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 /* Save fork info in the parent thread. */
493 event_lwp
->waitstatus
.kind
= TARGET_WAITKIND_FORKED
;
494 event_lwp
->waitstatus
.value
.related_pid
= ptid
;
495 /* The status_pending field contains bits denoting the
496 extended event, so when the pending event is handled,
497 the handler will look at lwp->waitstatus. */
498 event_lwp
->status_pending_p
= 1;
499 event_lwp
->status_pending
= wstat
;
501 /* Report the event. */
506 debug_printf ("HEW: Got clone event "
507 "from LWP %ld, new child is LWP %ld\n",
508 lwpid_of (event_thr
), new_pid
);
510 ptid
= ptid_build (pid_of (event_thr
), new_pid
, 0);
511 new_lwp
= add_lwp (ptid
);
513 /* Either we're going to immediately resume the new thread
514 or leave it stopped. linux_resume_one_lwp is a nop if it
515 thinks the thread is currently running, so set this first
516 before calling linux_resume_one_lwp. */
517 new_lwp
->stopped
= 1;
519 /* If we're suspending all threads, leave this one suspended
521 if (stopping_threads
== STOPPING_AND_SUSPENDING_THREADS
)
522 new_lwp
->suspended
= 1;
524 /* Normally we will get the pending SIGSTOP. But in some cases
525 we might get another signal delivered to the group first.
526 If we do get another signal, be sure not to lose it. */
527 if (WSTOPSIG (status
) != SIGSTOP
)
529 new_lwp
->stop_expected
= 1;
530 new_lwp
->status_pending_p
= 1;
531 new_lwp
->status_pending
= status
;
534 /* Don't report the event. */
538 internal_error (__FILE__
, __LINE__
, _("unknown ptrace event %d"), event
);
541 /* Return the PC as read from the regcache of LWP, without any
545 get_pc (struct lwp_info
*lwp
)
547 struct thread_info
*saved_thread
;
548 struct regcache
*regcache
;
551 if (the_low_target
.get_pc
== NULL
)
554 saved_thread
= current_thread
;
555 current_thread
= get_lwp_thread (lwp
);
557 regcache
= get_thread_regcache (current_thread
, 1);
558 pc
= (*the_low_target
.get_pc
) (regcache
);
561 debug_printf ("pc is 0x%lx\n", (long) pc
);
563 current_thread
= saved_thread
;
567 /* This function should only be called if LWP got a SIGTRAP.
568 The SIGTRAP could mean several things.
570 On i386, where decr_pc_after_break is non-zero:
572 If we were single-stepping this process using PTRACE_SINGLESTEP, we
573 will get only the one SIGTRAP. The value of $eip will be the next
574 instruction. If the instruction we stepped over was a breakpoint,
575 we need to decrement the PC.
577 If we continue the process using PTRACE_CONT, we will get a
578 SIGTRAP when we hit a breakpoint. The value of $eip will be
579 the instruction after the breakpoint (i.e. needs to be
580 decremented). If we report the SIGTRAP to GDB, we must also
581 report the undecremented PC. If the breakpoint is removed, we
582 must resume at the decremented PC.
584 On a non-decr_pc_after_break machine with hardware or kernel
587 If we either single-step a breakpoint instruction, or continue and
588 hit a breakpoint instruction, our PC will point at the breakpoint
592 check_stopped_by_breakpoint (struct lwp_info
*lwp
)
595 CORE_ADDR sw_breakpoint_pc
;
596 struct thread_info
*saved_thread
;
597 #if USE_SIGTRAP_SIGINFO
601 if (the_low_target
.get_pc
== NULL
)
605 sw_breakpoint_pc
= pc
- the_low_target
.decr_pc_after_break
;
607 /* breakpoint_at reads from the current thread. */
608 saved_thread
= current_thread
;
609 current_thread
= get_lwp_thread (lwp
);
611 #if USE_SIGTRAP_SIGINFO
612 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
613 (PTRACE_TYPE_ARG3
) 0, &siginfo
) == 0)
615 if (siginfo
.si_signo
== SIGTRAP
)
617 if (siginfo
.si_code
== GDB_ARCH_TRAP_BRKPT
)
621 struct thread_info
*thr
= get_lwp_thread (lwp
);
623 debug_printf ("CSBB: %s stopped by software breakpoint\n",
624 target_pid_to_str (ptid_of (thr
)));
627 /* Back up the PC if necessary. */
628 if (pc
!= sw_breakpoint_pc
)
630 struct regcache
*regcache
631 = get_thread_regcache (current_thread
, 1);
632 (*the_low_target
.set_pc
) (regcache
, sw_breakpoint_pc
);
635 lwp
->stop_pc
= sw_breakpoint_pc
;
636 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
637 current_thread
= saved_thread
;
640 else if (siginfo
.si_code
== TRAP_HWBKPT
)
644 struct thread_info
*thr
= get_lwp_thread (lwp
);
646 debug_printf ("CSBB: %s stopped by hardware "
647 "breakpoint/watchpoint\n",
648 target_pid_to_str (ptid_of (thr
)));
652 lwp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
653 current_thread
= saved_thread
;
656 else if (siginfo
.si_code
== TRAP_TRACE
)
660 struct thread_info
*thr
= get_lwp_thread (lwp
);
662 debug_printf ("CSBB: %s stopped by trace\n",
663 target_pid_to_str (ptid_of (thr
)));
669 /* We may have just stepped a breakpoint instruction. E.g., in
670 non-stop mode, GDB first tells the thread A to step a range, and
671 then the user inserts a breakpoint inside the range. In that
672 case we need to report the breakpoint PC. */
673 if ((!lwp
->stepping
|| lwp
->stop_pc
== sw_breakpoint_pc
)
674 && (*the_low_target
.breakpoint_at
) (sw_breakpoint_pc
))
678 struct thread_info
*thr
= get_lwp_thread (lwp
);
680 debug_printf ("CSBB: %s stopped by software breakpoint\n",
681 target_pid_to_str (ptid_of (thr
)));
684 /* Back up the PC if necessary. */
685 if (pc
!= sw_breakpoint_pc
)
687 struct regcache
*regcache
688 = get_thread_regcache (current_thread
, 1);
689 (*the_low_target
.set_pc
) (regcache
, sw_breakpoint_pc
);
692 lwp
->stop_pc
= sw_breakpoint_pc
;
693 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
694 current_thread
= saved_thread
;
698 if (hardware_breakpoint_inserted_here (pc
))
702 struct thread_info
*thr
= get_lwp_thread (lwp
);
704 debug_printf ("CSBB: %s stopped by hardware breakpoint\n",
705 target_pid_to_str (ptid_of (thr
)));
709 lwp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
710 current_thread
= saved_thread
;
715 current_thread
= saved_thread
;
719 static struct lwp_info
*
720 add_lwp (ptid_t ptid
)
722 struct lwp_info
*lwp
;
724 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
725 memset (lwp
, 0, sizeof (*lwp
));
727 if (the_low_target
.new_thread
!= NULL
)
728 the_low_target
.new_thread (lwp
);
730 lwp
->thread
= add_thread (ptid
, lwp
);
735 /* Start an inferior process and returns its pid.
736 ALLARGS is a vector of program-name and args. */
739 linux_create_inferior (char *program
, char **allargs
)
741 struct lwp_info
*new_lwp
;
744 struct cleanup
*restore_personality
745 = maybe_disable_address_space_randomization (disable_randomization
);
747 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
753 perror_with_name ("fork");
758 ptrace (PTRACE_TRACEME
, 0, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0);
760 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
761 signal (__SIGRTMIN
+ 1, SIG_DFL
);
766 /* If gdbserver is connected to gdb via stdio, redirect the inferior's
767 stdout to stderr so that inferior i/o doesn't corrupt the connection.
768 Also, redirect stdin to /dev/null. */
769 if (remote_connection_is_stdio ())
772 open ("/dev/null", O_RDONLY
);
774 if (write (2, "stdin/stdout redirected\n",
775 sizeof ("stdin/stdout redirected\n") - 1) < 0)
777 /* Errors ignored. */;
781 execv (program
, allargs
);
783 execvp (program
, allargs
);
785 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
791 do_cleanups (restore_personality
);
793 linux_add_process (pid
, 0);
795 ptid
= ptid_build (pid
, pid
, 0);
796 new_lwp
= add_lwp (ptid
);
797 new_lwp
->must_set_ptrace_flags
= 1;
802 /* Attach to an inferior process. Returns 0 on success, ERRNO on
806 linux_attach_lwp (ptid_t ptid
)
808 struct lwp_info
*new_lwp
;
809 int lwpid
= ptid_get_lwp (ptid
);
811 if (ptrace (PTRACE_ATTACH
, lwpid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0)
815 new_lwp
= add_lwp (ptid
);
817 /* We need to wait for SIGSTOP before being able to make the next
818 ptrace call on this LWP. */
819 new_lwp
->must_set_ptrace_flags
= 1;
821 if (linux_proc_pid_is_stopped (lwpid
))
824 debug_printf ("Attached to a stopped process\n");
826 /* The process is definitely stopped. It is in a job control
827 stop, unless the kernel predates the TASK_STOPPED /
828 TASK_TRACED distinction, in which case it might be in a
829 ptrace stop. Make sure it is in a ptrace stop; from there we
830 can kill it, signal it, et cetera.
832 First make sure there is a pending SIGSTOP. Since we are
833 already attached, the process can not transition from stopped
834 to running without a PTRACE_CONT; so we know this signal will
835 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
836 probably already in the queue (unless this kernel is old
837 enough to use TASK_STOPPED for ptrace stops); but since
838 SIGSTOP is not an RT signal, it can only be queued once. */
839 kill_lwp (lwpid
, SIGSTOP
);
841 /* Finally, resume the stopped process. This will deliver the
842 SIGSTOP (or a higher priority signal, just like normal
843 PTRACE_ATTACH), which we'll catch later on. */
844 ptrace (PTRACE_CONT
, lwpid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0);
847 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
850 There are several cases to consider here:
852 1) gdbserver has already attached to the process and is being notified
853 of a new thread that is being created.
854 In this case we should ignore that SIGSTOP and resume the
855 process. This is handled below by setting stop_expected = 1,
856 and the fact that add_thread sets last_resume_kind ==
859 2) This is the first thread (the process thread), and we're attaching
860 to it via attach_inferior.
861 In this case we want the process thread to stop.
862 This is handled by having linux_attach set last_resume_kind ==
863 resume_stop after we return.
865 If the pid we are attaching to is also the tgid, we attach to and
866 stop all the existing threads. Otherwise, we attach to pid and
867 ignore any other threads in the same group as this pid.
869 3) GDB is connecting to gdbserver and is requesting an enumeration of all
871 In this case we want the thread to stop.
872 FIXME: This case is currently not properly handled.
873 We should wait for the SIGSTOP but don't. Things work apparently
874 because enough time passes between when we ptrace (ATTACH) and when
875 gdb makes the next ptrace call on the thread.
877 On the other hand, if we are currently trying to stop all threads, we
878 should treat the new thread as if we had sent it a SIGSTOP. This works
879 because we are guaranteed that the add_lwp call above added us to the
880 end of the list, and so the new thread has not yet reached
881 wait_for_sigstop (but will). */
882 new_lwp
->stop_expected
= 1;
887 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
888 already attached. Returns true if a new LWP is found, false
892 attach_proc_task_lwp_callback (ptid_t ptid
)
894 /* Is this a new thread? */
895 if (find_thread_ptid (ptid
) == NULL
)
897 int lwpid
= ptid_get_lwp (ptid
);
901 debug_printf ("Found new lwp %d\n", lwpid
);
903 err
= linux_attach_lwp (ptid
);
905 /* Be quiet if we simply raced with the thread exiting. EPERM
906 is returned if the thread's task still exists, and is marked
907 as exited or zombie, as well as other conditions, so in that
908 case, confirm the status in /proc/PID/status. */
910 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
914 debug_printf ("Cannot attach to lwp %d: "
915 "thread is gone (%d: %s)\n",
916 lwpid
, err
, strerror (err
));
921 warning (_("Cannot attach to lwp %d: %s"),
923 linux_ptrace_attach_fail_reason_string (ptid
, err
));
931 /* Attach to PID. If PID is the tgid, attach to it and all
935 linux_attach (unsigned long pid
)
937 ptid_t ptid
= ptid_build (pid
, pid
, 0);
940 /* Attach to PID. We will check for other threads
942 err
= linux_attach_lwp (ptid
);
944 error ("Cannot attach to process %ld: %s",
945 pid
, linux_ptrace_attach_fail_reason_string (ptid
, err
));
947 linux_add_process (pid
, 1);
951 struct thread_info
*thread
;
953 /* Don't ignore the initial SIGSTOP if we just attached to this
954 process. It will be collected by wait shortly. */
955 thread
= find_thread_ptid (ptid_build (pid
, pid
, 0));
956 thread
->last_resume_kind
= resume_stop
;
959 /* We must attach to every LWP. If /proc is mounted, use that to
960 find them now. On the one hand, the inferior may be using raw
961 clone instead of using pthreads. On the other hand, even if it
962 is using pthreads, GDB may not be connected yet (thread_db needs
963 to do symbol lookups, through qSymbol). Also, thread_db walks
964 structures in the inferior's address space to find the list of
965 threads/LWPs, and those structures may well be corrupted. Note
966 that once thread_db is loaded, we'll still use it to list threads
967 and associate pthread info with each LWP. */
968 linux_proc_attach_tgid_threads (pid
, attach_proc_task_lwp_callback
);
979 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
981 struct counter
*counter
= args
;
983 if (ptid_get_pid (entry
->id
) == counter
->pid
)
985 if (++counter
->count
> 1)
993 last_thread_of_process_p (int pid
)
995 struct counter counter
= { pid
, 0 };
997 return (find_inferior (&all_threads
,
998 second_thread_of_pid_p
, &counter
) == NULL
);
1004 linux_kill_one_lwp (struct lwp_info
*lwp
)
1006 struct thread_info
*thr
= get_lwp_thread (lwp
);
1007 int pid
= lwpid_of (thr
);
1009 /* PTRACE_KILL is unreliable. After stepping into a signal handler,
1010 there is no signal context, and ptrace(PTRACE_KILL) (or
1011 ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
1012 ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
1013 alternative is to kill with SIGKILL. We only need one SIGKILL
1014 per process, not one for each thread. But since we still support
1015 linuxthreads, and we also support debugging programs using raw
1016 clone without CLONE_THREAD, we send one for each thread. For
1017 years, we used PTRACE_KILL only, so we're being a bit paranoid
1018 about some old kernels where PTRACE_KILL might work better
1019 (dubious if there are any such, but that's why it's paranoia), so
1020 we try SIGKILL first, PTRACE_KILL second, and so we're fine
1024 kill_lwp (pid
, SIGKILL
);
1027 int save_errno
= errno
;
1029 debug_printf ("LKL: kill_lwp (SIGKILL) %s, 0, 0 (%s)\n",
1030 target_pid_to_str (ptid_of (thr
)),
1031 save_errno
? strerror (save_errno
) : "OK");
1035 ptrace (PTRACE_KILL
, pid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0);
1038 int save_errno
= errno
;
1040 debug_printf ("LKL: PTRACE_KILL %s, 0, 0 (%s)\n",
1041 target_pid_to_str (ptid_of (thr
)),
1042 save_errno
? strerror (save_errno
) : "OK");
1046 /* Kill LWP and wait for it to die. */
1049 kill_wait_lwp (struct lwp_info
*lwp
)
1051 struct thread_info
*thr
= get_lwp_thread (lwp
);
1052 int pid
= ptid_get_pid (ptid_of (thr
));
1053 int lwpid
= ptid_get_lwp (ptid_of (thr
));
1058 debug_printf ("kwl: killing lwp %d, for pid: %d\n", lwpid
, pid
);
1062 linux_kill_one_lwp (lwp
);
1064 /* Make sure it died. Notes:
1066 - The loop is most likely unnecessary.
1068 - We don't use linux_wait_for_event as that could delete lwps
1069 while we're iterating over them. We're not interested in
1070 any pending status at this point, only in making sure all
1071 wait status on the kernel side are collected until the
1074 - We don't use __WALL here as the __WALL emulation relies on
1075 SIGCHLD, and killing a stopped process doesn't generate
1076 one, nor an exit status.
1078 res
= my_waitpid (lwpid
, &wstat
, 0);
1079 if (res
== -1 && errno
== ECHILD
)
1080 res
= my_waitpid (lwpid
, &wstat
, __WCLONE
);
1081 } while (res
> 0 && WIFSTOPPED (wstat
));
1083 gdb_assert (res
> 0);
1086 /* Callback for `find_inferior'. Kills an lwp of a given process,
1087 except the leader. */
1090 kill_one_lwp_callback (struct inferior_list_entry
*entry
, void *args
)
1092 struct thread_info
*thread
= (struct thread_info
*) entry
;
1093 struct lwp_info
*lwp
= get_thread_lwp (thread
);
1094 int pid
= * (int *) args
;
1096 if (ptid_get_pid (entry
->id
) != pid
)
1099 /* We avoid killing the first thread here, because of a Linux kernel (at
1100 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
1101 the children get a chance to be reaped, it will remain a zombie
1104 if (lwpid_of (thread
) == pid
)
1107 debug_printf ("lkop: is last of process %s\n",
1108 target_pid_to_str (entry
->id
));
1112 kill_wait_lwp (lwp
);
1117 linux_kill (int pid
)
1119 struct process_info
*process
;
1120 struct lwp_info
*lwp
;
1122 process
= find_process_pid (pid
);
1123 if (process
== NULL
)
1126 /* If we're killing a running inferior, make sure it is stopped
1127 first, as PTRACE_KILL will not work otherwise. */
1128 stop_all_lwps (0, NULL
);
1130 find_inferior (&all_threads
, kill_one_lwp_callback
, &pid
);
1132 /* See the comment in linux_kill_one_lwp. We did not kill the first
1133 thread in the list, so do so now. */
1134 lwp
= find_lwp_pid (pid_to_ptid (pid
));
1139 debug_printf ("lk_1: cannot find lwp for pid: %d\n",
1143 kill_wait_lwp (lwp
);
1145 the_target
->mourn (process
);
1147 /* Since we presently can only stop all lwps of all processes, we
1148 need to unstop lwps of other processes. */
1149 unstop_all_lwps (0, NULL
);
1153 /* Get pending signal of THREAD, for detaching purposes. This is the
1154 signal the thread last stopped for, which we need to deliver to the
1155 thread when detaching, otherwise, it'd be suppressed/lost. */
1158 get_detach_signal (struct thread_info
*thread
)
1160 enum gdb_signal signo
= GDB_SIGNAL_0
;
1162 struct lwp_info
*lp
= get_thread_lwp (thread
);
1164 if (lp
->status_pending_p
)
1165 status
= lp
->status_pending
;
1168 /* If the thread had been suspended by gdbserver, and it stopped
1169 cleanly, then it'll have stopped with SIGSTOP. But we don't
1170 want to deliver that SIGSTOP. */
1171 if (thread
->last_status
.kind
!= TARGET_WAITKIND_STOPPED
1172 || thread
->last_status
.value
.sig
== GDB_SIGNAL_0
)
1175 /* Otherwise, we may need to deliver the signal we
1177 status
= lp
->last_status
;
1180 if (!WIFSTOPPED (status
))
1183 debug_printf ("GPS: lwp %s hasn't stopped: no pending signal\n",
1184 target_pid_to_str (ptid_of (thread
)));
1188 /* Extended wait statuses aren't real SIGTRAPs. */
1189 if (WSTOPSIG (status
) == SIGTRAP
&& linux_is_extended_waitstatus (status
))
1192 debug_printf ("GPS: lwp %s had stopped with extended "
1193 "status: no pending signal\n",
1194 target_pid_to_str (ptid_of (thread
)));
1198 signo
= gdb_signal_from_host (WSTOPSIG (status
));
1200 if (program_signals_p
&& !program_signals
[signo
])
1203 debug_printf ("GPS: lwp %s had signal %s, but it is in nopass state\n",
1204 target_pid_to_str (ptid_of (thread
)),
1205 gdb_signal_to_string (signo
));
1208 else if (!program_signals_p
1209 /* If we have no way to know which signals GDB does not
1210 want to have passed to the program, assume
1211 SIGTRAP/SIGINT, which is GDB's default. */
1212 && (signo
== GDB_SIGNAL_TRAP
|| signo
== GDB_SIGNAL_INT
))
1215 debug_printf ("GPS: lwp %s had signal %s, "
1216 "but we don't know if we should pass it. "
1217 "Default to not.\n",
1218 target_pid_to_str (ptid_of (thread
)),
1219 gdb_signal_to_string (signo
));
1225 debug_printf ("GPS: lwp %s has pending signal %s: delivering it.\n",
1226 target_pid_to_str (ptid_of (thread
)),
1227 gdb_signal_to_string (signo
));
1229 return WSTOPSIG (status
);
1234 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
1236 struct thread_info
*thread
= (struct thread_info
*) entry
;
1237 struct lwp_info
*lwp
= get_thread_lwp (thread
);
1238 int pid
= * (int *) args
;
1241 if (ptid_get_pid (entry
->id
) != pid
)
1244 /* If there is a pending SIGSTOP, get rid of it. */
1245 if (lwp
->stop_expected
)
1248 debug_printf ("Sending SIGCONT to %s\n",
1249 target_pid_to_str (ptid_of (thread
)));
1251 kill_lwp (lwpid_of (thread
), SIGCONT
);
1252 lwp
->stop_expected
= 0;
1255 /* Flush any pending changes to the process's registers. */
1256 regcache_invalidate_thread (thread
);
1258 /* Pass on any pending signal for this thread. */
1259 sig
= get_detach_signal (thread
);
1261 /* Finally, let it resume. */
1262 if (the_low_target
.prepare_to_resume
!= NULL
)
1263 the_low_target
.prepare_to_resume (lwp
);
1264 if (ptrace (PTRACE_DETACH
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
1265 (PTRACE_TYPE_ARG4
) (long) sig
) < 0)
1266 error (_("Can't detach %s: %s"),
1267 target_pid_to_str (ptid_of (thread
)),
1275 linux_detach (int pid
)
1277 struct process_info
*process
;
1279 process
= find_process_pid (pid
);
1280 if (process
== NULL
)
1283 /* Stop all threads before detaching. First, ptrace requires that
1284 the thread is stopped to sucessfully detach. Second, thread_db
1285 may need to uninstall thread event breakpoints from memory, which
1286 only works with a stopped process anyway. */
1287 stop_all_lwps (0, NULL
);
1289 #ifdef USE_THREAD_DB
1290 thread_db_detach (process
);
1293 /* Stabilize threads (move out of jump pads). */
1294 stabilize_threads ();
1296 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
1298 the_target
->mourn (process
);
1300 /* Since we presently can only stop all lwps of all processes, we
1301 need to unstop lwps of other processes. */
1302 unstop_all_lwps (0, NULL
);
1306 /* Remove all LWPs that belong to process PROC from the lwp list. */
1309 delete_lwp_callback (struct inferior_list_entry
*entry
, void *proc
)
1311 struct thread_info
*thread
= (struct thread_info
*) entry
;
1312 struct lwp_info
*lwp
= get_thread_lwp (thread
);
1313 struct process_info
*process
= proc
;
1315 if (pid_of (thread
) == pid_of (process
))
1322 linux_mourn (struct process_info
*process
)
1324 struct process_info_private
*priv
;
1326 #ifdef USE_THREAD_DB
1327 thread_db_mourn (process
);
1330 find_inferior (&all_threads
, delete_lwp_callback
, process
);
1332 /* Freeing all private data. */
1333 priv
= process
->priv
;
1334 free (priv
->arch_private
);
1336 process
->priv
= NULL
;
1338 remove_process (process
);
1342 linux_join (int pid
)
1347 ret
= my_waitpid (pid
, &status
, 0);
1348 if (WIFEXITED (status
) || WIFSIGNALED (status
))
1350 } while (ret
!= -1 || errno
!= ECHILD
);
1353 /* Return nonzero if the given thread is still alive. */
1355 linux_thread_alive (ptid_t ptid
)
1357 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
1359 /* We assume we always know if a thread exits. If a whole process
1360 exited but we still haven't been able to report it to GDB, we'll
1361 hold on to the last lwp of the dead process. */
1368 /* Return 1 if this lwp still has an interesting status pending. If
1369 not (e.g., it had stopped for a breakpoint that is gone), return
1373 thread_still_has_status_pending_p (struct thread_info
*thread
)
1375 struct lwp_info
*lp
= get_thread_lwp (thread
);
1377 if (!lp
->status_pending_p
)
1380 /* If we got a `vCont;t', but we haven't reported a stop yet, do
1381 report any status pending the LWP may have. */
1382 if (thread
->last_resume_kind
== resume_stop
1383 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
1386 if (thread
->last_resume_kind
!= resume_stop
1387 && (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
1388 || lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
1390 struct thread_info
*saved_thread
;
1394 gdb_assert (lp
->last_status
!= 0);
1398 saved_thread
= current_thread
;
1399 current_thread
= thread
;
1401 if (pc
!= lp
->stop_pc
)
1404 debug_printf ("PC of %ld changed\n",
1409 #if !USE_SIGTRAP_SIGINFO
1410 else if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
1411 && !(*the_low_target
.breakpoint_at
) (pc
))
1414 debug_printf ("previous SW breakpoint of %ld gone\n",
1418 else if (lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
1419 && !hardware_breakpoint_inserted_here (pc
))
1422 debug_printf ("previous HW breakpoint of %ld gone\n",
1428 current_thread
= saved_thread
;
1433 debug_printf ("discarding pending breakpoint status\n");
1434 lp
->status_pending_p
= 0;
1442 /* Return 1 if this lwp has an interesting status pending. */
1444 status_pending_p_callback (struct inferior_list_entry
*entry
, void *arg
)
1446 struct thread_info
*thread
= (struct thread_info
*) entry
;
1447 struct lwp_info
*lp
= get_thread_lwp (thread
);
1448 ptid_t ptid
= * (ptid_t
*) arg
;
1450 /* Check if we're only interested in events from a specific process
1451 or a specific LWP. */
1452 if (!ptid_match (ptid_of (thread
), ptid
))
1455 if (lp
->status_pending_p
1456 && !thread_still_has_status_pending_p (thread
))
1458 linux_resume_one_lwp (lp
, lp
->stepping
, GDB_SIGNAL_0
, NULL
);
1462 return lp
->status_pending_p
;
1466 same_lwp (struct inferior_list_entry
*entry
, void *data
)
1468 ptid_t ptid
= *(ptid_t
*) data
;
1471 if (ptid_get_lwp (ptid
) != 0)
1472 lwp
= ptid_get_lwp (ptid
);
1474 lwp
= ptid_get_pid (ptid
);
1476 if (ptid_get_lwp (entry
->id
) == lwp
)
1483 find_lwp_pid (ptid_t ptid
)
1485 struct inferior_list_entry
*thread
1486 = find_inferior (&all_threads
, same_lwp
, &ptid
);
1491 return get_thread_lwp ((struct thread_info
*) thread
);
1494 /* Return the number of known LWPs in the tgid given by PID. */
1499 struct inferior_list_entry
*inf
, *tmp
;
1502 ALL_INFERIORS (&all_threads
, inf
, tmp
)
1504 if (ptid_get_pid (inf
->id
) == pid
)
1511 /* The arguments passed to iterate_over_lwps. */
1513 struct iterate_over_lwps_args
1515 /* The FILTER argument passed to iterate_over_lwps. */
1518 /* The CALLBACK argument passed to iterate_over_lwps. */
1519 iterate_over_lwps_ftype
*callback
;
1521 /* The DATA argument passed to iterate_over_lwps. */
1525 /* Callback for find_inferior used by iterate_over_lwps to filter
1526 calls to the callback supplied to that function. Returning a
1527 nonzero value causes find_inferiors to stop iterating and return
1528 the current inferior_list_entry. Returning zero indicates that
1529 find_inferiors should continue iterating. */
1532 iterate_over_lwps_filter (struct inferior_list_entry
*entry
, void *args_p
)
1534 struct iterate_over_lwps_args
*args
1535 = (struct iterate_over_lwps_args
*) args_p
;
1537 if (ptid_match (entry
->id
, args
->filter
))
1539 struct thread_info
*thr
= (struct thread_info
*) entry
;
1540 struct lwp_info
*lwp
= get_thread_lwp (thr
);
1542 return (*args
->callback
) (lwp
, args
->data
);
1548 /* See nat/linux-nat.h. */
1551 iterate_over_lwps (ptid_t filter
,
1552 iterate_over_lwps_ftype callback
,
1555 struct iterate_over_lwps_args args
= {filter
, callback
, data
};
1556 struct inferior_list_entry
*entry
;
1558 entry
= find_inferior (&all_threads
, iterate_over_lwps_filter
, &args
);
1562 return get_thread_lwp ((struct thread_info
*) entry
);
1565 /* Detect zombie thread group leaders, and "exit" them. We can't reap
1566 their exits until all other threads in the group have exited. */
1569 check_zombie_leaders (void)
1571 struct process_info
*proc
, *tmp
;
1573 ALL_PROCESSES (proc
, tmp
)
1575 pid_t leader_pid
= pid_of (proc
);
1576 struct lwp_info
*leader_lp
;
1578 leader_lp
= find_lwp_pid (pid_to_ptid (leader_pid
));
1581 debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, "
1582 "num_lwps=%d, zombie=%d\n",
1583 leader_pid
, leader_lp
!= NULL
, num_lwps (leader_pid
),
1584 linux_proc_pid_is_zombie (leader_pid
));
1586 if (leader_lp
!= NULL
1587 /* Check if there are other threads in the group, as we may
1588 have raced with the inferior simply exiting. */
1589 && !last_thread_of_process_p (leader_pid
)
1590 && linux_proc_pid_is_zombie (leader_pid
))
1592 /* A leader zombie can mean one of two things:
1594 - It exited, and there's an exit status pending
1595 available, or only the leader exited (not the whole
1596 program). In the latter case, we can't waitpid the
1597 leader's exit status until all other threads are gone.
1599 - There are 3 or more threads in the group, and a thread
1600 other than the leader exec'd. On an exec, the Linux
1601 kernel destroys all other threads (except the execing
1602 one) in the thread group, and resets the execing thread's
1603 tid to the tgid. No exit notification is sent for the
1604 execing thread -- from the ptracer's perspective, it
1605 appears as though the execing thread just vanishes.
1606 Until we reap all other threads except the leader and the
1607 execing thread, the leader will be zombie, and the
1608 execing thread will be in `D (disc sleep)'. As soon as
1609 all other threads are reaped, the execing thread changes
1610 it's tid to the tgid, and the previous (zombie) leader
1611 vanishes, giving place to the "new" leader. We could try
1612 distinguishing the exit and exec cases, by waiting once
1613 more, and seeing if something comes out, but it doesn't
1614 sound useful. The previous leader _does_ go away, and
1615 we'll re-add the new one once we see the exec event
1616 (which is just the same as what would happen if the
1617 previous leader did exit voluntarily before some other
1622 "CZL: Thread group leader %d zombie "
1623 "(it exited, or another thread execd).\n",
1626 delete_lwp (leader_lp
);
1631 /* Callback for `find_inferior'. Returns the first LWP that is not
1632 stopped. ARG is a PTID filter. */
1635 not_stopped_callback (struct inferior_list_entry
*entry
, void *arg
)
1637 struct thread_info
*thr
= (struct thread_info
*) entry
;
1638 struct lwp_info
*lwp
;
1639 ptid_t filter
= *(ptid_t
*) arg
;
1641 if (!ptid_match (ptid_of (thr
), filter
))
1644 lwp
= get_thread_lwp (thr
);
1651 /* This function should only be called if the LWP got a SIGTRAP.
1653 Handle any tracepoint steps or hits. Return true if a tracepoint
1654 event was handled, 0 otherwise. */
1657 handle_tracepoints (struct lwp_info
*lwp
)
1659 struct thread_info
*tinfo
= get_lwp_thread (lwp
);
1660 int tpoint_related_event
= 0;
1662 gdb_assert (lwp
->suspended
== 0);
1664 /* If this tracepoint hit causes a tracing stop, we'll immediately
1665 uninsert tracepoints. To do this, we temporarily pause all
1666 threads, unpatch away, and then unpause threads. We need to make
1667 sure the unpausing doesn't resume LWP too. */
1670 /* And we need to be sure that any all-threads-stopping doesn't try
1671 to move threads out of the jump pads, as it could deadlock the
1672 inferior (LWP could be in the jump pad, maybe even holding the
1675 /* Do any necessary step collect actions. */
1676 tpoint_related_event
|= tracepoint_finished_step (tinfo
, lwp
->stop_pc
);
1678 tpoint_related_event
|= handle_tracepoint_bkpts (tinfo
, lwp
->stop_pc
);
1680 /* See if we just hit a tracepoint and do its main collect
1682 tpoint_related_event
|= tracepoint_was_hit (tinfo
, lwp
->stop_pc
);
1686 gdb_assert (lwp
->suspended
== 0);
1687 gdb_assert (!stabilizing_threads
|| lwp
->collecting_fast_tracepoint
);
1689 if (tpoint_related_event
)
1692 debug_printf ("got a tracepoint event\n");
1699 /* Convenience wrapper. Returns true if LWP is presently collecting a
1703 linux_fast_tracepoint_collecting (struct lwp_info
*lwp
,
1704 struct fast_tpoint_collect_status
*status
)
1706 CORE_ADDR thread_area
;
1707 struct thread_info
*thread
= get_lwp_thread (lwp
);
1709 if (the_low_target
.get_thread_area
== NULL
)
1712 /* Get the thread area address. This is used to recognize which
1713 thread is which when tracing with the in-process agent library.
1714 We don't read anything from the address, and treat it as opaque;
1715 it's the address itself that we assume is unique per-thread. */
1716 if ((*the_low_target
.get_thread_area
) (lwpid_of (thread
), &thread_area
) == -1)
1719 return fast_tracepoint_collecting (thread_area
, lwp
->stop_pc
, status
);
1722 /* The reason we resume in the caller, is because we want to be able
1723 to pass lwp->status_pending as WSTAT, and we need to clear
1724 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1725 refuses to resume. */
1728 maybe_move_out_of_jump_pad (struct lwp_info
*lwp
, int *wstat
)
1730 struct thread_info
*saved_thread
;
1732 saved_thread
= current_thread
;
1733 current_thread
= get_lwp_thread (lwp
);
1736 || (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) != SIGTRAP
))
1737 && supports_fast_tracepoints ()
1738 && agent_loaded_p ())
1740 struct fast_tpoint_collect_status status
;
1744 debug_printf ("Checking whether LWP %ld needs to move out of the "
1746 lwpid_of (current_thread
));
1748 r
= linux_fast_tracepoint_collecting (lwp
, &status
);
1751 || (WSTOPSIG (*wstat
) != SIGILL
1752 && WSTOPSIG (*wstat
) != SIGFPE
1753 && WSTOPSIG (*wstat
) != SIGSEGV
1754 && WSTOPSIG (*wstat
) != SIGBUS
))
1756 lwp
->collecting_fast_tracepoint
= r
;
1760 if (r
== 1 && lwp
->exit_jump_pad_bkpt
== NULL
)
1762 /* Haven't executed the original instruction yet.
1763 Set breakpoint there, and wait till it's hit,
1764 then single-step until exiting the jump pad. */
1765 lwp
->exit_jump_pad_bkpt
1766 = set_breakpoint_at (status
.adjusted_insn_addr
, NULL
);
1770 debug_printf ("Checking whether LWP %ld needs to move out of "
1771 "the jump pad...it does\n",
1772 lwpid_of (current_thread
));
1773 current_thread
= saved_thread
;
1780 /* If we get a synchronous signal while collecting, *and*
1781 while executing the (relocated) original instruction,
1782 reset the PC to point at the tpoint address, before
1783 reporting to GDB. Otherwise, it's an IPA lib bug: just
1784 report the signal to GDB, and pray for the best. */
1786 lwp
->collecting_fast_tracepoint
= 0;
1789 && (status
.adjusted_insn_addr
<= lwp
->stop_pc
1790 && lwp
->stop_pc
< status
.adjusted_insn_addr_end
))
1793 struct regcache
*regcache
;
1795 /* The si_addr on a few signals references the address
1796 of the faulting instruction. Adjust that as
1798 if ((WSTOPSIG (*wstat
) == SIGILL
1799 || WSTOPSIG (*wstat
) == SIGFPE
1800 || WSTOPSIG (*wstat
) == SIGBUS
1801 || WSTOPSIG (*wstat
) == SIGSEGV
)
1802 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
1803 (PTRACE_TYPE_ARG3
) 0, &info
) == 0
1804 /* Final check just to make sure we don't clobber
1805 the siginfo of non-kernel-sent signals. */
1806 && (uintptr_t) info
.si_addr
== lwp
->stop_pc
)
1808 info
.si_addr
= (void *) (uintptr_t) status
.tpoint_addr
;
1809 ptrace (PTRACE_SETSIGINFO
, lwpid_of (current_thread
),
1810 (PTRACE_TYPE_ARG3
) 0, &info
);
1813 regcache
= get_thread_regcache (current_thread
, 1);
1814 (*the_low_target
.set_pc
) (regcache
, status
.tpoint_addr
);
1815 lwp
->stop_pc
= status
.tpoint_addr
;
1817 /* Cancel any fast tracepoint lock this thread was
1819 force_unlock_trace_buffer ();
1822 if (lwp
->exit_jump_pad_bkpt
!= NULL
)
1825 debug_printf ("Cancelling fast exit-jump-pad: removing bkpt. "
1826 "stopping all threads momentarily.\n");
1828 stop_all_lwps (1, lwp
);
1830 delete_breakpoint (lwp
->exit_jump_pad_bkpt
);
1831 lwp
->exit_jump_pad_bkpt
= NULL
;
1833 unstop_all_lwps (1, lwp
);
1835 gdb_assert (lwp
->suspended
>= 0);
1841 debug_printf ("Checking whether LWP %ld needs to move out of the "
1843 lwpid_of (current_thread
));
1845 current_thread
= saved_thread
;
1849 /* Enqueue one signal in the "signals to report later when out of the
1853 enqueue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1855 struct pending_signals
*p_sig
;
1856 struct thread_info
*thread
= get_lwp_thread (lwp
);
1859 debug_printf ("Deferring signal %d for LWP %ld.\n",
1860 WSTOPSIG (*wstat
), lwpid_of (thread
));
1864 struct pending_signals
*sig
;
1866 for (sig
= lwp
->pending_signals_to_report
;
1869 debug_printf (" Already queued %d\n",
1872 debug_printf (" (no more currently queued signals)\n");
1875 /* Don't enqueue non-RT signals if they are already in the deferred
1876 queue. (SIGSTOP being the easiest signal to see ending up here
1878 if (WSTOPSIG (*wstat
) < __SIGRTMIN
)
1880 struct pending_signals
*sig
;
1882 for (sig
= lwp
->pending_signals_to_report
;
1886 if (sig
->signal
== WSTOPSIG (*wstat
))
1889 debug_printf ("Not requeuing already queued non-RT signal %d"
1898 p_sig
= xmalloc (sizeof (*p_sig
));
1899 p_sig
->prev
= lwp
->pending_signals_to_report
;
1900 p_sig
->signal
= WSTOPSIG (*wstat
);
1901 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1902 ptrace (PTRACE_GETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
1905 lwp
->pending_signals_to_report
= p_sig
;
1908 /* Dequeue one signal from the "signals to report later when out of
1909 the jump pad" list. */
1912 dequeue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1914 struct thread_info
*thread
= get_lwp_thread (lwp
);
1916 if (lwp
->pending_signals_to_report
!= NULL
)
1918 struct pending_signals
**p_sig
;
1920 p_sig
= &lwp
->pending_signals_to_report
;
1921 while ((*p_sig
)->prev
!= NULL
)
1922 p_sig
= &(*p_sig
)->prev
;
1924 *wstat
= W_STOPCODE ((*p_sig
)->signal
);
1925 if ((*p_sig
)->info
.si_signo
!= 0)
1926 ptrace (PTRACE_SETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
1932 debug_printf ("Reporting deferred signal %d for LWP %ld.\n",
1933 WSTOPSIG (*wstat
), lwpid_of (thread
));
1937 struct pending_signals
*sig
;
1939 for (sig
= lwp
->pending_signals_to_report
;
1942 debug_printf (" Still queued %d\n",
1945 debug_printf (" (no more queued signals)\n");
1954 /* Fetch the possibly triggered data watchpoint info and store it in
1957 On some archs, like x86, that use debug registers to set
1958 watchpoints, it's possible that the way to know which watched
1959 address trapped, is to check the register that is used to select
1960 which address to watch. Problem is, between setting the watchpoint
1961 and reading back which data address trapped, the user may change
1962 the set of watchpoints, and, as a consequence, GDB changes the
1963 debug registers in the inferior. To avoid reading back a stale
1964 stopped-data-address when that happens, we cache in LP the fact
1965 that a watchpoint trapped, and the corresponding data address, as
1966 soon as we see CHILD stop with a SIGTRAP. If GDB changes the debug
1967 registers meanwhile, we have the cached data we can rely on. */
1970 check_stopped_by_watchpoint (struct lwp_info
*child
)
1972 if (the_low_target
.stopped_by_watchpoint
!= NULL
)
1974 struct thread_info
*saved_thread
;
1976 saved_thread
= current_thread
;
1977 current_thread
= get_lwp_thread (child
);
1979 if (the_low_target
.stopped_by_watchpoint ())
1981 child
->stop_reason
= TARGET_STOPPED_BY_WATCHPOINT
;
1983 if (the_low_target
.stopped_data_address
!= NULL
)
1984 child
->stopped_data_address
1985 = the_low_target
.stopped_data_address ();
1987 child
->stopped_data_address
= 0;
1990 current_thread
= saved_thread
;
1993 return child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
1996 /* Return the ptrace options that we want to try to enable. */
1999 linux_low_ptrace_options (int attached
)
2004 options
|= PTRACE_O_EXITKILL
;
2006 if (report_fork_events
)
2007 options
|= PTRACE_O_TRACEFORK
;
2012 /* Do low-level handling of the event, and check if we should go on
2013 and pass it to caller code. Return the affected lwp if we are, or
2016 static struct lwp_info
*
2017 linux_low_filter_event (int lwpid
, int wstat
)
2019 struct lwp_info
*child
;
2020 struct thread_info
*thread
;
2021 int have_stop_pc
= 0;
2023 child
= find_lwp_pid (pid_to_ptid (lwpid
));
2025 /* If we didn't find a process, one of two things presumably happened:
2026 - A process we started and then detached from has exited. Ignore it.
2027 - A process we are controlling has forked and the new child's stop
2028 was reported to us by the kernel. Save its PID. */
2029 if (child
== NULL
&& WIFSTOPPED (wstat
))
2031 add_to_pid_list (&stopped_pids
, lwpid
, wstat
);
2034 else if (child
== NULL
)
2037 thread
= get_lwp_thread (child
);
2041 child
->last_status
= wstat
;
2043 /* Check if the thread has exited. */
2044 if ((WIFEXITED (wstat
) || WIFSIGNALED (wstat
)))
2047 debug_printf ("LLFE: %d exited.\n", lwpid
);
2048 if (num_lwps (pid_of (thread
)) > 1)
2051 /* If there is at least one more LWP, then the exit signal was
2052 not the end of the debugged application and should be
2059 /* This was the last lwp in the process. Since events are
2060 serialized to GDB core, and we can't report this one
2061 right now, but GDB core and the other target layers will
2062 want to be notified about the exit code/signal, leave the
2063 status pending for the next time we're able to report
2065 mark_lwp_dead (child
, wstat
);
2070 gdb_assert (WIFSTOPPED (wstat
));
2072 if (WIFSTOPPED (wstat
))
2074 struct process_info
*proc
;
2076 /* Architecture-specific setup after inferior is running. This
2077 needs to happen after we have attached to the inferior and it
2078 is stopped for the first time, but before we access any
2079 inferior registers. */
2080 proc
= find_process_pid (pid_of (thread
));
2081 if (proc
->priv
->new_inferior
)
2083 struct thread_info
*saved_thread
;
2085 saved_thread
= current_thread
;
2086 current_thread
= thread
;
2088 the_low_target
.arch_setup ();
2090 current_thread
= saved_thread
;
2092 proc
->priv
->new_inferior
= 0;
2096 if (WIFSTOPPED (wstat
) && child
->must_set_ptrace_flags
)
2098 struct process_info
*proc
= find_process_pid (pid_of (thread
));
2099 int options
= linux_low_ptrace_options (proc
->attached
);
2101 linux_enable_event_reporting (lwpid
, options
);
2102 child
->must_set_ptrace_flags
= 0;
2105 /* Be careful to not overwrite stop_pc until
2106 check_stopped_by_breakpoint is called. */
2107 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGTRAP
2108 && linux_is_extended_waitstatus (wstat
))
2110 child
->stop_pc
= get_pc (child
);
2111 if (handle_extended_wait (child
, wstat
))
2113 /* The event has been handled, so just return without
2119 /* Check first whether this was a SW/HW breakpoint before checking
2120 watchpoints, because at least s390 can't tell the data address of
2121 hardware watchpoint hits, and returns stopped-by-watchpoint as
2122 long as there's a watchpoint set. */
2123 if (WIFSTOPPED (wstat
) && linux_wstatus_maybe_breakpoint (wstat
))
2125 if (check_stopped_by_breakpoint (child
))
2129 /* Note that TRAP_HWBKPT can indicate either a hardware breakpoint
2130 or hardware watchpoint. Check which is which if we got
2131 TARGET_STOPPED_BY_HW_BREAKPOINT. */
2132 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGTRAP
2133 && (child
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
2134 || child
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
2135 check_stopped_by_watchpoint (child
);
2138 child
->stop_pc
= get_pc (child
);
2140 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGSTOP
2141 && child
->stop_expected
)
2144 debug_printf ("Expected stop.\n");
2145 child
->stop_expected
= 0;
2147 if (thread
->last_resume_kind
== resume_stop
)
2149 /* We want to report the stop to the core. Treat the
2150 SIGSTOP as a normal event. */
2152 debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n",
2153 target_pid_to_str (ptid_of (thread
)));
2155 else if (stopping_threads
!= NOT_STOPPING_THREADS
)
2157 /* Stopping threads. We don't want this SIGSTOP to end up
2160 debug_printf ("LLW: SIGSTOP caught for %s "
2161 "while stopping threads.\n",
2162 target_pid_to_str (ptid_of (thread
)));
2167 /* This is a delayed SIGSTOP. Filter out the event. */
2169 debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
2170 child
->stepping
? "step" : "continue",
2171 target_pid_to_str (ptid_of (thread
)));
2173 linux_resume_one_lwp (child
, child
->stepping
, 0, NULL
);
2178 child
->status_pending_p
= 1;
2179 child
->status_pending
= wstat
;
2183 /* Resume LWPs that are currently stopped without any pending status
2184 to report, but are resumed from the core's perspective. */
2187 resume_stopped_resumed_lwps (struct inferior_list_entry
*entry
)
2189 struct thread_info
*thread
= (struct thread_info
*) entry
;
2190 struct lwp_info
*lp
= get_thread_lwp (thread
);
2193 && !lp
->status_pending_p
2194 && thread
->last_resume_kind
!= resume_stop
2195 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
)
2197 int step
= thread
->last_resume_kind
== resume_step
;
2200 debug_printf ("RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
2201 target_pid_to_str (ptid_of (thread
)),
2202 paddress (lp
->stop_pc
),
2205 linux_resume_one_lwp (lp
, step
, GDB_SIGNAL_0
, NULL
);
2209 /* Wait for an event from child(ren) WAIT_PTID, and return any that
2210 match FILTER_PTID (leaving others pending). The PTIDs can be:
2211 minus_one_ptid, to specify any child; a pid PTID, specifying all
2212 lwps of a thread group; or a PTID representing a single lwp. Store
2213 the stop status through the status pointer WSTAT. OPTIONS is
2214 passed to the waitpid call. Return 0 if no event was found and
2215 OPTIONS contains WNOHANG. Return -1 if no unwaited-for children
2216 was found. Return the PID of the stopped child otherwise. */
2219 linux_wait_for_event_filtered (ptid_t wait_ptid
, ptid_t filter_ptid
,
2220 int *wstatp
, int options
)
2222 struct thread_info
*event_thread
;
2223 struct lwp_info
*event_child
, *requested_child
;
2224 sigset_t block_mask
, prev_mask
;
2227 /* N.B. event_thread points to the thread_info struct that contains
2228 event_child. Keep them in sync. */
2229 event_thread
= NULL
;
2231 requested_child
= NULL
;
2233 /* Check for a lwp with a pending status. */
2235 if (ptid_equal (filter_ptid
, minus_one_ptid
) || ptid_is_pid (filter_ptid
))
2237 event_thread
= (struct thread_info
*)
2238 find_inferior (&all_threads
, status_pending_p_callback
, &filter_ptid
);
2239 if (event_thread
!= NULL
)
2240 event_child
= get_thread_lwp (event_thread
);
2241 if (debug_threads
&& event_thread
)
2242 debug_printf ("Got a pending child %ld\n", lwpid_of (event_thread
));
2244 else if (!ptid_equal (filter_ptid
, null_ptid
))
2246 requested_child
= find_lwp_pid (filter_ptid
);
2248 if (stopping_threads
== NOT_STOPPING_THREADS
2249 && requested_child
->status_pending_p
2250 && requested_child
->collecting_fast_tracepoint
)
2252 enqueue_one_deferred_signal (requested_child
,
2253 &requested_child
->status_pending
);
2254 requested_child
->status_pending_p
= 0;
2255 requested_child
->status_pending
= 0;
2256 linux_resume_one_lwp (requested_child
, 0, 0, NULL
);
2259 if (requested_child
->suspended
2260 && requested_child
->status_pending_p
)
2262 internal_error (__FILE__
, __LINE__
,
2263 "requesting an event out of a"
2264 " suspended child?");
2267 if (requested_child
->status_pending_p
)
2269 event_child
= requested_child
;
2270 event_thread
= get_lwp_thread (event_child
);
2274 if (event_child
!= NULL
)
2277 debug_printf ("Got an event from pending child %ld (%04x)\n",
2278 lwpid_of (event_thread
), event_child
->status_pending
);
2279 *wstatp
= event_child
->status_pending
;
2280 event_child
->status_pending_p
= 0;
2281 event_child
->status_pending
= 0;
2282 current_thread
= event_thread
;
2283 return lwpid_of (event_thread
);
2286 /* But if we don't find a pending event, we'll have to wait.
2288 We only enter this loop if no process has a pending wait status.
2289 Thus any action taken in response to a wait status inside this
2290 loop is responding as soon as we detect the status, not after any
2293 /* Make sure SIGCHLD is blocked until the sigsuspend below. Block
2294 all signals while here. */
2295 sigfillset (&block_mask
);
2296 sigprocmask (SIG_BLOCK
, &block_mask
, &prev_mask
);
2298 /* Always pull all events out of the kernel. We'll randomly select
2299 an event LWP out of all that have events, to prevent
2301 while (event_child
== NULL
)
2305 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
2308 - If the thread group leader exits while other threads in the
2309 thread group still exist, waitpid(TGID, ...) hangs. That
2310 waitpid won't return an exit status until the other threads
2311 in the group are reaped.
2313 - When a non-leader thread execs, that thread just vanishes
2314 without reporting an exit (so we'd hang if we waited for it
2315 explicitly in that case). The exec event is reported to
2316 the TGID pid (although we don't currently enable exec
2319 ret
= my_waitpid (-1, wstatp
, options
| WNOHANG
);
2322 debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n",
2323 ret
, errno
? strerror (errno
) : "ERRNO-OK");
2329 debug_printf ("LLW: waitpid %ld received %s\n",
2330 (long) ret
, status_to_str (*wstatp
));
2333 /* Filter all events. IOW, leave all events pending. We'll
2334 randomly select an event LWP out of all that have events
2336 linux_low_filter_event (ret
, *wstatp
);
2337 /* Retry until nothing comes out of waitpid. A single
2338 SIGCHLD can indicate more than one child stopped. */
2342 /* Now that we've pulled all events out of the kernel, resume
2343 LWPs that don't have an interesting event to report. */
2344 if (stopping_threads
== NOT_STOPPING_THREADS
)
2345 for_each_inferior (&all_threads
, resume_stopped_resumed_lwps
);
2347 /* ... and find an LWP with a status to report to the core, if
2349 event_thread
= (struct thread_info
*)
2350 find_inferior (&all_threads
, status_pending_p_callback
, &filter_ptid
);
2351 if (event_thread
!= NULL
)
2353 event_child
= get_thread_lwp (event_thread
);
2354 *wstatp
= event_child
->status_pending
;
2355 event_child
->status_pending_p
= 0;
2356 event_child
->status_pending
= 0;
2360 /* Check for zombie thread group leaders. Those can't be reaped
2361 until all other threads in the thread group are. */
2362 check_zombie_leaders ();
2364 /* If there are no resumed children left in the set of LWPs we
2365 want to wait for, bail. We can't just block in
2366 waitpid/sigsuspend, because lwps might have been left stopped
2367 in trace-stop state, and we'd be stuck forever waiting for
2368 their status to change (which would only happen if we resumed
2369 them). Even if WNOHANG is set, this return code is preferred
2370 over 0 (below), as it is more detailed. */
2371 if ((find_inferior (&all_threads
,
2372 not_stopped_callback
,
2373 &wait_ptid
) == NULL
))
2376 debug_printf ("LLW: exit (no unwaited-for LWP)\n");
2377 sigprocmask (SIG_SETMASK
, &prev_mask
, NULL
);
2381 /* No interesting event to report to the caller. */
2382 if ((options
& WNOHANG
))
2385 debug_printf ("WNOHANG set, no event found\n");
2387 sigprocmask (SIG_SETMASK
, &prev_mask
, NULL
);
2391 /* Block until we get an event reported with SIGCHLD. */
2393 debug_printf ("sigsuspend'ing\n");
2395 sigsuspend (&prev_mask
);
2396 sigprocmask (SIG_SETMASK
, &prev_mask
, NULL
);
2400 sigprocmask (SIG_SETMASK
, &prev_mask
, NULL
);
2402 current_thread
= event_thread
;
2404 /* Check for thread exit. */
2405 if (! WIFSTOPPED (*wstatp
))
2407 gdb_assert (last_thread_of_process_p (pid_of (event_thread
)));
2410 debug_printf ("LWP %d is the last lwp of process. "
2411 "Process %ld exiting.\n",
2412 pid_of (event_thread
), lwpid_of (event_thread
));
2413 return lwpid_of (event_thread
);
2416 return lwpid_of (event_thread
);
2419 /* Wait for an event from child(ren) PTID. PTIDs can be:
2420 minus_one_ptid, to specify any child; a pid PTID, specifying all
2421 lwps of a thread group; or a PTID representing a single lwp. Store
2422 the stop status through the status pointer WSTAT. OPTIONS is
2423 passed to the waitpid call. Return 0 if no event was found and
2424 OPTIONS contains WNOHANG. Return -1 if no unwaited-for children
2425 was found. Return the PID of the stopped child otherwise. */
2428 linux_wait_for_event (ptid_t ptid
, int *wstatp
, int options
)
2430 return linux_wait_for_event_filtered (ptid
, ptid
, wstatp
, options
);
2433 /* Count the LWP's that have had events. */
2436 count_events_callback (struct inferior_list_entry
*entry
, void *data
)
2438 struct thread_info
*thread
= (struct thread_info
*) entry
;
2439 struct lwp_info
*lp
= get_thread_lwp (thread
);
2442 gdb_assert (count
!= NULL
);
2444 /* Count only resumed LWPs that have an event pending. */
2445 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2446 && lp
->status_pending_p
)
2452 /* Select the LWP (if any) that is currently being single-stepped. */
2455 select_singlestep_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
2457 struct thread_info
*thread
= (struct thread_info
*) entry
;
2458 struct lwp_info
*lp
= get_thread_lwp (thread
);
2460 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2461 && thread
->last_resume_kind
== resume_step
2462 && lp
->status_pending_p
)
2468 /* Select the Nth LWP that has had an event. */
2471 select_event_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
2473 struct thread_info
*thread
= (struct thread_info
*) entry
;
2474 struct lwp_info
*lp
= get_thread_lwp (thread
);
2475 int *selector
= data
;
2477 gdb_assert (selector
!= NULL
);
2479 /* Select only resumed LWPs that have an event pending. */
2480 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2481 && lp
->status_pending_p
)
2482 if ((*selector
)-- == 0)
2488 /* Select one LWP out of those that have events pending. */
2491 select_event_lwp (struct lwp_info
**orig_lp
)
2494 int random_selector
;
2495 struct thread_info
*event_thread
= NULL
;
2497 /* In all-stop, give preference to the LWP that is being
2498 single-stepped. There will be at most one, and it's the LWP that
2499 the core is most interested in. If we didn't do this, then we'd
2500 have to handle pending step SIGTRAPs somehow in case the core
2501 later continues the previously-stepped thread, otherwise we'd
2502 report the pending SIGTRAP, and the core, not having stepped the
2503 thread, wouldn't understand what the trap was for, and therefore
2504 would report it to the user as a random signal. */
2508 = (struct thread_info
*) find_inferior (&all_threads
,
2509 select_singlestep_lwp_callback
,
2511 if (event_thread
!= NULL
)
2514 debug_printf ("SEL: Select single-step %s\n",
2515 target_pid_to_str (ptid_of (event_thread
)));
2518 if (event_thread
== NULL
)
2520 /* No single-stepping LWP. Select one at random, out of those
2521 which have had events. */
2523 /* First see how many events we have. */
2524 find_inferior (&all_threads
, count_events_callback
, &num_events
);
2525 gdb_assert (num_events
> 0);
2527 /* Now randomly pick a LWP out of those that have had
2529 random_selector
= (int)
2530 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2532 if (debug_threads
&& num_events
> 1)
2533 debug_printf ("SEL: Found %d SIGTRAP events, selecting #%d\n",
2534 num_events
, random_selector
);
2537 = (struct thread_info
*) find_inferior (&all_threads
,
2538 select_event_lwp_callback
,
2542 if (event_thread
!= NULL
)
2544 struct lwp_info
*event_lp
= get_thread_lwp (event_thread
);
2546 /* Switch the event LWP. */
2547 *orig_lp
= event_lp
;
2551 /* Decrement the suspend count of an LWP. */
2554 unsuspend_one_lwp (struct inferior_list_entry
*entry
, void *except
)
2556 struct thread_info
*thread
= (struct thread_info
*) entry
;
2557 struct lwp_info
*lwp
= get_thread_lwp (thread
);
2559 /* Ignore EXCEPT. */
2565 gdb_assert (lwp
->suspended
>= 0);
2569 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
2573 unsuspend_all_lwps (struct lwp_info
*except
)
2575 find_inferior (&all_threads
, unsuspend_one_lwp
, except
);
2578 static void move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
);
2579 static int stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
,
2581 static int lwp_running (struct inferior_list_entry
*entry
, void *data
);
2582 static ptid_t
linux_wait_1 (ptid_t ptid
,
2583 struct target_waitstatus
*ourstatus
,
2584 int target_options
);
2586 /* Stabilize threads (move out of jump pads).
2588 If a thread is midway collecting a fast tracepoint, we need to
2589 finish the collection and move it out of the jump pad before
2590 reporting the signal.
2592 This avoids recursion while collecting (when a signal arrives
2593 midway, and the signal handler itself collects), which would trash
2594 the trace buffer. In case the user set a breakpoint in a signal
2595 handler, this avoids the backtrace showing the jump pad, etc..
2596 Most importantly, there are certain things we can't do safely if
2597 threads are stopped in a jump pad (or in its callee's). For
2600 - starting a new trace run. A thread still collecting the
2601 previous run, could trash the trace buffer when resumed. The trace
2602 buffer control structures would have been reset but the thread had
2603 no way to tell. The thread could even midway memcpy'ing to the
2604 buffer, which would mean that when resumed, it would clobber the
2605 trace buffer that had been set for a new run.
2607 - we can't rewrite/reuse the jump pads for new tracepoints
2608 safely. Say you do tstart while a thread is stopped midway while
2609 collecting. When the thread is later resumed, it finishes the
2610 collection, and returns to the jump pad, to execute the original
2611 instruction that was under the tracepoint jump at the time the
2612 older run had been started. If the jump pad had been rewritten
2613 since for something else in the new run, the thread would now
2614 execute the wrong / random instructions. */
2617 linux_stabilize_threads (void)
2619 struct thread_info
*saved_thread
;
2620 struct thread_info
*thread_stuck
;
2623 = (struct thread_info
*) find_inferior (&all_threads
,
2624 stuck_in_jump_pad_callback
,
2626 if (thread_stuck
!= NULL
)
2629 debug_printf ("can't stabilize, LWP %ld is stuck in jump pad\n",
2630 lwpid_of (thread_stuck
));
2634 saved_thread
= current_thread
;
2636 stabilizing_threads
= 1;
2639 for_each_inferior (&all_threads
, move_out_of_jump_pad_callback
);
2641 /* Loop until all are stopped out of the jump pads. */
2642 while (find_inferior (&all_threads
, lwp_running
, NULL
) != NULL
)
2644 struct target_waitstatus ourstatus
;
2645 struct lwp_info
*lwp
;
2648 /* Note that we go through the full wait even loop. While
2649 moving threads out of jump pad, we need to be able to step
2650 over internal breakpoints and such. */
2651 linux_wait_1 (minus_one_ptid
, &ourstatus
, 0);
2653 if (ourstatus
.kind
== TARGET_WAITKIND_STOPPED
)
2655 lwp
= get_thread_lwp (current_thread
);
2660 if (ourstatus
.value
.sig
!= GDB_SIGNAL_0
2661 || current_thread
->last_resume_kind
== resume_stop
)
2663 wstat
= W_STOPCODE (gdb_signal_to_host (ourstatus
.value
.sig
));
2664 enqueue_one_deferred_signal (lwp
, &wstat
);
2669 find_inferior (&all_threads
, unsuspend_one_lwp
, NULL
);
2671 stabilizing_threads
= 0;
2673 current_thread
= saved_thread
;
2678 = (struct thread_info
*) find_inferior (&all_threads
,
2679 stuck_in_jump_pad_callback
,
2681 if (thread_stuck
!= NULL
)
2682 debug_printf ("couldn't stabilize, LWP %ld got stuck in jump pad\n",
2683 lwpid_of (thread_stuck
));
2687 static void async_file_mark (void);
2689 /* Convenience function that is called when the kernel reports an
2690 event that is not passed out to GDB. */
2693 ignore_event (struct target_waitstatus
*ourstatus
)
2695 /* If we got an event, there may still be others, as a single
2696 SIGCHLD can indicate more than one child stopped. This forces
2697 another target_wait call. */
2700 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2704 /* Return non-zero if WAITSTATUS reflects an extended linux
2705 event. Otherwise, return zero. */
2708 extended_event_reported (const struct target_waitstatus
*waitstatus
)
2710 if (waitstatus
== NULL
)
2713 return (waitstatus
->kind
== TARGET_WAITKIND_FORKED
);
2716 /* Wait for process, returns status. */
2719 linux_wait_1 (ptid_t ptid
,
2720 struct target_waitstatus
*ourstatus
, int target_options
)
2723 struct lwp_info
*event_child
;
2726 int step_over_finished
;
2727 int bp_explains_trap
;
2728 int maybe_internal_trap
;
2736 debug_printf ("linux_wait_1: [%s]\n", target_pid_to_str (ptid
));
2739 /* Translate generic target options into linux options. */
2741 if (target_options
& TARGET_WNOHANG
)
2744 bp_explains_trap
= 0;
2747 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2749 if (ptid_equal (step_over_bkpt
, null_ptid
))
2750 pid
= linux_wait_for_event (ptid
, &w
, options
);
2754 debug_printf ("step_over_bkpt set [%s], doing a blocking wait\n",
2755 target_pid_to_str (step_over_bkpt
));
2756 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
2761 gdb_assert (target_options
& TARGET_WNOHANG
);
2765 debug_printf ("linux_wait_1 ret = null_ptid, "
2766 "TARGET_WAITKIND_IGNORE\n");
2770 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2777 debug_printf ("linux_wait_1 ret = null_ptid, "
2778 "TARGET_WAITKIND_NO_RESUMED\n");
2782 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
2786 event_child
= get_thread_lwp (current_thread
);
2788 /* linux_wait_for_event only returns an exit status for the last
2789 child of a process. Report it. */
2790 if (WIFEXITED (w
) || WIFSIGNALED (w
))
2794 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
2795 ourstatus
->value
.integer
= WEXITSTATUS (w
);
2799 debug_printf ("linux_wait_1 ret = %s, exited with "
2801 target_pid_to_str (ptid_of (current_thread
)),
2808 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
2809 ourstatus
->value
.sig
= gdb_signal_from_host (WTERMSIG (w
));
2813 debug_printf ("linux_wait_1 ret = %s, terminated with "
2815 target_pid_to_str (ptid_of (current_thread
)),
2821 return ptid_of (current_thread
);
2824 /* If step-over executes a breakpoint instruction, it means a
2825 gdb/gdbserver breakpoint had been planted on top of a permanent
2826 breakpoint. The PC has been adjusted by
2827 check_stopped_by_breakpoint to point at the breakpoint address.
2828 Advance the PC manually past the breakpoint, otherwise the
2829 program would keep trapping the permanent breakpoint forever. */
2830 if (!ptid_equal (step_over_bkpt
, null_ptid
)
2831 && event_child
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
)
2833 unsigned int increment_pc
= the_low_target
.breakpoint_len
;
2837 debug_printf ("step-over for %s executed software breakpoint\n",
2838 target_pid_to_str (ptid_of (current_thread
)));
2841 if (increment_pc
!= 0)
2843 struct regcache
*regcache
2844 = get_thread_regcache (current_thread
, 1);
2846 event_child
->stop_pc
+= increment_pc
;
2847 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
2849 if (!(*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))
2850 event_child
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2854 /* If this event was not handled before, and is not a SIGTRAP, we
2855 report it. SIGILL and SIGSEGV are also treated as traps in case
2856 a breakpoint is inserted at the current PC. If this target does
2857 not support internal breakpoints at all, we also report the
2858 SIGTRAP without further processing; it's of no concern to us. */
2860 = (supports_breakpoints ()
2861 && (WSTOPSIG (w
) == SIGTRAP
2862 || ((WSTOPSIG (w
) == SIGILL
2863 || WSTOPSIG (w
) == SIGSEGV
)
2864 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
2866 if (maybe_internal_trap
)
2868 /* Handle anything that requires bookkeeping before deciding to
2869 report the event or continue waiting. */
2871 /* First check if we can explain the SIGTRAP with an internal
2872 breakpoint, or if we should possibly report the event to GDB.
2873 Do this before anything that may remove or insert a
2875 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
2877 /* We have a SIGTRAP, possibly a step-over dance has just
2878 finished. If so, tweak the state machine accordingly,
2879 reinsert breakpoints and delete any reinsert (software
2880 single-step) breakpoints. */
2881 step_over_finished
= finish_step_over (event_child
);
2883 /* Now invoke the callbacks of any internal breakpoints there. */
2884 check_breakpoints (event_child
->stop_pc
);
2886 /* Handle tracepoint data collecting. This may overflow the
2887 trace buffer, and cause a tracing stop, removing
2889 trace_event
= handle_tracepoints (event_child
);
2891 if (bp_explains_trap
)
2893 /* If we stepped or ran into an internal breakpoint, we've
2894 already handled it. So next time we resume (from this
2895 PC), we should step over it. */
2897 debug_printf ("Hit a gdbserver breakpoint.\n");
2899 if (breakpoint_here (event_child
->stop_pc
))
2900 event_child
->need_step_over
= 1;
2905 /* We have some other signal, possibly a step-over dance was in
2906 progress, and it should be cancelled too. */
2907 step_over_finished
= finish_step_over (event_child
);
2910 /* We have all the data we need. Either report the event to GDB, or
2911 resume threads and keep waiting for more. */
2913 /* If we're collecting a fast tracepoint, finish the collection and
2914 move out of the jump pad before delivering a signal. See
2915 linux_stabilize_threads. */
2918 && WSTOPSIG (w
) != SIGTRAP
2919 && supports_fast_tracepoints ()
2920 && agent_loaded_p ())
2923 debug_printf ("Got signal %d for LWP %ld. Check if we need "
2924 "to defer or adjust it.\n",
2925 WSTOPSIG (w
), lwpid_of (current_thread
));
2927 /* Allow debugging the jump pad itself. */
2928 if (current_thread
->last_resume_kind
!= resume_step
2929 && maybe_move_out_of_jump_pad (event_child
, &w
))
2931 enqueue_one_deferred_signal (event_child
, &w
);
2934 debug_printf ("Signal %d for LWP %ld deferred (in jump pad)\n",
2935 WSTOPSIG (w
), lwpid_of (current_thread
));
2937 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
2939 return ignore_event (ourstatus
);
2943 if (event_child
->collecting_fast_tracepoint
)
2946 debug_printf ("LWP %ld was trying to move out of the jump pad (%d). "
2947 "Check if we're already there.\n",
2948 lwpid_of (current_thread
),
2949 event_child
->collecting_fast_tracepoint
);
2953 event_child
->collecting_fast_tracepoint
2954 = linux_fast_tracepoint_collecting (event_child
, NULL
);
2956 if (event_child
->collecting_fast_tracepoint
!= 1)
2958 /* No longer need this breakpoint. */
2959 if (event_child
->exit_jump_pad_bkpt
!= NULL
)
2962 debug_printf ("No longer need exit-jump-pad bkpt; removing it."
2963 "stopping all threads momentarily.\n");
2965 /* Other running threads could hit this breakpoint.
2966 We don't handle moribund locations like GDB does,
2967 instead we always pause all threads when removing
2968 breakpoints, so that any step-over or
2969 decr_pc_after_break adjustment is always taken
2970 care of while the breakpoint is still
2972 stop_all_lwps (1, event_child
);
2974 delete_breakpoint (event_child
->exit_jump_pad_bkpt
);
2975 event_child
->exit_jump_pad_bkpt
= NULL
;
2977 unstop_all_lwps (1, event_child
);
2979 gdb_assert (event_child
->suspended
>= 0);
2983 if (event_child
->collecting_fast_tracepoint
== 0)
2986 debug_printf ("fast tracepoint finished "
2987 "collecting successfully.\n");
2989 /* We may have a deferred signal to report. */
2990 if (dequeue_one_deferred_signal (event_child
, &w
))
2993 debug_printf ("dequeued one signal.\n");
2998 debug_printf ("no deferred signals.\n");
3000 if (stabilizing_threads
)
3002 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
3003 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3007 debug_printf ("linux_wait_1 ret = %s, stopped "
3008 "while stabilizing threads\n",
3009 target_pid_to_str (ptid_of (current_thread
)));
3013 return ptid_of (current_thread
);
3019 /* Check whether GDB would be interested in this event. */
3021 /* If GDB is not interested in this signal, don't stop other
3022 threads, and don't report it to GDB. Just resume the inferior
3023 right away. We do this for threading-related signals as well as
3024 any that GDB specifically requested we ignore. But never ignore
3025 SIGSTOP if we sent it ourselves, and do not ignore signals when
3026 stepping - they may require special handling to skip the signal
3027 handler. Also never ignore signals that could be caused by a
3029 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
3032 && current_thread
->last_resume_kind
!= resume_step
3034 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
3035 (current_process ()->priv
->thread_db
!= NULL
3036 && (WSTOPSIG (w
) == __SIGRTMIN
3037 || WSTOPSIG (w
) == __SIGRTMIN
+ 1))
3040 (pass_signals
[gdb_signal_from_host (WSTOPSIG (w
))]
3041 && !(WSTOPSIG (w
) == SIGSTOP
3042 && current_thread
->last_resume_kind
== resume_stop
)
3043 && !linux_wstatus_maybe_breakpoint (w
))))
3045 siginfo_t info
, *info_p
;
3048 debug_printf ("Ignored signal %d for LWP %ld.\n",
3049 WSTOPSIG (w
), lwpid_of (current_thread
));
3051 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
3052 (PTRACE_TYPE_ARG3
) 0, &info
) == 0)
3056 linux_resume_one_lwp (event_child
, event_child
->stepping
,
3057 WSTOPSIG (w
), info_p
);
3058 return ignore_event (ourstatus
);
3061 /* Note that all addresses are always "out of the step range" when
3062 there's no range to begin with. */
3063 in_step_range
= lwp_in_step_range (event_child
);
3065 /* If GDB wanted this thread to single step, and the thread is out
3066 of the step range, we always want to report the SIGTRAP, and let
3067 GDB handle it. Watchpoints should always be reported. So should
3068 signals we can't explain. A SIGTRAP we can't explain could be a
3069 GDB breakpoint --- we may or not support Z0 breakpoints. If we
3070 do, we're be able to handle GDB breakpoints on top of internal
3071 breakpoints, by handling the internal breakpoint and still
3072 reporting the event to GDB. If we don't, we're out of luck, GDB
3073 won't see the breakpoint hit. */
3074 report_to_gdb
= (!maybe_internal_trap
3075 || (current_thread
->last_resume_kind
== resume_step
3077 || event_child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
3078 || (!step_over_finished
&& !in_step_range
3079 && !bp_explains_trap
&& !trace_event
)
3080 || (gdb_breakpoint_here (event_child
->stop_pc
)
3081 && gdb_condition_true_at_breakpoint (event_child
->stop_pc
)
3082 && gdb_no_commands_at_breakpoint (event_child
->stop_pc
))
3083 || extended_event_reported (&event_child
->waitstatus
));
3085 run_breakpoint_commands (event_child
->stop_pc
);
3087 /* We found no reason GDB would want us to stop. We either hit one
3088 of our own breakpoints, or finished an internal step GDB
3089 shouldn't know about. */
3094 if (bp_explains_trap
)
3095 debug_printf ("Hit a gdbserver breakpoint.\n");
3096 if (step_over_finished
)
3097 debug_printf ("Step-over finished.\n");
3099 debug_printf ("Tracepoint event.\n");
3100 if (lwp_in_step_range (event_child
))
3101 debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).\n",
3102 paddress (event_child
->stop_pc
),
3103 paddress (event_child
->step_range_start
),
3104 paddress (event_child
->step_range_end
));
3105 if (extended_event_reported (&event_child
->waitstatus
))
3107 char *str
= target_waitstatus_to_string (ourstatus
);
3108 debug_printf ("LWP %ld: extended event with waitstatus %s\n",
3109 lwpid_of (get_lwp_thread (event_child
)), str
);
3114 /* We're not reporting this breakpoint to GDB, so apply the
3115 decr_pc_after_break adjustment to the inferior's regcache
3118 if (the_low_target
.set_pc
!= NULL
)
3120 struct regcache
*regcache
3121 = get_thread_regcache (current_thread
, 1);
3122 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
3125 /* We may have finished stepping over a breakpoint. If so,
3126 we've stopped and suspended all LWPs momentarily except the
3127 stepping one. This is where we resume them all again. We're
3128 going to keep waiting, so use proceed, which handles stepping
3129 over the next breakpoint. */
3131 debug_printf ("proceeding all threads.\n");
3133 if (step_over_finished
)
3134 unsuspend_all_lwps (event_child
);
3136 proceed_all_lwps ();
3137 return ignore_event (ourstatus
);
3142 if (current_thread
->last_resume_kind
== resume_step
)
3144 if (event_child
->step_range_start
== event_child
->step_range_end
)
3145 debug_printf ("GDB wanted to single-step, reporting event.\n");
3146 else if (!lwp_in_step_range (event_child
))
3147 debug_printf ("Out of step range, reporting event.\n");
3149 if (event_child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
3150 debug_printf ("Stopped by watchpoint.\n");
3151 else if (gdb_breakpoint_here (event_child
->stop_pc
))
3152 debug_printf ("Stopped by GDB breakpoint.\n");
3154 debug_printf ("Hit a non-gdbserver trap event.\n");
3157 /* Alright, we're going to report a stop. */
3159 if (!stabilizing_threads
)
3161 /* In all-stop, stop all threads. */
3163 stop_all_lwps (0, NULL
);
3165 /* If we're not waiting for a specific LWP, choose an event LWP
3166 from among those that have had events. Giving equal priority
3167 to all LWPs that have had events helps prevent
3169 if (ptid_equal (ptid
, minus_one_ptid
))
3171 event_child
->status_pending_p
= 1;
3172 event_child
->status_pending
= w
;
3174 select_event_lwp (&event_child
);
3176 /* current_thread and event_child must stay in sync. */
3177 current_thread
= get_lwp_thread (event_child
);
3179 event_child
->status_pending_p
= 0;
3180 w
= event_child
->status_pending
;
3183 if (step_over_finished
)
3187 /* If we were doing a step-over, all other threads but
3188 the stepping one had been paused in start_step_over,
3189 with their suspend counts incremented. We don't want
3190 to do a full unstop/unpause, because we're in
3191 all-stop mode (so we want threads stopped), but we
3192 still need to unsuspend the other threads, to
3193 decrement their `suspended' count back. */
3194 unsuspend_all_lwps (event_child
);
3198 /* If we just finished a step-over, then all threads had
3199 been momentarily paused. In all-stop, that's fine,
3200 we want threads stopped by now anyway. In non-stop,
3201 we need to re-resume threads that GDB wanted to be
3203 unstop_all_lwps (1, event_child
);
3207 /* Stabilize threads (move out of jump pads). */
3209 stabilize_threads ();
3213 /* If we just finished a step-over, then all threads had been
3214 momentarily paused. In all-stop, that's fine, we want
3215 threads stopped by now anyway. In non-stop, we need to
3216 re-resume threads that GDB wanted to be running. */
3217 if (step_over_finished
)
3218 unstop_all_lwps (1, event_child
);
3221 if (extended_event_reported (&event_child
->waitstatus
))
3223 /* If the reported event is a fork, vfork or exec, let GDB know. */
3224 ourstatus
->kind
= event_child
->waitstatus
.kind
;
3225 ourstatus
->value
= event_child
->waitstatus
.value
;
3227 /* Clear the event lwp's waitstatus since we handled it already. */
3228 event_child
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3231 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
3233 /* Now that we've selected our final event LWP, un-adjust its PC if
3234 it was a software breakpoint, and the client doesn't know we can
3235 adjust the breakpoint ourselves. */
3236 if (event_child
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3237 && !swbreak_feature
)
3239 int decr_pc
= the_low_target
.decr_pc_after_break
;
3243 struct regcache
*regcache
3244 = get_thread_regcache (current_thread
, 1);
3245 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
+ decr_pc
);
3249 if (current_thread
->last_resume_kind
== resume_stop
3250 && WSTOPSIG (w
) == SIGSTOP
)
3252 /* A thread that has been requested to stop by GDB with vCont;t,
3253 and it stopped cleanly, so report as SIG0. The use of
3254 SIGSTOP is an implementation detail. */
3255 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3257 else if (current_thread
->last_resume_kind
== resume_stop
3258 && WSTOPSIG (w
) != SIGSTOP
)
3260 /* A thread that has been requested to stop by GDB with vCont;t,
3261 but, it stopped for other reasons. */
3262 ourstatus
->value
.sig
= gdb_signal_from_host (WSTOPSIG (w
));
3264 else if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
)
3266 ourstatus
->value
.sig
= gdb_signal_from_host (WSTOPSIG (w
));
3269 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
3273 debug_printf ("linux_wait_1 ret = %s, %d, %d\n",
3274 target_pid_to_str (ptid_of (current_thread
)),
3275 ourstatus
->kind
, ourstatus
->value
.sig
);
3279 return ptid_of (current_thread
);
3282 /* Get rid of any pending event in the pipe. */
3284 async_file_flush (void)
3290 ret
= read (linux_event_pipe
[0], &buf
, 1);
3291 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
3294 /* Put something in the pipe, so the event loop wakes up. */
3296 async_file_mark (void)
3300 async_file_flush ();
3303 ret
= write (linux_event_pipe
[1], "+", 1);
3304 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
3306 /* Ignore EAGAIN. If the pipe is full, the event loop will already
3307 be awakened anyway. */
3311 linux_wait (ptid_t ptid
,
3312 struct target_waitstatus
*ourstatus
, int target_options
)
3316 /* Flush the async file first. */
3317 if (target_is_async_p ())
3318 async_file_flush ();
3322 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
3324 while ((target_options
& TARGET_WNOHANG
) == 0
3325 && ptid_equal (event_ptid
, null_ptid
)
3326 && ourstatus
->kind
== TARGET_WAITKIND_IGNORE
);
3328 /* If at least one stop was reported, there may be more. A single
3329 SIGCHLD can signal more than one child stop. */
3330 if (target_is_async_p ()
3331 && (target_options
& TARGET_WNOHANG
) != 0
3332 && !ptid_equal (event_ptid
, null_ptid
))
3338 /* Send a signal to an LWP. */
3341 kill_lwp (unsigned long lwpid
, int signo
)
3343 /* Use tkill, if possible, in case we are using nptl threads. If tkill
3344 fails, then we are not using nptl threads and we should be using kill. */
3348 static int tkill_failed
;
3355 ret
= syscall (__NR_tkill
, lwpid
, signo
);
3356 if (errno
!= ENOSYS
)
3363 return kill (lwpid
, signo
);
3367 linux_stop_lwp (struct lwp_info
*lwp
)
3373 send_sigstop (struct lwp_info
*lwp
)
3377 pid
= lwpid_of (get_lwp_thread (lwp
));
3379 /* If we already have a pending stop signal for this process, don't
3381 if (lwp
->stop_expected
)
3384 debug_printf ("Have pending sigstop for lwp %d\n", pid
);
3390 debug_printf ("Sending sigstop to lwp %d\n", pid
);
3392 lwp
->stop_expected
= 1;
3393 kill_lwp (pid
, SIGSTOP
);
3397 send_sigstop_callback (struct inferior_list_entry
*entry
, void *except
)
3399 struct thread_info
*thread
= (struct thread_info
*) entry
;
3400 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3402 /* Ignore EXCEPT. */
3413 /* Increment the suspend count of an LWP, and stop it, if not stopped
3416 suspend_and_send_sigstop_callback (struct inferior_list_entry
*entry
,
3419 struct thread_info
*thread
= (struct thread_info
*) entry
;
3420 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3422 /* Ignore EXCEPT. */
3428 return send_sigstop_callback (entry
, except
);
3432 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
3434 /* It's dead, really. */
3437 /* Store the exit status for later. */
3438 lwp
->status_pending_p
= 1;
3439 lwp
->status_pending
= wstat
;
3441 /* Prevent trying to stop it. */
3444 /* No further stops are expected from a dead lwp. */
3445 lwp
->stop_expected
= 0;
3448 /* Wait for all children to stop for the SIGSTOPs we just queued. */
3451 wait_for_sigstop (void)
3453 struct thread_info
*saved_thread
;
3458 saved_thread
= current_thread
;
3459 if (saved_thread
!= NULL
)
3460 saved_tid
= saved_thread
->entry
.id
;
3462 saved_tid
= null_ptid
; /* avoid bogus unused warning */
3465 debug_printf ("wait_for_sigstop: pulling events\n");
3467 /* Passing NULL_PTID as filter indicates we want all events to be
3468 left pending. Eventually this returns when there are no
3469 unwaited-for children left. */
3470 ret
= linux_wait_for_event_filtered (minus_one_ptid
, null_ptid
,
3472 gdb_assert (ret
== -1);
3474 if (saved_thread
== NULL
|| linux_thread_alive (saved_tid
))
3475 current_thread
= saved_thread
;
3479 debug_printf ("Previously current thread died.\n");
3483 /* We can't change the current inferior behind GDB's back,
3484 otherwise, a subsequent command may apply to the wrong
3486 current_thread
= NULL
;
3490 /* Set a valid thread as current. */
3491 set_desired_thread (0);
3496 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
3497 move it out, because we need to report the stop event to GDB. For
3498 example, if the user puts a breakpoint in the jump pad, it's
3499 because she wants to debug it. */
3502 stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
, void *data
)
3504 struct thread_info
*thread
= (struct thread_info
*) entry
;
3505 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3507 gdb_assert (lwp
->suspended
== 0);
3508 gdb_assert (lwp
->stopped
);
3510 /* Allow debugging the jump pad, gdb_collect, etc.. */
3511 return (supports_fast_tracepoints ()
3512 && agent_loaded_p ()
3513 && (gdb_breakpoint_here (lwp
->stop_pc
)
3514 || lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
3515 || thread
->last_resume_kind
== resume_step
)
3516 && linux_fast_tracepoint_collecting (lwp
, NULL
));
3520 move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
)
3522 struct thread_info
*thread
= (struct thread_info
*) entry
;
3523 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3526 gdb_assert (lwp
->suspended
== 0);
3527 gdb_assert (lwp
->stopped
);
3529 wstat
= lwp
->status_pending_p
? &lwp
->status_pending
: NULL
;
3531 /* Allow debugging the jump pad, gdb_collect, etc. */
3532 if (!gdb_breakpoint_here (lwp
->stop_pc
)
3533 && lwp
->stop_reason
!= TARGET_STOPPED_BY_WATCHPOINT
3534 && thread
->last_resume_kind
!= resume_step
3535 && maybe_move_out_of_jump_pad (lwp
, wstat
))
3538 debug_printf ("LWP %ld needs stabilizing (in jump pad)\n",
3543 lwp
->status_pending_p
= 0;
3544 enqueue_one_deferred_signal (lwp
, wstat
);
3547 debug_printf ("Signal %d for LWP %ld deferred "
3549 WSTOPSIG (*wstat
), lwpid_of (thread
));
3552 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
3559 lwp_running (struct inferior_list_entry
*entry
, void *data
)
3561 struct thread_info
*thread
= (struct thread_info
*) entry
;
3562 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3571 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
3572 If SUSPEND, then also increase the suspend count of every LWP,
3576 stop_all_lwps (int suspend
, struct lwp_info
*except
)
3578 /* Should not be called recursively. */
3579 gdb_assert (stopping_threads
== NOT_STOPPING_THREADS
);
3584 debug_printf ("stop_all_lwps (%s, except=%s)\n",
3585 suspend
? "stop-and-suspend" : "stop",
3587 ? target_pid_to_str (ptid_of (get_lwp_thread (except
)))
3591 stopping_threads
= (suspend
3592 ? STOPPING_AND_SUSPENDING_THREADS
3593 : STOPPING_THREADS
);
3596 find_inferior (&all_threads
, suspend_and_send_sigstop_callback
, except
);
3598 find_inferior (&all_threads
, send_sigstop_callback
, except
);
3599 wait_for_sigstop ();
3600 stopping_threads
= NOT_STOPPING_THREADS
;
3604 debug_printf ("stop_all_lwps done, setting stopping_threads "
3605 "back to !stopping\n");
3610 /* Resume execution of LWP. If STEP is nonzero, single-step it. If
3611 SIGNAL is nonzero, give it that signal. */
3614 linux_resume_one_lwp_throw (struct lwp_info
*lwp
,
3615 int step
, int signal
, siginfo_t
*info
)
3617 struct thread_info
*thread
= get_lwp_thread (lwp
);
3618 struct thread_info
*saved_thread
;
3619 int fast_tp_collecting
;
3621 if (lwp
->stopped
== 0)
3624 fast_tp_collecting
= lwp
->collecting_fast_tracepoint
;
3626 gdb_assert (!stabilizing_threads
|| fast_tp_collecting
);
3628 /* Cancel actions that rely on GDB not changing the PC (e.g., the
3629 user used the "jump" command, or "set $pc = foo"). */
3630 if (lwp
->stop_pc
!= get_pc (lwp
))
3632 /* Collecting 'while-stepping' actions doesn't make sense
3634 release_while_stepping_state_list (thread
);
3637 /* If we have pending signals or status, and a new signal, enqueue the
3638 signal. Also enqueue the signal if we are waiting to reinsert a
3639 breakpoint; it will be picked up again below. */
3641 && (lwp
->status_pending_p
3642 || lwp
->pending_signals
!= NULL
3643 || lwp
->bp_reinsert
!= 0
3644 || fast_tp_collecting
))
3646 struct pending_signals
*p_sig
;
3647 p_sig
= xmalloc (sizeof (*p_sig
));
3648 p_sig
->prev
= lwp
->pending_signals
;
3649 p_sig
->signal
= signal
;
3651 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
3653 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
3654 lwp
->pending_signals
= p_sig
;
3657 if (lwp
->status_pending_p
)
3660 debug_printf ("Not resuming lwp %ld (%s, signal %d, stop %s);"
3661 " has pending status\n",
3662 lwpid_of (thread
), step
? "step" : "continue", signal
,
3663 lwp
->stop_expected
? "expected" : "not expected");
3667 saved_thread
= current_thread
;
3668 current_thread
= thread
;
3671 debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n",
3672 lwpid_of (thread
), step
? "step" : "continue", signal
,
3673 lwp
->stop_expected
? "expected" : "not expected");
3675 /* This bit needs some thinking about. If we get a signal that
3676 we must report while a single-step reinsert is still pending,
3677 we often end up resuming the thread. It might be better to
3678 (ew) allow a stack of pending events; then we could be sure that
3679 the reinsert happened right away and not lose any signals.
3681 Making this stack would also shrink the window in which breakpoints are
3682 uninserted (see comment in linux_wait_for_lwp) but not enough for
3683 complete correctness, so it won't solve that problem. It may be
3684 worthwhile just to solve this one, however. */
3685 if (lwp
->bp_reinsert
!= 0)
3688 debug_printf (" pending reinsert at 0x%s\n",
3689 paddress (lwp
->bp_reinsert
));
3691 if (can_hardware_single_step ())
3693 if (fast_tp_collecting
== 0)
3696 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
3698 fprintf (stderr
, "BAD - reinserting and suspended(%d).\n",
3705 /* Postpone any pending signal. It was enqueued above. */
3709 if (fast_tp_collecting
== 1)
3712 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
3713 " (exit-jump-pad-bkpt)\n",
3716 /* Postpone any pending signal. It was enqueued above. */
3719 else if (fast_tp_collecting
== 2)
3722 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
3723 " single-stepping\n",
3726 if (can_hardware_single_step ())
3730 internal_error (__FILE__
, __LINE__
,
3731 "moving out of jump pad single-stepping"
3732 " not implemented on this target");
3735 /* Postpone any pending signal. It was enqueued above. */
3739 /* If we have while-stepping actions in this thread set it stepping.
3740 If we have a signal to deliver, it may or may not be set to
3741 SIG_IGN, we don't know. Assume so, and allow collecting
3742 while-stepping into a signal handler. A possible smart thing to
3743 do would be to set an internal breakpoint at the signal return
3744 address, continue, and carry on catching this while-stepping
3745 action only when that breakpoint is hit. A future
3747 if (thread
->while_stepping
!= NULL
3748 && can_hardware_single_step ())
3751 debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n",
3756 if (the_low_target
.get_pc
!= NULL
)
3758 struct regcache
*regcache
= get_thread_regcache (current_thread
, 1);
3760 lwp
->stop_pc
= (*the_low_target
.get_pc
) (regcache
);
3764 debug_printf (" %s from pc 0x%lx\n", step
? "step" : "continue",
3765 (long) lwp
->stop_pc
);
3769 /* If we have pending signals, consume one unless we are trying to
3770 reinsert a breakpoint or we're trying to finish a fast tracepoint
3772 if (lwp
->pending_signals
!= NULL
3773 && lwp
->bp_reinsert
== 0
3774 && fast_tp_collecting
== 0)
3776 struct pending_signals
**p_sig
;
3778 p_sig
= &lwp
->pending_signals
;
3779 while ((*p_sig
)->prev
!= NULL
)
3780 p_sig
= &(*p_sig
)->prev
;
3782 signal
= (*p_sig
)->signal
;
3783 if ((*p_sig
)->info
.si_signo
!= 0)
3784 ptrace (PTRACE_SETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
3791 if (the_low_target
.prepare_to_resume
!= NULL
)
3792 the_low_target
.prepare_to_resume (lwp
);
3794 regcache_invalidate_thread (thread
);
3796 lwp
->stepping
= step
;
3797 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (thread
),
3798 (PTRACE_TYPE_ARG3
) 0,
3799 /* Coerce to a uintptr_t first to avoid potential gcc warning
3800 of coercing an 8 byte integer to a 4 byte pointer. */
3801 (PTRACE_TYPE_ARG4
) (uintptr_t) signal
);
3803 current_thread
= saved_thread
;
3805 perror_with_name ("resuming thread");
3807 /* Successfully resumed. Clear state that no longer makes sense,
3808 and mark the LWP as running. Must not do this before resuming
3809 otherwise if that fails other code will be confused. E.g., we'd
3810 later try to stop the LWP and hang forever waiting for a stop
3811 status. Note that we must not throw after this is cleared,
3812 otherwise handle_zombie_lwp_error would get confused. */
3814 lwp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3817 /* Called when we try to resume a stopped LWP and that errors out. If
3818 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
3819 or about to become), discard the error, clear any pending status
3820 the LWP may have, and return true (we'll collect the exit status
3821 soon enough). Otherwise, return false. */
3824 check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
)
3826 struct thread_info
*thread
= get_lwp_thread (lp
);
3828 /* If we get an error after resuming the LWP successfully, we'd
3829 confuse !T state for the LWP being gone. */
3830 gdb_assert (lp
->stopped
);
3832 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
3833 because even if ptrace failed with ESRCH, the tracee may be "not
3834 yet fully dead", but already refusing ptrace requests. In that
3835 case the tracee has 'R (Running)' state for a little bit
3836 (observed in Linux 3.18). See also the note on ESRCH in the
3837 ptrace(2) man page. Instead, check whether the LWP has any state
3838 other than ptrace-stopped. */
3840 /* Don't assume anything if /proc/PID/status can't be read. */
3841 if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread
)) == 0)
3843 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3844 lp
->status_pending_p
= 0;
3850 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
3851 disappears while we try to resume it. */
3854 linux_resume_one_lwp (struct lwp_info
*lwp
,
3855 int step
, int signal
, siginfo_t
*info
)
3859 linux_resume_one_lwp_throw (lwp
, step
, signal
, info
);
3861 CATCH (ex
, RETURN_MASK_ERROR
)
3863 if (!check_ptrace_stopped_lwp_gone (lwp
))
3864 throw_exception (ex
);
3869 struct thread_resume_array
3871 struct thread_resume
*resume
;
3875 /* This function is called once per thread via find_inferior.
3876 ARG is a pointer to a thread_resume_array struct.
3877 We look up the thread specified by ENTRY in ARG, and mark the thread
3878 with a pointer to the appropriate resume request.
3880 This algorithm is O(threads * resume elements), but resume elements
3881 is small (and will remain small at least until GDB supports thread
3885 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
3887 struct thread_info
*thread
= (struct thread_info
*) entry
;
3888 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3890 struct thread_resume_array
*r
;
3894 for (ndx
= 0; ndx
< r
->n
; ndx
++)
3896 ptid_t ptid
= r
->resume
[ndx
].thread
;
3897 if (ptid_equal (ptid
, minus_one_ptid
)
3898 || ptid_equal (ptid
, entry
->id
)
3899 /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads
3901 || (ptid_get_pid (ptid
) == pid_of (thread
)
3902 && (ptid_is_pid (ptid
)
3903 || ptid_get_lwp (ptid
) == -1)))
3905 if (r
->resume
[ndx
].kind
== resume_stop
3906 && thread
->last_resume_kind
== resume_stop
)
3909 debug_printf ("already %s LWP %ld at GDB's request\n",
3910 (thread
->last_status
.kind
3911 == TARGET_WAITKIND_STOPPED
)
3919 lwp
->resume
= &r
->resume
[ndx
];
3920 thread
->last_resume_kind
= lwp
->resume
->kind
;
3922 lwp
->step_range_start
= lwp
->resume
->step_range_start
;
3923 lwp
->step_range_end
= lwp
->resume
->step_range_end
;
3925 /* If we had a deferred signal to report, dequeue one now.
3926 This can happen if LWP gets more than one signal while
3927 trying to get out of a jump pad. */
3929 && !lwp
->status_pending_p
3930 && dequeue_one_deferred_signal (lwp
, &lwp
->status_pending
))
3932 lwp
->status_pending_p
= 1;
3935 debug_printf ("Dequeueing deferred signal %d for LWP %ld, "
3936 "leaving status pending.\n",
3937 WSTOPSIG (lwp
->status_pending
),
3945 /* No resume action for this thread. */
3951 /* find_inferior callback for linux_resume.
3952 Set *FLAG_P if this lwp has an interesting status pending. */
3955 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
3957 struct thread_info
*thread
= (struct thread_info
*) entry
;
3958 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3960 /* LWPs which will not be resumed are not interesting, because
3961 we might not wait for them next time through linux_wait. */
3962 if (lwp
->resume
== NULL
)
3965 if (thread_still_has_status_pending_p (thread
))
3966 * (int *) flag_p
= 1;
3971 /* Return 1 if this lwp that GDB wants running is stopped at an
3972 internal breakpoint that we need to step over. It assumes that any
3973 required STOP_PC adjustment has already been propagated to the
3974 inferior's regcache. */
3977 need_step_over_p (struct inferior_list_entry
*entry
, void *dummy
)
3979 struct thread_info
*thread
= (struct thread_info
*) entry
;
3980 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3981 struct thread_info
*saved_thread
;
3984 /* LWPs which will not be resumed are not interesting, because we
3985 might not wait for them next time through linux_wait. */
3990 debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped\n",
3995 if (thread
->last_resume_kind
== resume_stop
)
3998 debug_printf ("Need step over [LWP %ld]? Ignoring, should remain"
4004 gdb_assert (lwp
->suspended
>= 0);
4009 debug_printf ("Need step over [LWP %ld]? Ignoring, suspended\n",
4014 if (!lwp
->need_step_over
)
4017 debug_printf ("Need step over [LWP %ld]? No\n", lwpid_of (thread
));
4020 if (lwp
->status_pending_p
)
4023 debug_printf ("Need step over [LWP %ld]? Ignoring, has pending"
4029 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
4033 /* If the PC has changed since we stopped, then don't do anything,
4034 and let the breakpoint/tracepoint be hit. This happens if, for
4035 instance, GDB handled the decr_pc_after_break subtraction itself,
4036 GDB is OOL stepping this thread, or the user has issued a "jump"
4037 command, or poked thread's registers herself. */
4038 if (pc
!= lwp
->stop_pc
)
4041 debug_printf ("Need step over [LWP %ld]? Cancelling, PC was changed. "
4042 "Old stop_pc was 0x%s, PC is now 0x%s\n",
4044 paddress (lwp
->stop_pc
), paddress (pc
));
4046 lwp
->need_step_over
= 0;
4050 saved_thread
= current_thread
;
4051 current_thread
= thread
;
4053 /* We can only step over breakpoints we know about. */
4054 if (breakpoint_here (pc
) || fast_tracepoint_jump_here (pc
))
4056 /* Don't step over a breakpoint that GDB expects to hit
4057 though. If the condition is being evaluated on the target's side
4058 and it evaluate to false, step over this breakpoint as well. */
4059 if (gdb_breakpoint_here (pc
)
4060 && gdb_condition_true_at_breakpoint (pc
)
4061 && gdb_no_commands_at_breakpoint (pc
))
4064 debug_printf ("Need step over [LWP %ld]? yes, but found"
4065 " GDB breakpoint at 0x%s; skipping step over\n",
4066 lwpid_of (thread
), paddress (pc
));
4068 current_thread
= saved_thread
;
4074 debug_printf ("Need step over [LWP %ld]? yes, "
4075 "found breakpoint at 0x%s\n",
4076 lwpid_of (thread
), paddress (pc
));
4078 /* We've found an lwp that needs stepping over --- return 1 so
4079 that find_inferior stops looking. */
4080 current_thread
= saved_thread
;
4082 /* If the step over is cancelled, this is set again. */
4083 lwp
->need_step_over
= 0;
4088 current_thread
= saved_thread
;
4091 debug_printf ("Need step over [LWP %ld]? No, no breakpoint found"
4093 lwpid_of (thread
), paddress (pc
));
4098 /* Start a step-over operation on LWP. When LWP stopped at a
4099 breakpoint, to make progress, we need to remove the breakpoint out
4100 of the way. If we let other threads run while we do that, they may
4101 pass by the breakpoint location and miss hitting it. To avoid
4102 that, a step-over momentarily stops all threads while LWP is
4103 single-stepped while the breakpoint is temporarily uninserted from
4104 the inferior. When the single-step finishes, we reinsert the
4105 breakpoint, and let all threads that are supposed to be running,
4108 On targets that don't support hardware single-step, we don't
4109 currently support full software single-stepping. Instead, we only
4110 support stepping over the thread event breakpoint, by asking the
4111 low target where to place a reinsert breakpoint. Since this
4112 routine assumes the breakpoint being stepped over is a thread event
4113 breakpoint, it usually assumes the return address of the current
4114 function is a good enough place to set the reinsert breakpoint. */
4117 start_step_over (struct lwp_info
*lwp
)
4119 struct thread_info
*thread
= get_lwp_thread (lwp
);
4120 struct thread_info
*saved_thread
;
4125 debug_printf ("Starting step-over on LWP %ld. Stopping all threads\n",
4128 stop_all_lwps (1, lwp
);
4129 gdb_assert (lwp
->suspended
== 0);
4132 debug_printf ("Done stopping all threads for step-over.\n");
4134 /* Note, we should always reach here with an already adjusted PC,
4135 either by GDB (if we're resuming due to GDB's request), or by our
4136 caller, if we just finished handling an internal breakpoint GDB
4137 shouldn't care about. */
4140 saved_thread
= current_thread
;
4141 current_thread
= thread
;
4143 lwp
->bp_reinsert
= pc
;
4144 uninsert_breakpoints_at (pc
);
4145 uninsert_fast_tracepoint_jumps_at (pc
);
4147 if (can_hardware_single_step ())
4153 CORE_ADDR raddr
= (*the_low_target
.breakpoint_reinsert_addr
) ();
4154 set_reinsert_breakpoint (raddr
);
4158 current_thread
= saved_thread
;
4160 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
4162 /* Require next event from this LWP. */
4163 step_over_bkpt
= thread
->entry
.id
;
4167 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
4168 start_step_over, if still there, and delete any reinsert
4169 breakpoints we've set, on non hardware single-step targets. */
4172 finish_step_over (struct lwp_info
*lwp
)
4174 if (lwp
->bp_reinsert
!= 0)
4177 debug_printf ("Finished step over.\n");
4179 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
4180 may be no breakpoint to reinsert there by now. */
4181 reinsert_breakpoints_at (lwp
->bp_reinsert
);
4182 reinsert_fast_tracepoint_jumps_at (lwp
->bp_reinsert
);
4184 lwp
->bp_reinsert
= 0;
4186 /* Delete any software-single-step reinsert breakpoints. No
4187 longer needed. We don't have to worry about other threads
4188 hitting this trap, and later not being able to explain it,
4189 because we were stepping over a breakpoint, and we hold all
4190 threads but LWP stopped while doing that. */
4191 if (!can_hardware_single_step ())
4192 delete_reinsert_breakpoints ();
4194 step_over_bkpt
= null_ptid
;
4201 /* This function is called once per thread. We check the thread's resume
4202 request, which will tell us whether to resume, step, or leave the thread
4203 stopped; and what signal, if any, it should be sent.
4205 For threads which we aren't explicitly told otherwise, we preserve
4206 the stepping flag; this is used for stepping over gdbserver-placed
4209 If pending_flags was set in any thread, we queue any needed
4210 signals, since we won't actually resume. We already have a pending
4211 event to report, so we don't need to preserve any step requests;
4212 they should be re-issued if necessary. */
4215 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
4217 struct thread_info
*thread
= (struct thread_info
*) entry
;
4218 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4220 int leave_all_stopped
= * (int *) arg
;
4223 if (lwp
->resume
== NULL
)
4226 if (lwp
->resume
->kind
== resume_stop
)
4229 debug_printf ("resume_stop request for LWP %ld\n", lwpid_of (thread
));
4234 debug_printf ("stopping LWP %ld\n", lwpid_of (thread
));
4236 /* Stop the thread, and wait for the event asynchronously,
4237 through the event loop. */
4243 debug_printf ("already stopped LWP %ld\n",
4246 /* The LWP may have been stopped in an internal event that
4247 was not meant to be notified back to GDB (e.g., gdbserver
4248 breakpoint), so we should be reporting a stop event in
4251 /* If the thread already has a pending SIGSTOP, this is a
4252 no-op. Otherwise, something later will presumably resume
4253 the thread and this will cause it to cancel any pending
4254 operation, due to last_resume_kind == resume_stop. If
4255 the thread already has a pending status to report, we
4256 will still report it the next time we wait - see
4257 status_pending_p_callback. */
4259 /* If we already have a pending signal to report, then
4260 there's no need to queue a SIGSTOP, as this means we're
4261 midway through moving the LWP out of the jumppad, and we
4262 will report the pending signal as soon as that is
4264 if (lwp
->pending_signals_to_report
== NULL
)
4268 /* For stop requests, we're done. */
4270 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
4274 /* If this thread which is about to be resumed has a pending status,
4275 then don't resume any threads - we can just report the pending
4276 status. Make sure to queue any signals that would otherwise be
4277 sent. In all-stop mode, we do this decision based on if *any*
4278 thread has a pending status. If there's a thread that needs the
4279 step-over-breakpoint dance, then don't resume any other thread
4280 but that particular one. */
4281 leave_pending
= (lwp
->status_pending_p
|| leave_all_stopped
);
4286 debug_printf ("resuming LWP %ld\n", lwpid_of (thread
));
4288 step
= (lwp
->resume
->kind
== resume_step
);
4289 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
4294 debug_printf ("leaving LWP %ld stopped\n", lwpid_of (thread
));
4296 /* If we have a new signal, enqueue the signal. */
4297 if (lwp
->resume
->sig
!= 0)
4299 struct pending_signals
*p_sig
;
4300 p_sig
= xmalloc (sizeof (*p_sig
));
4301 p_sig
->prev
= lwp
->pending_signals
;
4302 p_sig
->signal
= lwp
->resume
->sig
;
4303 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
4305 /* If this is the same signal we were previously stopped by,
4306 make sure to queue its siginfo. We can ignore the return
4307 value of ptrace; if it fails, we'll skip
4308 PTRACE_SETSIGINFO. */
4309 if (WIFSTOPPED (lwp
->last_status
)
4310 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
4311 ptrace (PTRACE_GETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
4314 lwp
->pending_signals
= p_sig
;
4318 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
4324 linux_resume (struct thread_resume
*resume_info
, size_t n
)
4326 struct thread_resume_array array
= { resume_info
, n
};
4327 struct thread_info
*need_step_over
= NULL
;
4329 int leave_all_stopped
;
4334 debug_printf ("linux_resume:\n");
4337 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
4339 /* If there is a thread which would otherwise be resumed, which has
4340 a pending status, then don't resume any threads - we can just
4341 report the pending status. Make sure to queue any signals that
4342 would otherwise be sent. In non-stop mode, we'll apply this
4343 logic to each thread individually. We consume all pending events
4344 before considering to start a step-over (in all-stop). */
4347 find_inferior (&all_threads
, resume_status_pending_p
, &any_pending
);
4349 /* If there is a thread which would otherwise be resumed, which is
4350 stopped at a breakpoint that needs stepping over, then don't
4351 resume any threads - have it step over the breakpoint with all
4352 other threads stopped, then resume all threads again. Make sure
4353 to queue any signals that would otherwise be delivered or
4355 if (!any_pending
&& supports_breakpoints ())
4357 = (struct thread_info
*) find_inferior (&all_threads
,
4358 need_step_over_p
, NULL
);
4360 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
4364 if (need_step_over
!= NULL
)
4365 debug_printf ("Not resuming all, need step over\n");
4366 else if (any_pending
)
4367 debug_printf ("Not resuming, all-stop and found "
4368 "an LWP with pending status\n");
4370 debug_printf ("Resuming, no pending status or step over needed\n");
4373 /* Even if we're leaving threads stopped, queue all signals we'd
4374 otherwise deliver. */
4375 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
4378 start_step_over (get_thread_lwp (need_step_over
));
4382 debug_printf ("linux_resume done\n");
4387 /* This function is called once per thread. We check the thread's
4388 last resume request, which will tell us whether to resume, step, or
4389 leave the thread stopped. Any signal the client requested to be
4390 delivered has already been enqueued at this point.
4392 If any thread that GDB wants running is stopped at an internal
4393 breakpoint that needs stepping over, we start a step-over operation
4394 on that particular thread, and leave all others stopped. */
4397 proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
4399 struct thread_info
*thread
= (struct thread_info
*) entry
;
4400 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4407 debug_printf ("proceed_one_lwp: lwp %ld\n", lwpid_of (thread
));
4412 debug_printf (" LWP %ld already running\n", lwpid_of (thread
));
4416 if (thread
->last_resume_kind
== resume_stop
4417 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
4420 debug_printf (" client wants LWP to remain %ld stopped\n",
4425 if (lwp
->status_pending_p
)
4428 debug_printf (" LWP %ld has pending status, leaving stopped\n",
4433 gdb_assert (lwp
->suspended
>= 0);
4438 debug_printf (" LWP %ld is suspended\n", lwpid_of (thread
));
4442 if (thread
->last_resume_kind
== resume_stop
4443 && lwp
->pending_signals_to_report
== NULL
4444 && lwp
->collecting_fast_tracepoint
== 0)
4446 /* We haven't reported this LWP as stopped yet (otherwise, the
4447 last_status.kind check above would catch it, and we wouldn't
4448 reach here. This LWP may have been momentarily paused by a
4449 stop_all_lwps call while handling for example, another LWP's
4450 step-over. In that case, the pending expected SIGSTOP signal
4451 that was queued at vCont;t handling time will have already
4452 been consumed by wait_for_sigstop, and so we need to requeue
4453 another one here. Note that if the LWP already has a SIGSTOP
4454 pending, this is a no-op. */
4457 debug_printf ("Client wants LWP %ld to stop. "
4458 "Making sure it has a SIGSTOP pending\n",
4464 step
= thread
->last_resume_kind
== resume_step
;
4465 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
4470 unsuspend_and_proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
4472 struct thread_info
*thread
= (struct thread_info
*) entry
;
4473 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4479 gdb_assert (lwp
->suspended
>= 0);
4481 return proceed_one_lwp (entry
, except
);
4484 /* When we finish a step-over, set threads running again. If there's
4485 another thread that may need a step-over, now's the time to start
4486 it. Eventually, we'll move all threads past their breakpoints. */
4489 proceed_all_lwps (void)
4491 struct thread_info
*need_step_over
;
4493 /* If there is a thread which would otherwise be resumed, which is
4494 stopped at a breakpoint that needs stepping over, then don't
4495 resume any threads - have it step over the breakpoint with all
4496 other threads stopped, then resume all threads again. */
4498 if (supports_breakpoints ())
4501 = (struct thread_info
*) find_inferior (&all_threads
,
4502 need_step_over_p
, NULL
);
4504 if (need_step_over
!= NULL
)
4507 debug_printf ("proceed_all_lwps: found "
4508 "thread %ld needing a step-over\n",
4509 lwpid_of (need_step_over
));
4511 start_step_over (get_thread_lwp (need_step_over
));
4517 debug_printf ("Proceeding, no step-over needed\n");
4519 find_inferior (&all_threads
, proceed_one_lwp
, NULL
);
4522 /* Stopped LWPs that the client wanted to be running, that don't have
4523 pending statuses, are set to run again, except for EXCEPT, if not
4524 NULL. This undoes a stop_all_lwps call. */
4527 unstop_all_lwps (int unsuspend
, struct lwp_info
*except
)
4533 debug_printf ("unstopping all lwps, except=(LWP %ld)\n",
4534 lwpid_of (get_lwp_thread (except
)));
4536 debug_printf ("unstopping all lwps\n");
4540 find_inferior (&all_threads
, unsuspend_and_proceed_one_lwp
, except
);
4542 find_inferior (&all_threads
, proceed_one_lwp
, except
);
4546 debug_printf ("unstop_all_lwps done\n");
4552 #ifdef HAVE_LINUX_REGSETS
4554 #define use_linux_regsets 1
4556 /* Returns true if REGSET has been disabled. */
4559 regset_disabled (struct regsets_info
*info
, struct regset_info
*regset
)
4561 return (info
->disabled_regsets
!= NULL
4562 && info
->disabled_regsets
[regset
- info
->regsets
]);
4565 /* Disable REGSET. */
4568 disable_regset (struct regsets_info
*info
, struct regset_info
*regset
)
4572 dr_offset
= regset
- info
->regsets
;
4573 if (info
->disabled_regsets
== NULL
)
4574 info
->disabled_regsets
= xcalloc (1, info
->num_regsets
);
4575 info
->disabled_regsets
[dr_offset
] = 1;
4579 regsets_fetch_inferior_registers (struct regsets_info
*regsets_info
,
4580 struct regcache
*regcache
)
4582 struct regset_info
*regset
;
4583 int saw_general_regs
= 0;
4587 pid
= lwpid_of (current_thread
);
4588 for (regset
= regsets_info
->regsets
; regset
->size
>= 0; regset
++)
4593 if (regset
->size
== 0 || regset_disabled (regsets_info
, regset
))
4596 buf
= xmalloc (regset
->size
);
4598 nt_type
= regset
->nt_type
;
4602 iov
.iov_len
= regset
->size
;
4603 data
= (void *) &iov
;
4609 res
= ptrace (regset
->get_request
, pid
,
4610 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
4612 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
4618 /* If we get EIO on a regset, do not try it again for
4619 this process mode. */
4620 disable_regset (regsets_info
, regset
);
4622 else if (errno
== ENODATA
)
4624 /* ENODATA may be returned if the regset is currently
4625 not "active". This can happen in normal operation,
4626 so suppress the warning in this case. */
4631 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
4638 if (regset
->type
== GENERAL_REGS
)
4639 saw_general_regs
= 1;
4640 regset
->store_function (regcache
, buf
);
4644 if (saw_general_regs
)
4651 regsets_store_inferior_registers (struct regsets_info
*regsets_info
,
4652 struct regcache
*regcache
)
4654 struct regset_info
*regset
;
4655 int saw_general_regs
= 0;
4659 pid
= lwpid_of (current_thread
);
4660 for (regset
= regsets_info
->regsets
; regset
->size
>= 0; regset
++)
4665 if (regset
->size
== 0 || regset_disabled (regsets_info
, regset
)
4666 || regset
->fill_function
== NULL
)
4669 buf
= xmalloc (regset
->size
);
4671 /* First fill the buffer with the current register set contents,
4672 in case there are any items in the kernel's regset that are
4673 not in gdbserver's regcache. */
4675 nt_type
= regset
->nt_type
;
4679 iov
.iov_len
= regset
->size
;
4680 data
= (void *) &iov
;
4686 res
= ptrace (regset
->get_request
, pid
,
4687 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
4689 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
4694 /* Then overlay our cached registers on that. */
4695 regset
->fill_function (regcache
, buf
);
4697 /* Only now do we write the register set. */
4699 res
= ptrace (regset
->set_request
, pid
,
4700 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
4702 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
4710 /* If we get EIO on a regset, do not try it again for
4711 this process mode. */
4712 disable_regset (regsets_info
, regset
);
4714 else if (errno
== ESRCH
)
4716 /* At this point, ESRCH should mean the process is
4717 already gone, in which case we simply ignore attempts
4718 to change its registers. See also the related
4719 comment in linux_resume_one_lwp. */
4725 perror ("Warning: ptrace(regsets_store_inferior_registers)");
4728 else if (regset
->type
== GENERAL_REGS
)
4729 saw_general_regs
= 1;
4732 if (saw_general_regs
)
4738 #else /* !HAVE_LINUX_REGSETS */
4740 #define use_linux_regsets 0
4741 #define regsets_fetch_inferior_registers(regsets_info, regcache) 1
4742 #define regsets_store_inferior_registers(regsets_info, regcache) 1
4746 /* Return 1 if register REGNO is supported by one of the regset ptrace
4747 calls or 0 if it has to be transferred individually. */
4750 linux_register_in_regsets (const struct regs_info
*regs_info
, int regno
)
4752 unsigned char mask
= 1 << (regno
% 8);
4753 size_t index
= regno
/ 8;
4755 return (use_linux_regsets
4756 && (regs_info
->regset_bitmap
== NULL
4757 || (regs_info
->regset_bitmap
[index
] & mask
) != 0));
4760 #ifdef HAVE_LINUX_USRREGS
4763 register_addr (const struct usrregs_info
*usrregs
, int regnum
)
4767 if (regnum
< 0 || regnum
>= usrregs
->num_regs
)
4768 error ("Invalid register number %d.", regnum
);
4770 addr
= usrregs
->regmap
[regnum
];
4775 /* Fetch one register. */
4777 fetch_register (const struct usrregs_info
*usrregs
,
4778 struct regcache
*regcache
, int regno
)
4785 if (regno
>= usrregs
->num_regs
)
4787 if ((*the_low_target
.cannot_fetch_register
) (regno
))
4790 regaddr
= register_addr (usrregs
, regno
);
4794 size
= ((register_size (regcache
->tdesc
, regno
)
4795 + sizeof (PTRACE_XFER_TYPE
) - 1)
4796 & -sizeof (PTRACE_XFER_TYPE
));
4797 buf
= alloca (size
);
4799 pid
= lwpid_of (current_thread
);
4800 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
4803 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
4804 ptrace (PTRACE_PEEKUSER
, pid
,
4805 /* Coerce to a uintptr_t first to avoid potential gcc warning
4806 of coercing an 8 byte integer to a 4 byte pointer. */
4807 (PTRACE_TYPE_ARG3
) (uintptr_t) regaddr
, (PTRACE_TYPE_ARG4
) 0);
4808 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
4810 error ("reading register %d: %s", regno
, strerror (errno
));
4813 if (the_low_target
.supply_ptrace_register
)
4814 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
4816 supply_register (regcache
, regno
, buf
);
4819 /* Store one register. */
4821 store_register (const struct usrregs_info
*usrregs
,
4822 struct regcache
*regcache
, int regno
)
4829 if (regno
>= usrregs
->num_regs
)
4831 if ((*the_low_target
.cannot_store_register
) (regno
))
4834 regaddr
= register_addr (usrregs
, regno
);
4838 size
= ((register_size (regcache
->tdesc
, regno
)
4839 + sizeof (PTRACE_XFER_TYPE
) - 1)
4840 & -sizeof (PTRACE_XFER_TYPE
));
4841 buf
= alloca (size
);
4842 memset (buf
, 0, size
);
4844 if (the_low_target
.collect_ptrace_register
)
4845 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
4847 collect_register (regcache
, regno
, buf
);
4849 pid
= lwpid_of (current_thread
);
4850 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
4853 ptrace (PTRACE_POKEUSER
, pid
,
4854 /* Coerce to a uintptr_t first to avoid potential gcc warning
4855 about coercing an 8 byte integer to a 4 byte pointer. */
4856 (PTRACE_TYPE_ARG3
) (uintptr_t) regaddr
,
4857 (PTRACE_TYPE_ARG4
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
4860 /* At this point, ESRCH should mean the process is
4861 already gone, in which case we simply ignore attempts
4862 to change its registers. See also the related
4863 comment in linux_resume_one_lwp. */
4867 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
4868 error ("writing register %d: %s", regno
, strerror (errno
));
4870 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
4874 /* Fetch all registers, or just one, from the child process.
4875 If REGNO is -1, do this for all registers, skipping any that are
4876 assumed to have been retrieved by regsets_fetch_inferior_registers,
4877 unless ALL is non-zero.
4878 Otherwise, REGNO specifies which register (so we can save time). */
4880 usr_fetch_inferior_registers (const struct regs_info
*regs_info
,
4881 struct regcache
*regcache
, int regno
, int all
)
4883 struct usrregs_info
*usr
= regs_info
->usrregs
;
4887 for (regno
= 0; regno
< usr
->num_regs
; regno
++)
4888 if (all
|| !linux_register_in_regsets (regs_info
, regno
))
4889 fetch_register (usr
, regcache
, regno
);
4892 fetch_register (usr
, regcache
, regno
);
4895 /* Store our register values back into the inferior.
4896 If REGNO is -1, do this for all registers, skipping any that are
4897 assumed to have been saved by regsets_store_inferior_registers,
4898 unless ALL is non-zero.
4899 Otherwise, REGNO specifies which register (so we can save time). */
4901 usr_store_inferior_registers (const struct regs_info
*regs_info
,
4902 struct regcache
*regcache
, int regno
, int all
)
4904 struct usrregs_info
*usr
= regs_info
->usrregs
;
4908 for (regno
= 0; regno
< usr
->num_regs
; regno
++)
4909 if (all
|| !linux_register_in_regsets (regs_info
, regno
))
4910 store_register (usr
, regcache
, regno
);
4913 store_register (usr
, regcache
, regno
);
4916 #else /* !HAVE_LINUX_USRREGS */
4918 #define usr_fetch_inferior_registers(regs_info, regcache, regno, all) do {} while (0)
4919 #define usr_store_inferior_registers(regs_info, regcache, regno, all) do {} while (0)
4925 linux_fetch_registers (struct regcache
*regcache
, int regno
)
4929 const struct regs_info
*regs_info
= (*the_low_target
.regs_info
) ();
4933 if (the_low_target
.fetch_register
!= NULL
4934 && regs_info
->usrregs
!= NULL
)
4935 for (regno
= 0; regno
< regs_info
->usrregs
->num_regs
; regno
++)
4936 (*the_low_target
.fetch_register
) (regcache
, regno
);
4938 all
= regsets_fetch_inferior_registers (regs_info
->regsets_info
, regcache
);
4939 if (regs_info
->usrregs
!= NULL
)
4940 usr_fetch_inferior_registers (regs_info
, regcache
, -1, all
);
4944 if (the_low_target
.fetch_register
!= NULL
4945 && (*the_low_target
.fetch_register
) (regcache
, regno
))
4948 use_regsets
= linux_register_in_regsets (regs_info
, regno
);
4950 all
= regsets_fetch_inferior_registers (regs_info
->regsets_info
,
4952 if ((!use_regsets
|| all
) && regs_info
->usrregs
!= NULL
)
4953 usr_fetch_inferior_registers (regs_info
, regcache
, regno
, 1);
4958 linux_store_registers (struct regcache
*regcache
, int regno
)
4962 const struct regs_info
*regs_info
= (*the_low_target
.regs_info
) ();
4966 all
= regsets_store_inferior_registers (regs_info
->regsets_info
,
4968 if (regs_info
->usrregs
!= NULL
)
4969 usr_store_inferior_registers (regs_info
, regcache
, regno
, all
);
4973 use_regsets
= linux_register_in_regsets (regs_info
, regno
);
4975 all
= regsets_store_inferior_registers (regs_info
->regsets_info
,
4977 if ((!use_regsets
|| all
) && regs_info
->usrregs
!= NULL
)
4978 usr_store_inferior_registers (regs_info
, regcache
, regno
, 1);
4983 /* Copy LEN bytes from inferior's memory starting at MEMADDR
4984 to debugger memory starting at MYADDR. */
4987 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
4989 int pid
= lwpid_of (current_thread
);
4990 register PTRACE_XFER_TYPE
*buffer
;
4991 register CORE_ADDR addr
;
4998 /* Try using /proc. Don't bother for one word. */
4999 if (len
>= 3 * sizeof (long))
5003 /* We could keep this file open and cache it - possibly one per
5004 thread. That requires some juggling, but is even faster. */
5005 sprintf (filename
, "/proc/%d/mem", pid
);
5006 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
5010 /* If pread64 is available, use it. It's faster if the kernel
5011 supports it (only one syscall), and it's 64-bit safe even on
5012 32-bit platforms (for instance, SPARC debugging a SPARC64
5015 bytes
= pread64 (fd
, myaddr
, len
, memaddr
);
5018 if (lseek (fd
, memaddr
, SEEK_SET
) != -1)
5019 bytes
= read (fd
, myaddr
, len
);
5026 /* Some data was read, we'll try to get the rest with ptrace. */
5036 /* Round starting address down to longword boundary. */
5037 addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
5038 /* Round ending address up; get number of longwords that makes. */
5039 count
= ((((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
5040 / sizeof (PTRACE_XFER_TYPE
));
5041 /* Allocate buffer of that many longwords. */
5042 buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
5044 /* Read all the longwords */
5046 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
5048 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
5049 about coercing an 8 byte integer to a 4 byte pointer. */
5050 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
5051 (PTRACE_TYPE_ARG3
) (uintptr_t) addr
,
5052 (PTRACE_TYPE_ARG4
) 0);
5058 /* Copy appropriate bytes out of the buffer. */
5061 i
*= sizeof (PTRACE_XFER_TYPE
);
5062 i
-= memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1);
5064 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
5071 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
5072 memory at MEMADDR. On failure (cannot write to the inferior)
5073 returns the value of errno. Always succeeds if LEN is zero. */
5076 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
5079 /* Round starting address down to longword boundary. */
5080 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
5081 /* Round ending address up; get number of longwords that makes. */
5083 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
5084 / sizeof (PTRACE_XFER_TYPE
);
5086 /* Allocate buffer of that many longwords. */
5087 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*)
5088 alloca (count
* sizeof (PTRACE_XFER_TYPE
));
5090 int pid
= lwpid_of (current_thread
);
5094 /* Zero length write always succeeds. */
5100 /* Dump up to four bytes. */
5101 unsigned int val
= * (unsigned int *) myaddr
;
5107 val
= val
& 0xffffff;
5108 debug_printf ("Writing %0*x to 0x%08lx in process %d\n",
5109 2 * ((len
< 4) ? len
: 4), val
, (long)memaddr
, pid
);
5112 /* Fill start and end extra bytes of buffer with existing memory data. */
5115 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
5116 about coercing an 8 byte integer to a 4 byte pointer. */
5117 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
5118 (PTRACE_TYPE_ARG3
) (uintptr_t) addr
,
5119 (PTRACE_TYPE_ARG4
) 0);
5127 = ptrace (PTRACE_PEEKTEXT
, pid
,
5128 /* Coerce to a uintptr_t first to avoid potential gcc warning
5129 about coercing an 8 byte integer to a 4 byte pointer. */
5130 (PTRACE_TYPE_ARG3
) (uintptr_t) (addr
+ (count
- 1)
5131 * sizeof (PTRACE_XFER_TYPE
)),
5132 (PTRACE_TYPE_ARG4
) 0);
5137 /* Copy data to be written over corresponding part of buffer. */
5139 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
5142 /* Write the entire buffer. */
5144 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
5147 ptrace (PTRACE_POKETEXT
, pid
,
5148 /* Coerce to a uintptr_t first to avoid potential gcc warning
5149 about coercing an 8 byte integer to a 4 byte pointer. */
5150 (PTRACE_TYPE_ARG3
) (uintptr_t) addr
,
5151 (PTRACE_TYPE_ARG4
) buffer
[i
]);
5160 linux_look_up_symbols (void)
5162 #ifdef USE_THREAD_DB
5163 struct process_info
*proc
= current_process ();
5165 if (proc
->priv
->thread_db
!= NULL
)
5168 /* If the kernel supports tracing clones, then we don't need to
5169 use the magic thread event breakpoint to learn about
5171 thread_db_init (!linux_supports_traceclone ());
5176 linux_request_interrupt (void)
5178 extern unsigned long signal_pid
;
5180 /* Send a SIGINT to the process group. This acts just like the user
5181 typed a ^C on the controlling terminal. */
5182 kill (-signal_pid
, SIGINT
);
5185 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
5186 to debugger memory starting at MYADDR. */
5189 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
5191 char filename
[PATH_MAX
];
5193 int pid
= lwpid_of (current_thread
);
5195 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
5197 fd
= open (filename
, O_RDONLY
);
5201 if (offset
!= (CORE_ADDR
) 0
5202 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
5205 n
= read (fd
, myaddr
, len
);
5212 /* These breakpoint and watchpoint related wrapper functions simply
5213 pass on the function call if the target has registered a
5214 corresponding function. */
5217 linux_supports_z_point_type (char z_type
)
5219 return (the_low_target
.supports_z_point_type
!= NULL
5220 && the_low_target
.supports_z_point_type (z_type
));
5224 linux_insert_point (enum raw_bkpt_type type
, CORE_ADDR addr
,
5225 int size
, struct raw_breakpoint
*bp
)
5227 if (type
== raw_bkpt_type_sw
)
5228 return insert_memory_breakpoint (bp
);
5229 else if (the_low_target
.insert_point
!= NULL
)
5230 return the_low_target
.insert_point (type
, addr
, size
, bp
);
5232 /* Unsupported (see target.h). */
5237 linux_remove_point (enum raw_bkpt_type type
, CORE_ADDR addr
,
5238 int size
, struct raw_breakpoint
*bp
)
5240 if (type
== raw_bkpt_type_sw
)
5241 return remove_memory_breakpoint (bp
);
5242 else if (the_low_target
.remove_point
!= NULL
)
5243 return the_low_target
.remove_point (type
, addr
, size
, bp
);
5245 /* Unsupported (see target.h). */
5249 /* Implement the to_stopped_by_sw_breakpoint target_ops
5253 linux_stopped_by_sw_breakpoint (void)
5255 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5257 return (lwp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
);
5260 /* Implement the to_supports_stopped_by_sw_breakpoint target_ops
5264 linux_supports_stopped_by_sw_breakpoint (void)
5266 return USE_SIGTRAP_SIGINFO
;
5269 /* Implement the to_stopped_by_hw_breakpoint target_ops
5273 linux_stopped_by_hw_breakpoint (void)
5275 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5277 return (lwp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
);
5280 /* Implement the to_supports_stopped_by_hw_breakpoint target_ops
5284 linux_supports_stopped_by_hw_breakpoint (void)
5286 return USE_SIGTRAP_SIGINFO
;
5289 /* Implement the supports_conditional_breakpoints target_ops
5293 linux_supports_conditional_breakpoints (void)
5295 /* GDBserver needs to step over the breakpoint if the condition is
5296 false. GDBserver software single step is too simple, so disable
5297 conditional breakpoints if the target doesn't have hardware single
5299 return can_hardware_single_step ();
5303 linux_stopped_by_watchpoint (void)
5305 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5307 return lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
5311 linux_stopped_data_address (void)
5313 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5315 return lwp
->stopped_data_address
;
5318 #if defined(__UCLIBC__) && defined(HAS_NOMMU) \
5319 && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
5320 && defined(PT_TEXT_END_ADDR)
5322 /* This is only used for targets that define PT_TEXT_ADDR,
5323 PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly
5324 the target has different ways of acquiring this information, like
5327 /* Under uClinux, programs are loaded at non-zero offsets, which we need
5328 to tell gdb about. */
5331 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
5333 unsigned long text
, text_end
, data
;
5334 int pid
= lwpid_of (current_thread
);
5338 text
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_TEXT_ADDR
,
5339 (PTRACE_TYPE_ARG4
) 0);
5340 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_TEXT_END_ADDR
,
5341 (PTRACE_TYPE_ARG4
) 0);
5342 data
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_DATA_ADDR
,
5343 (PTRACE_TYPE_ARG4
) 0);
5347 /* Both text and data offsets produced at compile-time (and so
5348 used by gdb) are relative to the beginning of the program,
5349 with the data segment immediately following the text segment.
5350 However, the actual runtime layout in memory may put the data
5351 somewhere else, so when we send gdb a data base-address, we
5352 use the real data base address and subtract the compile-time
5353 data base-address from it (which is just the length of the
5354 text segment). BSS immediately follows data in both
5357 *data_p
= data
- (text_end
- text
);
5366 linux_qxfer_osdata (const char *annex
,
5367 unsigned char *readbuf
, unsigned const char *writebuf
,
5368 CORE_ADDR offset
, int len
)
5370 return linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
5373 /* Convert a native/host siginfo object, into/from the siginfo in the
5374 layout of the inferiors' architecture. */
5377 siginfo_fixup (siginfo_t
*siginfo
, void *inf_siginfo
, int direction
)
5381 if (the_low_target
.siginfo_fixup
!= NULL
)
5382 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
5384 /* If there was no callback, or the callback didn't do anything,
5385 then just do a straight memcpy. */
5389 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
5391 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
5396 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
5397 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
5401 char inf_siginfo
[sizeof (siginfo_t
)];
5403 if (current_thread
== NULL
)
5406 pid
= lwpid_of (current_thread
);
5409 debug_printf ("%s siginfo for lwp %d.\n",
5410 readbuf
!= NULL
? "Reading" : "Writing",
5413 if (offset
>= sizeof (siginfo
))
5416 if (ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
) != 0)
5419 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
5420 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
5421 inferior with a 64-bit GDBSERVER should look the same as debugging it
5422 with a 32-bit GDBSERVER, we need to convert it. */
5423 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
5425 if (offset
+ len
> sizeof (siginfo
))
5426 len
= sizeof (siginfo
) - offset
;
5428 if (readbuf
!= NULL
)
5429 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
5432 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
5434 /* Convert back to ptrace layout before flushing it out. */
5435 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
5437 if (ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
) != 0)
5444 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
5445 so we notice when children change state; as the handler for the
5446 sigsuspend in my_waitpid. */
5449 sigchld_handler (int signo
)
5451 int old_errno
= errno
;
5457 /* fprintf is not async-signal-safe, so call write
5459 if (write (2, "sigchld_handler\n",
5460 sizeof ("sigchld_handler\n") - 1) < 0)
5461 break; /* just ignore */
5465 if (target_is_async_p ())
5466 async_file_mark (); /* trigger a linux_wait */
5472 linux_supports_non_stop (void)
5478 linux_async (int enable
)
5480 int previous
= target_is_async_p ();
5483 debug_printf ("linux_async (%d), previous=%d\n",
5486 if (previous
!= enable
)
5489 sigemptyset (&mask
);
5490 sigaddset (&mask
, SIGCHLD
);
5492 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
5496 if (pipe (linux_event_pipe
) == -1)
5498 linux_event_pipe
[0] = -1;
5499 linux_event_pipe
[1] = -1;
5500 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
5502 warning ("creating event pipe failed.");
5506 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
5507 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
5509 /* Register the event loop handler. */
5510 add_file_handler (linux_event_pipe
[0],
5511 handle_target_event
, NULL
);
5513 /* Always trigger a linux_wait. */
5518 delete_file_handler (linux_event_pipe
[0]);
5520 close (linux_event_pipe
[0]);
5521 close (linux_event_pipe
[1]);
5522 linux_event_pipe
[0] = -1;
5523 linux_event_pipe
[1] = -1;
5526 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
5533 linux_start_non_stop (int nonstop
)
5535 /* Register or unregister from event-loop accordingly. */
5536 linux_async (nonstop
);
5538 if (target_is_async_p () != (nonstop
!= 0))
5545 linux_supports_multi_process (void)
5550 /* Check if fork events are supported. */
5553 linux_supports_fork_events (void)
5555 return linux_supports_tracefork ();
5558 /* Check if vfork events are supported. */
5561 linux_supports_vfork_events (void)
5563 return linux_supports_tracefork ();
5566 /* Callback for 'find_inferior'. Set the (possibly changed) ptrace
5567 options for the specified lwp. */
5570 reset_lwp_ptrace_options_callback (struct inferior_list_entry
*entry
,
5573 struct thread_info
*thread
= (struct thread_info
*) entry
;
5574 struct lwp_info
*lwp
= get_thread_lwp (thread
);
5578 /* Stop the lwp so we can modify its ptrace options. */
5579 lwp
->must_set_ptrace_flags
= 1;
5580 linux_stop_lwp (lwp
);
5584 /* Already stopped; go ahead and set the ptrace options. */
5585 struct process_info
*proc
= find_process_pid (pid_of (thread
));
5586 int options
= linux_low_ptrace_options (proc
->attached
);
5588 linux_enable_event_reporting (lwpid_of (thread
), options
);
5589 lwp
->must_set_ptrace_flags
= 0;
5595 /* Target hook for 'handle_new_gdb_connection'. Causes a reset of the
5596 ptrace flags for all inferiors. This is in case the new GDB connection
5597 doesn't support the same set of events that the previous one did. */
5600 linux_handle_new_gdb_connection (void)
5604 /* Request that all the lwps reset their ptrace options. */
5605 find_inferior (&all_threads
, reset_lwp_ptrace_options_callback
, &pid
);
5609 linux_supports_disable_randomization (void)
5611 #ifdef HAVE_PERSONALITY
5619 linux_supports_agent (void)
5625 linux_supports_range_stepping (void)
5627 if (*the_low_target
.supports_range_stepping
== NULL
)
5630 return (*the_low_target
.supports_range_stepping
) ();
5633 /* Enumerate spufs IDs for process PID. */
5635 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
5641 struct dirent
*entry
;
5643 sprintf (path
, "/proc/%ld/fd", pid
);
5644 dir
= opendir (path
);
5649 while ((entry
= readdir (dir
)) != NULL
)
5655 fd
= atoi (entry
->d_name
);
5659 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
5660 if (stat (path
, &st
) != 0)
5662 if (!S_ISDIR (st
.st_mode
))
5665 if (statfs (path
, &stfs
) != 0)
5667 if (stfs
.f_type
!= SPUFS_MAGIC
)
5670 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
5672 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
5682 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
5683 object type, using the /proc file system. */
5685 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
5686 unsigned const char *writebuf
,
5687 CORE_ADDR offset
, int len
)
5689 long pid
= lwpid_of (current_thread
);
5694 if (!writebuf
&& !readbuf
)
5702 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
5705 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
5706 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
5711 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
5718 ret
= write (fd
, writebuf
, (size_t) len
);
5720 ret
= read (fd
, readbuf
, (size_t) len
);
5726 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
5727 struct target_loadseg
5729 /* Core address to which the segment is mapped. */
5731 /* VMA recorded in the program header. */
5733 /* Size of this segment in memory. */
5737 # if defined PT_GETDSBT
5738 struct target_loadmap
5740 /* Protocol version number, must be zero. */
5742 /* Pointer to the DSBT table, its size, and the DSBT index. */
5743 unsigned *dsbt_table
;
5744 unsigned dsbt_size
, dsbt_index
;
5745 /* Number of segments in this map. */
5747 /* The actual memory map. */
5748 struct target_loadseg segs
[/*nsegs*/];
5750 # define LINUX_LOADMAP PT_GETDSBT
5751 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
5752 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
5754 struct target_loadmap
5756 /* Protocol version number, must be zero. */
5758 /* Number of segments in this map. */
5760 /* The actual memory map. */
5761 struct target_loadseg segs
[/*nsegs*/];
5763 # define LINUX_LOADMAP PTRACE_GETFDPIC
5764 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
5765 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
5769 linux_read_loadmap (const char *annex
, CORE_ADDR offset
,
5770 unsigned char *myaddr
, unsigned int len
)
5772 int pid
= lwpid_of (current_thread
);
5774 struct target_loadmap
*data
= NULL
;
5775 unsigned int actual_length
, copy_length
;
5777 if (strcmp (annex
, "exec") == 0)
5778 addr
= (int) LINUX_LOADMAP_EXEC
;
5779 else if (strcmp (annex
, "interp") == 0)
5780 addr
= (int) LINUX_LOADMAP_INTERP
;
5784 if (ptrace (LINUX_LOADMAP
, pid
, addr
, &data
) != 0)
5790 actual_length
= sizeof (struct target_loadmap
)
5791 + sizeof (struct target_loadseg
) * data
->nsegs
;
5793 if (offset
< 0 || offset
> actual_length
)
5796 copy_length
= actual_length
- offset
< len
? actual_length
- offset
: len
;
5797 memcpy (myaddr
, (char *) data
+ offset
, copy_length
);
5801 # define linux_read_loadmap NULL
5802 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
5805 linux_process_qsupported (const char *query
)
5807 if (the_low_target
.process_qsupported
!= NULL
)
5808 the_low_target
.process_qsupported (query
);
5812 linux_supports_tracepoints (void)
5814 if (*the_low_target
.supports_tracepoints
== NULL
)
5817 return (*the_low_target
.supports_tracepoints
) ();
5821 linux_read_pc (struct regcache
*regcache
)
5823 if (the_low_target
.get_pc
== NULL
)
5826 return (*the_low_target
.get_pc
) (regcache
);
5830 linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
5832 gdb_assert (the_low_target
.set_pc
!= NULL
);
5834 (*the_low_target
.set_pc
) (regcache
, pc
);
5838 linux_thread_stopped (struct thread_info
*thread
)
5840 return get_thread_lwp (thread
)->stopped
;
5843 /* This exposes stop-all-threads functionality to other modules. */
5846 linux_pause_all (int freeze
)
5848 stop_all_lwps (freeze
, NULL
);
5851 /* This exposes unstop-all-threads functionality to other gdbserver
5855 linux_unpause_all (int unfreeze
)
5857 unstop_all_lwps (unfreeze
, NULL
);
5861 linux_prepare_to_access_memory (void)
5863 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5866 linux_pause_all (1);
5871 linux_done_accessing_memory (void)
5873 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5876 linux_unpause_all (1);
5880 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint
, CORE_ADDR tpaddr
,
5881 CORE_ADDR collector
,
5884 CORE_ADDR
*jump_entry
,
5885 CORE_ADDR
*trampoline
,
5886 ULONGEST
*trampoline_size
,
5887 unsigned char *jjump_pad_insn
,
5888 ULONGEST
*jjump_pad_insn_size
,
5889 CORE_ADDR
*adjusted_insn_addr
,
5890 CORE_ADDR
*adjusted_insn_addr_end
,
5893 return (*the_low_target
.install_fast_tracepoint_jump_pad
)
5894 (tpoint
, tpaddr
, collector
, lockaddr
, orig_size
,
5895 jump_entry
, trampoline
, trampoline_size
,
5896 jjump_pad_insn
, jjump_pad_insn_size
,
5897 adjusted_insn_addr
, adjusted_insn_addr_end
,
5901 static struct emit_ops
*
5902 linux_emit_ops (void)
5904 if (the_low_target
.emit_ops
!= NULL
)
5905 return (*the_low_target
.emit_ops
) ();
5911 linux_get_min_fast_tracepoint_insn_len (void)
5913 return (*the_low_target
.get_min_fast_tracepoint_insn_len
) ();
5916 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
5919 get_phdr_phnum_from_proc_auxv (const int pid
, const int is_elf64
,
5920 CORE_ADDR
*phdr_memaddr
, int *num_phdr
)
5922 char filename
[PATH_MAX
];
5924 const int auxv_size
= is_elf64
5925 ? sizeof (Elf64_auxv_t
) : sizeof (Elf32_auxv_t
);
5926 char buf
[sizeof (Elf64_auxv_t
)]; /* The larger of the two. */
5928 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
5930 fd
= open (filename
, O_RDONLY
);
5936 while (read (fd
, buf
, auxv_size
) == auxv_size
5937 && (*phdr_memaddr
== 0 || *num_phdr
== 0))
5941 Elf64_auxv_t
*const aux
= (Elf64_auxv_t
*) buf
;
5943 switch (aux
->a_type
)
5946 *phdr_memaddr
= aux
->a_un
.a_val
;
5949 *num_phdr
= aux
->a_un
.a_val
;
5955 Elf32_auxv_t
*const aux
= (Elf32_auxv_t
*) buf
;
5957 switch (aux
->a_type
)
5960 *phdr_memaddr
= aux
->a_un
.a_val
;
5963 *num_phdr
= aux
->a_un
.a_val
;
5971 if (*phdr_memaddr
== 0 || *num_phdr
== 0)
5973 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
5974 "phdr_memaddr = %ld, phdr_num = %d",
5975 (long) *phdr_memaddr
, *num_phdr
);
5982 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
5985 get_dynamic (const int pid
, const int is_elf64
)
5987 CORE_ADDR phdr_memaddr
, relocation
;
5989 unsigned char *phdr_buf
;
5990 const int phdr_size
= is_elf64
? sizeof (Elf64_Phdr
) : sizeof (Elf32_Phdr
);
5992 if (get_phdr_phnum_from_proc_auxv (pid
, is_elf64
, &phdr_memaddr
, &num_phdr
))
5995 gdb_assert (num_phdr
< 100); /* Basic sanity check. */
5996 phdr_buf
= alloca (num_phdr
* phdr_size
);
5998 if (linux_read_memory (phdr_memaddr
, phdr_buf
, num_phdr
* phdr_size
))
6001 /* Compute relocation: it is expected to be 0 for "regular" executables,
6002 non-zero for PIE ones. */
6004 for (i
= 0; relocation
== -1 && i
< num_phdr
; i
++)
6007 Elf64_Phdr
*const p
= (Elf64_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6009 if (p
->p_type
== PT_PHDR
)
6010 relocation
= phdr_memaddr
- p
->p_vaddr
;
6014 Elf32_Phdr
*const p
= (Elf32_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6016 if (p
->p_type
== PT_PHDR
)
6017 relocation
= phdr_memaddr
- p
->p_vaddr
;
6020 if (relocation
== -1)
6022 /* PT_PHDR is optional, but necessary for PIE in general. Fortunately
6023 any real world executables, including PIE executables, have always
6024 PT_PHDR present. PT_PHDR is not present in some shared libraries or
6025 in fpc (Free Pascal 2.4) binaries but neither of those have a need for
6026 or present DT_DEBUG anyway (fpc binaries are statically linked).
6028 Therefore if there exists DT_DEBUG there is always also PT_PHDR.
6030 GDB could find RELOCATION also from AT_ENTRY - e_entry. */
6035 for (i
= 0; i
< num_phdr
; i
++)
6039 Elf64_Phdr
*const p
= (Elf64_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6041 if (p
->p_type
== PT_DYNAMIC
)
6042 return p
->p_vaddr
+ relocation
;
6046 Elf32_Phdr
*const p
= (Elf32_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6048 if (p
->p_type
== PT_DYNAMIC
)
6049 return p
->p_vaddr
+ relocation
;
6056 /* Return &_r_debug in the inferior, or -1 if not present. Return value
6057 can be 0 if the inferior does not yet have the library list initialized.
6058 We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of
6059 DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */
6062 get_r_debug (const int pid
, const int is_elf64
)
6064 CORE_ADDR dynamic_memaddr
;
6065 const int dyn_size
= is_elf64
? sizeof (Elf64_Dyn
) : sizeof (Elf32_Dyn
);
6066 unsigned char buf
[sizeof (Elf64_Dyn
)]; /* The larger of the two. */
6069 dynamic_memaddr
= get_dynamic (pid
, is_elf64
);
6070 if (dynamic_memaddr
== 0)
6073 while (linux_read_memory (dynamic_memaddr
, buf
, dyn_size
) == 0)
6077 Elf64_Dyn
*const dyn
= (Elf64_Dyn
*) buf
;
6078 #ifdef DT_MIPS_RLD_MAP
6082 unsigned char buf
[sizeof (Elf64_Xword
)];
6086 if (dyn
->d_tag
== DT_MIPS_RLD_MAP
)
6088 if (linux_read_memory (dyn
->d_un
.d_val
,
6089 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6094 #endif /* DT_MIPS_RLD_MAP */
6096 if (dyn
->d_tag
== DT_DEBUG
&& map
== -1)
6097 map
= dyn
->d_un
.d_val
;
6099 if (dyn
->d_tag
== DT_NULL
)
6104 Elf32_Dyn
*const dyn
= (Elf32_Dyn
*) buf
;
6105 #ifdef DT_MIPS_RLD_MAP
6109 unsigned char buf
[sizeof (Elf32_Word
)];
6113 if (dyn
->d_tag
== DT_MIPS_RLD_MAP
)
6115 if (linux_read_memory (dyn
->d_un
.d_val
,
6116 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6121 #endif /* DT_MIPS_RLD_MAP */
6123 if (dyn
->d_tag
== DT_DEBUG
&& map
== -1)
6124 map
= dyn
->d_un
.d_val
;
6126 if (dyn
->d_tag
== DT_NULL
)
6130 dynamic_memaddr
+= dyn_size
;
6136 /* Read one pointer from MEMADDR in the inferior. */
6139 read_one_ptr (CORE_ADDR memaddr
, CORE_ADDR
*ptr
, int ptr_size
)
6143 /* Go through a union so this works on either big or little endian
6144 hosts, when the inferior's pointer size is smaller than the size
6145 of CORE_ADDR. It is assumed the inferior's endianness is the
6146 same of the superior's. */
6149 CORE_ADDR core_addr
;
6154 ret
= linux_read_memory (memaddr
, &addr
.uc
, ptr_size
);
6157 if (ptr_size
== sizeof (CORE_ADDR
))
6158 *ptr
= addr
.core_addr
;
6159 else if (ptr_size
== sizeof (unsigned int))
6162 gdb_assert_not_reached ("unhandled pointer size");
6167 struct link_map_offsets
6169 /* Offset and size of r_debug.r_version. */
6170 int r_version_offset
;
6172 /* Offset and size of r_debug.r_map. */
6175 /* Offset to l_addr field in struct link_map. */
6178 /* Offset to l_name field in struct link_map. */
6181 /* Offset to l_ld field in struct link_map. */
6184 /* Offset to l_next field in struct link_map. */
6187 /* Offset to l_prev field in struct link_map. */
6191 /* Construct qXfer:libraries-svr4:read reply. */
6194 linux_qxfer_libraries_svr4 (const char *annex
, unsigned char *readbuf
,
6195 unsigned const char *writebuf
,
6196 CORE_ADDR offset
, int len
)
6199 unsigned document_len
;
6200 struct process_info_private
*const priv
= current_process ()->priv
;
6201 char filename
[PATH_MAX
];
6204 static const struct link_map_offsets lmo_32bit_offsets
=
6206 0, /* r_version offset. */
6207 4, /* r_debug.r_map offset. */
6208 0, /* l_addr offset in link_map. */
6209 4, /* l_name offset in link_map. */
6210 8, /* l_ld offset in link_map. */
6211 12, /* l_next offset in link_map. */
6212 16 /* l_prev offset in link_map. */
6215 static const struct link_map_offsets lmo_64bit_offsets
=
6217 0, /* r_version offset. */
6218 8, /* r_debug.r_map offset. */
6219 0, /* l_addr offset in link_map. */
6220 8, /* l_name offset in link_map. */
6221 16, /* l_ld offset in link_map. */
6222 24, /* l_next offset in link_map. */
6223 32 /* l_prev offset in link_map. */
6225 const struct link_map_offsets
*lmo
;
6226 unsigned int machine
;
6228 CORE_ADDR lm_addr
= 0, lm_prev
= 0;
6229 int allocated
= 1024;
6231 CORE_ADDR l_name
, l_addr
, l_ld
, l_next
, l_prev
;
6232 int header_done
= 0;
6234 if (writebuf
!= NULL
)
6236 if (readbuf
== NULL
)
6239 pid
= lwpid_of (current_thread
);
6240 xsnprintf (filename
, sizeof filename
, "/proc/%d/exe", pid
);
6241 is_elf64
= elf_64_file_p (filename
, &machine
);
6242 lmo
= is_elf64
? &lmo_64bit_offsets
: &lmo_32bit_offsets
;
6243 ptr_size
= is_elf64
? 8 : 4;
6245 while (annex
[0] != '\0')
6251 sep
= strchr (annex
, '=');
6256 if (len
== 5 && startswith (annex
, "start"))
6258 else if (len
== 4 && startswith (annex
, "prev"))
6262 annex
= strchr (sep
, ';');
6269 annex
= decode_address_to_semicolon (addrp
, sep
+ 1);
6276 if (priv
->r_debug
== 0)
6277 priv
->r_debug
= get_r_debug (pid
, is_elf64
);
6279 /* We failed to find DT_DEBUG. Such situation will not change
6280 for this inferior - do not retry it. Report it to GDB as
6281 E01, see for the reasons at the GDB solib-svr4.c side. */
6282 if (priv
->r_debug
== (CORE_ADDR
) -1)
6285 if (priv
->r_debug
!= 0)
6287 if (linux_read_memory (priv
->r_debug
+ lmo
->r_version_offset
,
6288 (unsigned char *) &r_version
,
6289 sizeof (r_version
)) != 0
6292 warning ("unexpected r_debug version %d", r_version
);
6294 else if (read_one_ptr (priv
->r_debug
+ lmo
->r_map_offset
,
6295 &lm_addr
, ptr_size
) != 0)
6297 warning ("unable to read r_map from 0x%lx",
6298 (long) priv
->r_debug
+ lmo
->r_map_offset
);
6303 document
= xmalloc (allocated
);
6304 strcpy (document
, "<library-list-svr4 version=\"1.0\"");
6305 p
= document
+ strlen (document
);
6308 && read_one_ptr (lm_addr
+ lmo
->l_name_offset
,
6309 &l_name
, ptr_size
) == 0
6310 && read_one_ptr (lm_addr
+ lmo
->l_addr_offset
,
6311 &l_addr
, ptr_size
) == 0
6312 && read_one_ptr (lm_addr
+ lmo
->l_ld_offset
,
6313 &l_ld
, ptr_size
) == 0
6314 && read_one_ptr (lm_addr
+ lmo
->l_prev_offset
,
6315 &l_prev
, ptr_size
) == 0
6316 && read_one_ptr (lm_addr
+ lmo
->l_next_offset
,
6317 &l_next
, ptr_size
) == 0)
6319 unsigned char libname
[PATH_MAX
];
6321 if (lm_prev
!= l_prev
)
6323 warning ("Corrupted shared library list: 0x%lx != 0x%lx",
6324 (long) lm_prev
, (long) l_prev
);
6328 /* Ignore the first entry even if it has valid name as the first entry
6329 corresponds to the main executable. The first entry should not be
6330 skipped if the dynamic loader was loaded late by a static executable
6331 (see solib-svr4.c parameter ignore_first). But in such case the main
6332 executable does not have PT_DYNAMIC present and this function already
6333 exited above due to failed get_r_debug. */
6336 sprintf (p
, " main-lm=\"0x%lx\"", (unsigned long) lm_addr
);
6341 /* Not checking for error because reading may stop before
6342 we've got PATH_MAX worth of characters. */
6344 linux_read_memory (l_name
, libname
, sizeof (libname
) - 1);
6345 libname
[sizeof (libname
) - 1] = '\0';
6346 if (libname
[0] != '\0')
6348 /* 6x the size for xml_escape_text below. */
6349 size_t len
= 6 * strlen ((char *) libname
);
6354 /* Terminate `<library-list-svr4'. */
6359 while (allocated
< p
- document
+ len
+ 200)
6361 /* Expand to guarantee sufficient storage. */
6362 uintptr_t document_len
= p
- document
;
6364 document
= xrealloc (document
, 2 * allocated
);
6366 p
= document
+ document_len
;
6369 name
= xml_escape_text ((char *) libname
);
6370 p
+= sprintf (p
, "<library name=\"%s\" lm=\"0x%lx\" "
6371 "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
6372 name
, (unsigned long) lm_addr
,
6373 (unsigned long) l_addr
, (unsigned long) l_ld
);
6384 /* Empty list; terminate `<library-list-svr4'. */
6388 strcpy (p
, "</library-list-svr4>");
6390 document_len
= strlen (document
);
6391 if (offset
< document_len
)
6392 document_len
-= offset
;
6395 if (len
> document_len
)
6398 memcpy (readbuf
, document
+ offset
, len
);
6404 #ifdef HAVE_LINUX_BTRACE
6406 /* See to_enable_btrace target method. */
6408 static struct btrace_target_info
*
6409 linux_low_enable_btrace (ptid_t ptid
, const struct btrace_config
*conf
)
6411 struct btrace_target_info
*tinfo
;
6413 tinfo
= linux_enable_btrace (ptid
, conf
);
6415 if (tinfo
!= NULL
&& tinfo
->ptr_bits
== 0)
6417 struct thread_info
*thread
= find_thread_ptid (ptid
);
6418 struct regcache
*regcache
= get_thread_regcache (thread
, 0);
6420 tinfo
->ptr_bits
= register_size (regcache
->tdesc
, 0) * 8;
6426 /* See to_disable_btrace target method. */
6429 linux_low_disable_btrace (struct btrace_target_info
*tinfo
)
6431 enum btrace_error err
;
6433 err
= linux_disable_btrace (tinfo
);
6434 return (err
== BTRACE_ERR_NONE
? 0 : -1);
6437 /* See to_read_btrace target method. */
6440 linux_low_read_btrace (struct btrace_target_info
*tinfo
, struct buffer
*buffer
,
6443 struct btrace_data btrace
;
6444 struct btrace_block
*block
;
6445 enum btrace_error err
;
6448 btrace_data_init (&btrace
);
6450 err
= linux_read_btrace (&btrace
, tinfo
, type
);
6451 if (err
!= BTRACE_ERR_NONE
)
6453 if (err
== BTRACE_ERR_OVERFLOW
)
6454 buffer_grow_str0 (buffer
, "E.Overflow.");
6456 buffer_grow_str0 (buffer
, "E.Generic Error.");
6458 btrace_data_fini (&btrace
);
6462 switch (btrace
.format
)
6464 case BTRACE_FORMAT_NONE
:
6465 buffer_grow_str0 (buffer
, "E.No Trace.");
6468 case BTRACE_FORMAT_BTS
:
6469 buffer_grow_str (buffer
, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n");
6470 buffer_grow_str (buffer
, "<btrace version=\"1.0\">\n");
6473 VEC_iterate (btrace_block_s
, btrace
.variant
.bts
.blocks
, i
, block
);
6475 buffer_xml_printf (buffer
, "<block begin=\"0x%s\" end=\"0x%s\"/>\n",
6476 paddress (block
->begin
), paddress (block
->end
));
6478 buffer_grow_str0 (buffer
, "</btrace>\n");
6482 buffer_grow_str0 (buffer
, "E.Unknown Trace Format.");
6484 btrace_data_fini (&btrace
);
6488 btrace_data_fini (&btrace
);
6492 /* See to_btrace_conf target method. */
6495 linux_low_btrace_conf (const struct btrace_target_info
*tinfo
,
6496 struct buffer
*buffer
)
6498 const struct btrace_config
*conf
;
6500 buffer_grow_str (buffer
, "<!DOCTYPE btrace-conf SYSTEM \"btrace-conf.dtd\">\n");
6501 buffer_grow_str (buffer
, "<btrace-conf version=\"1.0\">\n");
6503 conf
= linux_btrace_conf (tinfo
);
6506 switch (conf
->format
)
6508 case BTRACE_FORMAT_NONE
:
6511 case BTRACE_FORMAT_BTS
:
6512 buffer_xml_printf (buffer
, "<bts");
6513 buffer_xml_printf (buffer
, " size=\"0x%x\"", conf
->bts
.size
);
6514 buffer_xml_printf (buffer
, " />\n");
6519 buffer_grow_str0 (buffer
, "</btrace-conf>\n");
6522 #endif /* HAVE_LINUX_BTRACE */
6524 /* See nat/linux-nat.h. */
6527 current_lwp_ptid (void)
6529 return ptid_of (current_thread
);
6532 static struct target_ops linux_target_ops
= {
6533 linux_create_inferior
,
6542 linux_fetch_registers
,
6543 linux_store_registers
,
6544 linux_prepare_to_access_memory
,
6545 linux_done_accessing_memory
,
6548 linux_look_up_symbols
,
6549 linux_request_interrupt
,
6551 linux_supports_z_point_type
,
6554 linux_stopped_by_sw_breakpoint
,
6555 linux_supports_stopped_by_sw_breakpoint
,
6556 linux_stopped_by_hw_breakpoint
,
6557 linux_supports_stopped_by_hw_breakpoint
,
6558 linux_supports_conditional_breakpoints
,
6559 linux_stopped_by_watchpoint
,
6560 linux_stopped_data_address
,
6561 #if defined(__UCLIBC__) && defined(HAS_NOMMU) \
6562 && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
6563 && defined(PT_TEXT_END_ADDR)
6568 #ifdef USE_THREAD_DB
6569 thread_db_get_tls_address
,
6574 hostio_last_error_from_errno
,
6577 linux_supports_non_stop
,
6579 linux_start_non_stop
,
6580 linux_supports_multi_process
,
6581 linux_supports_fork_events
,
6582 linux_supports_vfork_events
,
6583 linux_handle_new_gdb_connection
,
6584 #ifdef USE_THREAD_DB
6585 thread_db_handle_monitor_command
,
6589 linux_common_core_of_thread
,
6591 linux_process_qsupported
,
6592 linux_supports_tracepoints
,
6595 linux_thread_stopped
,
6599 linux_stabilize_threads
,
6600 linux_install_fast_tracepoint_jump_pad
,
6602 linux_supports_disable_randomization
,
6603 linux_get_min_fast_tracepoint_insn_len
,
6604 linux_qxfer_libraries_svr4
,
6605 linux_supports_agent
,
6606 #ifdef HAVE_LINUX_BTRACE
6607 linux_supports_btrace
,
6608 linux_low_enable_btrace
,
6609 linux_low_disable_btrace
,
6610 linux_low_read_btrace
,
6611 linux_low_btrace_conf
,
6619 linux_supports_range_stepping
,
6620 linux_proc_pid_to_exec_file
,
6624 linux_init_signals ()
6626 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
6627 to find what the cancel signal actually is. */
6628 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
6629 signal (__SIGRTMIN
+1, SIG_IGN
);
6633 #ifdef HAVE_LINUX_REGSETS
6635 initialize_regsets_info (struct regsets_info
*info
)
6637 for (info
->num_regsets
= 0;
6638 info
->regsets
[info
->num_regsets
].size
>= 0;
6639 info
->num_regsets
++)
6645 initialize_low (void)
6647 struct sigaction sigchld_action
;
6648 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
6649 set_target_ops (&linux_target_ops
);
6650 set_breakpoint_data (the_low_target
.breakpoint
,
6651 the_low_target
.breakpoint_len
);
6652 linux_init_signals ();
6653 linux_ptrace_init_warnings ();
6655 sigchld_action
.sa_handler
= sigchld_handler
;
6656 sigemptyset (&sigchld_action
.sa_mask
);
6657 sigchld_action
.sa_flags
= SA_RESTART
;
6658 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
6660 initialize_low_arch ();
6662 linux_check_ptrace_features ();