types.h>
45 #include "filestuff.h"
46 #include "tracepoint.h"
49 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
50 then ELFMAG0 will have been defined. If it didn't get included by
51 gdb_proc_service.h then including it will likely introduce a duplicate
52 definition of elf_fpregset_t. */
57 #define SPUFS_MAGIC 0x23c9b64e
60 #ifdef HAVE_PERSONALITY
61 # include <sys/personality.h>
62 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
63 # define ADDR_NO_RANDOMIZE 0x0040000
72 #define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
75 /* This is the kernel's hard limit. Not to be confused with
81 /* Some targets did not define these ptrace constants from the start,
82 so gdbserver defines them locally here. In the future, these may
83 be removed after they are added to asm/ptrace.h. */
84 #if !(defined(PT_TEXT_ADDR) \
85 || defined(PT_DATA_ADDR) \
86 || defined(PT_TEXT_END_ADDR))
87 #if defined(__mcoldfire__)
88 /* These are still undefined in 3.10 kernels. */
89 #define PT_TEXT_ADDR 49*4
90 #define PT_DATA_ADDR 50*4
91 #define PT_TEXT_END_ADDR 51*4
92 /* BFIN already defines these since at least 2.6.32 kernels. */
94 #define PT_TEXT_ADDR 220
95 #define PT_TEXT_END_ADDR 224
96 #define PT_DATA_ADDR 228
97 /* These are still undefined in 3.10 kernels. */
98 #elif defined(__TMS320C6X__)
99 #define PT_TEXT_ADDR (0x10000*4)
100 #define PT_DATA_ADDR (0x10004*4)
101 #define PT_TEXT_END_ADDR (0x10008*4)
105 #ifdef HAVE_LINUX_BTRACE
106 # include "nat/linux-btrace.h"
107 # include "btrace-common.h"
110 #ifndef HAVE_ELF32_AUXV_T
111 /* Copied from glibc's elf.h. */
114 uint32_t a_type
; /* Entry type */
117 uint32_t a_val
; /* Integer value */
118 /* We use to have pointer elements added here. We cannot do that,
119 though, since it does not work when using 32-bit definitions
120 on 64-bit platforms and vice versa. */
125 #ifndef HAVE_ELF64_AUXV_T
126 /* Copied from glibc's elf.h. */
129 uint64_t a_type
; /* Entry type */
132 uint64_t a_val
; /* Integer value */
133 /* We use to have pointer elements added here. We cannot do that,
134 though, since it does not work when using 32-bit definitions
135 on 64-bit platforms and vice versa. */
142 /* See nat/linux-nat.h. */
145 ptid_of_lwp (struct lwp_info
*lwp
)
147 return ptid_of (get_lwp_thread (lwp
));
150 /* See nat/linux-nat.h. */
153 lwp_set_arch_private_info (struct lwp_info
*lwp
,
154 struct arch_lwp_info
*info
)
156 lwp
->arch_private
= info
;
159 /* See nat/linux-nat.h. */
161 struct arch_lwp_info
*
162 lwp_arch_private_info (struct lwp_info
*lwp
)
164 return lwp
->arch_private
;
167 /* See nat/linux-nat.h. */
170 lwp_is_stopped (struct lwp_info
*lwp
)
175 /* See nat/linux-nat.h. */
177 enum target_stop_reason
178 lwp_stop_reason (struct lwp_info
*lwp
)
180 return lwp
->stop_reason
;
183 /* A list of all unknown processes which receive stop signals. Some
184 other process will presumably claim each of these as forked
185 children momentarily. */
187 struct simple_pid_list
189 /* The process ID. */
192 /* The status as reported by waitpid. */
196 struct simple_pid_list
*next
;
198 struct simple_pid_list
*stopped_pids
;
200 /* Trivial list manipulation functions to keep track of a list of new
201 stopped processes. */
204 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
206 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
209 new_pid
->status
= status
;
210 new_pid
->next
= *listp
;
215 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
217 struct simple_pid_list
**p
;
219 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
220 if ((*p
)->pid
== pid
)
222 struct simple_pid_list
*next
= (*p
)->next
;
224 *statusp
= (*p
)->status
;
232 enum stopping_threads_kind
234 /* Not stopping threads presently. */
235 NOT_STOPPING_THREADS
,
237 /* Stopping threads. */
240 /* Stopping and suspending threads. */
241 STOPPING_AND_SUSPENDING_THREADS
244 /* This is set while stop_all_lwps is in effect. */
245 enum stopping_threads_kind stopping_threads
= NOT_STOPPING_THREADS
;
247 /* FIXME make into a target method? */
248 int using_threads
= 1;
250 /* True if we're presently stabilizing threads (moving them out of
252 static int stabilizing_threads
;
254 static void linux_resume_one_lwp (struct lwp_info
*lwp
,
255 int step
, int signal
, siginfo_t
*info
);
256 static void linux_resume (struct thread_resume
*resume_info
, size_t n
);
257 static void stop_all_lwps (int suspend
, struct lwp_info
*except
);
258 static void unstop_all_lwps (int unsuspend
, struct lwp_info
*except
);
259 static int linux_wait_for_event_filtered (ptid_t wait_ptid
, ptid_t filter_ptid
,
260 int *wstat
, int options
);
261 static int linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
);
262 static struct lwp_info
*add_lwp (ptid_t ptid
);
263 static int linux_stopped_by_watchpoint (void);
264 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
265 static void proceed_all_lwps (void);
266 static int finish_step_over (struct lwp_info
*lwp
);
267 static int kill_lwp (unsigned long lwpid
, int signo
);
269 /* When the event-loop is doing a step-over, this points at the thread
271 ptid_t step_over_bkpt
;
273 /* True if the low target can hardware single-step. Such targets
274 don't need a BREAKPOINT_REINSERT_ADDR callback. */
277 can_hardware_single_step (void)
279 return (the_low_target
.breakpoint_reinsert_addr
== NULL
);
282 /* True if the low target supports memory breakpoints. If so, we'll
283 have a GET_PC implementation. */
286 supports_breakpoints (void)
288 return (the_low_target
.get_pc
!= NULL
);
291 /* Returns true if this target can support fast tracepoints. This
292 does not mean that the in-process agent has been loaded in the
296 supports_fast_tracepoints (void)
298 return the_low_target
.install_fast_tracepoint_jump_pad
!= NULL
;
301 /* True if LWP is stopped in its stepping range. */
304 lwp_in_step_range (struct lwp_info
*lwp
)
306 CORE_ADDR pc
= lwp
->stop_pc
;
308 return (pc
>= lwp
->step_range_start
&& pc
< lwp
->step_range_end
);
311 struct pending_signals
315 struct pending_signals
*prev
;
318 /* The read/write ends of the pipe registered as waitable file in the
320 static int linux_event_pipe
[2] = { -1, -1 };
322 /* True if we're currently in async mode. */
323 #define target_is_async_p() (linux_event_pipe[0] != -1)
325 static void send_sigstop (struct lwp_info
*lwp
);
326 static void wait_for_sigstop (void);
328 /* Return non-zero if HEADER is a 64-bit ELF file. */
331 elf_64_header_p (const Elf64_Ehdr
*header
, unsigned int *machine
)
333 if (header
->e_ident
[EI_MAG0
] == ELFMAG0
334 && header
->e_ident
[EI_MAG1
] == ELFMAG1
335 && header
->e_ident
[EI_MAG2
] == ELFMAG2
336 && header
->e_ident
[EI_MAG3
] == ELFMAG3
)
338 *machine
= header
->e_machine
;
339 return header
->e_ident
[EI_CLASS
] == ELFCLASS64
;
346 /* Return non-zero if FILE is a 64-bit ELF file,
347 zero if the file is not a 64-bit ELF file,
348 and -1 if the file is not accessible or doesn't exist. */
351 elf_64_file_p (const char *file
, unsigned int *machine
)
356 fd
= open (file
, O_RDONLY
);
360 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
367 return elf_64_header_p (&header
, machine
);
370 /* Accepts an integer PID; Returns true if the executable PID is
371 running is a 64-bit ELF file.. */
374 linux_pid_exe_is_elf_64_file (int pid
, unsigned int *machine
)
378 sprintf (file
, "/proc/%d/exe", pid
);
379 return elf_64_file_p (file
, machine
);
383 delete_lwp (struct lwp_info
*lwp
)
385 struct thread_info
*thr
= get_lwp_thread (lwp
);
388 debug_printf ("deleting %ld\n", lwpid_of (thr
));
391 free (lwp
->arch_private
);
395 /* Add a process to the common process list, and set its private
398 static struct process_info
*
399 linux_add_process (int pid
, int attached
)
401 struct process_info
*proc
;
403 proc
= add_process (pid
, attached
);
404 proc
->priv
= xcalloc (1, sizeof (*proc
->priv
));
406 /* Set the arch when the first LWP stops. */
407 proc
->priv
->new_inferior
= 1;
409 if (the_low_target
.new_process
!= NULL
)
410 proc
->priv
->arch_private
= the_low_target
.new_process ();
415 static CORE_ADDR
get_pc (struct lwp_info
*lwp
);
417 /* Handle a GNU/Linux extended wait response. If we see a clone
418 event, we need to add the new LWP to our list (and return 0 so as
419 not to report the trap to higher layers). */
422 handle_extended_wait (struct lwp_info
*event_lwp
, int wstat
)
424 int event
= linux_ptrace_get_extended_event (wstat
);
425 struct thread_info
*event_thr
= get_lwp_thread (event_lwp
);
426 struct lwp_info
*new_lwp
;
428 if ((event
== PTRACE_EVENT_FORK
) || (event
== PTRACE_EVENT_CLONE
))
431 unsigned long new_pid
;
434 /* Get the pid of the new lwp. */
435 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_thr
), (PTRACE_TYPE_ARG3
) 0,
438 /* If we haven't already seen the new PID stop, wait for it now. */
439 if (!pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
441 /* The new child has a pending SIGSTOP. We can't affect it until it
442 hits the SIGSTOP, but we're already attached. */
444 ret
= my_waitpid (new_pid
, &status
, __WALL
);
447 perror_with_name ("waiting for new child");
448 else if (ret
!= new_pid
)
449 warning ("wait returned unexpected PID %d", ret
);
450 else if (!WIFSTOPPED (status
))
451 warning ("wait returned unexpected status 0x%x", status
);
454 if (event
== PTRACE_EVENT_FORK
)
456 struct process_info
*parent_proc
;
457 struct process_info
*child_proc
;
458 struct lwp_info
*child_lwp
;
459 struct target_desc
*tdesc
;
461 ptid
= ptid_build (new_pid
, new_pid
, 0);
465 debug_printf ("HEW: Got fork event from LWP %ld, "
467 ptid_get_lwp (ptid_of (event_thr
)),
468 ptid_get_pid (ptid
));
471 /* Add the new process to the tables and clone the breakpoint
472 lists of the parent. We need to do this even if the new process
473 will be detached, since we will need the process object and the
474 breakpoints to remove any breakpoints from memory when we
475 detach, and the client side will access registers. */
476 child_proc
= linux_add_process (new_pid
, 0);
477 gdb_assert (child_proc
!= NULL
);
478 child_lwp
= add_lwp (ptid
);
479 gdb_assert (child_lwp
!= NULL
);
480 child_lwp
->stopped
= 1;
481 parent_proc
= get_thread_process (event_thr
);
482 child_proc
->attached
= parent_proc
->attached
;
483 clone_all_breakpoints (&child_proc
->breakpoints
,
484 &child_proc
->raw_breakpoints
,
485 parent_proc
->breakpoints
);
487 tdesc
= xmalloc (sizeof (struct target_desc
));
488 copy_target_description (tdesc
, parent_proc
->tdesc
);
489 child_proc
->tdesc
= tdesc
;
490 child_lwp
->must_set_ptrace_flags
= 1;
492 /* Clone arch-specific process data. */
493 if (the_low_target
.new_fork
!= NULL
)
494 the_low_target
.new_fork (parent_proc
, child_proc
);
496 /* Save fork info in the parent thread. */
497 event_lwp
->waitstatus
.kind
= TARGET_WAITKIND_FORKED
;
498 event_lwp
->waitstatus
.value
.related_pid
= ptid
;
499 /* The status_pending field contains bits denoting the
500 extended event, so when the pending event is handled,
501 the handler will look at lwp->waitstatus. */
502 event_lwp
->status_pending_p
= 1;
503 event_lwp
->status_pending
= wstat
;
505 /* Report the event. */
510 debug_printf ("HEW: Got clone event "
511 "from LWP %ld, new child is LWP %ld\n",
512 lwpid_of (event_thr
), new_pid
);
514 ptid
= ptid_build (pid_of (event_thr
), new_pid
, 0);
515 new_lwp
= add_lwp (ptid
);
517 /* Either we're going to immediately resume the new thread
518 or leave it stopped. linux_resume_one_lwp is a nop if it
519 thinks the thread is currently running, so set this first
520 before calling linux_resume_one_lwp. */
521 new_lwp
->stopped
= 1;
523 /* If we're suspending all threads, leave this one suspended
525 if (stopping_threads
== STOPPING_AND_SUSPENDING_THREADS
)
526 new_lwp
->suspended
= 1;
528 /* Normally we will get the pending SIGSTOP. But in some cases
529 we might get another signal delivered to the group first.
530 If we do get another signal, be sure not to lose it. */
531 if (WSTOPSIG (status
) != SIGSTOP
)
533 new_lwp
->stop_expected
= 1;
534 new_lwp
->status_pending_p
= 1;
535 new_lwp
->status_pending
= status
;
538 /* Don't report the event. */
542 internal_error (__FILE__
, __LINE__
, _("unknown ptrace event %d"), event
);
545 /* Return the PC as read from the regcache of LWP, without any
549 get_pc (struct lwp_info
*lwp
)
551 struct thread_info
*saved_thread
;
552 struct regcache
*regcache
;
555 if (the_low_target
.get_pc
== NULL
)
558 saved_thread
= current_thread
;
559 current_thread
= get_lwp_thread (lwp
);
561 regcache
= get_thread_regcache (current_thread
, 1);
562 pc
= (*the_low_target
.get_pc
) (regcache
);
565 debug_printf ("pc is 0x%lx\n", (long) pc
);
567 current_thread
= saved_thread
;
571 /* This function should only be called if LWP got a SIGTRAP.
572 The SIGTRAP could mean several things.
574 On i386, where decr_pc_after_break is non-zero:
576 If we were single-stepping this process using PTRACE_SINGLESTEP, we
577 will get only the one SIGTRAP. The value of $eip will be the next
578 instruction. If the instruction we stepped over was a breakpoint,
579 we need to decrement the PC.
581 If we continue the process using PTRACE_CONT, we will get a
582 SIGTRAP when we hit a breakpoint. The value of $eip will be
583 the instruction after the breakpoint (i.e. needs to be
584 decremented). If we report the SIGTRAP to GDB, we must also
585 report the undecremented PC. If the breakpoint is removed, we
586 must resume at the decremented PC.
588 On a non-decr_pc_after_break machine with hardware or kernel
591 If we either single-step a breakpoint instruction, or continue and
592 hit a breakpoint instruction, our PC will point at the breakpoint
596 check_stopped_by_breakpoint (struct lwp_info
*lwp
)
599 CORE_ADDR sw_breakpoint_pc
;
600 struct thread_info
*saved_thread
;
601 #if USE_SIGTRAP_SIGINFO
605 if (the_low_target
.get_pc
== NULL
)
609 sw_breakpoint_pc
= pc
- the_low_target
.decr_pc_after_break
;
611 /* breakpoint_at reads from the current thread. */
612 saved_thread
= current_thread
;
613 current_thread
= get_lwp_thread (lwp
);
615 #if USE_SIGTRAP_SIGINFO
616 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
617 (PTRACE_TYPE_ARG3
) 0, &siginfo
) == 0)
619 if (siginfo
.si_signo
== SIGTRAP
)
621 if (siginfo
.si_code
== GDB_ARCH_TRAP_BRKPT
)
625 struct thread_info
*thr
= get_lwp_thread (lwp
);
627 debug_printf ("CSBB: %s stopped by software breakpoint\n",
628 target_pid_to_str (ptid_of (thr
)));
631 /* Back up the PC if necessary. */
632 if (pc
!= sw_breakpoint_pc
)
634 struct regcache
*regcache
635 = get_thread_regcache (current_thread
, 1);
636 (*the_low_target
.set_pc
) (regcache
, sw_breakpoint_pc
);
639 lwp
->stop_pc
= sw_breakpoint_pc
;
640 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
641 current_thread
= saved_thread
;
644 else if (siginfo
.si_code
== TRAP_HWBKPT
)
648 struct thread_info
*thr
= get_lwp_thread (lwp
);
650 debug_printf ("CSBB: %s stopped by hardware "
651 "breakpoint/watchpoint\n",
652 target_pid_to_str (ptid_of (thr
)));
656 lwp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
657 current_thread
= saved_thread
;
660 else if (siginfo
.si_code
== TRAP_TRACE
)
664 struct thread_info
*thr
= get_lwp_thread (lwp
);
666 debug_printf ("CSBB: %s stopped by trace\n",
667 target_pid_to_str (ptid_of (thr
)));
673 /* We may have just stepped a breakpoint instruction. E.g., in
674 non-stop mode, GDB first tells the thread A to step a range, and
675 then the user inserts a breakpoint inside the range. In that
676 case we need to report the breakpoint PC. */
677 if ((!lwp
->stepping
|| lwp
->stop_pc
== sw_breakpoint_pc
)
678 && (*the_low_target
.breakpoint_at
) (sw_breakpoint_pc
))
682 struct thread_info
*thr
= get_lwp_thread (lwp
);
684 debug_printf ("CSBB: %s stopped by software breakpoint\n",
685 target_pid_to_str (ptid_of (thr
)));
688 /* Back up the PC if necessary. */
689 if (pc
!= sw_breakpoint_pc
)
691 struct regcache
*regcache
692 = get_thread_regcache (current_thread
, 1);
693 (*the_low_target
.set_pc
) (regcache
, sw_breakpoint_pc
);
696 lwp
->stop_pc
= sw_breakpoint_pc
;
697 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
698 current_thread
= saved_thread
;
702 if (hardware_breakpoint_inserted_here (pc
))
706 struct thread_info
*thr
= get_lwp_thread (lwp
);
708 debug_printf ("CSBB: %s stopped by hardware breakpoint\n",
709 target_pid_to_str (ptid_of (thr
)));
713 lwp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
714 current_thread
= saved_thread
;
719 current_thread
= saved_thread
;
723 static struct lwp_info
*
724 add_lwp (ptid_t ptid
)
726 struct lwp_info
*lwp
;
728 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
729 memset (lwp
, 0, sizeof (*lwp
));
731 if (the_low_target
.new_thread
!= NULL
)
732 the_low_target
.new_thread (lwp
);
734 lwp
->thread
= add_thread (ptid
, lwp
);
739 /* Start an inferior process and returns its pid.
740 ALLARGS is a vector of program-name and args. */
743 linux_create_inferior (char *program
, char **allargs
)
745 struct lwp_info
*new_lwp
;
748 struct cleanup
*restore_personality
749 = maybe_disable_address_space_randomization (disable_randomization
);
751 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
757 perror_with_name ("fork");
762 ptrace (PTRACE_TRACEME
, 0, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0);
764 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
765 signal (__SIGRTMIN
+ 1, SIG_DFL
);
770 /* If gdbserver is connected to gdb via stdio, redirect the inferior's
771 stdout to stderr so that inferior i/o doesn't corrupt the connection.
772 Also, redirect stdin to /dev/null. */
773 if (remote_connection_is_stdio ())
776 open ("/dev/null", O_RDONLY
);
778 if (write (2, "stdin/stdout redirected\n",
779 sizeof ("stdin/stdout redirected\n") - 1) < 0)
781 /* Errors ignored. */;
785 execv (program
, allargs
);
787 execvp (program
, allargs
);
789 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
795 do_cleanups (restore_personality
);
797 linux_add_process (pid
, 0);
799 ptid
= ptid_build (pid
, pid
, 0);
800 new_lwp
= add_lwp (ptid
);
801 new_lwp
->must_set_ptrace_flags
= 1;
806 /* Attach to an inferior process. Returns 0 on success, ERRNO on
810 linux_attach_lwp (ptid_t ptid
)
812 struct lwp_info
*new_lwp
;
813 int lwpid
= ptid_get_lwp (ptid
);
815 if (ptrace (PTRACE_ATTACH
, lwpid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0)
819 new_lwp
= add_lwp (ptid
);
821 /* We need to wait for SIGSTOP before being able to make the next
822 ptrace call on this LWP. */
823 new_lwp
->must_set_ptrace_flags
= 1;
825 if (linux_proc_pid_is_stopped (lwpid
))
828 debug_printf ("Attached to a stopped process\n");
830 /* The process is definitely stopped. It is in a job control
831 stop, unless the kernel predates the TASK_STOPPED /
832 TASK_TRACED distinction, in which case it might be in a
833 ptrace stop. Make sure it is in a ptrace stop; from there we
834 can kill it, signal it, et cetera.
836 First make sure there is a pending SIGSTOP. Since we are
837 already attached, the process can not transition from stopped
838 to running without a PTRACE_CONT; so we know this signal will
839 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
840 probably already in the queue (unless this kernel is old
841 enough to use TASK_STOPPED for ptrace stops); but since
842 SIGSTOP is not an RT signal, it can only be queued once. */
843 kill_lwp (lwpid
, SIGSTOP
);
845 /* Finally, resume the stopped process. This will deliver the
846 SIGSTOP (or a higher priority signal, just like normal
847 PTRACE_ATTACH), which we'll catch later on. */
848 ptrace (PTRACE_CONT
, lwpid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0);
851 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
854 There are several cases to consider here:
856 1) gdbserver has already attached to the process and is being notified
857 of a new thread that is being created.
858 In this case we should ignore that SIGSTOP and resume the
859 process. This is handled below by setting stop_expected = 1,
860 and the fact that add_thread sets last_resume_kind ==
863 2) This is the first thread (the process thread), and we're attaching
864 to it via attach_inferior.
865 In this case we want the process thread to stop.
866 This is handled by having linux_attach set last_resume_kind ==
867 resume_stop after we return.
869 If the pid we are attaching to is also the tgid, we attach to and
870 stop all the existing threads. Otherwise, we attach to pid and
871 ignore any other threads in the same group as this pid.
873 3) GDB is connecting to gdbserver and is requesting an enumeration of all
875 In this case we want the thread to stop.
876 FIXME: This case is currently not properly handled.
877 We should wait for the SIGSTOP but don't. Things work apparently
878 because enough time passes between when we ptrace (ATTACH) and when
879 gdb makes the next ptrace call on the thread.
881 On the other hand, if we are currently trying to stop all threads, we
882 should treat the new thread as if we had sent it a SIGSTOP. This works
883 because we are guaranteed that the add_lwp call above added us to the
884 end of the list, and so the new thread has not yet reached
885 wait_for_sigstop (but will). */
886 new_lwp
->stop_expected
= 1;
891 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
892 already attached. Returns true if a new LWP is found, false
896 attach_proc_task_lwp_callback (ptid_t ptid
)
898 /* Is this a new thread? */
899 if (find_thread_ptid (ptid
) == NULL
)
901 int lwpid
= ptid_get_lwp (ptid
);
905 debug_printf ("Found new lwp %d\n", lwpid
);
907 err
= linux_attach_lwp (ptid
);
909 /* Be quiet if we simply raced with the thread exiting. EPERM
910 is returned if the thread's task still exists, and is marked
911 as exited or zombie, as well as other conditions, so in that
912 case, confirm the status in /proc/PID/status. */
914 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
918 debug_printf ("Cannot attach to lwp %d: "
919 "thread is gone (%d: %s)\n",
920 lwpid
, err
, strerror (err
));
925 warning (_("Cannot attach to lwp %d: %s"),
927 linux_ptrace_attach_fail_reason_string (ptid
, err
));
935 /* Attach to PID. If PID is the tgid, attach to it and all
939 linux_attach (unsigned long pid
)
941 ptid_t ptid
= ptid_build (pid
, pid
, 0);
944 /* Attach to PID. We will check for other threads
946 err
= linux_attach_lwp (ptid
);
948 error ("Cannot attach to process %ld: %s",
949 pid
, linux_ptrace_attach_fail_reason_string (ptid
, err
));
951 linux_add_process (pid
, 1);
955 struct thread_info
*thread
;
957 /* Don't ignore the initial SIGSTOP if we just attached to this
958 process. It will be collected by wait shortly. */
959 thread
= find_thread_ptid (ptid_build (pid
, pid
, 0));
960 thread
->last_resume_kind
= resume_stop
;
963 /* We must attach to every LWP. If /proc is mounted, use that to
964 find them now. On the one hand, the inferior may be using raw
965 clone instead of using pthreads. On the other hand, even if it
966 is using pthreads, GDB may not be connected yet (thread_db needs
967 to do symbol lookups, through qSymbol). Also, thread_db walks
968 structures in the inferior's address space to find the list of
969 threads/LWPs, and those structures may well be corrupted. Note
970 that once thread_db is loaded, we'll still use it to list threads
971 and associate pthread info with each LWP. */
972 linux_proc_attach_tgid_threads (pid
, attach_proc_task_lwp_callback
);
983 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
985 struct counter
*counter
= args
;
987 if (ptid_get_pid (entry
->id
) == counter
->pid
)
989 if (++counter
->count
> 1)
997 last_thread_of_process_p (int pid
)
999 struct counter counter
= { pid
, 0 };
1001 return (find_inferior (&all_threads
,
1002 second_thread_of_pid_p
, &counter
) == NULL
);
1008 linux_kill_one_lwp (struct lwp_info
*lwp
)
1010 struct thread_info
*thr
= get_lwp_thread (lwp
);
1011 int pid
= lwpid_of (thr
);
1013 /* PTRACE_KILL is unreliable. After stepping into a signal handler,
1014 there is no signal context, and ptrace(PTRACE_KILL) (or
1015 ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
1016 ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
1017 alternative is to kill with SIGKILL. We only need one SIGKILL
1018 per process, not one for each thread. But since we still support
1019 linuxthreads, and we also support debugging programs using raw
1020 clone without CLONE_THREAD, we send one for each thread. For
1021 years, we used PTRACE_KILL only, so we're being a bit paranoid
1022 about some old kernels where PTRACE_KILL might work better
1023 (dubious if there are any such, but that's why it's paranoia), so
1024 we try SIGKILL first, PTRACE_KILL second, and so we're fine
1028 kill_lwp (pid
, SIGKILL
);
1031 int save_errno
= errno
;
1033 debug_printf ("LKL: kill_lwp (SIGKILL) %s, 0, 0 (%s)\n",
1034 target_pid_to_str (ptid_of (thr
)),
1035 save_errno
? strerror (save_errno
) : "OK");
1039 ptrace (PTRACE_KILL
, pid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0);
1042 int save_errno
= errno
;
1044 debug_printf ("LKL: PTRACE_KILL %s, 0, 0 (%s)\n",
1045 target_pid_to_str (ptid_of (thr
)),
1046 save_errno
? strerror (save_errno
) : "OK");
1050 /* Kill LWP and wait for it to die. */
1053 kill_wait_lwp (struct lwp_info
*lwp
)
1055 struct thread_info
*thr
= get_lwp_thread (lwp
);
1056 int pid
= ptid_get_pid (ptid_of (thr
));
1057 int lwpid
= ptid_get_lwp (ptid_of (thr
));
1062 debug_printf ("kwl: killing lwp %d, for pid: %d\n", lwpid
, pid
);
1066 linux_kill_one_lwp (lwp
);
1068 /* Make sure it died. Notes:
1070 - The loop is most likely unnecessary.
1072 - We don't use linux_wait_for_event as that could delete lwps
1073 while we're iterating over them. We're not interested in
1074 any pending status at this point, only in making sure all
1075 wait status on the kernel side are collected until the
1078 - We don't use __WALL here as the __WALL emulation relies on
1079 SIGCHLD, and killing a stopped process doesn't generate
1080 one, nor an exit status.
1082 res
= my_waitpid (lwpid
, &wstat
, 0);
1083 if (res
== -1 && errno
== ECHILD
)
1084 res
= my_waitpid (lwpid
, &wstat
, __WCLONE
);
1085 } while (res
> 0 && WIFSTOPPED (wstat
));
1087 gdb_assert (res
> 0);
1090 /* Callback for `find_inferior'. Kills an lwp of a given process,
1091 except the leader. */
1094 kill_one_lwp_callback (struct inferior_list_entry
*entry
, void *args
)
1096 struct thread_info
*thread
= (struct thread_info
*) entry
;
1097 struct lwp_info
*lwp
= get_thread_lwp (thread
);
1098 int pid
= * (int *) args
;
1100 if (ptid_get_pid (entry
->id
) != pid
)
1103 /* We avoid killing the first thread here, because of a Linux kernel (at
1104 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
1105 the children get a chance to be reaped, it will remain a zombie
1108 if (lwpid_of (thread
) == pid
)
1111 debug_printf ("lkop: is last of process %s\n",
1112 target_pid_to_str (entry
->id
));
1116 kill_wait_lwp (lwp
);
1121 linux_kill (int pid
)
1123 struct process_info
*process
;
1124 struct lwp_info
*lwp
;
1126 process
= find_process_pid (pid
);
1127 if (process
== NULL
)
1130 /* If we're killing a running inferior, make sure it is stopped
1131 first, as PTRACE_KILL will not work otherwise. */
1132 stop_all_lwps (0, NULL
);
1134 find_inferior (&all_threads
, kill_one_lwp_callback
, &pid
);
1136 /* See the comment in linux_kill_one_lwp. We did not kill the first
1137 thread in the list, so do so now. */
1138 lwp
= find_lwp_pid (pid_to_ptid (pid
));
1143 debug_printf ("lk_1: cannot find lwp for pid: %d\n",
1147 kill_wait_lwp (lwp
);
1149 the_target
->mourn (process
);
1151 /* Since we presently can only stop all lwps of all processes, we
1152 need to unstop lwps of other processes. */
1153 unstop_all_lwps (0, NULL
);
1157 /* Get pending signal of THREAD, for detaching purposes. This is the
1158 signal the thread last stopped for, which we need to deliver to the
1159 thread when detaching, otherwise, it'd be suppressed/lost. */
1162 get_detach_signal (struct thread_info
*thread
)
1164 enum gdb_signal signo
= GDB_SIGNAL_0
;
1166 struct lwp_info
*lp
= get_thread_lwp (thread
);
1168 if (lp
->status_pending_p
)
1169 status
= lp
->status_pending
;
1172 /* If the thread had been suspended by gdbserver, and it stopped
1173 cleanly, then it'll have stopped with SIGSTOP. But we don't
1174 want to deliver that SIGSTOP. */
1175 if (thread
->last_status
.kind
!= TARGET_WAITKIND_STOPPED
1176 || thread
->last_status
.value
.sig
== GDB_SIGNAL_0
)
1179 /* Otherwise, we may need to deliver the signal we
1181 status
= lp
->last_status
;
1184 if (!WIFSTOPPED (status
))
1187 debug_printf ("GPS: lwp %s hasn't stopped: no pending signal\n",
1188 target_pid_to_str (ptid_of (thread
)));
1192 /* Extended wait statuses aren't real SIGTRAPs. */
1193 if (WSTOPSIG (status
) == SIGTRAP
&& linux_is_extended_waitstatus (status
))
1196 debug_printf ("GPS: lwp %s had stopped with extended "
1197 "status: no pending signal\n",
1198 target_pid_to_str (ptid_of (thread
)));
1202 signo
= gdb_signal_from_host (WSTOPSIG (status
));
1204 if (program_signals_p
&& !program_signals
[signo
])
1207 debug_printf ("GPS: lwp %s had signal %s, but it is in nopass state\n",
1208 target_pid_to_str (ptid_of (thread
)),
1209 gdb_signal_to_string (signo
));
1212 else if (!program_signals_p
1213 /* If we have no way to know which signals GDB does not
1214 want to have passed to the program, assume
1215 SIGTRAP/SIGINT, which is GDB's default. */
1216 && (signo
== GDB_SIGNAL_TRAP
|| signo
== GDB_SIGNAL_INT
))
1219 debug_printf ("GPS: lwp %s had signal %s, "
1220 "but we don't know if we should pass it. "
1221 "Default to not.\n",
1222 target_pid_to_str (ptid_of (thread
)),
1223 gdb_signal_to_string (signo
));
1229 debug_printf ("GPS: lwp %s has pending signal %s: delivering it.\n",
1230 target_pid_to_str (ptid_of (thread
)),
1231 gdb_signal_to_string (signo
));
1233 return WSTOPSIG (status
);
1238 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
1240 struct thread_info
*thread
= (struct thread_info
*) entry
;
1241 struct lwp_info
*lwp
= get_thread_lwp (thread
);
1242 int pid
= * (int *) args
;
1245 if (ptid_get_pid (entry
->id
) != pid
)
1248 /* If there is a pending SIGSTOP, get rid of it. */
1249 if (lwp
->stop_expected
)
1252 debug_printf ("Sending SIGCONT to %s\n",
1253 target_pid_to_str (ptid_of (thread
)));
1255 kill_lwp (lwpid_of (thread
), SIGCONT
);
1256 lwp
->stop_expected
= 0;
1259 /* Flush any pending changes to the process's registers. */
1260 regcache_invalidate_thread (thread
);
1262 /* Pass on any pending signal for this thread. */
1263 sig
= get_detach_signal (thread
);
1265 /* Finally, let it resume. */
1266 if (the_low_target
.prepare_to_resume
!= NULL
)
1267 the_low_target
.prepare_to_resume (lwp
);
1268 if (ptrace (PTRACE_DETACH
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
1269 (PTRACE_TYPE_ARG4
) (long) sig
) < 0)
1270 error (_("Can't detach %s: %s"),
1271 target_pid_to_str (ptid_of (thread
)),
1279 linux_detach (int pid
)
1281 struct process_info
*process
;
1283 process
= find_process_pid (pid
);
1284 if (process
== NULL
)
1287 /* Stop all threads before detaching. First, ptrace requires that
1288 the thread is stopped to sucessfully detach. Second, thread_db
1289 may need to uninstall thread event breakpoints from memory, which
1290 only works with a stopped process anyway. */
1291 stop_all_lwps (0, NULL
);
1293 #ifdef USE_THREAD_DB
1294 thread_db_detach (process
);
1297 /* Stabilize threads (move out of jump pads). */
1298 stabilize_threads ();
1300 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
1302 the_target
->mourn (process
);
1304 /* Since we presently can only stop all lwps of all processes, we
1305 need to unstop lwps of other processes. */
1306 unstop_all_lwps (0, NULL
);
1310 /* Remove all LWPs that belong to process PROC from the lwp list. */
1313 delete_lwp_callback (struct inferior_list_entry
*entry
, void *proc
)
1315 struct thread_info
*thread
= (struct thread_info
*) entry
;
1316 struct lwp_info
*lwp
= get_thread_lwp (thread
);
1317 struct process_info
*process
= proc
;
1319 if (pid_of (thread
) == pid_of (process
))
1326 linux_mourn (struct process_info
*process
)
1328 struct process_info_private
*priv
;
1330 #ifdef USE_THREAD_DB
1331 thread_db_mourn (process
);
1334 find_inferior (&all_threads
, delete_lwp_callback
, process
);
1336 /* Freeing all private data. */
1337 priv
= process
->priv
;
1338 free (priv
->arch_private
);
1340 process
->priv
= NULL
;
1342 remove_process (process
);
1346 linux_join (int pid
)
1351 ret
= my_waitpid (pid
, &status
, 0);
1352 if (WIFEXITED (status
) || WIFSIGNALED (status
))
1354 } while (ret
!= -1 || errno
!= ECHILD
);
1357 /* Return nonzero if the given thread is still alive. */
1359 linux_thread_alive (ptid_t ptid
)
1361 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
1363 /* We assume we always know if a thread exits. If a whole process
1364 exited but we still haven't been able to report it to GDB, we'll
1365 hold on to the last lwp of the dead process. */
1372 /* Return 1 if this lwp still has an interesting status pending. If
1373 not (e.g., it had stopped for a breakpoint that is gone), return
1377 thread_still_has_status_pending_p (struct thread_info
*thread
)
1379 struct lwp_info
*lp
= get_thread_lwp (thread
);
1381 if (!lp
->status_pending_p
)
1384 /* If we got a `vCont;t', but we haven't reported a stop yet, do
1385 report any status pending the LWP may have. */
1386 if (thread
->last_resume_kind
== resume_stop
1387 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
1390 if (thread
->last_resume_kind
!= resume_stop
1391 && (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
1392 || lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
1394 struct thread_info
*saved_thread
;
1398 gdb_assert (lp
->last_status
!= 0);
1402 saved_thread
= current_thread
;
1403 current_thread
= thread
;
1405 if (pc
!= lp
->stop_pc
)
1408 debug_printf ("PC of %ld changed\n",
1413 #if !USE_SIGTRAP_SIGINFO
1414 else if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
1415 && !(*the_low_target
.breakpoint_at
) (pc
))
1418 debug_printf ("previous SW breakpoint of %ld gone\n",
1422 else if (lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
1423 && !hardware_breakpoint_inserted_here (pc
))
1426 debug_printf ("previous HW breakpoint of %ld gone\n",
1432 current_thread
= saved_thread
;
1437 debug_printf ("discarding pending breakpoint status\n");
1438 lp
->status_pending_p
= 0;
1446 /* Return 1 if this lwp has an interesting status pending. */
1448 status_pending_p_callback (struct inferior_list_entry
*entry
, void *arg
)
1450 struct thread_info
*thread
= (struct thread_info
*) entry
;
1451 struct lwp_info
*lp
= get_thread_lwp (thread
);
1452 ptid_t ptid
= * (ptid_t
*) arg
;
1454 /* Check if we're only interested in events from a specific process
1455 or a specific LWP. */
1456 if (!ptid_match (ptid_of (thread
), ptid
))
1459 if (lp
->status_pending_p
1460 && !thread_still_has_status_pending_p (thread
))
1462 linux_resume_one_lwp (lp
, lp
->stepping
, GDB_SIGNAL_0
, NULL
);
1466 return lp
->status_pending_p
;
1470 same_lwp (struct inferior_list_entry
*entry
, void *data
)
1472 ptid_t ptid
= *(ptid_t
*) data
;
1475 if (ptid_get_lwp (ptid
) != 0)
1476 lwp
= ptid_get_lwp (ptid
);
1478 lwp
= ptid_get_pid (ptid
);
1480 if (ptid_get_lwp (entry
->id
) == lwp
)
1487 find_lwp_pid (ptid_t ptid
)
1489 struct inferior_list_entry
*thread
1490 = find_inferior (&all_threads
, same_lwp
, &ptid
);
1495 return get_thread_lwp ((struct thread_info
*) thread
);
1498 /* Return the number of known LWPs in the tgid given by PID. */
1503 struct inferior_list_entry
*inf
, *tmp
;
1506 ALL_INFERIORS (&all_threads
, inf
, tmp
)
1508 if (ptid_get_pid (inf
->id
) == pid
)
1515 /* The arguments passed to iterate_over_lwps. */
1517 struct iterate_over_lwps_args
1519 /* The FILTER argument passed to iterate_over_lwps. */
1522 /* The CALLBACK argument passed to iterate_over_lwps. */
1523 iterate_over_lwps_ftype
*callback
;
1525 /* The DATA argument passed to iterate_over_lwps. */
1529 /* Callback for find_inferior used by iterate_over_lwps to filter
1530 calls to the callback supplied to that function. Returning a
1531 nonzero value causes find_inferiors to stop iterating and return
1532 the current inferior_list_entry. Returning zero indicates that
1533 find_inferiors should continue iterating. */
1536 iterate_over_lwps_filter (struct inferior_list_entry
*entry
, void *args_p
)
1538 struct iterate_over_lwps_args
*args
1539 = (struct iterate_over_lwps_args
*) args_p
;
1541 if (ptid_match (entry
->id
, args
->filter
))
1543 struct thread_info
*thr
= (struct thread_info
*) entry
;
1544 struct lwp_info
*lwp
= get_thread_lwp (thr
);
1546 return (*args
->callback
) (lwp
, args
->data
);
1552 /* See nat/linux-nat.h. */
1555 iterate_over_lwps (ptid_t filter
,
1556 iterate_over_lwps_ftype callback
,
1559 struct iterate_over_lwps_args args
= {filter
, callback
, data
};
1560 struct inferior_list_entry
*entry
;
1562 entry
= find_inferior (&all_threads
, iterate_over_lwps_filter
, &args
);
1566 return get_thread_lwp ((struct thread_info
*) entry
);
1569 /* Detect zombie thread group leaders, and "exit" them. We can't reap
1570 their exits until all other threads in the group have exited. */
1573 check_zombie_leaders (void)
1575 struct process_info
*proc
, *tmp
;
1577 ALL_PROCESSES (proc
, tmp
)
1579 pid_t leader_pid
= pid_of (proc
);
1580 struct lwp_info
*leader_lp
;
1582 leader_lp
= find_lwp_pid (pid_to_ptid (leader_pid
));
1585 debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, "
1586 "num_lwps=%d, zombie=%d\n",
1587 leader_pid
, leader_lp
!= NULL
, num_lwps (leader_pid
),
1588 linux_proc_pid_is_zombie (leader_pid
));
1590 if (leader_lp
!= NULL
1591 /* Check if there are other threads in the group, as we may
1592 have raced with the inferior simply exiting. */
1593 && !last_thread_of_process_p (leader_pid
)
1594 && linux_proc_pid_is_zombie (leader_pid
))
1596 /* A leader zombie can mean one of two things:
1598 - It exited, and there's an exit status pending
1599 available, or only the leader exited (not the whole
1600 program). In the latter case, we can't waitpid the
1601 leader's exit status until all other threads are gone.
1603 - There are 3 or more threads in the group, and a thread
1604 other than the leader exec'd. On an exec, the Linux
1605 kernel destroys all other threads (except the execing
1606 one) in the thread group, and resets the execing thread's
1607 tid to the tgid. No exit notification is sent for the
1608 execing thread -- from the ptracer's perspective, it
1609 appears as though the execing thread just vanishes.
1610 Until we reap all other threads except the leader and the
1611 execing thread, the leader will be zombie, and the
1612 execing thread will be in `D (disc sleep)'. As soon as
1613 all other threads are reaped, the execing thread changes
1614 it's tid to the tgid, and the previous (zombie) leader
1615 vanishes, giving place to the "new" leader. We could try
1616 distinguishing the exit and exec cases, by waiting once
1617 more, and seeing if something comes out, but it doesn't
1618 sound useful. The previous leader _does_ go away, and
1619 we'll re-add the new one once we see the exec event
1620 (which is just the same as what would happen if the
1621 previous leader did exit voluntarily before some other
1626 "CZL: Thread group leader %d zombie "
1627 "(it exited, or another thread execd).\n",
1630 delete_lwp (leader_lp
);
1635 /* Callback for `find_inferior'. Returns the first LWP that is not
1636 stopped. ARG is a PTID filter. */
1639 not_stopped_callback (struct inferior_list_entry
*entry
, void *arg
)
1641 struct thread_info
*thr
= (struct thread_info
*) entry
;
1642 struct lwp_info
*lwp
;
1643 ptid_t filter
= *(ptid_t
*) arg
;
1645 if (!ptid_match (ptid_of (thr
), filter
))
1648 lwp
= get_thread_lwp (thr
);
1655 /* This function should only be called if the LWP got a SIGTRAP.
1657 Handle any tracepoint steps or hits. Return true if a tracepoint
1658 event was handled, 0 otherwise. */
1661 handle_tracepoints (struct lwp_info
*lwp
)
1663 struct thread_info
*tinfo
= get_lwp_thread (lwp
);
1664 int tpoint_related_event
= 0;
1666 gdb_assert (lwp
->suspended
== 0);
1668 /* If this tracepoint hit causes a tracing stop, we'll immediately
1669 uninsert tracepoints. To do this, we temporarily pause all
1670 threads, unpatch away, and then unpause threads. We need to make
1671 sure the unpausing doesn't resume LWP too. */
1674 /* And we need to be sure that any all-threads-stopping doesn't try
1675 to move threads out of the jump pads, as it could deadlock the
1676 inferior (LWP could be in the jump pad, maybe even holding the
1679 /* Do any necessary step collect actions. */
1680 tpoint_related_event
|= tracepoint_finished_step (tinfo
, lwp
->stop_pc
);
1682 tpoint_related_event
|= handle_tracepoint_bkpts (tinfo
, lwp
->stop_pc
);
1684 /* See if we just hit a tracepoint and do its main collect
1686 tpoint_related_event
|= tracepoint_was_hit (tinfo
, lwp
->stop_pc
);
1690 gdb_assert (lwp
->suspended
== 0);
1691 gdb_assert (!stabilizing_threads
|| lwp
->collecting_fast_tracepoint
);
1693 if (tpoint_related_event
)
1696 debug_printf ("got a tracepoint event\n");
1703 /* Convenience wrapper. Returns true if LWP is presently collecting a
1707 linux_fast_tracepoint_collecting (struct lwp_info
*lwp
,
1708 struct fast_tpoint_collect_status
*status
)
1710 CORE_ADDR thread_area
;
1711 struct thread_info
*thread
= get_lwp_thread (lwp
);
1713 if (the_low_target
.get_thread_area
== NULL
)
1716 /* Get the thread area address. This is used to recognize which
1717 thread is which when tracing with the in-process agent library.
1718 We don't read anything from the address, and treat it as opaque;
1719 it's the address itself that we assume is unique per-thread. */
1720 if ((*the_low_target
.get_thread_area
) (lwpid_of (thread
), &thread_area
) == -1)
1723 return fast_tracepoint_collecting (thread_area
, lwp
->stop_pc
, status
);
1726 /* The reason we resume in the caller, is because we want to be able
1727 to pass lwp->status_pending as WSTAT, and we need to clear
1728 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1729 refuses to resume. */
1732 maybe_move_out_of_jump_pad (struct lwp_info
*lwp
, int *wstat
)
1734 struct thread_info
*saved_thread
;
1736 saved_thread
= current_thread
;
1737 current_thread
= get_lwp_thread (lwp
);
1740 || (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) != SIGTRAP
))
1741 && supports_fast_tracepoints ()
1742 && agent_loaded_p ())
1744 struct fast_tpoint_collect_status status
;
1748 debug_printf ("Checking whether LWP %ld needs to move out of the "
1750 lwpid_of (current_thread
));
1752 r
= linux_fast_tracepoint_collecting (lwp
, &status
);
1755 || (WSTOPSIG (*wstat
) != SIGILL
1756 && WSTOPSIG (*wstat
) != SIGFPE
1757 && WSTOPSIG (*wstat
) != SIGSEGV
1758 && WSTOPSIG (*wstat
) != SIGBUS
))
1760 lwp
->collecting_fast_tracepoint
= r
;
1764 if (r
== 1 && lwp
->exit_jump_pad_bkpt
== NULL
)
1766 /* Haven't executed the original instruction yet.
1767 Set breakpoint there, and wait till it's hit,
1768 then single-step until exiting the jump pad. */
1769 lwp
->exit_jump_pad_bkpt
1770 = set_breakpoint_at (status
.adjusted_insn_addr
, NULL
);
1774 debug_printf ("Checking whether LWP %ld needs to move out of "
1775 "the jump pad...it does\n",
1776 lwpid_of (current_thread
));
1777 current_thread
= saved_thread
;
1784 /* If we get a synchronous signal while collecting, *and*
1785 while executing the (relocated) original instruction,
1786 reset the PC to point at the tpoint address, before
1787 reporting to GDB. Otherwise, it's an IPA lib bug: just
1788 report the signal to GDB, and pray for the best. */
1790 lwp
->collecting_fast_tracepoint
= 0;
1793 && (status
.adjusted_insn_addr
<= lwp
->stop_pc
1794 && lwp
->stop_pc
< status
.adjusted_insn_addr_end
))
1797 struct regcache
*regcache
;
1799 /* The si_addr on a few signals references the address
1800 of the faulting instruction. Adjust that as
1802 if ((WSTOPSIG (*wstat
) == SIGILL
1803 || WSTOPSIG (*wstat
) == SIGFPE
1804 || WSTOPSIG (*wstat
) == SIGBUS
1805 || WSTOPSIG (*wstat
) == SIGSEGV
)
1806 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
1807 (PTRACE_TYPE_ARG3
) 0, &info
) == 0
1808 /* Final check just to make sure we don't clobber
1809 the siginfo of non-kernel-sent signals. */
1810 && (uintptr_t) info
.si_addr
== lwp
->stop_pc
)
1812 info
.si_addr
= (void *) (uintptr_t) status
.tpoint_addr
;
1813 ptrace (PTRACE_SETSIGINFO
, lwpid_of (current_thread
),
1814 (PTRACE_TYPE_ARG3
) 0, &info
);
1817 regcache
= get_thread_regcache (current_thread
, 1);
1818 (*the_low_target
.set_pc
) (regcache
, status
.tpoint_addr
);
1819 lwp
->stop_pc
= status
.tpoint_addr
;
1821 /* Cancel any fast tracepoint lock this thread was
1823 force_unlock_trace_buffer ();
1826 if (lwp
->exit_jump_pad_bkpt
!= NULL
)
1829 debug_printf ("Cancelling fast exit-jump-pad: removing bkpt. "
1830 "stopping all threads momentarily.\n");
1832 stop_all_lwps (1, lwp
);
1834 delete_breakpoint (lwp
->exit_jump_pad_bkpt
);
1835 lwp
->exit_jump_pad_bkpt
= NULL
;
1837 unstop_all_lwps (1, lwp
);
1839 gdb_assert (lwp
->suspended
>= 0);
1845 debug_printf ("Checking whether LWP %ld needs to move out of the "
1847 lwpid_of (current_thread
));
1849 current_thread
= saved_thread
;
1853 /* Enqueue one signal in the "signals to report later when out of the
1857 enqueue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1859 struct pending_signals
*p_sig
;
1860 struct thread_info
*thread
= get_lwp_thread (lwp
);
1863 debug_printf ("Deferring signal %d for LWP %ld.\n",
1864 WSTOPSIG (*wstat
), lwpid_of (thread
));
1868 struct pending_signals
*sig
;
1870 for (sig
= lwp
->pending_signals_to_report
;
1873 debug_printf (" Already queued %d\n",
1876 debug_printf (" (no more currently queued signals)\n");
1879 /* Don't enqueue non-RT signals if they are already in the deferred
1880 queue. (SIGSTOP being the easiest signal to see ending up here
1882 if (WSTOPSIG (*wstat
) < __SIGRTMIN
)
1884 struct pending_signals
*sig
;
1886 for (sig
= lwp
->pending_signals_to_report
;
1890 if (sig
->signal
== WSTOPSIG (*wstat
))
1893 debug_printf ("Not requeuing already queued non-RT signal %d"
1902 p_sig
= xmalloc (sizeof (*p_sig
));
1903 p_sig
->prev
= lwp
->pending_signals_to_report
;
1904 p_sig
->signal
= WSTOPSIG (*wstat
);
1905 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1906 ptrace (PTRACE_GETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
1909 lwp
->pending_signals_to_report
= p_sig
;
1912 /* Dequeue one signal from the "signals to report later when out of
1913 the jump pad" list. */
1916 dequeue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1918 struct thread_info
*thread
= get_lwp_thread (lwp
);
1920 if (lwp
->pending_signals_to_report
!= NULL
)
1922 struct pending_signals
**p_sig
;
1924 p_sig
= &lwp
->pending_signals_to_report
;
1925 while ((*p_sig
)->prev
!= NULL
)
1926 p_sig
= &(*p_sig
)->prev
;
1928 *wstat
= W_STOPCODE ((*p_sig
)->signal
);
1929 if ((*p_sig
)->info
.si_signo
!= 0)
1930 ptrace (PTRACE_SETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
1936 debug_printf ("Reporting deferred signal %d for LWP %ld.\n",
1937 WSTOPSIG (*wstat
), lwpid_of (thread
));
1941 struct pending_signals
*sig
;
1943 for (sig
= lwp
->pending_signals_to_report
;
1946 debug_printf (" Still queued %d\n",
1949 debug_printf (" (no more queued signals)\n");
1958 /* Fetch the possibly triggered data watchpoint info and store it in
1961 On some archs, like x86, that use debug registers to set
1962 watchpoints, it's possible that the way to know which watched
1963 address trapped, is to check the register that is used to select
1964 which address to watch. Problem is, between setting the watchpoint
1965 and reading back which data address trapped, the user may change
1966 the set of watchpoints, and, as a consequence, GDB changes the
1967 debug registers in the inferior. To avoid reading back a stale
1968 stopped-data-address when that happens, we cache in LP the fact
1969 that a watchpoint trapped, and the corresponding data address, as
1970 soon as we see CHILD stop with a SIGTRAP. If GDB changes the debug
1971 registers meanwhile, we have the cached data we can rely on. */
1974 check_stopped_by_watchpoint (struct lwp_info
*child
)
1976 if (the_low_target
.stopped_by_watchpoint
!= NULL
)
1978 struct thread_info
*saved_thread
;
1980 saved_thread
= current_thread
;
1981 current_thread
= get_lwp_thread (child
);
1983 if (the_low_target
.stopped_by_watchpoint ())
1985 child
->stop_reason
= TARGET_STOPPED_BY_WATCHPOINT
;
1987 if (the_low_target
.stopped_data_address
!= NULL
)
1988 child
->stopped_data_address
1989 = the_low_target
.stopped_data_address ();
1991 child
->stopped_data_address
= 0;
1994 current_thread
= saved_thread
;
1997 return child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2000 /* Return the ptrace options that we want to try to enable. */
2003 linux_low_ptrace_options (int attached
)
2008 options
|= PTRACE_O_EXITKILL
;
2010 if (report_fork_events
)
2011 options
|= PTRACE_O_TRACEFORK
;
2016 /* Do low-level handling of the event, and check if we should go on
2017 and pass it to caller code. Return the affected lwp if we are, or
2020 static struct lwp_info
*
2021 linux_low_filter_event (int lwpid
, int wstat
)
2023 struct lwp_info
*child
;
2024 struct thread_info
*thread
;
2025 int have_stop_pc
= 0;
2027 child
= find_lwp_pid (pid_to_ptid (lwpid
));
2029 /* If we didn't find a process, one of two things presumably happened:
2030 - A process we started and then detached from has exited. Ignore it.
2031 - A process we are controlling has forked and the new child's stop
2032 was reported to us by the kernel. Save its PID. */
2033 if (child
== NULL
&& WIFSTOPPED (wstat
))
2035 add_to_pid_list (&stopped_pids
, lwpid
, wstat
);
2038 else if (child
== NULL
)
2041 thread
= get_lwp_thread (child
);
2045 child
->last_status
= wstat
;
2047 /* Check if the thread has exited. */
2048 if ((WIFEXITED (wstat
) || WIFSIGNALED (wstat
)))
2051 debug_printf ("LLFE: %d exited.\n", lwpid
);
2052 if (num_lwps (pid_of (thread
)) > 1)
2055 /* If there is at least one more LWP, then the exit signal was
2056 not the end of the debugged application and should be
2063 /* This was the last lwp in the process. Since events are
2064 serialized to GDB core, and we can't report this one
2065 right now, but GDB core and the other target layers will
2066 want to be notified about the exit code/signal, leave the
2067 status pending for the next time we're able to report
2069 mark_lwp_dead (child
, wstat
);
2074 gdb_assert (WIFSTOPPED (wstat
));
2076 if (WIFSTOPPED (wstat
))
2078 struct process_info
*proc
;
2080 /* Architecture-specific setup after inferior is running. This
2081 needs to happen after we have attached to the inferior and it
2082 is stopped for the first time, but before we access any
2083 inferior registers. */
2084 proc
= find_process_pid (pid_of (thread
));
2085 if (proc
->priv
->new_inferior
)
2087 struct thread_info
*saved_thread
;
2089 saved_thread
= current_thread
;
2090 current_thread
= thread
;
2092 the_low_target
.arch_setup ();
2094 current_thread
= saved_thread
;
2096 proc
->priv
->new_inferior
= 0;
2100 if (WIFSTOPPED (wstat
) && child
->must_set_ptrace_flags
)
2102 struct process_info
*proc
= find_process_pid (pid_of (thread
));
2103 int options
= linux_low_ptrace_options (proc
->attached
);
2105 linux_enable_event_reporting (lwpid
, options
);
2106 child
->must_set_ptrace_flags
= 0;
2109 /* Be careful to not overwrite stop_pc until
2110 check_stopped_by_breakpoint is called. */
2111 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGTRAP
2112 && linux_is_extended_waitstatus (wstat
))
2114 child
->stop_pc
= get_pc (child
);
2115 if (handle_extended_wait (child
, wstat
))
2117 /* The event has been handled, so just return without
2123 /* Check first whether this was a SW/HW breakpoint before checking
2124 watchpoints, because at least s390 can't tell the data address of
2125 hardware watchpoint hits, and returns stopped-by-watchpoint as
2126 long as there's a watchpoint set. */
2127 if (WIFSTOPPED (wstat
) && linux_wstatus_maybe_breakpoint (wstat
))
2129 if (check_stopped_by_breakpoint (child
))
2133 /* Note that TRAP_HWBKPT can indicate either a hardware breakpoint
2134 or hardware watchpoint. Check which is which if we got
2135 TARGET_STOPPED_BY_HW_BREAKPOINT. */
2136 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGTRAP
2137 && (child
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
2138 || child
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
2139 check_stopped_by_watchpoint (child
);
2142 child
->stop_pc
= get_pc (child
);
2144 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGSTOP
2145 && child
->stop_expected
)
2148 debug_printf ("Expected stop.\n");
2149 child
->stop_expected
= 0;
2151 if (thread
->last_resume_kind
== resume_stop
)
2153 /* We want to report the stop to the core. Treat the
2154 SIGSTOP as a normal event. */
2156 debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n",
2157 target_pid_to_str (ptid_of (thread
)));
2159 else if (stopping_threads
!= NOT_STOPPING_THREADS
)
2161 /* Stopping threads. We don't want this SIGSTOP to end up
2164 debug_printf ("LLW: SIGSTOP caught for %s "
2165 "while stopping threads.\n",
2166 target_pid_to_str (ptid_of (thread
)));
2171 /* This is a delayed SIGSTOP. Filter out the event. */
2173 debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
2174 child
->stepping
? "step" : "continue",
2175 target_pid_to_str (ptid_of (thread
)));
2177 linux_resume_one_lwp (child
, child
->stepping
, 0, NULL
);
2182 child
->status_pending_p
= 1;
2183 child
->status_pending
= wstat
;
2187 /* Resume LWPs that are currently stopped without any pending status
2188 to report, but are resumed from the core's perspective. */
2191 resume_stopped_resumed_lwps (struct inferior_list_entry
*entry
)
2193 struct thread_info
*thread
= (struct thread_info
*) entry
;
2194 struct lwp_info
*lp
= get_thread_lwp (thread
);
2197 && !lp
->status_pending_p
2198 && thread
->last_resume_kind
!= resume_stop
2199 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
)
2201 int step
= thread
->last_resume_kind
== resume_step
;
2204 debug_printf ("RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
2205 target_pid_to_str (ptid_of (thread
)),
2206 paddress (lp
->stop_pc
),
2209 linux_resume_one_lwp (lp
, step
, GDB_SIGNAL_0
, NULL
);
2213 /* Wait for an event from child(ren) WAIT_PTID, and return any that
2214 match FILTER_PTID (leaving others pending). The PTIDs can be:
2215 minus_one_ptid, to specify any child; a pid PTID, specifying all
2216 lwps of a thread group; or a PTID representing a single lwp. Store
2217 the stop status through the status pointer WSTAT. OPTIONS is
2218 passed to the waitpid call. Return 0 if no event was found and
2219 OPTIONS contains WNOHANG. Return -1 if no unwaited-for children
2220 was found. Return the PID of the stopped child otherwise. */
2223 linux_wait_for_event_filtered (ptid_t wait_ptid
, ptid_t filter_ptid
,
2224 int *wstatp
, int options
)
2226 struct thread_info
*event_thread
;
2227 struct lwp_info
*event_child
, *requested_child
;
2228 sigset_t block_mask
, prev_mask
;
2231 /* N.B. event_thread points to the thread_info struct that contains
2232 event_child. Keep them in sync. */
2233 event_thread
= NULL
;
2235 requested_child
= NULL
;
2237 /* Check for a lwp with a pending status. */
2239 if (ptid_equal (filter_ptid
, minus_one_ptid
) || ptid_is_pid (filter_ptid
))
2241 event_thread
= (struct thread_info
*)
2242 find_inferior (&all_threads
, status_pending_p_callback
, &filter_ptid
);
2243 if (event_thread
!= NULL
)
2244 event_child
= get_thread_lwp (event_thread
);
2245 if (debug_threads
&& event_thread
)
2246 debug_printf ("Got a pending child %ld\n", lwpid_of (event_thread
));
2248 else if (!ptid_equal (filter_ptid
, null_ptid
))
2250 requested_child
= find_lwp_pid (filter_ptid
);
2252 if (stopping_threads
== NOT_STOPPING_THREADS
2253 && requested_child
->status_pending_p
2254 && requested_child
->collecting_fast_tracepoint
)
2256 enqueue_one_deferred_signal (requested_child
,
2257 &requested_child
->status_pending
);
2258 requested_child
->status_pending_p
= 0;
2259 requested_child
->status_pending
= 0;
2260 linux_resume_one_lwp (requested_child
, 0, 0, NULL
);
2263 if (requested_child
->suspended
2264 && requested_child
->status_pending_p
)
2266 internal_error (__FILE__
, __LINE__
,
2267 "requesting an event out of a"
2268 " suspended child?");
2271 if (requested_child
->status_pending_p
)
2273 event_child
= requested_child
;
2274 event_thread
= get_lwp_thread (event_child
);
2278 if (event_child
!= NULL
)
2281 debug_printf ("Got an event from pending child %ld (%04x)\n",
2282 lwpid_of (event_thread
), event_child
->status_pending
);
2283 *wstatp
= event_child
->status_pending
;
2284 event_child
->status_pending_p
= 0;
2285 event_child
->status_pending
= 0;
2286 current_thread
= event_thread
;
2287 return lwpid_of (event_thread
);
2290 /* But if we don't find a pending event, we'll have to wait.
2292 We only enter this loop if no process has a pending wait status.
2293 Thus any action taken in response to a wait status inside this
2294 loop is responding as soon as we detect the status, not after any
2297 /* Make sure SIGCHLD is blocked until the sigsuspend below. Block
2298 all signals while here. */
2299 sigfillset (&block_mask
);
2300 sigprocmask (SIG_BLOCK
, &block_mask
, &prev_mask
);
2302 /* Always pull all events out of the kernel. We'll randomly select
2303 an event LWP out of all that have events, to prevent
2305 while (event_child
== NULL
)
2309 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
2312 - If the thread group leader exits while other threads in the
2313 thread group still exist, waitpid(TGID, ...) hangs. That
2314 waitpid won't return an exit status until the other threads
2315 in the group are reaped.
2317 - When a non-leader thread execs, that thread just vanishes
2318 without reporting an exit (so we'd hang if we waited for it
2319 explicitly in that case). The exec event is reported to
2320 the TGID pid (although we don't currently enable exec
2323 ret
= my_waitpid (-1, wstatp
, options
| WNOHANG
);
2326 debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n",
2327 ret
, errno
? strerror (errno
) : "ERRNO-OK");
2333 debug_printf ("LLW: waitpid %ld received %s\n",
2334 (long) ret
, status_to_str (*wstatp
));
2337 /* Filter all events. IOW, leave all events pending. We'll
2338 randomly select an event LWP out of all that have events
2340 linux_low_filter_event (ret
, *wstatp
);
2341 /* Retry until nothing comes out of waitpid. A single
2342 SIGCHLD can indicate more than one child stopped. */
2346 /* Now that we've pulled all events out of the kernel, resume
2347 LWPs that don't have an interesting event to report. */
2348 if (stopping_threads
== NOT_STOPPING_THREADS
)
2349 for_each_inferior (&all_threads
, resume_stopped_resumed_lwps
);
2351 /* ... and find an LWP with a status to report to the core, if
2353 event_thread
= (struct thread_info
*)
2354 find_inferior (&all_threads
, status_pending_p_callback
, &filter_ptid
);
2355 if (event_thread
!= NULL
)
2357 event_child
= get_thread_lwp (event_thread
);
2358 *wstatp
= event_child
->status_pending
;
2359 event_child
->status_pending_p
= 0;
2360 event_child
->status_pending
= 0;
2364 /* Check for zombie thread group leaders. Those can't be reaped
2365 until all other threads in the thread group are. */
2366 check_zombie_leaders ();
2368 /* If there are no resumed children left in the set of LWPs we
2369 want to wait for, bail. We can't just block in
2370 waitpid/sigsuspend, because lwps might have been left stopped
2371 in trace-stop state, and we'd be stuck forever waiting for
2372 their status to change (which would only happen if we resumed
2373 them). Even if WNOHANG is set, this return code is preferred
2374 over 0 (below), as it is more detailed. */
2375 if ((find_inferior (&all_threads
,
2376 not_stopped_callback
,
2377 &wait_ptid
) == NULL
))
2380 debug_printf ("LLW: exit (no unwaited-for LWP)\n");
2381 sigprocmask (SIG_SETMASK
, &prev_mask
, NULL
);
2385 /* No interesting event to report to the caller. */
2386 if ((options
& WNOHANG
))
2389 debug_printf ("WNOHANG set, no event found\n");
2391 sigprocmask (SIG_SETMASK
, &prev_mask
, NULL
);
2395 /* Block until we get an event reported with SIGCHLD. */
2397 debug_printf ("sigsuspend'ing\n");
2399 sigsuspend (&prev_mask
);
2400 sigprocmask (SIG_SETMASK
, &prev_mask
, NULL
);
2404 sigprocmask (SIG_SETMASK
, &prev_mask
, NULL
);
2406 current_thread
= event_thread
;
2408 /* Check for thread exit. */
2409 if (! WIFSTOPPED (*wstatp
))
2411 gdb_assert (last_thread_of_process_p (pid_of (event_thread
)));
2414 debug_printf ("LWP %d is the last lwp of process. "
2415 "Process %ld exiting.\n",
2416 pid_of (event_thread
), lwpid_of (event_thread
));
2417 return lwpid_of (event_thread
);
2420 return lwpid_of (event_thread
);
2423 /* Wait for an event from child(ren) PTID. PTIDs can be:
2424 minus_one_ptid, to specify any child; a pid PTID, specifying all
2425 lwps of a thread group; or a PTID representing a single lwp. Store
2426 the stop status through the status pointer WSTAT. OPTIONS is
2427 passed to the waitpid call. Return 0 if no event was found and
2428 OPTIONS contains WNOHANG. Return -1 if no unwaited-for children
2429 was found. Return the PID of the stopped child otherwise. */
2432 linux_wait_for_event (ptid_t ptid
, int *wstatp
, int options
)
2434 return linux_wait_for_event_filtered (ptid
, ptid
, wstatp
, options
);
2437 /* Count the LWP's that have had events. */
2440 count_events_callback (struct inferior_list_entry
*entry
, void *data
)
2442 struct thread_info
*thread
= (struct thread_info
*) entry
;
2443 struct lwp_info
*lp
= get_thread_lwp (thread
);
2446 gdb_assert (count
!= NULL
);
2448 /* Count only resumed LWPs that have an event pending. */
2449 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2450 && lp
->status_pending_p
)
2456 /* Select the LWP (if any) that is currently being single-stepped. */
2459 select_singlestep_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
2461 struct thread_info
*thread
= (struct thread_info
*) entry
;
2462 struct lwp_info
*lp
= get_thread_lwp (thread
);
2464 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2465 && thread
->last_resume_kind
== resume_step
2466 && lp
->status_pending_p
)
2472 /* Select the Nth LWP that has had an event. */
2475 select_event_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
2477 struct thread_info
*thread
= (struct thread_info
*) entry
;
2478 struct lwp_info
*lp
= get_thread_lwp (thread
);
2479 int *selector
= data
;
2481 gdb_assert (selector
!= NULL
);
2483 /* Select only resumed LWPs that have an event pending. */
2484 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2485 && lp
->status_pending_p
)
2486 if ((*selector
)-- == 0)
2492 /* Select one LWP out of those that have events pending. */
2495 select_event_lwp (struct lwp_info
**orig_lp
)
2498 int random_selector
;
2499 struct thread_info
*event_thread
= NULL
;
2501 /* In all-stop, give preference to the LWP that is being
2502 single-stepped. There will be at most one, and it's the LWP that
2503 the core is most interested in. If we didn't do this, then we'd
2504 have to handle pending step SIGTRAPs somehow in case the core
2505 later continues the previously-stepped thread, otherwise we'd
2506 report the pending SIGTRAP, and the core, not having stepped the
2507 thread, wouldn't understand what the trap was for, and therefore
2508 would report it to the user as a random signal. */
2512 = (struct thread_info
*) find_inferior (&all_threads
,
2513 select_singlestep_lwp_callback
,
2515 if (event_thread
!= NULL
)
2518 debug_printf ("SEL: Select single-step %s\n",
2519 target_pid_to_str (ptid_of (event_thread
)));
2522 if (event_thread
== NULL
)
2524 /* No single-stepping LWP. Select one at random, out of those
2525 which have had events. */
2527 /* First see how many events we have. */
2528 find_inferior (&all_threads
, count_events_callback
, &num_events
);
2529 gdb_assert (num_events
> 0);
2531 /* Now randomly pick a LWP out of those that have had
2533 random_selector
= (int)
2534 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2536 if (debug_threads
&& num_events
> 1)
2537 debug_printf ("SEL: Found %d SIGTRAP events, selecting #%d\n",
2538 num_events
, random_selector
);
2541 = (struct thread_info
*) find_inferior (&all_threads
,
2542 select_event_lwp_callback
,
2546 if (event_thread
!= NULL
)
2548 struct lwp_info
*event_lp
= get_thread_lwp (event_thread
);
2550 /* Switch the event LWP. */
2551 *orig_lp
= event_lp
;
2555 /* Decrement the suspend count of an LWP. */
2558 unsuspend_one_lwp (struct inferior_list_entry
*entry
, void *except
)
2560 struct thread_info
*thread
= (struct thread_info
*) entry
;
2561 struct lwp_info
*lwp
= get_thread_lwp (thread
);
2563 /* Ignore EXCEPT. */
2569 gdb_assert (lwp
->suspended
>= 0);
2573 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
2577 unsuspend_all_lwps (struct lwp_info
*except
)
2579 find_inferior (&all_threads
, unsuspend_one_lwp
, except
);
2582 static void move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
);
2583 static int stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
,
2585 static int lwp_running (struct inferior_list_entry
*entry
, void *data
);
2586 static ptid_t
linux_wait_1 (ptid_t ptid
,
2587 struct target_waitstatus
*ourstatus
,
2588 int target_options
);
2590 /* Stabilize threads (move out of jump pads).
2592 If a thread is midway collecting a fast tracepoint, we need to
2593 finish the collection and move it out of the jump pad before
2594 reporting the signal.
2596 This avoids recursion while collecting (when a signal arrives
2597 midway, and the signal handler itself collects), which would trash
2598 the trace buffer. In case the user set a breakpoint in a signal
2599 handler, this avoids the backtrace showing the jump pad, etc..
2600 Most importantly, there are certain things we can't do safely if
2601 threads are stopped in a jump pad (or in its callee's). For
2604 - starting a new trace run. A thread still collecting the
2605 previous run, could trash the trace buffer when resumed. The trace
2606 buffer control structures would have been reset but the thread had
2607 no way to tell. The thread could even midway memcpy'ing to the
2608 buffer, which would mean that when resumed, it would clobber the
2609 trace buffer that had been set for a new run.
2611 - we can't rewrite/reuse the jump pads for new tracepoints
2612 safely. Say you do tstart while a thread is stopped midway while
2613 collecting. When the thread is later resumed, it finishes the
2614 collection, and returns to the jump pad, to execute the original
2615 instruction that was under the tracepoint jump at the time the
2616 older run had been started. If the jump pad had been rewritten
2617 since for something else in the new run, the thread would now
2618 execute the wrong / random instructions. */
2621 linux_stabilize_threads (void)
2623 struct thread_info
*saved_thread
;
2624 struct thread_info
*thread_stuck
;
2627 = (struct thread_info
*) find_inferior (&all_threads
,
2628 stuck_in_jump_pad_callback
,
2630 if (thread_stuck
!= NULL
)
2633 debug_printf ("can't stabilize, LWP %ld is stuck in jump pad\n",
2634 lwpid_of (thread_stuck
));
2638 saved_thread
= current_thread
;
2640 stabilizing_threads
= 1;
2643 for_each_inferior (&all_threads
, move_out_of_jump_pad_callback
);
2645 /* Loop until all are stopped out of the jump pads. */
2646 while (find_inferior (&all_threads
, lwp_running
, NULL
) != NULL
)
2648 struct target_waitstatus ourstatus
;
2649 struct lwp_info
*lwp
;
2652 /* Note that we go through the full wait even loop. While
2653 moving threads out of jump pad, we need to be able to step
2654 over internal breakpoints and such. */
2655 linux_wait_1 (minus_one_ptid
, &ourstatus
, 0);
2657 if (ourstatus
.kind
== TARGET_WAITKIND_STOPPED
)
2659 lwp
= get_thread_lwp (current_thread
);
2664 if (ourstatus
.value
.sig
!= GDB_SIGNAL_0
2665 || current_thread
->last_resume_kind
== resume_stop
)
2667 wstat
= W_STOPCODE (gdb_signal_to_host (ourstatus
.value
.sig
));
2668 enqueue_one_deferred_signal (lwp
, &wstat
);
2673 find_inferior (&all_threads
, unsuspend_one_lwp
, NULL
);
2675 stabilizing_threads
= 0;
2677 current_thread
= saved_thread
;
2682 = (struct thread_info
*) find_inferior (&all_threads
,
2683 stuck_in_jump_pad_callback
,
2685 if (thread_stuck
!= NULL
)
2686 debug_printf ("couldn't stabilize, LWP %ld got stuck in jump pad\n",
2687 lwpid_of (thread_stuck
));
2691 static void async_file_mark (void);
2693 /* Convenience function that is called when the kernel reports an
2694 event that is not passed out to GDB. */
2697 ignore_event (struct target_waitstatus
*ourstatus
)
2699 /* If we got an event, there may still be others, as a single
2700 SIGCHLD can indicate more than one child stopped. This forces
2701 another target_wait call. */
2704 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2708 /* Return non-zero if WAITSTATUS reflects an extended linux
2709 event. Otherwise, return zero. */
2712 extended_event_reported (const struct target_waitstatus
*waitstatus
)
2714 if (waitstatus
== NULL
)
2717 return (waitstatus
->kind
== TARGET_WAITKIND_FORKED
);
2720 /* Wait for process, returns status. */
2723 linux_wait_1 (ptid_t ptid
,
2724 struct target_waitstatus
*ourstatus
, int target_options
)
2727 struct lwp_info
*event_child
;
2730 int step_over_finished
;
2731 int bp_explains_trap
;
2732 int maybe_internal_trap
;
2740 debug_printf ("linux_wait_1: [%s]\n", target_pid_to_str (ptid
));
2743 /* Translate generic target options into linux options. */
2745 if (target_options
& TARGET_WNOHANG
)
2748 bp_explains_trap
= 0;
2751 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2753 if (ptid_equal (step_over_bkpt
, null_ptid
))
2754 pid
= linux_wait_for_event (ptid
, &w
, options
);
2758 debug_printf ("step_over_bkpt set [%s], doing a blocking wait\n",
2759 target_pid_to_str (step_over_bkpt
));
2760 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
2765 gdb_assert (target_options
& TARGET_WNOHANG
);
2769 debug_printf ("linux_wait_1 ret = null_ptid, "
2770 "TARGET_WAITKIND_IGNORE\n");
2774 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2781 debug_printf ("linux_wait_1 ret = null_ptid, "
2782 "TARGET_WAITKIND_NO_RESUMED\n");
2786 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
2790 event_child
= get_thread_lwp (current_thread
);
2792 /* linux_wait_for_event only returns an exit status for the last
2793 child of a process. Report it. */
2794 if (WIFEXITED (w
) || WIFSIGNALED (w
))
2798 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
2799 ourstatus
->value
.integer
= WEXITSTATUS (w
);
2803 debug_printf ("linux_wait_1 ret = %s, exited with "
2805 target_pid_to_str (ptid_of (current_thread
)),
2812 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
2813 ourstatus
->value
.sig
= gdb_signal_from_host (WTERMSIG (w
));
2817 debug_printf ("linux_wait_1 ret = %s, terminated with "
2819 target_pid_to_str (ptid_of (current_thread
)),
2825 return ptid_of (current_thread
);
2828 /* If step-over executes a breakpoint instruction, it means a
2829 gdb/gdbserver breakpoint had been planted on top of a permanent
2830 breakpoint. The PC has been adjusted by
2831 check_stopped_by_breakpoint to point at the breakpoint address.
2832 Advance the PC manually past the breakpoint, otherwise the
2833 program would keep trapping the permanent breakpoint forever. */
2834 if (!ptid_equal (step_over_bkpt
, null_ptid
)
2835 && event_child
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
)
2837 unsigned int increment_pc
= the_low_target
.breakpoint_len
;
2841 debug_printf ("step-over for %s executed software breakpoint\n",
2842 target_pid_to_str (ptid_of (current_thread
)));
2845 if (increment_pc
!= 0)
2847 struct regcache
*regcache
2848 = get_thread_regcache (current_thread
, 1);
2850 event_child
->stop_pc
+= increment_pc
;
2851 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
2853 if (!(*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))
2854 event_child
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2858 /* If this event was not handled before, and is not a SIGTRAP, we
2859 report it. SIGILL and SIGSEGV are also treated as traps in case
2860 a breakpoint is inserted at the current PC. If this target does
2861 not support internal breakpoints at all, we also report the
2862 SIGTRAP without further processing; it's of no concern to us. */
2864 = (supports_breakpoints ()
2865 && (WSTOPSIG (w
) == SIGTRAP
2866 || ((WSTOPSIG (w
) == SIGILL
2867 || WSTOPSIG (w
) == SIGSEGV
)
2868 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
2870 if (maybe_internal_trap
)
2872 /* Handle anything that requires bookkeeping before deciding to
2873 report the event or continue waiting. */
2875 /* First check if we can explain the SIGTRAP with an internal
2876 breakpoint, or if we should possibly report the event to GDB.
2877 Do this before anything that may remove or insert a
2879 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
2881 /* We have a SIGTRAP, possibly a step-over dance has just
2882 finished. If so, tweak the state machine accordingly,
2883 reinsert breakpoints and delete any reinsert (software
2884 single-step) breakpoints. */
2885 step_over_finished
= finish_step_over (event_child
);
2887 /* Now invoke the callbacks of any internal breakpoints there. */
2888 check_breakpoints (event_child
->stop_pc
);
2890 /* Handle tracepoint data collecting. This may overflow the
2891 trace buffer, and cause a tracing stop, removing
2893 trace_event
= handle_tracepoints (event_child
);
2895 if (bp_explains_trap
)
2897 /* If we stepped or ran into an internal breakpoint, we've
2898 already handled it. So next time we resume (from this
2899 PC), we should step over it. */
2901 debug_printf ("Hit a gdbserver breakpoint.\n");
2903 if (breakpoint_here (event_child
->stop_pc
))
2904 event_child
->need_step_over
= 1;
2909 /* We have some other signal, possibly a step-over dance was in
2910 progress, and it should be cancelled too. */
2911 step_over_finished
= finish_step_over (event_child
);
2914 /* We have all the data we need. Either report the event to GDB, or
2915 resume threads and keep waiting for more. */
2917 /* If we're collecting a fast tracepoint, finish the collection and
2918 move out of the jump pad before delivering a signal. See
2919 linux_stabilize_threads. */
2922 && WSTOPSIG (w
) != SIGTRAP
2923 && supports_fast_tracepoints ()
2924 && agent_loaded_p ())
2927 debug_printf ("Got signal %d for LWP %ld. Check if we need "
2928 "to defer or adjust it.\n",
2929 WSTOPSIG (w
), lwpid_of (current_thread
));
2931 /* Allow debugging the jump pad itself. */
2932 if (current_thread
->last_resume_kind
!= resume_step
2933 && maybe_move_out_of_jump_pad (event_child
, &w
))
2935 enqueue_one_deferred_signal (event_child
, &w
);
2938 debug_printf ("Signal %d for LWP %ld deferred (in jump pad)\n",
2939 WSTOPSIG (w
), lwpid_of (current_thread
));
2941 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
2943 return ignore_event (ourstatus
);
2947 if (event_child
->collecting_fast_tracepoint
)
2950 debug_printf ("LWP %ld was trying to move out of the jump pad (%d). "
2951 "Check if we're already there.\n",
2952 lwpid_of (current_thread
),
2953 event_child
->collecting_fast_tracepoint
);
2957 event_child
->collecting_fast_tracepoint
2958 = linux_fast_tracepoint_collecting (event_child
, NULL
);
2960 if (event_child
->collecting_fast_tracepoint
!= 1)
2962 /* No longer need this breakpoint. */
2963 if (event_child
->exit_jump_pad_bkpt
!= NULL
)
2966 debug_printf ("No longer need exit-jump-pad bkpt; removing it."
2967 "stopping all threads momentarily.\n");
2969 /* Other running threads could hit this breakpoint.
2970 We don't handle moribund locations like GDB does,
2971 instead we always pause all threads when removing
2972 breakpoints, so that any step-over or
2973 decr_pc_after_break adjustment is always taken
2974 care of while the breakpoint is still
2976 stop_all_lwps (1, event_child
);
2978 delete_breakpoint (event_child
->exit_jump_pad_bkpt
);
2979 event_child
->exit_jump_pad_bkpt
= NULL
;
2981 unstop_all_lwps (1, event_child
);
2983 gdb_assert (event_child
->suspended
>= 0);
2987 if (event_child
->collecting_fast_tracepoint
== 0)
2990 debug_printf ("fast tracepoint finished "
2991 "collecting successfully.\n");
2993 /* We may have a deferred signal to report. */
2994 if (dequeue_one_deferred_signal (event_child
, &w
))
2997 debug_printf ("dequeued one signal.\n");
3002 debug_printf ("no deferred signals.\n");
3004 if (stabilizing_threads
)
3006 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
3007 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3011 debug_printf ("linux_wait_1 ret = %s, stopped "
3012 "while stabilizing threads\n",
3013 target_pid_to_str (ptid_of (current_thread
)));
3017 return ptid_of (current_thread
);
3023 /* Check whether GDB would be interested in this event. */
3025 /* If GDB is not interested in this signal, don't stop other
3026 threads, and don't report it to GDB. Just resume the inferior
3027 right away. We do this for threading-related signals as well as
3028 any that GDB specifically requested we ignore. But never ignore
3029 SIGSTOP if we sent it ourselves, and do not ignore signals when
3030 stepping - they may require special handling to skip the signal
3031 handler. Also never ignore signals that could be caused by a
3033 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
3036 && current_thread
->last_resume_kind
!= resume_step
3038 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
3039 (current_process ()->priv
->thread_db
!= NULL
3040 && (WSTOPSIG (w
) == __SIGRTMIN
3041 || WSTOPSIG (w
) == __SIGRTMIN
+ 1))
3044 (pass_signals
[gdb_signal_from_host (WSTOPSIG (w
))]
3045 && !(WSTOPSIG (w
) == SIGSTOP
3046 && current_thread
->last_resume_kind
== resume_stop
)
3047 && !linux_wstatus_maybe_breakpoint (w
))))
3049 siginfo_t info
, *info_p
;
3052 debug_printf ("Ignored signal %d for LWP %ld.\n",
3053 WSTOPSIG (w
), lwpid_of (current_thread
));
3055 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
3056 (PTRACE_TYPE_ARG3
) 0, &info
) == 0)
3060 linux_resume_one_lwp (event_child
, event_child
->stepping
,
3061 WSTOPSIG (w
), info_p
);
3062 return ignore_event (ourstatus
);
3065 /* Note that all addresses are always "out of the step range" when
3066 there's no range to begin with. */
3067 in_step_range
= lwp_in_step_range (event_child
);
3069 /* If GDB wanted this thread to single step, and the thread is out
3070 of the step range, we always want to report the SIGTRAP, and let
3071 GDB handle it. Watchpoints should always be reported. So should
3072 signals we can't explain. A SIGTRAP we can't explain could be a
3073 GDB breakpoint --- we may or not support Z0 breakpoints. If we
3074 do, we're be able to handle GDB breakpoints on top of internal
3075 breakpoints, by handling the internal breakpoint and still
3076 reporting the event to GDB. If we don't, we're out of luck, GDB
3077 won't see the breakpoint hit. */
3078 report_to_gdb
= (!maybe_internal_trap
3079 || (current_thread
->last_resume_kind
== resume_step
3081 || event_child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
3082 || (!step_over_finished
&& !in_step_range
3083 && !bp_explains_trap
&& !trace_event
)
3084 || (gdb_breakpoint_here (event_child
->stop_pc
)
3085 && gdb_condition_true_at_breakpoint (event_child
->stop_pc
)
3086 && gdb_no_commands_at_breakpoint (event_child
->stop_pc
))
3087 || extended_event_reported (&event_child
->waitstatus
));
3089 run_breakpoint_commands (event_child
->stop_pc
);
3091 /* We found no reason GDB would want us to stop. We either hit one
3092 of our own breakpoints, or finished an internal step GDB
3093 shouldn't know about. */
3098 if (bp_explains_trap
)
3099 debug_printf ("Hit a gdbserver breakpoint.\n");
3100 if (step_over_finished
)
3101 debug_printf ("Step-over finished.\n");
3103 debug_printf ("Tracepoint event.\n");
3104 if (lwp_in_step_range (event_child
))
3105 debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).\n",
3106 paddress (event_child
->stop_pc
),
3107 paddress (event_child
->step_range_start
),
3108 paddress (event_child
->step_range_end
));
3109 if (extended_event_reported (&event_child
->waitstatus
))
3111 char *str
= target_waitstatus_to_string (ourstatus
);
3112 debug_printf ("LWP %ld: extended event with waitstatus %s\n",
3113 lwpid_of (get_lwp_thread (event_child
)), str
);
3118 /* We're not reporting this breakpoint to GDB, so apply the
3119 decr_pc_after_break adjustment to the inferior's regcache
3122 if (the_low_target
.set_pc
!= NULL
)
3124 struct regcache
*regcache
3125 = get_thread_regcache (current_thread
, 1);
3126 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
3129 /* We may have finished stepping over a breakpoint. If so,
3130 we've stopped and suspended all LWPs momentarily except the
3131 stepping one. This is where we resume them all again. We're
3132 going to keep waiting, so use proceed, which handles stepping
3133 over the next breakpoint. */
3135 debug_printf ("proceeding all threads.\n");
3137 if (step_over_finished
)
3138 unsuspend_all_lwps (event_child
);
3140 proceed_all_lwps ();
3141 return ignore_event (ourstatus
);
3146 if (current_thread
->last_resume_kind
== resume_step
)
3148 if (event_child
->step_range_start
== event_child
->step_range_end
)
3149 debug_printf ("GDB wanted to single-step, reporting event.\n");
3150 else if (!lwp_in_step_range (event_child
))
3151 debug_printf ("Out of step range, reporting event.\n");
3153 if (event_child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
3154 debug_printf ("Stopped by watchpoint.\n");
3155 else if (gdb_breakpoint_here (event_child
->stop_pc
))
3156 debug_printf ("Stopped by GDB breakpoint.\n");
3158 debug_printf ("Hit a non-gdbserver trap event.\n");
3161 /* Alright, we're going to report a stop. */
3163 if (!stabilizing_threads
)
3165 /* In all-stop, stop all threads. */
3167 stop_all_lwps (0, NULL
);
3169 /* If we're not waiting for a specific LWP, choose an event LWP
3170 from among those that have had events. Giving equal priority
3171 to all LWPs that have had events helps prevent
3173 if (ptid_equal (ptid
, minus_one_ptid
))
3175 event_child
->status_pending_p
= 1;
3176 event_child
->status_pending
= w
;
3178 select_event_lwp (&event_child
);
3180 /* current_thread and event_child must stay in sync. */
3181 current_thread
= get_lwp_thread (event_child
);
3183 event_child
->status_pending_p
= 0;
3184 w
= event_child
->status_pending
;
3187 if (step_over_finished
)
3191 /* If we were doing a step-over, all other threads but
3192 the stepping one had been paused in start_step_over,
3193 with their suspend counts incremented. We don't want
3194 to do a full unstop/unpause, because we're in
3195 all-stop mode (so we want threads stopped), but we
3196 still need to unsuspend the other threads, to
3197 decrement their `suspended' count back. */
3198 unsuspend_all_lwps (event_child
);
3202 /* If we just finished a step-over, then all threads had
3203 been momentarily paused. In all-stop, that's fine,
3204 we want threads stopped by now anyway. In non-stop,
3205 we need to re-resume threads that GDB wanted to be
3207 unstop_all_lwps (1, event_child
);
3211 /* Stabilize threads (move out of jump pads). */
3213 stabilize_threads ();
3217 /* If we just finished a step-over, then all threads had been
3218 momentarily paused. In all-stop, that's fine, we want
3219 threads stopped by now anyway. In non-stop, we need to
3220 re-resume threads that GDB wanted to be running. */
3221 if (step_over_finished
)
3222 unstop_all_lwps (1, event_child
);
3225 if (extended_event_reported (&event_child
->waitstatus
))
3227 /* If the reported event is a fork, vfork or exec, let GDB know. */
3228 ourstatus
->kind
= event_child
->waitstatus
.kind
;
3229 ourstatus
->value
= event_child
->waitstatus
.value
;
3231 /* Clear the event lwp's waitstatus since we handled it already. */
3232 event_child
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3235 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
3237 /* Now that we've selected our final event LWP, un-adjust its PC if
3238 it was a software breakpoint, and the client doesn't know we can
3239 adjust the breakpoint ourselves. */
3240 if (event_child
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3241 && !swbreak_feature
)
3243 int decr_pc
= the_low_target
.decr_pc_after_break
;
3247 struct regcache
*regcache
3248 = get_thread_regcache (current_thread
, 1);
3249 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
+ decr_pc
);
3253 if (current_thread
->last_resume_kind
== resume_stop
3254 && WSTOPSIG (w
) == SIGSTOP
)
3256 /* A thread that has been requested to stop by GDB with vCont;t,
3257 and it stopped cleanly, so report as SIG0. The use of
3258 SIGSTOP is an implementation detail. */
3259 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3261 else if (current_thread
->last_resume_kind
== resume_stop
3262 && WSTOPSIG (w
) != SIGSTOP
)
3264 /* A thread that has been requested to stop by GDB with vCont;t,
3265 but, it stopped for other reasons. */
3266 ourstatus
->value
.sig
= gdb_signal_from_host (WSTOPSIG (w
));
3268 else if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
)
3270 ourstatus
->value
.sig
= gdb_signal_from_host (WSTOPSIG (w
));
3273 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
3277 debug_printf ("linux_wait_1 ret = %s, %d, %d\n",
3278 target_pid_to_str (ptid_of (current_thread
)),
3279 ourstatus
->kind
, ourstatus
->value
.sig
);
3283 return ptid_of (current_thread
);
3286 /* Get rid of any pending event in the pipe. */
3288 async_file_flush (void)
3294 ret
= read (linux_event_pipe
[0], &buf
, 1);
3295 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
3298 /* Put something in the pipe, so the event loop wakes up. */
3300 async_file_mark (void)
3304 async_file_flush ();
3307 ret
= write (linux_event_pipe
[1], "+", 1);
3308 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
3310 /* Ignore EAGAIN. If the pipe is full, the event loop will already
3311 be awakened anyway. */
3315 linux_wait (ptid_t ptid
,
3316 struct target_waitstatus
*ourstatus
, int target_options
)
3320 /* Flush the async file first. */
3321 if (target_is_async_p ())
3322 async_file_flush ();
3326 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
3328 while ((target_options
& TARGET_WNOHANG
) == 0
3329 && ptid_equal (event_ptid
, null_ptid
)
3330 && ourstatus
->kind
== TARGET_WAITKIND_IGNORE
);
3332 /* If at least one stop was reported, there may be more. A single
3333 SIGCHLD can signal more than one child stop. */
3334 if (target_is_async_p ()
3335 && (target_options
& TARGET_WNOHANG
) != 0
3336 && !ptid_equal (event_ptid
, null_ptid
))
3342 /* Send a signal to an LWP. */
3345 kill_lwp (unsigned long lwpid
, int signo
)
3347 /* Use tkill, if possible, in case we are using nptl threads. If tkill
3348 fails, then we are not using nptl threads and we should be using kill. */
3352 static int tkill_failed
;
3359 ret
= syscall (__NR_tkill
, lwpid
, signo
);
3360 if (errno
!= ENOSYS
)
3367 return kill (lwpid
, signo
);
3371 linux_stop_lwp (struct lwp_info
*lwp
)
3377 send_sigstop (struct lwp_info
*lwp
)
3381 pid
= lwpid_of (get_lwp_thread (lwp
));
3383 /* If we already have a pending stop signal for this process, don't
3385 if (lwp
->stop_expected
)
3388 debug_printf ("Have pending sigstop for lwp %d\n", pid
);
3394 debug_printf ("Sending sigstop to lwp %d\n", pid
);
3396 lwp
->stop_expected
= 1;
3397 kill_lwp (pid
, SIGSTOP
);
3401 send_sigstop_callback (struct inferior_list_entry
*entry
, void *except
)
3403 struct thread_info
*thread
= (struct thread_info
*) entry
;
3404 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3406 /* Ignore EXCEPT. */
3417 /* Increment the suspend count of an LWP, and stop it, if not stopped
3420 suspend_and_send_sigstop_callback (struct inferior_list_entry
*entry
,
3423 struct thread_info
*thread
= (struct thread_info
*) entry
;
3424 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3426 /* Ignore EXCEPT. */
3432 return send_sigstop_callback (entry
, except
);
3436 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
3438 /* It's dead, really. */
3441 /* Store the exit status for later. */
3442 lwp
->status_pending_p
= 1;
3443 lwp
->status_pending
= wstat
;
3445 /* Prevent trying to stop it. */
3448 /* No further stops are expected from a dead lwp. */
3449 lwp
->stop_expected
= 0;
3452 /* Wait for all children to stop for the SIGSTOPs we just queued. */
3455 wait_for_sigstop (void)
3457 struct thread_info
*saved_thread
;
3462 saved_thread
= current_thread
;
3463 if (saved_thread
!= NULL
)
3464 saved_tid
= saved_thread
->entry
.id
;
3466 saved_tid
= null_ptid
; /* avoid bogus unused warning */
3469 debug_printf ("wait_for_sigstop: pulling events\n");
3471 /* Passing NULL_PTID as filter indicates we want all events to be
3472 left pending. Eventually this returns when there are no
3473 unwaited-for children left. */
3474 ret
= linux_wait_for_event_filtered (minus_one_ptid
, null_ptid
,
3476 gdb_assert (ret
== -1);
3478 if (saved_thread
== NULL
|| linux_thread_alive (saved_tid
))
3479 current_thread
= saved_thread
;
3483 debug_printf ("Previously current thread died.\n");
3487 /* We can't change the current inferior behind GDB's back,
3488 otherwise, a subsequent command may apply to the wrong
3490 current_thread
= NULL
;
3494 /* Set a valid thread as current. */
3495 set_desired_thread (0);
3500 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
3501 move it out, because we need to report the stop event to GDB. For
3502 example, if the user puts a breakpoint in the jump pad, it's
3503 because she wants to debug it. */
3506 stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
, void *data
)
3508 struct thread_info
*thread
= (struct thread_info
*) entry
;
3509 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3511 gdb_assert (lwp
->suspended
== 0);
3512 gdb_assert (lwp
->stopped
);
3514 /* Allow debugging the jump pad, gdb_collect, etc.. */
3515 return (supports_fast_tracepoints ()
3516 && agent_loaded_p ()
3517 && (gdb_breakpoint_here (lwp
->stop_pc
)
3518 || lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
3519 || thread
->last_resume_kind
== resume_step
)
3520 && linux_fast_tracepoint_collecting (lwp
, NULL
));
3524 move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
)
3526 struct thread_info
*thread
= (struct thread_info
*) entry
;
3527 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3530 gdb_assert (lwp
->suspended
== 0);
3531 gdb_assert (lwp
->stopped
);
3533 wstat
= lwp
->status_pending_p
? &lwp
->status_pending
: NULL
;
3535 /* Allow debugging the jump pad, gdb_collect, etc. */
3536 if (!gdb_breakpoint_here (lwp
->stop_pc
)
3537 && lwp
->stop_reason
!= TARGET_STOPPED_BY_WATCHPOINT
3538 && thread
->last_resume_kind
!= resume_step
3539 && maybe_move_out_of_jump_pad (lwp
, wstat
))
3542 debug_printf ("LWP %ld needs stabilizing (in jump pad)\n",
3547 lwp
->status_pending_p
= 0;
3548 enqueue_one_deferred_signal (lwp
, wstat
);
3551 debug_printf ("Signal %d for LWP %ld deferred "
3553 WSTOPSIG (*wstat
), lwpid_of (thread
));
3556 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
3563 lwp_running (struct inferior_list_entry
*entry
, void *data
)
3565 struct thread_info
*thread
= (struct thread_info
*) entry
;
3566 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3575 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
3576 If SUSPEND, then also increase the suspend count of every LWP,
3580 stop_all_lwps (int suspend
, struct lwp_info
*except
)
3582 /* Should not be called recursively. */
3583 gdb_assert (stopping_threads
== NOT_STOPPING_THREADS
);
3588 debug_printf ("stop_all_lwps (%s, except=%s)\n",
3589 suspend
? "stop-and-suspend" : "stop",
3591 ? target_pid_to_str (ptid_of (get_lwp_thread (except
)))
3595 stopping_threads
= (suspend
3596 ? STOPPING_AND_SUSPENDING_THREADS
3597 : STOPPING_THREADS
);
3600 find_inferior (&all_threads
, suspend_and_send_sigstop_callback
, except
);
3602 find_inferior (&all_threads
, send_sigstop_callback
, except
);
3603 wait_for_sigstop ();
3604 stopping_threads
= NOT_STOPPING_THREADS
;
3608 debug_printf ("stop_all_lwps done, setting stopping_threads "
3609 "back to !stopping\n");
3614 /* Resume execution of LWP. If STEP is nonzero, single-step it. If
3615 SIGNAL is nonzero, give it that signal. */
3618 linux_resume_one_lwp_throw (struct lwp_info
*lwp
,
3619 int step
, int signal
, siginfo_t
*info
)
3621 struct thread_info
*thread
= get_lwp_thread (lwp
);
3622 struct thread_info
*saved_thread
;
3623 int fast_tp_collecting
;
3625 if (lwp
->stopped
== 0)
3628 fast_tp_collecting
= lwp
->collecting_fast_tracepoint
;
3630 gdb_assert (!stabilizing_threads
|| fast_tp_collecting
);
3632 /* Cancel actions that rely on GDB not changing the PC (e.g., the
3633 user used the "jump" command, or "set $pc = foo"). */
3634 if (lwp
->stop_pc
!= get_pc (lwp
))
3636 /* Collecting 'while-stepping' actions doesn't make sense
3638 release_while_stepping_state_list (thread
);
3641 /* If we have pending signals or status, and a new signal, enqueue the
3642 signal. Also enqueue the signal if we are waiting to reinsert a
3643 breakpoint; it will be picked up again below. */
3645 && (lwp
->status_pending_p
3646 || lwp
->pending_signals
!= NULL
3647 || lwp
->bp_reinsert
!= 0
3648 || fast_tp_collecting
))
3650 struct pending_signals
*p_sig
;
3651 p_sig
= xmalloc (sizeof (*p_sig
));
3652 p_sig
->prev
= lwp
->pending_signals
;
3653 p_sig
->signal
= signal
;
3655 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
3657 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
3658 lwp
->pending_signals
= p_sig
;
3661 if (lwp
->status_pending_p
)
3664 debug_printf ("Not resuming lwp %ld (%s, signal %d, stop %s);"
3665 " has pending status\n",
3666 lwpid_of (thread
), step
? "step" : "continue", signal
,
3667 lwp
->stop_expected
? "expected" : "not expected");
3671 saved_thread
= current_thread
;
3672 current_thread
= thread
;
3675 debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n",
3676 lwpid_of (thread
), step
? "step" : "continue", signal
,
3677 lwp
->stop_expected
? "expected" : "not expected");
3679 /* This bit needs some thinking about. If we get a signal that
3680 we must report while a single-step reinsert is still pending,
3681 we often end up resuming the thread. It might be better to
3682 (ew) allow a stack of pending events; then we could be sure that
3683 the reinsert happened right away and not lose any signals.
3685 Making this stack would also shrink the window in which breakpoints are
3686 uninserted (see comment in linux_wait_for_lwp) but not enough for
3687 complete correctness, so it won't solve that problem. It may be
3688 worthwhile just to solve this one, however. */
3689 if (lwp
->bp_reinsert
!= 0)
3692 debug_printf (" pending reinsert at 0x%s\n",
3693 paddress (lwp
->bp_reinsert
));
3695 if (can_hardware_single_step ())
3697 if (fast_tp_collecting
== 0)
3700 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
3702 fprintf (stderr
, "BAD - reinserting and suspended(%d).\n",
3709 /* Postpone any pending signal. It was enqueued above. */
3713 if (fast_tp_collecting
== 1)
3716 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
3717 " (exit-jump-pad-bkpt)\n",
3720 /* Postpone any pending signal. It was enqueued above. */
3723 else if (fast_tp_collecting
== 2)
3726 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
3727 " single-stepping\n",
3730 if (can_hardware_single_step ())
3734 internal_error (__FILE__
, __LINE__
,
3735 "moving out of jump pad single-stepping"
3736 " not implemented on this target");
3739 /* Postpone any pending signal. It was enqueued above. */
3743 /* If we have while-stepping actions in this thread set it stepping.
3744 If we have a signal to deliver, it may or may not be set to
3745 SIG_IGN, we don't know. Assume so, and allow collecting
3746 while-stepping into a signal handler. A possible smart thing to
3747 do would be to set an internal breakpoint at the signal return
3748 address, continue, and carry on catching this while-stepping
3749 action only when that breakpoint is hit. A future
3751 if (thread
->while_stepping
!= NULL
3752 && can_hardware_single_step ())
3755 debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n",
3760 if (the_low_target
.get_pc
!= NULL
)
3762 struct regcache
*regcache
= get_thread_regcache (current_thread
, 1);
3764 lwp
->stop_pc
= (*the_low_target
.get_pc
) (regcache
);
3768 debug_printf (" %s from pc 0x%lx\n", step
? "step" : "continue",
3769 (long) lwp
->stop_pc
);
3773 /* If we have pending signals, consume one unless we are trying to
3774 reinsert a breakpoint or we're trying to finish a fast tracepoint
3776 if (lwp
->pending_signals
!= NULL
3777 && lwp
->bp_reinsert
== 0
3778 && fast_tp_collecting
== 0)
3780 struct pending_signals
**p_sig
;
3782 p_sig
= &lwp
->pending_signals
;
3783 while ((*p_sig
)->prev
!= NULL
)
3784 p_sig
= &(*p_sig
)->prev
;
3786 signal
= (*p_sig
)->signal
;
3787 if ((*p_sig
)->info
.si_signo
!= 0)
3788 ptrace (PTRACE_SETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
3795 if (the_low_target
.prepare_to_resume
!= NULL
)
3796 the_low_target
.prepare_to_resume (lwp
);
3798 regcache_invalidate_thread (thread
);
3800 lwp
->stepping
= step
;
3801 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (thread
),
3802 (PTRACE_TYPE_ARG3
) 0,
3803 /* Coerce to a uintptr_t first to avoid potential gcc warning
3804 of coercing an 8 byte integer to a 4 byte pointer. */
3805 (PTRACE_TYPE_ARG4
) (uintptr_t) signal
);
3807 current_thread
= saved_thread
;
3809 perror_with_name ("resuming thread");
3811 /* Successfully resumed. Clear state that no longer makes sense,
3812 and mark the LWP as running. Must not do this before resuming
3813 otherwise if that fails other code will be confused. E.g., we'd
3814 later try to stop the LWP and hang forever waiting for a stop
3815 status. Note that we must not throw after this is cleared,
3816 otherwise handle_zombie_lwp_error would get confused. */
3818 lwp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3821 /* Called when we try to resume a stopped LWP and that errors out. If
3822 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
3823 or about to become), discard the error, clear any pending status
3824 the LWP may have, and return true (we'll collect the exit status
3825 soon enough). Otherwise, return false. */
3828 check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
)
3830 struct thread_info
*thread
= get_lwp_thread (lp
);
3832 /* If we get an error after resuming the LWP successfully, we'd
3833 confuse !T state for the LWP being gone. */
3834 gdb_assert (lp
->stopped
);
3836 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
3837 because even if ptrace failed with ESRCH, the tracee may be "not
3838 yet fully dead", but already refusing ptrace requests. In that
3839 case the tracee has 'R (Running)' state for a little bit
3840 (observed in Linux 3.18). See also the note on ESRCH in the
3841 ptrace(2) man page. Instead, check whether the LWP has any state
3842 other than ptrace-stopped. */
3844 /* Don't assume anything if /proc/PID/status can't be read. */
3845 if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread
)) == 0)
3847 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3848 lp
->status_pending_p
= 0;
3854 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
3855 disappears while we try to resume it. */
3858 linux_resume_one_lwp (struct lwp_info
*lwp
,
3859 int step
, int signal
, siginfo_t
*info
)
3863 linux_resume_one_lwp_throw (lwp
, step
, signal
, info
);
3865 CATCH (ex
, RETURN_MASK_ERROR
)
3867 if (!check_ptrace_stopped_lwp_gone (lwp
))
3868 throw_exception (ex
);
3873 struct thread_resume_array
3875 struct thread_resume
*resume
;
3879 /* This function is called once per thread via find_inferior.
3880 ARG is a pointer to a thread_resume_array struct.
3881 We look up the thread specified by ENTRY in ARG, and mark the thread
3882 with a pointer to the appropriate resume request.
3884 This algorithm is O(threads * resume elements), but resume elements
3885 is small (and will remain small at least until GDB supports thread
3889 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
3891 struct thread_info
*thread
= (struct thread_info
*) entry
;
3892 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3894 struct thread_resume_array
*r
;
3898 for (ndx
= 0; ndx
< r
->n
; ndx
++)
3900 ptid_t ptid
= r
->resume
[ndx
].thread
;
3901 if (ptid_equal (ptid
, minus_one_ptid
)
3902 || ptid_equal (ptid
, entry
->id
)
3903 /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads
3905 || (ptid_get_pid (ptid
) == pid_of (thread
)
3906 && (ptid_is_pid (ptid
)
3907 || ptid_get_lwp (ptid
) == -1)))
3909 if (r
->resume
[ndx
].kind
== resume_stop
3910 && thread
->last_resume_kind
== resume_stop
)
3913 debug_printf ("already %s LWP %ld at GDB's request\n",
3914 (thread
->last_status
.kind
3915 == TARGET_WAITKIND_STOPPED
)
3923 lwp
->resume
= &r
->resume
[ndx
];
3924 thread
->last_resume_kind
= lwp
->resume
->kind
;
3926 lwp
->step_range_start
= lwp
->resume
->step_range_start
;
3927 lwp
->step_range_end
= lwp
->resume
->step_range_end
;
3929 /* If we had a deferred signal to report, dequeue one now.
3930 This can happen if LWP gets more than one signal while
3931 trying to get out of a jump pad. */
3933 && !lwp
->status_pending_p
3934 && dequeue_one_deferred_signal (lwp
, &lwp
->status_pending
))
3936 lwp
->status_pending_p
= 1;
3939 debug_printf ("Dequeueing deferred signal %d for LWP %ld, "
3940 "leaving status pending.\n",
3941 WSTOPSIG (lwp
->status_pending
),
3949 /* No resume action for this thread. */
3955 /* find_inferior callback for linux_resume.
3956 Set *FLAG_P if this lwp has an interesting status pending. */
3959 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
3961 struct thread_info
*thread
= (struct thread_info
*) entry
;
3962 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3964 /* LWPs which will not be resumed are not interesting, because
3965 we might not wait for them next time through linux_wait. */
3966 if (lwp
->resume
== NULL
)
3969 if (thread_still_has_status_pending_p (thread
))
3970 * (int *) flag_p
= 1;
3975 /* Return 1 if this lwp that GDB wants running is stopped at an
3976 internal breakpoint that we need to step over. It assumes that any
3977 required STOP_PC adjustment has already been propagated to the
3978 inferior's regcache. */
3981 need_step_over_p (struct inferior_list_entry
*entry
, void *dummy
)
3983 struct thread_info
*thread
= (struct thread_info
*) entry
;
3984 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3985 struct thread_info
*saved_thread
;
3988 /* LWPs which will not be resumed are not interesting, because we
3989 might not wait for them next time through linux_wait. */
3994 debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped\n",
3999 if (thread
->last_resume_kind
== resume_stop
)
4002 debug_printf ("Need step over [LWP %ld]? Ignoring, should remain"
4008 gdb_assert (lwp
->suspended
>= 0);
4013 debug_printf ("Need step over [LWP %ld]? Ignoring, suspended\n",
4018 if (!lwp
->need_step_over
)
4021 debug_printf ("Need step over [LWP %ld]? No\n", lwpid_of (thread
));
4024 if (lwp
->status_pending_p
)
4027 debug_printf ("Need step over [LWP %ld]? Ignoring, has pending"
4033 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
4037 /* If the PC has changed since we stopped, then don't do anything,
4038 and let the breakpoint/tracepoint be hit. This happens if, for
4039 instance, GDB handled the decr_pc_after_break subtraction itself,
4040 GDB is OOL stepping this thread, or the user has issued a "jump"
4041 command, or poked thread's registers herself. */
4042 if (pc
!= lwp
->stop_pc
)
4045 debug_printf ("Need step over [LWP %ld]? Cancelling, PC was changed. "
4046 "Old stop_pc was 0x%s, PC is now 0x%s\n",
4048 paddress (lwp
->stop_pc
), paddress (pc
));
4050 lwp
->need_step_over
= 0;
4054 saved_thread
= current_thread
;
4055 current_thread
= thread
;
4057 /* We can only step over breakpoints we know about. */
4058 if (breakpoint_here (pc
) || fast_tracepoint_jump_here (pc
))
4060 /* Don't step over a breakpoint that GDB expects to hit
4061 though. If the condition is being evaluated on the target's side
4062 and it evaluate to false, step over this breakpoint as well. */
4063 if (gdb_breakpoint_here (pc
)
4064 && gdb_condition_true_at_breakpoint (pc
)
4065 && gdb_no_commands_at_breakpoint (pc
))
4068 debug_printf ("Need step over [LWP %ld]? yes, but found"
4069 " GDB breakpoint at 0x%s; skipping step over\n",
4070 lwpid_of (thread
), paddress (pc
));
4072 current_thread
= saved_thread
;
4078 debug_printf ("Need step over [LWP %ld]? yes, "
4079 "found breakpoint at 0x%s\n",
4080 lwpid_of (thread
), paddress (pc
));
4082 /* We've found an lwp that needs stepping over --- return 1 so
4083 that find_inferior stops looking. */
4084 current_thread
= saved_thread
;
4086 /* If the step over is cancelled, this is set again. */
4087 lwp
->need_step_over
= 0;
4092 current_thread
= saved_thread
;
4095 debug_printf ("Need step over [LWP %ld]? No, no breakpoint found"
4097 lwpid_of (thread
), paddress (pc
));
4102 /* Start a step-over operation on LWP. When LWP stopped at a
4103 breakpoint, to make progress, we need to remove the breakpoint out
4104 of the way. If we let other threads run while we do that, they may
4105 pass by the breakpoint location and miss hitting it. To avoid
4106 that, a step-over momentarily stops all threads while LWP is
4107 single-stepped while the breakpoint is temporarily uninserted from
4108 the inferior. When the single-step finishes, we reinsert the
4109 breakpoint, and let all threads that are supposed to be running,
4112 On targets that don't support hardware single-step, we don't
4113 currently support full software single-stepping. Instead, we only
4114 support stepping over the thread event breakpoint, by asking the
4115 low target where to place a reinsert breakpoint. Since this
4116 routine assumes the breakpoint being stepped over is a thread event
4117 breakpoint, it usually assumes the return address of the current
4118 function is a good enough place to set the reinsert breakpoint. */
4121 start_step_over (struct lwp_info
*lwp
)
4123 struct thread_info
*thread
= get_lwp_thread (lwp
);
4124 struct thread_info
*saved_thread
;
4129 debug_printf ("Starting step-over on LWP %ld. Stopping all threads\n",
4132 stop_all_lwps (1, lwp
);
4133 gdb_assert (lwp
->suspended
== 0);
4136 debug_printf ("Done stopping all threads for step-over.\n");
4138 /* Note, we should always reach here with an already adjusted PC,
4139 either by GDB (if we're resuming due to GDB's request), or by our
4140 caller, if we just finished handling an internal breakpoint GDB
4141 shouldn't care about. */
4144 saved_thread
= current_thread
;
4145 current_thread
= thread
;
4147 lwp
->bp_reinsert
= pc
;
4148 uninsert_breakpoints_at (pc
);
4149 uninsert_fast_tracepoint_jumps_at (pc
);
4151 if (can_hardware_single_step ())
4157 CORE_ADDR raddr
= (*the_low_target
.breakpoint_reinsert_addr
) ();
4158 set_reinsert_breakpoint (raddr
);
4162 current_thread
= saved_thread
;
4164 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
4166 /* Require next event from this LWP. */
4167 step_over_bkpt
= thread
->entry
.id
;
4171 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
4172 start_step_over, if still there, and delete any reinsert
4173 breakpoints we've set, on non hardware single-step targets. */
4176 finish_step_over (struct lwp_info
*lwp
)
4178 if (lwp
->bp_reinsert
!= 0)
4181 debug_printf ("Finished step over.\n");
4183 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
4184 may be no breakpoint to reinsert there by now. */
4185 reinsert_breakpoints_at (lwp
->bp_reinsert
);
4186 reinsert_fast_tracepoint_jumps_at (lwp
->bp_reinsert
);
4188 lwp
->bp_reinsert
= 0;
4190 /* Delete any software-single-step reinsert breakpoints. No
4191 longer needed. We don't have to worry about other threads
4192 hitting this trap, and later not being able to explain it,
4193 because we were stepping over a breakpoint, and we hold all
4194 threads but LWP stopped while doing that. */
4195 if (!can_hardware_single_step ())
4196 delete_reinsert_breakpoints ();
4198 step_over_bkpt
= null_ptid
;
4205 /* This function is called once per thread. We check the thread's resume
4206 request, which will tell us whether to resume, step, or leave the thread
4207 stopped; and what signal, if any, it should be sent.
4209 For threads which we aren't explicitly told otherwise, we preserve
4210 the stepping flag; this is used for stepping over gdbserver-placed
4213 If pending_flags was set in any thread, we queue any needed
4214 signals, since we won't actually resume. We already have a pending
4215 event to report, so we don't need to preserve any step requests;
4216 they should be re-issued if necessary. */
4219 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
4221 struct thread_info
*thread
= (struct thread_info
*) entry
;
4222 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4224 int leave_all_stopped
= * (int *) arg
;
4227 if (lwp
->resume
== NULL
)
4230 if (lwp
->resume
->kind
== resume_stop
)
4233 debug_printf ("resume_stop request for LWP %ld\n", lwpid_of (thread
));
4238 debug_printf ("stopping LWP %ld\n", lwpid_of (thread
));
4240 /* Stop the thread, and wait for the event asynchronously,
4241 through the event loop. */
4247 debug_printf ("already stopped LWP %ld\n",
4250 /* The LWP may have been stopped in an internal event that
4251 was not meant to be notified back to GDB (e.g., gdbserver
4252 breakpoint), so we should be reporting a stop event in
4255 /* If the thread already has a pending SIGSTOP, this is a
4256 no-op. Otherwise, something later will presumably resume
4257 the thread and this will cause it to cancel any pending
4258 operation, due to last_resume_kind == resume_stop. If
4259 the thread already has a pending status to report, we
4260 will still report it the next time we wait - see
4261 status_pending_p_callback. */
4263 /* If we already have a pending signal to report, then
4264 there's no need to queue a SIGSTOP, as this means we're
4265 midway through moving the LWP out of the jumppad, and we
4266 will report the pending signal as soon as that is
4268 if (lwp
->pending_signals_to_report
== NULL
)
4272 /* For stop requests, we're done. */
4274 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
4278 /* If this thread which is about to be resumed has a pending status,
4279 then don't resume any threads - we can just report the pending
4280 status. Make sure to queue any signals that would otherwise be
4281 sent. In all-stop mode, we do this decision based on if *any*
4282 thread has a pending status. If there's a thread that needs the
4283 step-over-breakpoint dance, then don't resume any other thread
4284 but that particular one. */
4285 leave_pending
= (lwp
->status_pending_p
|| leave_all_stopped
);
4290 debug_printf ("resuming LWP %ld\n", lwpid_of (thread
));
4292 step
= (lwp
->resume
->kind
== resume_step
);
4293 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
4298 debug_printf ("leaving LWP %ld stopped\n", lwpid_of (thread
));
4300 /* If we have a new signal, enqueue the signal. */
4301 if (lwp
->resume
->sig
!= 0)
4303 struct pending_signals
*p_sig
;
4304 p_sig
= xmalloc (sizeof (*p_sig
));
4305 p_sig
->prev
= lwp
->pending_signals
;
4306 p_sig
->signal
= lwp
->resume
->sig
;
4307 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
4309 /* If this is the same signal we were previously stopped by,
4310 make sure to queue its siginfo. We can ignore the return
4311 value of ptrace; if it fails, we'll skip
4312 PTRACE_SETSIGINFO. */
4313 if (WIFSTOPPED (lwp
->last_status
)
4314 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
4315 ptrace (PTRACE_GETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
4318 lwp
->pending_signals
= p_sig
;
4322 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
4328 linux_resume (struct thread_resume
*resume_info
, size_t n
)
4330 struct thread_resume_array array
= { resume_info
, n
};
4331 struct thread_info
*need_step_over
= NULL
;
4333 int leave_all_stopped
;
4338 debug_printf ("linux_resume:\n");
4341 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
4343 /* If there is a thread which would otherwise be resumed, which has
4344 a pending status, then don't resume any threads - we can just
4345 report the pending status. Make sure to queue any signals that
4346 would otherwise be sent. In non-stop mode, we'll apply this
4347 logic to each thread individually. We consume all pending events
4348 before considering to start a step-over (in all-stop). */
4351 find_inferior (&all_threads
, resume_status_pending_p
, &any_pending
);
4353 /* If there is a thread which would otherwise be resumed, which is
4354 stopped at a breakpoint that needs stepping over, then don't
4355 resume any threads - have it step over the breakpoint with all
4356 other threads stopped, then resume all threads again. Make sure
4357 to queue any signals that would otherwise be delivered or
4359 if (!any_pending
&& supports_breakpoints ())
4361 = (struct thread_info
*) find_inferior (&all_threads
,
4362 need_step_over_p
, NULL
);
4364 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
4368 if (need_step_over
!= NULL
)
4369 debug_printf ("Not resuming all, need step over\n");
4370 else if (any_pending
)
4371 debug_printf ("Not resuming, all-stop and found "
4372 "an LWP with pending status\n");
4374 debug_printf ("Resuming, no pending status or step over needed\n");
4377 /* Even if we're leaving threads stopped, queue all signals we'd
4378 otherwise deliver. */
4379 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
4382 start_step_over (get_thread_lwp (need_step_over
));
4386 debug_printf ("linux_resume done\n");
4391 /* This function is called once per thread. We check the thread's
4392 last resume request, which will tell us whether to resume, step, or
4393 leave the thread stopped. Any signal the client requested to be
4394 delivered has already been enqueued at this point.
4396 If any thread that GDB wants running is stopped at an internal
4397 breakpoint that needs stepping over, we start a step-over operation
4398 on that particular thread, and leave all others stopped. */
4401 proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
4403 struct thread_info
*thread
= (struct thread_info
*) entry
;
4404 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4411 debug_printf ("proceed_one_lwp: lwp %ld\n", lwpid_of (thread
));
4416 debug_printf (" LWP %ld already running\n", lwpid_of (thread
));
4420 if (thread
->last_resume_kind
== resume_stop
4421 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
4424 debug_printf (" client wants LWP to remain %ld stopped\n",
4429 if (lwp
->status_pending_p
)
4432 debug_printf (" LWP %ld has pending status, leaving stopped\n",
4437 gdb_assert (lwp
->suspended
>= 0);
4442 debug_printf (" LWP %ld is suspended\n", lwpid_of (thread
));
4446 if (thread
->last_resume_kind
== resume_stop
4447 && lwp
->pending_signals_to_report
== NULL
4448 && lwp
->collecting_fast_tracepoint
== 0)
4450 /* We haven't reported this LWP as stopped yet (otherwise, the
4451 last_status.kind check above would catch it, and we wouldn't
4452 reach here. This LWP may have been momentarily paused by a
4453 stop_all_lwps call while handling for example, another LWP's
4454 step-over. In that case, the pending expected SIGSTOP signal
4455 that was queued at vCont;t handling time will have already
4456 been consumed by wait_for_sigstop, and so we need to requeue
4457 another one here. Note that if the LWP already has a SIGSTOP
4458 pending, this is a no-op. */
4461 debug_printf ("Client wants LWP %ld to stop. "
4462 "Making sure it has a SIGSTOP pending\n",
4468 step
= thread
->last_resume_kind
== resume_step
;
4469 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
4474 unsuspend_and_proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
4476 struct thread_info
*thread
= (struct thread_info
*) entry
;
4477 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4483 gdb_assert (lwp
->suspended
>= 0);
4485 return proceed_one_lwp (entry
, except
);
4488 /* When we finish a step-over, set threads running again. If there's
4489 another thread that may need a step-over, now's the time to start
4490 it. Eventually, we'll move all threads past their breakpoints. */
4493 proceed_all_lwps (void)
4495 struct thread_info
*need_step_over
;
4497 /* If there is a thread which would otherwise be resumed, which is
4498 stopped at a breakpoint that needs stepping over, then don't
4499 resume any threads - have it step over the breakpoint with all
4500 other threads stopped, then resume all threads again. */
4502 if (supports_breakpoints ())
4505 = (struct thread_info
*) find_inferior (&all_threads
,
4506 need_step_over_p
, NULL
);
4508 if (need_step_over
!= NULL
)
4511 debug_printf ("proceed_all_lwps: found "
4512 "thread %ld needing a step-over\n",
4513 lwpid_of (need_step_over
));
4515 start_step_over (get_thread_lwp (need_step_over
));
4521 debug_printf ("Proceeding, no step-over needed\n");
4523 find_inferior (&all_threads
, proceed_one_lwp
, NULL
);
4526 /* Stopped LWPs that the client wanted to be running, that don't have
4527 pending statuses, are set to run again, except for EXCEPT, if not
4528 NULL. This undoes a stop_all_lwps call. */
4531 unstop_all_lwps (int unsuspend
, struct lwp_info
*except
)
4537 debug_printf ("unstopping all lwps, except=(LWP %ld)\n",
4538 lwpid_of (get_lwp_thread (except
)));
4540 debug_printf ("unstopping all lwps\n");
4544 find_inferior (&all_threads
, unsuspend_and_proceed_one_lwp
, except
);
4546 find_inferior (&all_threads
, proceed_one_lwp
, except
);
4550 debug_printf ("unstop_all_lwps done\n");
4556 #ifdef HAVE_LINUX_REGSETS
4558 #define use_linux_regsets 1
4560 /* Returns true if REGSET has been disabled. */
4563 regset_disabled (struct regsets_info
*info
, struct regset_info
*regset
)
4565 return (info
->disabled_regsets
!= NULL
4566 && info
->disabled_regsets
[regset
- info
->regsets
]);
4569 /* Disable REGSET. */
4572 disable_regset (struct regsets_info
*info
, struct regset_info
*regset
)
4576 dr_offset
= regset
- info
->regsets
;
4577 if (info
->disabled_regsets
== NULL
)
4578 info
->disabled_regsets
= xcalloc (1, info
->num_regsets
);
4579 info
->disabled_regsets
[dr_offset
] = 1;
4583 regsets_fetch_inferior_registers (struct regsets_info
*regsets_info
,
4584 struct regcache
*regcache
)
4586 struct regset_info
*regset
;
4587 int saw_general_regs
= 0;
4591 pid
= lwpid_of (current_thread
);
4592 for (regset
= regsets_info
->regsets
; regset
->size
>= 0; regset
++)
4597 if (regset
->size
== 0 || regset_disabled (regsets_info
, regset
))
4600 buf
= xmalloc (regset
->size
);
4602 nt_type
= regset
->nt_type
;
4606 iov
.iov_len
= regset
->size
;
4607 data
= (void *) &iov
;
4613 res
= ptrace (regset
->get_request
, pid
,
4614 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
4616 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
4622 /* If we get EIO on a regset, do not try it again for
4623 this process mode. */
4624 disable_regset (regsets_info
, regset
);
4626 else if (errno
== ENODATA
)
4628 /* ENODATA may be returned if the regset is currently
4629 not "active". This can happen in normal operation,
4630 so suppress the warning in this case. */
4635 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
4642 if (regset
->type
== GENERAL_REGS
)
4643 saw_general_regs
= 1;
4644 regset
->store_function (regcache
, buf
);
4648 if (saw_general_regs
)
4655 regsets_store_inferior_registers (struct regsets_info
*regsets_info
,
4656 struct regcache
*regcache
)
4658 struct regset_info
*regset
;
4659 int saw_general_regs
= 0;
4663 pid
= lwpid_of (current_thread
);
4664 for (regset
= regsets_info
->regsets
; regset
->size
>= 0; regset
++)
4669 if (regset
->size
== 0 || regset_disabled (regsets_info
, regset
)
4670 || regset
->fill_function
== NULL
)
4673 buf
= xmalloc (regset
->size
);
4675 /* First fill the buffer with the current register set contents,
4676 in case there are any items in the kernel's regset that are
4677 not in gdbserver's regcache. */
4679 nt_type
= regset
->nt_type
;
4683 iov
.iov_len
= regset
->size
;
4684 data
= (void *) &iov
;
4690 res
= ptrace (regset
->get_request
, pid
,
4691 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
4693 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
4698 /* Then overlay our cached registers on that. */
4699 regset
->fill_function (regcache
, buf
);
4701 /* Only now do we write the register set. */
4703 res
= ptrace (regset
->set_request
, pid
,
4704 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
4706 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
4714 /* If we get EIO on a regset, do not try it again for
4715 this process mode. */
4716 disable_regset (regsets_info
, regset
);
4718 else if (errno
== ESRCH
)
4720 /* At this point, ESRCH should mean the process is
4721 already gone, in which case we simply ignore attempts
4722 to change its registers. See also the related
4723 comment in linux_resume_one_lwp. */
4729 perror ("Warning: ptrace(regsets_store_inferior_registers)");
4732 else if (regset
->type
== GENERAL_REGS
)
4733 saw_general_regs
= 1;
4736 if (saw_general_regs
)
4742 #else /* !HAVE_LINUX_REGSETS */
4744 #define use_linux_regsets 0
4745 #define regsets_fetch_inferior_registers(regsets_info, regcache) 1
4746 #define regsets_store_inferior_registers(regsets_info, regcache) 1
4750 /* Return 1 if register REGNO is supported by one of the regset ptrace
4751 calls or 0 if it has to be transferred individually. */
4754 linux_register_in_regsets (const struct regs_info
*regs_info
, int regno
)
4756 unsigned char mask
= 1 << (regno
% 8);
4757 size_t index
= regno
/ 8;
4759 return (use_linux_regsets
4760 && (regs_info
->regset_bitmap
== NULL
4761 || (regs_info
->regset_bitmap
[index
] & mask
) != 0));
4764 #ifdef HAVE_LINUX_USRREGS
4767 register_addr (const struct usrregs_info
*usrregs
, int regnum
)
4771 if (regnum
< 0 || regnum
>= usrregs
->num_regs
)
4772 error ("Invalid register number %d.", regnum
);
4774 addr
= usrregs
->regmap
[regnum
];
4779 /* Fetch one register. */
4781 fetch_register (const struct usrregs_info
*usrregs
,
4782 struct regcache
*regcache
, int regno
)
4789 if (regno
>= usrregs
->num_regs
)
4791 if ((*the_low_target
.cannot_fetch_register
) (regno
))
4794 regaddr
= register_addr (usrregs
, regno
);
4798 size
= ((register_size (regcache
->tdesc
, regno
)
4799 + sizeof (PTRACE_XFER_TYPE
) - 1)
4800 & -sizeof (PTRACE_XFER_TYPE
));
4801 buf
= alloca (size
);
4803 pid
= lwpid_of (current_thread
);
4804 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
4807 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
4808 ptrace (PTRACE_PEEKUSER
, pid
,
4809 /* Coerce to a uintptr_t first to avoid potential gcc warning
4810 of coercing an 8 byte integer to a 4 byte pointer. */
4811 (PTRACE_TYPE_ARG3
) (uintptr_t) regaddr
, (PTRACE_TYPE_ARG4
) 0);
4812 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
4814 error ("reading register %d: %s", regno
, strerror (errno
));
4817 if (the_low_target
.supply_ptrace_register
)
4818 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
4820 supply_register (regcache
, regno
, buf
);
4823 /* Store one register. */
4825 store_register (const struct usrregs_info
*usrregs
,
4826 struct regcache
*regcache
, int regno
)
4833 if (regno
>= usrregs
->num_regs
)
4835 if ((*the_low_target
.cannot_store_register
) (regno
))
4838 regaddr
= register_addr (usrregs
, regno
);
4842 size
= ((register_size (regcache
->tdesc
, regno
)
4843 + sizeof (PTRACE_XFER_TYPE
) - 1)
4844 & -sizeof (PTRACE_XFER_TYPE
));
4845 buf
= alloca (size
);
4846 memset (buf
, 0, size
);
4848 if (the_low_target
.collect_ptrace_register
)
4849 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
4851 collect_register (regcache
, regno
, buf
);
4853 pid
= lwpid_of (current_thread
);
4854 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
4857 ptrace (PTRACE_POKEUSER
, pid
,
4858 /* Coerce to a uintptr_t first to avoid potential gcc warning
4859 about coercing an 8 byte integer to a 4 byte pointer. */
4860 (PTRACE_TYPE_ARG3
) (uintptr_t) regaddr
,
4861 (PTRACE_TYPE_ARG4
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
4864 /* At this point, ESRCH should mean the process is
4865 already gone, in which case we simply ignore attempts
4866 to change its registers. See also the related
4867 comment in linux_resume_one_lwp. */
4871 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
4872 error ("writing register %d: %s", regno
, strerror (errno
));
4874 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
4878 /* Fetch all registers, or just one, from the child process.
4879 If REGNO is -1, do this for all registers, skipping any that are
4880 assumed to have been retrieved by regsets_fetch_inferior_registers,
4881 unless ALL is non-zero.
4882 Otherwise, REGNO specifies which register (so we can save time). */
4884 usr_fetch_inferior_registers (const struct regs_info
*regs_info
,
4885 struct regcache
*regcache
, int regno
, int all
)
4887 struct usrregs_info
*usr
= regs_info
->usrregs
;
4891 for (regno
= 0; regno
< usr
->num_regs
; regno
++)
4892 if (all
|| !linux_register_in_regsets (regs_info
, regno
))
4893 fetch_register (usr
, regcache
, regno
);
4896 fetch_register (usr
, regcache
, regno
);
4899 /* Store our register values back into the inferior.
4900 If REGNO is -1, do this for all registers, skipping any that are
4901 assumed to have been saved by regsets_store_inferior_registers,
4902 unless ALL is non-zero.
4903 Otherwise, REGNO specifies which register (so we can save time). */
4905 usr_store_inferior_registers (const struct regs_info
*regs_info
,
4906 struct regcache
*regcache
, int regno
, int all
)
4908 struct usrregs_info
*usr
= regs_info
->usrregs
;
4912 for (regno
= 0; regno
< usr
->num_regs
; regno
++)
4913 if (all
|| !linux_register_in_regsets (regs_info
, regno
))
4914 store_register (usr
, regcache
, regno
);
4917 store_register (usr
, regcache
, regno
);
4920 #else /* !HAVE_LINUX_USRREGS */
4922 #define usr_fetch_inferior_registers(regs_info, regcache, regno, all) do {} while (0)
4923 #define usr_store_inferior_registers(regs_info, regcache, regno, all) do {} while (0)
4929 linux_fetch_registers (struct regcache
*regcache
, int regno
)
4933 const struct regs_info
*regs_info
= (*the_low_target
.regs_info
) ();
4937 if (the_low_target
.fetch_register
!= NULL
4938 && regs_info
->usrregs
!= NULL
)
4939 for (regno
= 0; regno
< regs_info
->usrregs
->num_regs
; regno
++)
4940 (*the_low_target
.fetch_register
) (regcache
, regno
);
4942 all
= regsets_fetch_inferior_registers (regs_info
->regsets_info
, regcache
);
4943 if (regs_info
->usrregs
!= NULL
)
4944 usr_fetch_inferior_registers (regs_info
, regcache
, -1, all
);
4948 if (the_low_target
.fetch_register
!= NULL
4949 && (*the_low_target
.fetch_register
) (regcache
, regno
))
4952 use_regsets
= linux_register_in_regsets (regs_info
, regno
);
4954 all
= regsets_fetch_inferior_registers (regs_info
->regsets_info
,
4956 if ((!use_regsets
|| all
) && regs_info
->usrregs
!= NULL
)
4957 usr_fetch_inferior_registers (regs_info
, regcache
, regno
, 1);
4962 linux_store_registers (struct regcache
*regcache
, int regno
)
4966 const struct regs_info
*regs_info
= (*the_low_target
.regs_info
) ();
4970 all
= regsets_store_inferior_registers (regs_info
->regsets_info
,
4972 if (regs_info
->usrregs
!= NULL
)
4973 usr_store_inferior_registers (regs_info
, regcache
, regno
, all
);
4977 use_regsets
= linux_register_in_regsets (regs_info
, regno
);
4979 all
= regsets_store_inferior_registers (regs_info
->regsets_info
,
4981 if ((!use_regsets
|| all
) && regs_info
->usrregs
!= NULL
)
4982 usr_store_inferior_registers (regs_info
, regcache
, regno
, 1);
4987 /* Copy LEN bytes from inferior's memory starting at MEMADDR
4988 to debugger memory starting at MYADDR. */
4991 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
4993 int pid
= lwpid_of (current_thread
);
4994 register PTRACE_XFER_TYPE
*buffer
;
4995 register CORE_ADDR addr
;
5002 /* Try using /proc. Don't bother for one word. */
5003 if (len
>= 3 * sizeof (long))
5007 /* We could keep this file open and cache it - possibly one per
5008 thread. That requires some juggling, but is even faster. */
5009 sprintf (filename
, "/proc/%d/mem", pid
);
5010 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
5014 /* If pread64 is available, use it. It's faster if the kernel
5015 supports it (only one syscall), and it's 64-bit safe even on
5016 32-bit platforms (for instance, SPARC debugging a SPARC64
5019 bytes
= pread64 (fd
, myaddr
, len
, memaddr
);
5022 if (lseek (fd
, memaddr
, SEEK_SET
) != -1)
5023 bytes
= read (fd
, myaddr
, len
);
5030 /* Some data was read, we'll try to get the rest with ptrace. */
5040 /* Round starting address down to longword boundary. */
5041 addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
5042 /* Round ending address up; get number of longwords that makes. */
5043 count
= ((((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
5044 / sizeof (PTRACE_XFER_TYPE
));
5045 /* Allocate buffer of that many longwords. */
5046 buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
5048 /* Read all the longwords */
5050 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
5052 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
5053 about coercing an 8 byte integer to a 4 byte pointer. */
5054 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
5055 (PTRACE_TYPE_ARG3
) (uintptr_t) addr
,
5056 (PTRACE_TYPE_ARG4
) 0);
5062 /* Copy appropriate bytes out of the buffer. */
5065 i
*= sizeof (PTRACE_XFER_TYPE
);
5066 i
-= memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1);
5068 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
5075 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
5076 memory at MEMADDR. On failure (cannot write to the inferior)
5077 returns the value of errno. Always succeeds if LEN is zero. */
5080 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
5083 /* Round starting address down to longword boundary. */
5084 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
5085 /* Round ending address up; get number of longwords that makes. */
5087 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
5088 / sizeof (PTRACE_XFER_TYPE
);
5090 /* Allocate buffer of that many longwords. */
5091 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*)
5092 alloca (count
* sizeof (PTRACE_XFER_TYPE
));
5094 int pid
= lwpid_of (current_thread
);
5098 /* Zero length write always succeeds. */
5104 /* Dump up to four bytes. */
5105 unsigned int val
= * (unsigned int *) myaddr
;
5111 val
= val
& 0xffffff;
5112 debug_printf ("Writing %0*x to 0x%08lx in process %d\n",
5113 2 * ((len
< 4) ? len
: 4), val
, (long)memaddr
, pid
);
5116 /* Fill start and end extra bytes of buffer with existing memory data. */
5119 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
5120 about coercing an 8 byte integer to a 4 byte pointer. */
5121 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
5122 (PTRACE_TYPE_ARG3
) (uintptr_t) addr
,
5123 (PTRACE_TYPE_ARG4
) 0);
5131 = ptrace (PTRACE_PEEKTEXT
, pid
,
5132 /* Coerce to a uintptr_t first to avoid potential gcc warning
5133 about coercing an 8 byte integer to a 4 byte pointer. */
5134 (PTRACE_TYPE_ARG3
) (uintptr_t) (addr
+ (count
- 1)
5135 * sizeof (PTRACE_XFER_TYPE
)),
5136 (PTRACE_TYPE_ARG4
) 0);
5141 /* Copy data to be written over corresponding part of buffer. */
5143 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
5146 /* Write the entire buffer. */
5148 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
5151 ptrace (PTRACE_POKETEXT
, pid
,
5152 /* Coerce to a uintptr_t first to avoid potential gcc warning
5153 about coercing an 8 byte integer to a 4 byte pointer. */
5154 (PTRACE_TYPE_ARG3
) (uintptr_t) addr
,
5155 (PTRACE_TYPE_ARG4
) buffer
[i
]);
5164 linux_look_up_symbols (void)
5166 #ifdef USE_THREAD_DB
5167 struct process_info
*proc
= current_process ();
5169 if (proc
->priv
->thread_db
!= NULL
)
5172 /* If the kernel supports tracing clones, then we don't need to
5173 use the magic thread event breakpoint to learn about
5175 thread_db_init (!linux_supports_traceclone ());
5180 linux_request_interrupt (void)
5182 extern unsigned long signal_pid
;
5184 /* Send a SIGINT to the process group. This acts just like the user
5185 typed a ^C on the controlling terminal. */
5186 kill (-signal_pid
, SIGINT
);
5189 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
5190 to debugger memory starting at MYADDR. */
5193 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
5195 char filename
[PATH_MAX
];
5197 int pid
= lwpid_of (current_thread
);
5199 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
5201 fd
= open (filename
, O_RDONLY
);
5205 if (offset
!= (CORE_ADDR
) 0
5206 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
5209 n
= read (fd
, myaddr
, len
);
5216 /* These breakpoint and watchpoint related wrapper functions simply
5217 pass on the function call if the target has registered a
5218 corresponding function. */
5221 linux_supports_z_point_type (char z_type
)
5223 return (the_low_target
.supports_z_point_type
!= NULL
5224 && the_low_target
.supports_z_point_type (z_type
));
5228 linux_insert_point (enum raw_bkpt_type type
, CORE_ADDR addr
,
5229 int size
, struct raw_breakpoint
*bp
)
5231 if (type
== raw_bkpt_type_sw
)
5232 return insert_memory_breakpoint (bp
);
5233 else if (the_low_target
.insert_point
!= NULL
)
5234 return the_low_target
.insert_point (type
, addr
, size
, bp
);
5236 /* Unsupported (see target.h). */
5241 linux_remove_point (enum raw_bkpt_type type
, CORE_ADDR addr
,
5242 int size
, struct raw_breakpoint
*bp
)
5244 if (type
== raw_bkpt_type_sw
)
5245 return remove_memory_breakpoint (bp
);
5246 else if (the_low_target
.remove_point
!= NULL
)
5247 return the_low_target
.remove_point (type
, addr
, size
, bp
);
5249 /* Unsupported (see target.h). */
5253 /* Implement the to_stopped_by_sw_breakpoint target_ops
5257 linux_stopped_by_sw_breakpoint (void)
5259 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5261 return (lwp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
);
5264 /* Implement the to_supports_stopped_by_sw_breakpoint target_ops
5268 linux_supports_stopped_by_sw_breakpoint (void)
5270 return USE_SIGTRAP_SIGINFO
;
5273 /* Implement the to_stopped_by_hw_breakpoint target_ops
5277 linux_stopped_by_hw_breakpoint (void)
5279 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5281 return (lwp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
);
5284 /* Implement the to_supports_stopped_by_hw_breakpoint target_ops
5288 linux_supports_stopped_by_hw_breakpoint (void)
5290 return USE_SIGTRAP_SIGINFO
;
5293 /* Implement the supports_conditional_breakpoints target_ops
5297 linux_supports_conditional_breakpoints (void)
5299 /* GDBserver needs to step over the breakpoint if the condition is
5300 false. GDBserver software single step is too simple, so disable
5301 conditional breakpoints if the target doesn't have hardware single
5303 return can_hardware_single_step ();
5307 linux_stopped_by_watchpoint (void)
5309 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5311 return lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
5315 linux_stopped_data_address (void)
5317 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5319 return lwp
->stopped_data_address
;
5322 #if defined(__UCLIBC__) && defined(HAS_NOMMU) \
5323 && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
5324 && defined(PT_TEXT_END_ADDR)
5326 /* This is only used for targets that define PT_TEXT_ADDR,
5327 PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly
5328 the target has different ways of acquiring this information, like
5331 /* Under uClinux, programs are loaded at non-zero offsets, which we need
5332 to tell gdb about. */
5335 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
5337 unsigned long text
, text_end
, data
;
5338 int pid
= lwpid_of (current_thread
);
5342 text
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_TEXT_ADDR
,
5343 (PTRACE_TYPE_ARG4
) 0);
5344 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_TEXT_END_ADDR
,
5345 (PTRACE_TYPE_ARG4
) 0);
5346 data
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_DATA_ADDR
,
5347 (PTRACE_TYPE_ARG4
) 0);
5351 /* Both text and data offsets produced at compile-time (and so
5352 used by gdb) are relative to the beginning of the program,
5353 with the data segment immediately following the text segment.
5354 However, the actual runtime layout in memory may put the data
5355 somewhere else, so when we send gdb a data base-address, we
5356 use the real data base address and subtract the compile-time
5357 data base-address from it (which is just the length of the
5358 text segment). BSS immediately follows data in both
5361 *data_p
= data
- (text_end
- text
);
5370 linux_qxfer_osdata (const char *annex
,
5371 unsigned char *readbuf
, unsigned const char *writebuf
,
5372 CORE_ADDR offset
, int len
)
5374 return linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
5377 /* Convert a native/host siginfo object, into/from the siginfo in the
5378 layout of the inferiors' architecture. */
5381 siginfo_fixup (siginfo_t
*siginfo
, void *inf_siginfo
, int direction
)
5385 if (the_low_target
.siginfo_fixup
!= NULL
)
5386 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
5388 /* If there was no callback, or the callback didn't do anything,
5389 then just do a straight memcpy. */
5393 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
5395 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
5400 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
5401 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
5405 char inf_siginfo
[sizeof (siginfo_t
)];
5407 if (current_thread
== NULL
)
5410 pid
= lwpid_of (current_thread
);
5413 debug_printf ("%s siginfo for lwp %d.\n",
5414 readbuf
!= NULL
? "Reading" : "Writing",
5417 if (offset
>= sizeof (siginfo
))
5420 if (ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
) != 0)
5423 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
5424 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
5425 inferior with a 64-bit GDBSERVER should look the same as debugging it
5426 with a 32-bit GDBSERVER, we need to convert it. */
5427 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
5429 if (offset
+ len
> sizeof (siginfo
))
5430 len
= sizeof (siginfo
) - offset
;
5432 if (readbuf
!= NULL
)
5433 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
5436 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
5438 /* Convert back to ptrace layout before flushing it out. */
5439 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
5441 if (ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
) != 0)
5448 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
5449 so we notice when children change state; as the handler for the
5450 sigsuspend in my_waitpid. */
5453 sigchld_handler (int signo
)
5455 int old_errno
= errno
;
5461 /* fprintf is not async-signal-safe, so call write
5463 if (write (2, "sigchld_handler\n",
5464 sizeof ("sigchld_handler\n") - 1) < 0)
5465 break; /* just ignore */
5469 if (target_is_async_p ())
5470 async_file_mark (); /* trigger a linux_wait */
5476 linux_supports_non_stop (void)
5482 linux_async (int enable
)
5484 int previous
= target_is_async_p ();
5487 debug_printf ("linux_async (%d), previous=%d\n",
5490 if (previous
!= enable
)
5493 sigemptyset (&mask
);
5494 sigaddset (&mask
, SIGCHLD
);
5496 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
5500 if (pipe (linux_event_pipe
) == -1)
5502 linux_event_pipe
[0] = -1;
5503 linux_event_pipe
[1] = -1;
5504 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
5506 warning ("creating event pipe failed.");
5510 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
5511 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
5513 /* Register the event loop handler. */
5514 add_file_handler (linux_event_pipe
[0],
5515 handle_target_event
, NULL
);
5517 /* Always trigger a linux_wait. */
5522 delete_file_handler (linux_event_pipe
[0]);
5524 close (linux_event_pipe
[0]);
5525 close (linux_event_pipe
[1]);
5526 linux_event_pipe
[0] = -1;
5527 linux_event_pipe
[1] = -1;
5530 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
5537 linux_start_non_stop (int nonstop
)
5539 /* Register or unregister from event-loop accordingly. */
5540 linux_async (nonstop
);
5542 if (target_is_async_p () != (nonstop
!= 0))
5549 linux_supports_multi_process (void)
5554 /* Check if fork events are supported. */
5557 linux_supports_fork_events (void)
5559 return linux_supports_tracefork ();
5562 /* Check if vfork events are supported. */
5565 linux_supports_vfork_events (void)
5567 return linux_supports_tracefork ();
5570 /* Callback for 'find_inferior'. Set the (possibly changed) ptrace
5571 options for the specified lwp. */
5574 reset_lwp_ptrace_options_callback (struct inferior_list_entry
*entry
,
5577 struct thread_info
*thread
= (struct thread_info
*) entry
;
5578 struct lwp_info
*lwp
= get_thread_lwp (thread
);
5582 /* Stop the lwp so we can modify its ptrace options. */
5583 lwp
->must_set_ptrace_flags
= 1;
5584 linux_stop_lwp (lwp
);
5588 /* Already stopped; go ahead and set the ptrace options. */
5589 struct process_info
*proc
= find_process_pid (pid_of (thread
));
5590 int options
= linux_low_ptrace_options (proc
->attached
);
5592 linux_enable_event_reporting (lwpid_of (thread
), options
);
5593 lwp
->must_set_ptrace_flags
= 0;
5599 /* Target hook for 'handle_new_gdb_connection'. Causes a reset of the
5600 ptrace flags for all inferiors. This is in case the new GDB connection
5601 doesn't support the same set of events that the previous one did. */
5604 linux_handle_new_gdb_connection (void)
5608 /* Request that all the lwps reset their ptrace options. */
5609 find_inferior (&all_threads
, reset_lwp_ptrace_options_callback
, &pid
);
5613 linux_supports_disable_randomization (void)
5615 #ifdef HAVE_PERSONALITY
5623 linux_supports_agent (void)
5629 linux_supports_range_stepping (void)
5631 if (*the_low_target
.supports_range_stepping
== NULL
)
5634 return (*the_low_target
.supports_range_stepping
) ();
5637 /* Enumerate spufs IDs for process PID. */
5639 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
5645 struct dirent
*entry
;
5647 sprintf (path
, "/proc/%ld/fd", pid
);
5648 dir
= opendir (path
);
5653 while ((entry
= readdir (dir
)) != NULL
)
5659 fd
= atoi (entry
->d_name
);
5663 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
5664 if (stat (path
, &st
) != 0)
5666 if (!S_ISDIR (st
.st_mode
))
5669 if (statfs (path
, &stfs
) != 0)
5671 if (stfs
.f_type
!= SPUFS_MAGIC
)
5674 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
5676 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
5686 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
5687 object type, using the /proc file system. */
5689 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
5690 unsigned const char *writebuf
,
5691 CORE_ADDR offset
, int len
)
5693 long pid
= lwpid_of (current_thread
);
5698 if (!writebuf
&& !readbuf
)
5706 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
5709 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
5710 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
5715 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
5722 ret
= write (fd
, writebuf
, (size_t) len
);
5724 ret
= read (fd
, readbuf
, (size_t) len
);
5730 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
5731 struct target_loadseg
5733 /* Core address to which the segment is mapped. */
5735 /* VMA recorded in the program header. */
5737 /* Size of this segment in memory. */
5741 # if defined PT_GETDSBT
5742 struct target_loadmap
5744 /* Protocol version number, must be zero. */
5746 /* Pointer to the DSBT table, its size, and the DSBT index. */
5747 unsigned *dsbt_table
;
5748 unsigned dsbt_size
, dsbt_index
;
5749 /* Number of segments in this map. */
5751 /* The actual memory map. */
5752 struct target_loadseg segs
[/*nsegs*/];
5754 # define LINUX_LOADMAP PT_GETDSBT
5755 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
5756 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
5758 struct target_loadmap
5760 /* Protocol version number, must be zero. */
5762 /* Number of segments in this map. */
5764 /* The actual memory map. */
5765 struct target_loadseg segs
[/*nsegs*/];
5767 # define LINUX_LOADMAP PTRACE_GETFDPIC
5768 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
5769 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
5773 linux_read_loadmap (const char *annex
, CORE_ADDR offset
,
5774 unsigned char *myaddr
, unsigned int len
)
5776 int pid
= lwpid_of (current_thread
);
5778 struct target_loadmap
*data
= NULL
;
5779 unsigned int actual_length
, copy_length
;
5781 if (strcmp (annex
, "exec") == 0)
5782 addr
= (int) LINUX_LOADMAP_EXEC
;
5783 else if (strcmp (annex
, "interp") == 0)
5784 addr
= (int) LINUX_LOADMAP_INTERP
;
5788 if (ptrace (LINUX_LOADMAP
, pid
, addr
, &data
) != 0)
5794 actual_length
= sizeof (struct target_loadmap
)
5795 + sizeof (struct target_loadseg
) * data
->nsegs
;
5797 if (offset
< 0 || offset
> actual_length
)
5800 copy_length
= actual_length
- offset
< len
? actual_length
- offset
: len
;
5801 memcpy (myaddr
, (char *) data
+ offset
, copy_length
);
5805 # define linux_read_loadmap NULL
5806 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
5809 linux_process_qsupported (const char *query
)
5811 if (the_low_target
.process_qsupported
!= NULL
)
5812 the_low_target
.process_qsupported (query
);
5816 linux_supports_tracepoints (void)
5818 if (*the_low_target
.supports_tracepoints
== NULL
)
5821 return (*the_low_target
.supports_tracepoints
) ();
5825 linux_read_pc (struct regcache
*regcache
)
5827 if (the_low_target
.get_pc
== NULL
)
5830 return (*the_low_target
.get_pc
) (regcache
);
5834 linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
5836 gdb_assert (the_low_target
.set_pc
!= NULL
);
5838 (*the_low_target
.set_pc
) (regcache
, pc
);
5842 linux_thread_stopped (struct thread_info
*thread
)
5844 return get_thread_lwp (thread
)->stopped
;
5847 /* This exposes stop-all-threads functionality to other modules. */
5850 linux_pause_all (int freeze
)
5852 stop_all_lwps (freeze
, NULL
);
5855 /* This exposes unstop-all-threads functionality to other gdbserver
5859 linux_unpause_all (int unfreeze
)
5861 unstop_all_lwps (unfreeze
, NULL
);
5865 linux_prepare_to_access_memory (void)
5867 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5870 linux_pause_all (1);
5875 linux_done_accessing_memory (void)
5877 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5880 linux_unpause_all (1);
5884 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint
, CORE_ADDR tpaddr
,
5885 CORE_ADDR collector
,
5888 CORE_ADDR
*jump_entry
,
5889 CORE_ADDR
*trampoline
,
5890 ULONGEST
*trampoline_size
,
5891 unsigned char *jjump_pad_insn
,
5892 ULONGEST
*jjump_pad_insn_size
,
5893 CORE_ADDR
*adjusted_insn_addr
,
5894 CORE_ADDR
*adjusted_insn_addr_end
,
5897 return (*the_low_target
.install_fast_tracepoint_jump_pad
)
5898 (tpoint
, tpaddr
, collector
, lockaddr
, orig_size
,
5899 jump_entry
, trampoline
, trampoline_size
,
5900 jjump_pad_insn
, jjump_pad_insn_size
,
5901 adjusted_insn_addr
, adjusted_insn_addr_end
,
5905 static struct emit_ops
*
5906 linux_emit_ops (void)
5908 if (the_low_target
.emit_ops
!= NULL
)
5909 return (*the_low_target
.emit_ops
) ();
5915 linux_get_min_fast_tracepoint_insn_len (void)
5917 return (*the_low_target
.get_min_fast_tracepoint_insn_len
) ();
5920 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
5923 get_phdr_phnum_from_proc_auxv (const int pid
, const int is_elf64
,
5924 CORE_ADDR
*phdr_memaddr
, int *num_phdr
)
5926 char filename
[PATH_MAX
];
5928 const int auxv_size
= is_elf64
5929 ? sizeof (Elf64_auxv_t
) : sizeof (Elf32_auxv_t
);
5930 char buf
[sizeof (Elf64_auxv_t
)]; /* The larger of the two. */
5932 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
5934 fd
= open (filename
, O_RDONLY
);
5940 while (read (fd
, buf
, auxv_size
) == auxv_size
5941 && (*phdr_memaddr
== 0 || *num_phdr
== 0))
5945 Elf64_auxv_t
*const aux
= (Elf64_auxv_t
*) buf
;
5947 switch (aux
->a_type
)
5950 *phdr_memaddr
= aux
->a_un
.a_val
;
5953 *num_phdr
= aux
->a_un
.a_val
;
5959 Elf32_auxv_t
*const aux
= (Elf32_auxv_t
*) buf
;
5961 switch (aux
->a_type
)
5964 *phdr_memaddr
= aux
->a_un
.a_val
;
5967 *num_phdr
= aux
->a_un
.a_val
;
5975 if (*phdr_memaddr
== 0 || *num_phdr
== 0)
5977 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
5978 "phdr_memaddr = %ld, phdr_num = %d",
5979 (long) *phdr_memaddr
, *num_phdr
);
5986 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
5989 get_dynamic (const int pid
, const int is_elf64
)
5991 CORE_ADDR phdr_memaddr
, relocation
;
5993 unsigned char *phdr_buf
;
5994 const int phdr_size
= is_elf64
? sizeof (Elf64_Phdr
) : sizeof (Elf32_Phdr
);
5996 if (get_phdr_phnum_from_proc_auxv (pid
, is_elf64
, &phdr_memaddr
, &num_phdr
))
5999 gdb_assert (num_phdr
< 100); /* Basic sanity check. */
6000 phdr_buf
= alloca (num_phdr
* phdr_size
);
6002 if (linux_read_memory (phdr_memaddr
, phdr_buf
, num_phdr
* phdr_size
))
6005 /* Compute relocation: it is expected to be 0 for "regular" executables,
6006 non-zero for PIE ones. */
6008 for (i
= 0; relocation
== -1 && i
< num_phdr
; i
++)
6011 Elf64_Phdr
*const p
= (Elf64_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6013 if (p
->p_type
== PT_PHDR
)
6014 relocation
= phdr_memaddr
- p
->p_vaddr
;
6018 Elf32_Phdr
*const p
= (Elf32_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6020 if (p
->p_type
== PT_PHDR
)
6021 relocation
= phdr_memaddr
- p
->p_vaddr
;
6024 if (relocation
== -1)
6026 /* PT_PHDR is optional, but necessary for PIE in general. Fortunately
6027 any real world executables, including PIE executables, have always
6028 PT_PHDR present. PT_PHDR is not present in some shared libraries or
6029 in fpc (Free Pascal 2.4) binaries but neither of those have a need for
6030 or present DT_DEBUG anyway (fpc binaries are statically linked).
6032 Therefore if there exists DT_DEBUG there is always also PT_PHDR.
6034 GDB could find RELOCATION also from AT_ENTRY - e_entry. */
6039 for (i
= 0; i
< num_phdr
; i
++)
6043 Elf64_Phdr
*const p
= (Elf64_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6045 if (p
->p_type
== PT_DYNAMIC
)
6046 return p
->p_vaddr
+ relocation
;
6050 Elf32_Phdr
*const p
= (Elf32_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6052 if (p
->p_type
== PT_DYNAMIC
)
6053 return p
->p_vaddr
+ relocation
;
6060 /* Return &_r_debug in the inferior, or -1 if not present. Return value
6061 can be 0 if the inferior does not yet have the library list initialized.
6062 We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of
6063 DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */
6066 get_r_debug (const int pid
, const int is_elf64
)
6068 CORE_ADDR dynamic_memaddr
;
6069 const int dyn_size
= is_elf64
? sizeof (Elf64_Dyn
) : sizeof (Elf32_Dyn
);
6070 unsigned char buf
[sizeof (Elf64_Dyn
)]; /* The larger of the two. */
6073 dynamic_memaddr
= get_dynamic (pid
, is_elf64
);
6074 if (dynamic_memaddr
== 0)
6077 while (linux_read_memory (dynamic_memaddr
, buf
, dyn_size
) == 0)
6081 Elf64_Dyn
*const dyn
= (Elf64_Dyn
*) buf
;
6082 #ifdef DT_MIPS_RLD_MAP
6086 unsigned char buf
[sizeof (Elf64_Xword
)];
6090 if (dyn
->d_tag
== DT_MIPS_RLD_MAP
)
6092 if (linux_read_memory (dyn
->d_un
.d_val
,
6093 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6098 #endif /* DT_MIPS_RLD_MAP */
6100 if (dyn
->d_tag
== DT_DEBUG
&& map
== -1)
6101 map
= dyn
->d_un
.d_val
;
6103 if (dyn
->d_tag
== DT_NULL
)
6108 Elf32_Dyn
*const dyn
= (Elf32_Dyn
*) buf
;
6109 #ifdef DT_MIPS_RLD_MAP
6113 unsigned char buf
[sizeof (Elf32_Word
)];
6117 if (dyn
->d_tag
== DT_MIPS_RLD_MAP
)
6119 if (linux_read_memory (dyn
->d_un
.d_val
,
6120 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6125 #endif /* DT_MIPS_RLD_MAP */
6127 if (dyn
->d_tag
== DT_DEBUG
&& map
== -1)
6128 map
= dyn
->d_un
.d_val
;
6130 if (dyn
->d_tag
== DT_NULL
)
6134 dynamic_memaddr
+= dyn_size
;
6140 /* Read one pointer from MEMADDR in the inferior. */
6143 read_one_ptr (CORE_ADDR memaddr
, CORE_ADDR
*ptr
, int ptr_size
)
6147 /* Go through a union so this works on either big or little endian
6148 hosts, when the inferior's pointer size is smaller than the size
6149 of CORE_ADDR. It is assumed the inferior's endianness is the
6150 same of the superior's. */
6153 CORE_ADDR core_addr
;
6158 ret
= linux_read_memory (memaddr
, &addr
.uc
, ptr_size
);
6161 if (ptr_size
== sizeof (CORE_ADDR
))
6162 *ptr
= addr
.core_addr
;
6163 else if (ptr_size
== sizeof (unsigned int))
6166 gdb_assert_not_reached ("unhandled pointer size");
6171 struct link_map_offsets
6173 /* Offset and size of r_debug.r_version. */
6174 int r_version_offset
;
6176 /* Offset and size of r_debug.r_map. */
6179 /* Offset to l_addr field in struct link_map. */
6182 /* Offset to l_name field in struct link_map. */
6185 /* Offset to l_ld field in struct link_map. */
6188 /* Offset to l_next field in struct link_map. */
6191 /* Offset to l_prev field in struct link_map. */
6195 /* Construct qXfer:libraries-svr4:read reply. */
6198 linux_qxfer_libraries_svr4 (const char *annex
, unsigned char *readbuf
,
6199 unsigned const char *writebuf
,
6200 CORE_ADDR offset
, int len
)
6203 unsigned document_len
;
6204 struct process_info_private
*const priv
= current_process ()->priv
;
6205 char filename
[PATH_MAX
];
6208 static const struct link_map_offsets lmo_32bit_offsets
=
6210 0, /* r_version offset. */
6211 4, /* r_debug.r_map offset. */
6212 0, /* l_addr offset in link_map. */
6213 4, /* l_name offset in link_map. */
6214 8, /* l_ld offset in link_map. */
6215 12, /* l_next offset in link_map. */
6216 16 /* l_prev offset in link_map. */
6219 static const struct link_map_offsets lmo_64bit_offsets
=
6221 0, /* r_version offset. */
6222 8, /* r_debug.r_map offset. */
6223 0, /* l_addr offset in link_map. */
6224 8, /* l_name offset in link_map. */
6225 16, /* l_ld offset in link_map. */
6226 24, /* l_next offset in link_map. */
6227 32 /* l_prev offset in link_map. */
6229 const struct link_map_offsets
*lmo
;
6230 unsigned int machine
;
6232 CORE_ADDR lm_addr
= 0, lm_prev
= 0;
6233 int allocated
= 1024;
6235 CORE_ADDR l_name
, l_addr
, l_ld
, l_next
, l_prev
;
6236 int header_done
= 0;
6238 if (writebuf
!= NULL
)
6240 if (readbuf
== NULL
)
6243 pid
= lwpid_of (current_thread
);
6244 xsnprintf (filename
, sizeof filename
, "/proc/%d/exe", pid
);
6245 is_elf64
= elf_64_file_p (filename
, &machine
);
6246 lmo
= is_elf64
? &lmo_64bit_offsets
: &lmo_32bit_offsets
;
6247 ptr_size
= is_elf64
? 8 : 4;
6249 while (annex
[0] != '\0')
6255 sep
= strchr (annex
, '=');
6260 if (len
== 5 && startswith (annex
, "start"))
6262 else if (len
== 4 && startswith (annex
, "prev"))
6266 annex
= strchr (sep
, ';');
6273 annex
= decode_address_to_semicolon (addrp
, sep
+ 1);
6280 if (priv
->r_debug
== 0)
6281 priv
->r_debug
= get_r_debug (pid
, is_elf64
);
6283 /* We failed to find DT_DEBUG. Such situation will not change
6284 for this inferior - do not retry it. Report it to GDB as
6285 E01, see for the reasons at the GDB solib-svr4.c side. */
6286 if (priv
->r_debug
== (CORE_ADDR
) -1)
6289 if (priv
->r_debug
!= 0)
6291 if (linux_read_memory (priv
->r_debug
+ lmo
->r_version_offset
,
6292 (unsigned char *) &r_version
,
6293 sizeof (r_version
)) != 0
6296 warning ("unexpected r_debug version %d", r_version
);
6298 else if (read_one_ptr (priv
->r_debug
+ lmo
->r_map_offset
,
6299 &lm_addr
, ptr_size
) != 0)
6301 warning ("unable to read r_map from 0x%lx",
6302 (long) priv
->r_debug
+ lmo
->r_map_offset
);
6307 document
= xmalloc (allocated
);
6308 strcpy (document
, "<library-list-svr4 version=\"1.0\"");
6309 p
= document
+ strlen (document
);
6312 && read_one_ptr (lm_addr
+ lmo
->l_name_offset
,
6313 &l_name
, ptr_size
) == 0
6314 && read_one_ptr (lm_addr
+ lmo
->l_addr_offset
,
6315 &l_addr
, ptr_size
) == 0
6316 && read_one_ptr (lm_addr
+ lmo
->l_ld_offset
,
6317 &l_ld
, ptr_size
) == 0
6318 && read_one_ptr (lm_addr
+ lmo
->l_prev_offset
,
6319 &l_prev
, ptr_size
) == 0
6320 && read_one_ptr (lm_addr
+ lmo
->l_next_offset
,
6321 &l_next
, ptr_size
) == 0)
6323 unsigned char libname
[PATH_MAX
];
6325 if (lm_prev
!= l_prev
)
6327 warning ("Corrupted shared library list: 0x%lx != 0x%lx",
6328 (long) lm_prev
, (long) l_prev
);
6332 /* Ignore the first entry even if it has valid name as the first entry
6333 corresponds to the main executable. The first entry should not be
6334 skipped if the dynamic loader was loaded late by a static executable
6335 (see solib-svr4.c parameter ignore_first). But in such case the main
6336 executable does not have PT_DYNAMIC present and this function already
6337 exited above due to failed get_r_debug. */
6340 sprintf (p
, " main-lm=\"0x%lx\"", (unsigned long) lm_addr
);
6345 /* Not checking for error because reading may stop before
6346 we've got PATH_MAX worth of characters. */
6348 linux_read_memory (l_name
, libname
, sizeof (libname
) - 1);
6349 libname
[sizeof (libname
) - 1] = '\0';
6350 if (libname
[0] != '\0')
6352 /* 6x the size for xml_escape_text below. */
6353 size_t len
= 6 * strlen ((char *) libname
);
6358 /* Terminate `<library-list-svr4'. */
6363 while (allocated
< p
- document
+ len
+ 200)
6365 /* Expand to guarantee sufficient storage. */
6366 uintptr_t document_len
= p
- document
;
6368 document
= xrealloc (document
, 2 * allocated
);
6370 p
= document
+ document_len
;
6373 name
= xml_escape_text ((char *) libname
);
6374 p
+= sprintf (p
, "<library name=\"%s\" lm=\"0x%lx\" "
6375 "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
6376 name
, (unsigned long) lm_addr
,
6377 (unsigned long) l_addr
, (unsigned long) l_ld
);
6388 /* Empty list; terminate `<library-list-svr4'. */
6392 strcpy (p
, "</library-list-svr4>");
6394 document_len
= strlen (document
);
6395 if (offset
< document_len
)
6396 document_len
-= offset
;
6399 if (len
> document_len
)
6402 memcpy (readbuf
, document
+ offset
, len
);
6408 #ifdef HAVE_LINUX_BTRACE
6410 /* See to_enable_btrace target method. */
6412 static struct btrace_target_info
*
6413 linux_low_enable_btrace (ptid_t ptid
, const struct btrace_config
*conf
)
6415 struct btrace_target_info
*tinfo
;
6417 tinfo
= linux_enable_btrace (ptid
, conf
);
6419 if (tinfo
!= NULL
&& tinfo
->ptr_bits
== 0)
6421 struct thread_info
*thread
= find_thread_ptid (ptid
);
6422 struct regcache
*regcache
= get_thread_regcache (thread
, 0);
6424 tinfo
->ptr_bits
= register_size (regcache
->tdesc
, 0) * 8;
6430 /* See to_disable_btrace target method. */
6433 linux_low_disable_btrace (struct btrace_target_info
*tinfo
)
6435 enum btrace_error err
;
6437 err
= linux_disable_btrace (tinfo
);
6438 return (err
== BTRACE_ERR_NONE
? 0 : -1);
6441 /* See to_read_btrace target method. */
6444 linux_low_read_btrace (struct btrace_target_info
*tinfo
, struct buffer
*buffer
,
6447 struct btrace_data btrace
;
6448 struct btrace_block
*block
;
6449 enum btrace_error err
;
6452 btrace_data_init (&btrace
);
6454 err
= linux_read_btrace (&btrace
, tinfo
, type
);
6455 if (err
!= BTRACE_ERR_NONE
)
6457 if (err
== BTRACE_ERR_OVERFLOW
)
6458 buffer_grow_str0 (buffer
, "E.Overflow.");
6460 buffer_grow_str0 (buffer
, "E.Generic Error.");
6462 btrace_data_fini (&btrace
);
6466 switch (btrace
.format
)
6468 case BTRACE_FORMAT_NONE
:
6469 buffer_grow_str0 (buffer
, "E.No Trace.");
6472 case BTRACE_FORMAT_BTS
:
6473 buffer_grow_str (buffer
, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n");
6474 buffer_grow_str (buffer
, "<btrace version=\"1.0\">\n");
6477 VEC_iterate (btrace_block_s
, btrace
.variant
.bts
.blocks
, i
, block
);
6479 buffer_xml_printf (buffer
, "<block begin=\"0x%s\" end=\"0x%s\"/>\n",
6480 paddress (block
->begin
), paddress (block
->end
));
6482 buffer_grow_str0 (buffer
, "</btrace>\n");
6486 buffer_grow_str0 (buffer
, "E.Unknown Trace Format.");
6488 btrace_data_fini (&btrace
);
6492 btrace_data_fini (&btrace
);
6496 /* See to_btrace_conf target method. */
6499 linux_low_btrace_conf (const struct btrace_target_info
*tinfo
,
6500 struct buffer
*buffer
)
6502 const struct btrace_config
*conf
;
6504 buffer_grow_str (buffer
, "<!DOCTYPE btrace-conf SYSTEM \"btrace-conf.dtd\">\n");
6505 buffer_grow_str (buffer
, "<btrace-conf version=\"1.0\">\n");
6507 conf
= linux_btrace_conf (tinfo
);
6510 switch (conf
->format
)
6512 case BTRACE_FORMAT_NONE
:
6515 case BTRACE_FORMAT_BTS
:
6516 buffer_xml_printf (buffer
, "<bts");
6517 buffer_xml_printf (buffer
, " size=\"0x%x\"", conf
->bts
.size
);
6518 buffer_xml_printf (buffer
, " />\n");
6523 buffer_grow_str0 (buffer
, "</btrace-conf>\n");
6526 #endif /* HAVE_LINUX_BTRACE */
6528 /* See nat/linux-nat.h. */
6531 current_lwp_ptid (void)
6533 return ptid_of (current_thread
);
6536 static struct target_ops linux_target_ops
= {
6537 linux_create_inferior
,
6546 linux_fetch_registers
,
6547 linux_store_registers
,
6548 linux_prepare_to_access_memory
,
6549 linux_done_accessing_memory
,
6552 linux_look_up_symbols
,
6553 linux_request_interrupt
,
6555 linux_supports_z_point_type
,
6558 linux_stopped_by_sw_breakpoint
,
6559 linux_supports_stopped_by_sw_breakpoint
,
6560 linux_stopped_by_hw_breakpoint
,
6561 linux_supports_stopped_by_hw_breakpoint
,
6562 linux_supports_conditional_breakpoints
,
6563 linux_stopped_by_watchpoint
,
6564 linux_stopped_data_address
,
6565 #if defined(__UCLIBC__) && defined(HAS_NOMMU) \
6566 && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
6567 && defined(PT_TEXT_END_ADDR)
6572 #ifdef USE_THREAD_DB
6573 thread_db_get_tls_address
,
6578 hostio_last_error_from_errno
,
6581 linux_supports_non_stop
,
6583 linux_start_non_stop
,
6584 linux_supports_multi_process
,
6585 linux_supports_fork_events
,
6586 linux_supports_vfork_events
,
6587 linux_handle_new_gdb_connection
,
6588 #ifdef USE_THREAD_DB
6589 thread_db_handle_monitor_command
,
6593 linux_common_core_of_thread
,
6595 linux_process_qsupported
,
6596 linux_supports_tracepoints
,
6599 linux_thread_stopped
,
6603 linux_stabilize_threads
,
6604 linux_install_fast_tracepoint_jump_pad
,
6606 linux_supports_disable_randomization
,
6607 linux_get_min_fast_tracepoint_insn_len
,
6608 linux_qxfer_libraries_svr4
,
6609 linux_supports_agent
,
6610 #ifdef HAVE_LINUX_BTRACE
6611 linux_supports_btrace
,
6612 linux_low_enable_btrace
,
6613 linux_low_disable_btrace
,
6614 linux_low_read_btrace
,
6615 linux_low_btrace_conf
,
6623 linux_supports_range_stepping
,
6624 linux_proc_pid_to_exec_file
,
6628 linux_init_signals ()
6630 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
6631 to find what the cancel signal actually is. */
6632 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
6633 signal (__SIGRTMIN
+1, SIG_IGN
);
6637 #ifdef HAVE_LINUX_REGSETS
6639 initialize_regsets_info (struct regsets_info
*info
)
6641 for (info
->num_regsets
= 0;
6642 info
->regsets
[info
->num_regsets
].size
>= 0;
6643 info
->num_regsets
++)
6649 initialize_low (void)
6651 struct sigaction sigchld_action
;
6652 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
6653 set_target_ops (&linux_target_ops
);
6654 set_breakpoint_data (the_low_target
.breakpoint
,
6655 the_low_target
.breakpoint_len
);
6656 linux_init_signals ();
6657 linux_ptrace_init_warnings ();
6659 sigchld_action
.sa_handler
= sigchld_handler
;
6660 sigemptyset (&sigchld_action
.sa_mask
);
6661 sigchld_action
.sa_flags
= SA_RESTART
;
6662 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
6664 initialize_low_arch ();
6666 linux_check_ptrace_features ();