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"
26 #include "nat/linux-nat.h"
27 #include "nat/linux-waitpid.h"
29 #include "nat/gdb_ptrace.h"
30 #include "nat/linux-ptrace.h"
31 #include "nat/linux-procfs.h"
32 #include "nat/linux-personality.h"
34 #include <sys/ioctl.h>
37 #include <sys/syscall.h>
41 #include <sys/types.h>
46 #include "filestuff.h"
47 #include "tracepoint.h"
50 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
51 then ELFMAG0 will have been defined. If it didn't get included by
52 gdb_proc_service.h then including it will likely introduce a duplicate
53 definition of elf_fpregset_t. */
56 #include "nat/linux-namespaces.h"
59 #define SPUFS_MAGIC 0x23c9b64e
62 #ifdef HAVE_PERSONALITY
63 # include <sys/personality.h>
64 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
65 # define ADDR_NO_RANDOMIZE 0x0040000
74 #define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
77 /* This is the kernel's hard limit. Not to be confused with
83 /* Some targets did not define these ptrace constants from the start,
84 so gdbserver defines them locally here. In the future, these may
85 be removed after they are added to asm/ptrace.h. */
86 #if !(defined(PT_TEXT_ADDR) \
87 || defined(PT_DATA_ADDR) \
88 || defined(PT_TEXT_END_ADDR))
89 #if defined(__mcoldfire__)
90 /* These are still undefined in 3.10 kernels. */
91 #define PT_TEXT_ADDR 49*4
92 #define PT_DATA_ADDR 50*4
93 #define PT_TEXT_END_ADDR 51*4
94 /* BFIN already defines these since at least 2.6.32 kernels. */
96 #define PT_TEXT_ADDR 220
97 #define PT_TEXT_END_ADDR 224
98 #define PT_DATA_ADDR 228
99 /* These are still undefined in 3.10 kernels. */
100 #elif defined(__TMS320C6X__)
101 #define PT_TEXT_ADDR (0x10000*4)
102 #define PT_DATA_ADDR (0x10004*4)
103 #define PT_TEXT_END_ADDR (0x10008*4)
107 #ifdef HAVE_LINUX_BTRACE
108 # include "nat/linux-btrace.h"
109 # include "btrace-common.h"
112 #ifndef HAVE_ELF32_AUXV_T
113 /* Copied from glibc's elf.h. */
116 uint32_t a_type; /* Entry type */
119 uint32_t a_val; /* Integer value */
120 /* We use to have pointer elements added here. We cannot do that,
121 though, since it does not work when using 32-bit definitions
122 on 64-bit platforms and vice versa. */
127 #ifndef HAVE_ELF64_AUXV_T
128 /* Copied from glibc's elf.h. */
131 uint64_t a_type; /* Entry type */
134 uint64_t a_val; /* Integer value */
135 /* We use to have pointer elements added here. We cannot do that,
136 though, since it does not work when using 32-bit definitions
137 on 64-bit platforms and vice versa. */
142 /* Does the current host support PTRACE_GETREGSET? */
143 int have_ptrace_getregset = -1;
147 /* See nat/linux-nat.h. */
150 ptid_of_lwp (struct lwp_info *lwp)
152 return ptid_of (get_lwp_thread (lwp));
155 /* See nat/linux-nat.h. */
158 lwp_set_arch_private_info (struct lwp_info *lwp,
159 struct arch_lwp_info *info)
161 lwp->arch_private = info;
164 /* See nat/linux-nat.h. */
166 struct arch_lwp_info *
167 lwp_arch_private_info (struct lwp_info *lwp)
169 return lwp->arch_private;
172 /* See nat/linux-nat.h. */
175 lwp_is_stopped (struct lwp_info *lwp)
180 /* See nat/linux-nat.h. */
182 enum target_stop_reason
183 lwp_stop_reason (struct lwp_info *lwp)
185 return lwp->stop_reason;
188 /* A list of all unknown processes which receive stop signals. Some
189 other process will presumably claim each of these as forked
190 children momentarily. */
192 struct simple_pid_list
194 /* The process ID. */
197 /* The status as reported by waitpid. */
201 struct simple_pid_list *next;
203 struct simple_pid_list *stopped_pids;
205 /* Trivial list manipulation functions to keep track of a list of new
206 stopped processes. */
209 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
211 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
214 new_pid->status = status;
215 new_pid->next = *listp;
220 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
222 struct simple_pid_list **p;
224 for (p = listp; *p != NULL; p = &(*p)->next)
225 if ((*p)->pid == pid)
227 struct simple_pid_list *next = (*p)->next;
229 *statusp = (*p)->status;
237 enum stopping_threads_kind
239 /* Not stopping threads presently. */
240 NOT_STOPPING_THREADS,
242 /* Stopping threads. */
245 /* Stopping and suspending threads. */
246 STOPPING_AND_SUSPENDING_THREADS
249 /* This is set while stop_all_lwps is in effect. */
250 enum stopping_threads_kind stopping_threads = NOT_STOPPING_THREADS;
252 /* FIXME make into a target method? */
253 int using_threads = 1;
255 /* True if we're presently stabilizing threads (moving them out of
257 static int stabilizing_threads;
259 static void linux_resume_one_lwp (struct lwp_info *lwp,
260 int step, int signal, siginfo_t *info);
261 static void linux_resume (struct thread_resume *resume_info, size_t n);
262 static void stop_all_lwps (int suspend, struct lwp_info *except);
263 static void unstop_all_lwps (int unsuspend, struct lwp_info *except);
264 static int linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
265 int *wstat, int options);
266 static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
267 static struct lwp_info *add_lwp (ptid_t ptid);
268 static int linux_stopped_by_watchpoint (void);
269 static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
270 static void proceed_all_lwps (void);
271 static int finish_step_over (struct lwp_info *lwp);
272 static int kill_lwp (unsigned long lwpid, int signo);
274 /* When the event-loop is doing a step-over, this points at the thread
276 ptid_t step_over_bkpt;
278 /* True if the low target can hardware single-step. Such targets
279 don't need a BREAKPOINT_REINSERT_ADDR callback. */
282 can_hardware_single_step (void)
284 return (the_low_target.breakpoint_reinsert_addr == NULL);
287 /* True if the low target supports memory breakpoints. If so, we'll
288 have a GET_PC implementation. */
291 supports_breakpoints (void)
293 return (the_low_target.get_pc != NULL);
296 /* Returns true if this target can support fast tracepoints. This
297 does not mean that the in-process agent has been loaded in the
301 supports_fast_tracepoints (void)
303 return the_low_target.install_fast_tracepoint_jump_pad != NULL;
306 /* True if LWP is stopped in its stepping range. */
309 lwp_in_step_range (struct lwp_info *lwp)
311 CORE_ADDR pc = lwp->stop_pc;
313 return (pc >= lwp->step_range_start && pc < lwp->step_range_end);
316 struct pending_signals
320 struct pending_signals *prev;
323 /* The read/write ends of the pipe registered as waitable file in the
325 static int linux_event_pipe[2] = { -1, -1 };
327 /* True if we're currently in async mode. */
328 #define target_is_async_p() (linux_event_pipe[0] != -1)
330 static void send_sigstop (struct lwp_info *lwp);
331 static void wait_for_sigstop (void);
333 /* Return non-zero if HEADER is a 64-bit ELF file. */
336 elf_64_header_p (const Elf64_Ehdr *header, unsigned int *machine)
338 if (header->e_ident[EI_MAG0] == ELFMAG0
339 && header->e_ident[EI_MAG1] == ELFMAG1
340 && header->e_ident[EI_MAG2] == ELFMAG2
341 && header->e_ident[EI_MAG3] == ELFMAG3)
343 *machine = header->e_machine;
344 return header->e_ident[EI_CLASS] == ELFCLASS64;
351 /* Return non-zero if FILE is a 64-bit ELF file,
352 zero if the file is not a 64-bit ELF file,
353 and -1 if the file is not accessible or doesn't exist. */
356 elf_64_file_p (const char *file, unsigned int *machine)
361 fd = open (file, O_RDONLY);
365 if (read (fd, &header, sizeof (header)) != sizeof (header))
372 return elf_64_header_p (&header, machine);
375 /* Accepts an integer PID; Returns true if the executable PID is
376 running is a 64-bit ELF file.. */
379 linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine)
383 sprintf (file, "/proc/%d/exe", pid);
384 return elf_64_file_p (file, machine);
388 delete_lwp (struct lwp_info *lwp)
390 struct thread_info *thr = get_lwp_thread (lwp);
393 debug_printf ("deleting %ld\n", lwpid_of (thr));
396 free (lwp->arch_private);
400 /* Add a process to the common process list, and set its private
403 static struct process_info *
404 linux_add_process (int pid, int attached)
406 struct process_info *proc;
408 proc = add_process (pid, attached);
409 proc->priv = xcalloc (1, sizeof (*proc->priv));
411 if (the_low_target.new_process != NULL)
412 proc->priv->arch_private = the_low_target.new_process ();
417 static CORE_ADDR get_pc (struct lwp_info *lwp);
419 /* Handle a GNU/Linux extended wait response. If we see a clone
420 event, we need to add the new LWP to our list (and return 0 so as
421 not to report the trap to higher layers). */
424 handle_extended_wait (struct lwp_info *event_lwp, int wstat)
426 int event = linux_ptrace_get_extended_event (wstat);
427 struct thread_info *event_thr = get_lwp_thread (event_lwp);
428 struct lwp_info *new_lwp;
430 if ((event == PTRACE_EVENT_FORK) || (event == PTRACE_EVENT_VFORK)
431 || (event == PTRACE_EVENT_CLONE))
434 unsigned long new_pid;
437 /* Get the pid of the new lwp. */
438 ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_thr), (PTRACE_TYPE_ARG3) 0,
441 /* If we haven't already seen the new PID stop, wait for it now. */
442 if (!pull_pid_from_list (&stopped_pids, new_pid, &status))
444 /* The new child has a pending SIGSTOP. We can't affect it until it
445 hits the SIGSTOP, but we're already attached. */
447 ret = my_waitpid (new_pid, &status, __WALL);
450 perror_with_name ("waiting for new child");
451 else if (ret != new_pid)
452 warning ("wait returned unexpected PID %d", ret);
453 else if (!WIFSTOPPED (status))
454 warning ("wait returned unexpected status 0x%x", status);
457 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK)
459 struct process_info *parent_proc;
460 struct process_info *child_proc;
461 struct lwp_info *child_lwp;
462 struct thread_info *child_thr;
463 struct target_desc *tdesc;
465 ptid = ptid_build (new_pid, new_pid, 0);
469 debug_printf ("HEW: Got fork event from LWP %ld, "
471 ptid_get_lwp (ptid_of (event_thr)),
472 ptid_get_pid (ptid));
475 /* Add the new process to the tables and clone the breakpoint
476 lists of the parent. We need to do this even if the new process
477 will be detached, since we will need the process object and the
478 breakpoints to remove any breakpoints from memory when we
479 detach, and the client side will access registers. */
480 child_proc = linux_add_process (new_pid, 0);
481 gdb_assert (child_proc != NULL);
482 child_lwp = add_lwp (ptid);
483 gdb_assert (child_lwp != NULL);
484 child_lwp->stopped = 1;
485 child_lwp->must_set_ptrace_flags = 1;
486 child_lwp->status_pending_p = 0;
487 child_thr = get_lwp_thread (child_lwp);
488 child_thr->last_resume_kind = resume_stop;
489 child_thr->last_status.kind = TARGET_WAITKIND_STOPPED;
491 parent_proc = get_thread_process (event_thr);
492 child_proc->attached = parent_proc->attached;
493 clone_all_breakpoints (&child_proc->breakpoints,
494 &child_proc->raw_breakpoints,
495 parent_proc->breakpoints);
497 tdesc = xmalloc (sizeof (struct target_desc));
498 copy_target_description (tdesc, parent_proc->tdesc);
499 child_proc->tdesc = tdesc;
501 /* Clone arch-specific process data. */
502 if (the_low_target.new_fork != NULL)
503 the_low_target.new_fork (parent_proc, child_proc);
505 /* Save fork info in the parent thread. */
506 if (event == PTRACE_EVENT_FORK)
507 event_lwp->waitstatus.kind = TARGET_WAITKIND_FORKED;
508 else if (event == PTRACE_EVENT_VFORK)
509 event_lwp->waitstatus.kind = TARGET_WAITKIND_VFORKED;
511 event_lwp->waitstatus.value.related_pid = ptid;
513 /* The status_pending field contains bits denoting the
514 extended event, so when the pending event is handled,
515 the handler will look at lwp->waitstatus. */
516 event_lwp->status_pending_p = 1;
517 event_lwp->status_pending = wstat;
519 /* Report the event. */
524 debug_printf ("HEW: Got clone event "
525 "from LWP %ld, new child is LWP %ld\n",
526 lwpid_of (event_thr), new_pid);
528 ptid = ptid_build (pid_of (event_thr), new_pid, 0);
529 new_lwp = add_lwp (ptid);
531 /* Either we're going to immediately resume the new thread
532 or leave it stopped. linux_resume_one_lwp is a nop if it
533 thinks the thread is currently running, so set this first
534 before calling linux_resume_one_lwp. */
535 new_lwp->stopped = 1;
537 /* If we're suspending all threads, leave this one suspended
539 if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS)
540 new_lwp->suspended = 1;
542 /* Normally we will get the pending SIGSTOP. But in some cases
543 we might get another signal delivered to the group first.
544 If we do get another signal, be sure not to lose it. */
545 if (WSTOPSIG (status) != SIGSTOP)
547 new_lwp->stop_expected = 1;
548 new_lwp->status_pending_p = 1;
549 new_lwp->status_pending = status;
552 /* Don't report the event. */
555 else if (event == PTRACE_EVENT_VFORK_DONE)
557 event_lwp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
559 /* Report the event. */
563 internal_error (__FILE__, __LINE__, _("unknown ptrace event %d"), event);
566 /* Return the PC as read from the regcache of LWP, without any
570 get_pc (struct lwp_info *lwp)
572 struct thread_info *saved_thread;
573 struct regcache *regcache;
576 if (the_low_target.get_pc == NULL)
579 saved_thread = current_thread;
580 current_thread = get_lwp_thread (lwp);
582 regcache = get_thread_regcache (current_thread, 1);
583 pc = (*the_low_target.get_pc) (regcache);
586 debug_printf ("pc is 0x%lx\n", (long) pc);
588 current_thread = saved_thread;
592 /* This function should only be called if LWP got a SIGTRAP.
593 The SIGTRAP could mean several things.
595 On i386, where decr_pc_after_break is non-zero:
597 If we were single-stepping this process using PTRACE_SINGLESTEP, we
598 will get only the one SIGTRAP. The value of $eip will be the next
599 instruction. If the instruction we stepped over was a breakpoint,
600 we need to decrement the PC.
602 If we continue the process using PTRACE_CONT, we will get a
603 SIGTRAP when we hit a breakpoint. The value of $eip will be
604 the instruction after the breakpoint (i.e. needs to be
605 decremented). If we report the SIGTRAP to GDB, we must also
606 report the undecremented PC. If the breakpoint is removed, we
607 must resume at the decremented PC.
609 On a non-decr_pc_after_break machine with hardware or kernel
612 If we either single-step a breakpoint instruction, or continue and
613 hit a breakpoint instruction, our PC will point at the breakpoint
617 check_stopped_by_breakpoint (struct lwp_info *lwp)
620 CORE_ADDR sw_breakpoint_pc;
621 struct thread_info *saved_thread;
622 #if USE_SIGTRAP_SIGINFO
626 if (the_low_target.get_pc == NULL)
630 sw_breakpoint_pc = pc - the_low_target.decr_pc_after_break;
632 /* breakpoint_at reads from the current thread. */
633 saved_thread = current_thread;
634 current_thread = get_lwp_thread (lwp);
636 #if USE_SIGTRAP_SIGINFO
637 if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread),
638 (PTRACE_TYPE_ARG3) 0, &siginfo) == 0)
640 if (siginfo.si_signo == SIGTRAP)
642 if (siginfo.si_code == GDB_ARCH_TRAP_BRKPT)
646 struct thread_info *thr = get_lwp_thread (lwp);
648 debug_printf ("CSBB: %s stopped by software breakpoint\n",
649 target_pid_to_str (ptid_of (thr)));
652 /* Back up the PC if necessary. */
653 if (pc != sw_breakpoint_pc)
655 struct regcache *regcache
656 = get_thread_regcache (current_thread, 1);
657 (*the_low_target.set_pc) (regcache, sw_breakpoint_pc);
660 lwp->stop_pc = sw_breakpoint_pc;
661 lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
662 current_thread = saved_thread;
665 else if (siginfo.si_code == TRAP_HWBKPT)
669 struct thread_info *thr = get_lwp_thread (lwp);
671 debug_printf ("CSBB: %s stopped by hardware "
672 "breakpoint/watchpoint\n",
673 target_pid_to_str (ptid_of (thr)));
677 lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
678 current_thread = saved_thread;
681 else if (siginfo.si_code == TRAP_TRACE)
685 struct thread_info *thr = get_lwp_thread (lwp);
687 debug_printf ("CSBB: %s stopped by trace\n",
688 target_pid_to_str (ptid_of (thr)));
694 /* We may have just stepped a breakpoint instruction. E.g., in
695 non-stop mode, GDB first tells the thread A to step a range, and
696 then the user inserts a breakpoint inside the range. In that
697 case we need to report the breakpoint PC. */
698 if ((!lwp->stepping || lwp->stop_pc == sw_breakpoint_pc)
699 && (*the_low_target.breakpoint_at) (sw_breakpoint_pc))
703 struct thread_info *thr = get_lwp_thread (lwp);
705 debug_printf ("CSBB: %s stopped by software breakpoint\n",
706 target_pid_to_str (ptid_of (thr)));
709 /* Back up the PC if necessary. */
710 if (pc != sw_breakpoint_pc)
712 struct regcache *regcache
713 = get_thread_regcache (current_thread, 1);
714 (*the_low_target.set_pc) (regcache, sw_breakpoint_pc);
717 lwp->stop_pc = sw_breakpoint_pc;
718 lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
719 current_thread = saved_thread;
723 if (hardware_breakpoint_inserted_here (pc))
727 struct thread_info *thr = get_lwp_thread (lwp);
729 debug_printf ("CSBB: %s stopped by hardware breakpoint\n",
730 target_pid_to_str (ptid_of (thr)));
734 lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
735 current_thread = saved_thread;
740 current_thread = saved_thread;
744 static struct lwp_info *
745 add_lwp (ptid_t ptid)
747 struct lwp_info *lwp;
749 lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
750 memset (lwp, 0, sizeof (*lwp));
752 if (the_low_target.new_thread != NULL)
753 the_low_target.new_thread (lwp);
755 lwp->thread = add_thread (ptid, lwp);
760 /* Start an inferior process and returns its pid.
761 ALLARGS is a vector of program-name and args. */
764 linux_create_inferior (char *program, char **allargs)
766 struct lwp_info *new_lwp;
769 struct cleanup *restore_personality
770 = maybe_disable_address_space_randomization (disable_randomization);
772 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
778 perror_with_name ("fork");
783 ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0);
785 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
786 signal (__SIGRTMIN + 1, SIG_DFL);
791 /* If gdbserver is connected to gdb via stdio, redirect the inferior's
792 stdout to stderr so that inferior i/o doesn't corrupt the connection.
793 Also, redirect stdin to /dev/null. */
794 if (remote_connection_is_stdio ())
797 open ("/dev/null", O_RDONLY);
799 if (write (2, "stdin/stdout redirected\n",
800 sizeof ("stdin/stdout redirected\n") - 1) < 0)
802 /* Errors ignored. */;
806 execv (program, allargs);
808 execvp (program, allargs);
810 fprintf (stderr, "Cannot exec %s: %s.\n", program,
816 do_cleanups (restore_personality);
818 linux_add_process (pid, 0);
820 ptid = ptid_build (pid, pid, 0);
821 new_lwp = add_lwp (ptid);
822 new_lwp->must_set_ptrace_flags = 1;
827 /* Implement the arch_setup target_ops method. */
830 linux_arch_setup (void)
832 the_low_target.arch_setup ();
835 /* Attach to an inferior process. Returns 0 on success, ERRNO on
839 linux_attach_lwp (ptid_t ptid)
841 struct lwp_info *new_lwp;
842 int lwpid = ptid_get_lwp (ptid);
844 if (ptrace (PTRACE_ATTACH, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0)
848 new_lwp = add_lwp (ptid);
850 /* We need to wait for SIGSTOP before being able to make the next
851 ptrace call on this LWP. */
852 new_lwp->must_set_ptrace_flags = 1;
854 if (linux_proc_pid_is_stopped (lwpid))
857 debug_printf ("Attached to a stopped process\n");
859 /* The process is definitely stopped. It is in a job control
860 stop, unless the kernel predates the TASK_STOPPED /
861 TASK_TRACED distinction, in which case it might be in a
862 ptrace stop. Make sure it is in a ptrace stop; from there we
863 can kill it, signal it, et cetera.
865 First make sure there is a pending SIGSTOP. Since we are
866 already attached, the process can not transition from stopped
867 to running without a PTRACE_CONT; so we know this signal will
868 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
869 probably already in the queue (unless this kernel is old
870 enough to use TASK_STOPPED for ptrace stops); but since
871 SIGSTOP is not an RT signal, it can only be queued once. */
872 kill_lwp (lwpid, SIGSTOP);
874 /* Finally, resume the stopped process. This will deliver the
875 SIGSTOP (or a higher priority signal, just like normal
876 PTRACE_ATTACH), which we'll catch later on. */
877 ptrace (PTRACE_CONT, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0);
880 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
883 There are several cases to consider here:
885 1) gdbserver has already attached to the process and is being notified
886 of a new thread that is being created.
887 In this case we should ignore that SIGSTOP and resume the
888 process. This is handled below by setting stop_expected = 1,
889 and the fact that add_thread sets last_resume_kind ==
892 2) This is the first thread (the process thread), and we're attaching
893 to it via attach_inferior.
894 In this case we want the process thread to stop.
895 This is handled by having linux_attach set last_resume_kind ==
896 resume_stop after we return.
898 If the pid we are attaching to is also the tgid, we attach to and
899 stop all the existing threads. Otherwise, we attach to pid and
900 ignore any other threads in the same group as this pid.
902 3) GDB is connecting to gdbserver and is requesting an enumeration of all
904 In this case we want the thread to stop.
905 FIXME: This case is currently not properly handled.
906 We should wait for the SIGSTOP but don't. Things work apparently
907 because enough time passes between when we ptrace (ATTACH) and when
908 gdb makes the next ptrace call on the thread.
910 On the other hand, if we are currently trying to stop all threads, we
911 should treat the new thread as if we had sent it a SIGSTOP. This works
912 because we are guaranteed that the add_lwp call above added us to the
913 end of the list, and so the new thread has not yet reached
914 wait_for_sigstop (but will). */
915 new_lwp->stop_expected = 1;
920 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
921 already attached. Returns true if a new LWP is found, false
925 attach_proc_task_lwp_callback (ptid_t ptid)
927 /* Is this a new thread? */
928 if (find_thread_ptid (ptid) == NULL)
930 int lwpid = ptid_get_lwp (ptid);
934 debug_printf ("Found new lwp %d\n", lwpid);
936 err = linux_attach_lwp (ptid);
938 /* Be quiet if we simply raced with the thread exiting. EPERM
939 is returned if the thread's task still exists, and is marked
940 as exited or zombie, as well as other conditions, so in that
941 case, confirm the status in /proc/PID/status. */
943 || (err == EPERM && linux_proc_pid_is_gone (lwpid)))
947 debug_printf ("Cannot attach to lwp %d: "
948 "thread is gone (%d: %s)\n",
949 lwpid, err, strerror (err));
954 warning (_("Cannot attach to lwp %d: %s"),
956 linux_ptrace_attach_fail_reason_string (ptid, err));
964 /* Attach to PID. If PID is the tgid, attach to it and all
968 linux_attach (unsigned long pid)
970 ptid_t ptid = ptid_build (pid, pid, 0);
973 /* Attach to PID. We will check for other threads
975 err = linux_attach_lwp (ptid);
977 error ("Cannot attach to process %ld: %s",
978 pid, linux_ptrace_attach_fail_reason_string (ptid, err));
980 linux_add_process (pid, 1);
984 struct thread_info *thread;
986 /* Don't ignore the initial SIGSTOP if we just attached to this
987 process. It will be collected by wait shortly. */
988 thread = find_thread_ptid (ptid_build (pid, pid, 0));
989 thread->last_resume_kind = resume_stop;
992 /* We must attach to every LWP. If /proc is mounted, use that to
993 find them now. On the one hand, the inferior may be using raw
994 clone instead of using pthreads. On the other hand, even if it
995 is using pthreads, GDB may not be connected yet (thread_db needs
996 to do symbol lookups, through qSymbol). Also, thread_db walks
997 structures in the inferior's address space to find the list of
998 threads/LWPs, and those structures may well be corrupted. Note
999 that once thread_db is loaded, we'll still use it to list threads
1000 and associate pthread info with each LWP. */
1001 linux_proc_attach_tgid_threads (pid, attach_proc_task_lwp_callback);
1012 second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
1014 struct counter *counter = args;
1016 if (ptid_get_pid (entry->id) == counter->pid)
1018 if (++counter->count > 1)
1026 last_thread_of_process_p (int pid)
1028 struct counter counter = { pid , 0 };
1030 return (find_inferior (&all_threads,
1031 second_thread_of_pid_p, &counter) == NULL);
1037 linux_kill_one_lwp (struct lwp_info *lwp)
1039 struct thread_info *thr = get_lwp_thread (lwp);
1040 int pid = lwpid_of (thr);
1042 /* PTRACE_KILL is unreliable. After stepping into a signal handler,
1043 there is no signal context, and ptrace(PTRACE_KILL) (or
1044 ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
1045 ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
1046 alternative is to kill with SIGKILL. We only need one SIGKILL
1047 per process, not one for each thread. But since we still support
1048 linuxthreads, and we also support debugging programs using raw
1049 clone without CLONE_THREAD, we send one for each thread. For
1050 years, we used PTRACE_KILL only, so we're being a bit paranoid
1051 about some old kernels where PTRACE_KILL might work better
1052 (dubious if there are any such, but that's why it's paranoia), so
1053 we try SIGKILL first, PTRACE_KILL second, and so we're fine
1057 kill_lwp (pid, SIGKILL);
1060 int save_errno = errno;
1062 debug_printf ("LKL: kill_lwp (SIGKILL) %s, 0, 0 (%s)\n",
1063 target_pid_to_str (ptid_of (thr)),
1064 save_errno ? strerror (save_errno) : "OK");
1068 ptrace (PTRACE_KILL, pid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0);
1071 int save_errno = errno;
1073 debug_printf ("LKL: PTRACE_KILL %s, 0, 0 (%s)\n",
1074 target_pid_to_str (ptid_of (thr)),
1075 save_errno ? strerror (save_errno) : "OK");
1079 /* Kill LWP and wait for it to die. */
1082 kill_wait_lwp (struct lwp_info *lwp)
1084 struct thread_info *thr = get_lwp_thread (lwp);
1085 int pid = ptid_get_pid (ptid_of (thr));
1086 int lwpid = ptid_get_lwp (ptid_of (thr));
1091 debug_printf ("kwl: killing lwp %d, for pid: %d\n", lwpid, pid);
1095 linux_kill_one_lwp (lwp);
1097 /* Make sure it died. Notes:
1099 - The loop is most likely unnecessary.
1101 - We don't use linux_wait_for_event as that could delete lwps
1102 while we're iterating over them. We're not interested in
1103 any pending status at this point, only in making sure all
1104 wait status on the kernel side are collected until the
1107 - We don't use __WALL here as the __WALL emulation relies on
1108 SIGCHLD, and killing a stopped process doesn't generate
1109 one, nor an exit status.
1111 res = my_waitpid (lwpid, &wstat, 0);
1112 if (res == -1 && errno == ECHILD)
1113 res = my_waitpid (lwpid, &wstat, __WCLONE);
1114 } while (res > 0 && WIFSTOPPED (wstat));
1116 /* Even if it was stopped, the child may have already disappeared.
1117 E.g., if it was killed by SIGKILL. */
1118 if (res < 0 && errno != ECHILD)
1119 perror_with_name ("kill_wait_lwp");
1122 /* Callback for `find_inferior'. Kills an lwp of a given process,
1123 except the leader. */
1126 kill_one_lwp_callback (struct inferior_list_entry *entry, void *args)
1128 struct thread_info *thread = (struct thread_info *) entry;
1129 struct lwp_info *lwp = get_thread_lwp (thread);
1130 int pid = * (int *) args;
1132 if (ptid_get_pid (entry->id) != pid)
1135 /* We avoid killing the first thread here, because of a Linux kernel (at
1136 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
1137 the children get a chance to be reaped, it will remain a zombie
1140 if (lwpid_of (thread) == pid)
1143 debug_printf ("lkop: is last of process %s\n",
1144 target_pid_to_str (entry->id));
1148 kill_wait_lwp (lwp);
1153 linux_kill (int pid)
1155 struct process_info *process;
1156 struct lwp_info *lwp;
1158 process = find_process_pid (pid);
1159 if (process == NULL)
1162 /* If we're killing a running inferior, make sure it is stopped
1163 first, as PTRACE_KILL will not work otherwise. */
1164 stop_all_lwps (0, NULL);
1166 find_inferior (&all_threads, kill_one_lwp_callback , &pid);
1168 /* See the comment in linux_kill_one_lwp. We did not kill the first
1169 thread in the list, so do so now. */
1170 lwp = find_lwp_pid (pid_to_ptid (pid));
1175 debug_printf ("lk_1: cannot find lwp for pid: %d\n",
1179 kill_wait_lwp (lwp);
1181 the_target->mourn (process);
1183 /* Since we presently can only stop all lwps of all processes, we
1184 need to unstop lwps of other processes. */
1185 unstop_all_lwps (0, NULL);
1189 /* Get pending signal of THREAD, for detaching purposes. This is the
1190 signal the thread last stopped for, which we need to deliver to the
1191 thread when detaching, otherwise, it'd be suppressed/lost. */
1194 get_detach_signal (struct thread_info *thread)
1196 enum gdb_signal signo = GDB_SIGNAL_0;
1198 struct lwp_info *lp = get_thread_lwp (thread);
1200 if (lp->status_pending_p)
1201 status = lp->status_pending;
1204 /* If the thread had been suspended by gdbserver, and it stopped
1205 cleanly, then it'll have stopped with SIGSTOP. But we don't
1206 want to deliver that SIGSTOP. */
1207 if (thread->last_status.kind != TARGET_WAITKIND_STOPPED
1208 || thread->last_status.value.sig == GDB_SIGNAL_0)
1211 /* Otherwise, we may need to deliver the signal we
1213 status = lp->last_status;
1216 if (!WIFSTOPPED (status))
1219 debug_printf ("GPS: lwp %s hasn't stopped: no pending signal\n",
1220 target_pid_to_str (ptid_of (thread)));
1224 /* Extended wait statuses aren't real SIGTRAPs. */
1225 if (WSTOPSIG (status) == SIGTRAP && linux_is_extended_waitstatus (status))
1228 debug_printf ("GPS: lwp %s had stopped with extended "
1229 "status: no pending signal\n",
1230 target_pid_to_str (ptid_of (thread)));
1234 signo = gdb_signal_from_host (WSTOPSIG (status));
1236 if (program_signals_p && !program_signals[signo])
1239 debug_printf ("GPS: lwp %s had signal %s, but it is in nopass state\n",
1240 target_pid_to_str (ptid_of (thread)),
1241 gdb_signal_to_string (signo));
1244 else if (!program_signals_p
1245 /* If we have no way to know which signals GDB does not
1246 want to have passed to the program, assume
1247 SIGTRAP/SIGINT, which is GDB's default. */
1248 && (signo == GDB_SIGNAL_TRAP || signo == GDB_SIGNAL_INT))
1251 debug_printf ("GPS: lwp %s had signal %s, "
1252 "but we don't know if we should pass it. "
1253 "Default to not.\n",
1254 target_pid_to_str (ptid_of (thread)),
1255 gdb_signal_to_string (signo));
1261 debug_printf ("GPS: lwp %s has pending signal %s: delivering it.\n",
1262 target_pid_to_str (ptid_of (thread)),
1263 gdb_signal_to_string (signo));
1265 return WSTOPSIG (status);
1270 linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
1272 struct thread_info *thread = (struct thread_info *) entry;
1273 struct lwp_info *lwp = get_thread_lwp (thread);
1274 int pid = * (int *) args;
1277 if (ptid_get_pid (entry->id) != pid)
1280 /* If there is a pending SIGSTOP, get rid of it. */
1281 if (lwp->stop_expected)
1284 debug_printf ("Sending SIGCONT to %s\n",
1285 target_pid_to_str (ptid_of (thread)));
1287 kill_lwp (lwpid_of (thread), SIGCONT);
1288 lwp->stop_expected = 0;
1291 /* Flush any pending changes to the process's registers. */
1292 regcache_invalidate_thread (thread);
1294 /* Pass on any pending signal for this thread. */
1295 sig = get_detach_signal (thread);
1297 /* Finally, let it resume. */
1298 if (the_low_target.prepare_to_resume != NULL)
1299 the_low_target.prepare_to_resume (lwp);
1300 if (ptrace (PTRACE_DETACH, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
1301 (PTRACE_TYPE_ARG4) (long) sig) < 0)
1302 error (_("Can't detach %s: %s"),
1303 target_pid_to_str (ptid_of (thread)),
1311 linux_detach (int pid)
1313 struct process_info *process;
1315 process = find_process_pid (pid);
1316 if (process == NULL)
1319 /* Stop all threads before detaching. First, ptrace requires that
1320 the thread is stopped to sucessfully detach. Second, thread_db
1321 may need to uninstall thread event breakpoints from memory, which
1322 only works with a stopped process anyway. */
1323 stop_all_lwps (0, NULL);
1325 #ifdef USE_THREAD_DB
1326 thread_db_detach (process);
1329 /* Stabilize threads (move out of jump pads). */
1330 stabilize_threads ();
1332 find_inferior (&all_threads, linux_detach_one_lwp, &pid);
1334 the_target->mourn (process);
1336 /* Since we presently can only stop all lwps of all processes, we
1337 need to unstop lwps of other processes. */
1338 unstop_all_lwps (0, NULL);
1342 /* Remove all LWPs that belong to process PROC from the lwp list. */
1345 delete_lwp_callback (struct inferior_list_entry *entry, void *proc)
1347 struct thread_info *thread = (struct thread_info *) entry;
1348 struct lwp_info *lwp = get_thread_lwp (thread);
1349 struct process_info *process = proc;
1351 if (pid_of (thread) == pid_of (process))
1358 linux_mourn (struct process_info *process)
1360 struct process_info_private *priv;
1362 #ifdef USE_THREAD_DB
1363 thread_db_mourn (process);
1366 find_inferior (&all_threads, delete_lwp_callback, process);
1368 /* Freeing all private data. */
1369 priv = process->priv;
1370 free (priv->arch_private);
1372 process->priv = NULL;
1374 remove_process (process);
1378 linux_join (int pid)
1383 ret = my_waitpid (pid, &status, 0);
1384 if (WIFEXITED (status) || WIFSIGNALED (status))
1386 } while (ret != -1 || errno != ECHILD);
1389 /* Return nonzero if the given thread is still alive. */
1391 linux_thread_alive (ptid_t ptid)
1393 struct lwp_info *lwp = find_lwp_pid (ptid);
1395 /* We assume we always know if a thread exits. If a whole process
1396 exited but we still haven't been able to report it to GDB, we'll
1397 hold on to the last lwp of the dead process. */
1404 /* Return 1 if this lwp still has an interesting status pending. If
1405 not (e.g., it had stopped for a breakpoint that is gone), return
1409 thread_still_has_status_pending_p (struct thread_info *thread)
1411 struct lwp_info *lp = get_thread_lwp (thread);
1413 if (!lp->status_pending_p)
1416 /* If we got a `vCont;t', but we haven't reported a stop yet, do
1417 report any status pending the LWP may have. */
1418 if (thread->last_resume_kind == resume_stop
1419 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
1422 if (thread->last_resume_kind != resume_stop
1423 && (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
1424 || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
1426 struct thread_info *saved_thread;
1430 gdb_assert (lp->last_status != 0);
1434 saved_thread = current_thread;
1435 current_thread = thread;
1437 if (pc != lp->stop_pc)
1440 debug_printf ("PC of %ld changed\n",
1445 #if !USE_SIGTRAP_SIGINFO
1446 else if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
1447 && !(*the_low_target.breakpoint_at) (pc))
1450 debug_printf ("previous SW breakpoint of %ld gone\n",
1454 else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT
1455 && !hardware_breakpoint_inserted_here (pc))
1458 debug_printf ("previous HW breakpoint of %ld gone\n",
1464 current_thread = saved_thread;
1469 debug_printf ("discarding pending breakpoint status\n");
1470 lp->status_pending_p = 0;
1478 /* Return 1 if this lwp has an interesting status pending. */
1480 status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
1482 struct thread_info *thread = (struct thread_info *) entry;
1483 struct lwp_info *lp = get_thread_lwp (thread);
1484 ptid_t ptid = * (ptid_t *) arg;
1486 /* Check if we're only interested in events from a specific process
1487 or a specific LWP. */
1488 if (!ptid_match (ptid_of (thread), ptid))
1491 if (lp->status_pending_p
1492 && !thread_still_has_status_pending_p (thread))
1494 linux_resume_one_lwp (lp, lp->stepping, GDB_SIGNAL_0, NULL);
1498 return lp->status_pending_p;
1502 same_lwp (struct inferior_list_entry *entry, void *data)
1504 ptid_t ptid = *(ptid_t *) data;
1507 if (ptid_get_lwp (ptid) != 0)
1508 lwp = ptid_get_lwp (ptid);
1510 lwp = ptid_get_pid (ptid);
1512 if (ptid_get_lwp (entry->id) == lwp)
1519 find_lwp_pid (ptid_t ptid)
1521 struct inferior_list_entry *thread
1522 = find_inferior (&all_threads, same_lwp, &ptid);
1527 return get_thread_lwp ((struct thread_info *) thread);
1530 /* Return the number of known LWPs in the tgid given by PID. */
1535 struct inferior_list_entry *inf, *tmp;
1538 ALL_INFERIORS (&all_threads, inf, tmp)
1540 if (ptid_get_pid (inf->id) == pid)
1547 /* The arguments passed to iterate_over_lwps. */
1549 struct iterate_over_lwps_args
1551 /* The FILTER argument passed to iterate_over_lwps. */
1554 /* The CALLBACK argument passed to iterate_over_lwps. */
1555 iterate_over_lwps_ftype *callback;
1557 /* The DATA argument passed to iterate_over_lwps. */
1561 /* Callback for find_inferior used by iterate_over_lwps to filter
1562 calls to the callback supplied to that function. Returning a
1563 nonzero value causes find_inferiors to stop iterating and return
1564 the current inferior_list_entry. Returning zero indicates that
1565 find_inferiors should continue iterating. */
1568 iterate_over_lwps_filter (struct inferior_list_entry *entry, void *args_p)
1570 struct iterate_over_lwps_args *args
1571 = (struct iterate_over_lwps_args *) args_p;
1573 if (ptid_match (entry->id, args->filter))
1575 struct thread_info *thr = (struct thread_info *) entry;
1576 struct lwp_info *lwp = get_thread_lwp (thr);
1578 return (*args->callback) (lwp, args->data);
1584 /* See nat/linux-nat.h. */
1587 iterate_over_lwps (ptid_t filter,
1588 iterate_over_lwps_ftype callback,
1591 struct iterate_over_lwps_args args = {filter, callback, data};
1592 struct inferior_list_entry *entry;
1594 entry = find_inferior (&all_threads, iterate_over_lwps_filter, &args);
1598 return get_thread_lwp ((struct thread_info *) entry);
1601 /* Detect zombie thread group leaders, and "exit" them. We can't reap
1602 their exits until all other threads in the group have exited. */
1605 check_zombie_leaders (void)
1607 struct process_info *proc, *tmp;
1609 ALL_PROCESSES (proc, tmp)
1611 pid_t leader_pid = pid_of (proc);
1612 struct lwp_info *leader_lp;
1614 leader_lp = find_lwp_pid (pid_to_ptid (leader_pid));
1617 debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, "
1618 "num_lwps=%d, zombie=%d\n",
1619 leader_pid, leader_lp!= NULL, num_lwps (leader_pid),
1620 linux_proc_pid_is_zombie (leader_pid));
1622 if (leader_lp != NULL
1623 /* Check if there are other threads in the group, as we may
1624 have raced with the inferior simply exiting. */
1625 && !last_thread_of_process_p (leader_pid)
1626 && linux_proc_pid_is_zombie (leader_pid))
1628 /* A leader zombie can mean one of two things:
1630 - It exited, and there's an exit status pending
1631 available, or only the leader exited (not the whole
1632 program). In the latter case, we can't waitpid the
1633 leader's exit status until all other threads are gone.
1635 - There are 3 or more threads in the group, and a thread
1636 other than the leader exec'd. On an exec, the Linux
1637 kernel destroys all other threads (except the execing
1638 one) in the thread group, and resets the execing thread's
1639 tid to the tgid. No exit notification is sent for the
1640 execing thread -- from the ptracer's perspective, it
1641 appears as though the execing thread just vanishes.
1642 Until we reap all other threads except the leader and the
1643 execing thread, the leader will be zombie, and the
1644 execing thread will be in `D (disc sleep)'. As soon as
1645 all other threads are reaped, the execing thread changes
1646 it's tid to the tgid, and the previous (zombie) leader
1647 vanishes, giving place to the "new" leader. We could try
1648 distinguishing the exit and exec cases, by waiting once
1649 more, and seeing if something comes out, but it doesn't
1650 sound useful. The previous leader _does_ go away, and
1651 we'll re-add the new one once we see the exec event
1652 (which is just the same as what would happen if the
1653 previous leader did exit voluntarily before some other
1658 "CZL: Thread group leader %d zombie "
1659 "(it exited, or another thread execd).\n",
1662 delete_lwp (leader_lp);
1667 /* Callback for `find_inferior'. Returns the first LWP that is not
1668 stopped. ARG is a PTID filter. */
1671 not_stopped_callback (struct inferior_list_entry *entry, void *arg)
1673 struct thread_info *thr = (struct thread_info *) entry;
1674 struct lwp_info *lwp;
1675 ptid_t filter = *(ptid_t *) arg;
1677 if (!ptid_match (ptid_of (thr), filter))
1680 lwp = get_thread_lwp (thr);
1687 /* This function should only be called if the LWP got a SIGTRAP.
1689 Handle any tracepoint steps or hits. Return true if a tracepoint
1690 event was handled, 0 otherwise. */
1693 handle_tracepoints (struct lwp_info *lwp)
1695 struct thread_info *tinfo = get_lwp_thread (lwp);
1696 int tpoint_related_event = 0;
1698 gdb_assert (lwp->suspended == 0);
1700 /* If this tracepoint hit causes a tracing stop, we'll immediately
1701 uninsert tracepoints. To do this, we temporarily pause all
1702 threads, unpatch away, and then unpause threads. We need to make
1703 sure the unpausing doesn't resume LWP too. */
1706 /* And we need to be sure that any all-threads-stopping doesn't try
1707 to move threads out of the jump pads, as it could deadlock the
1708 inferior (LWP could be in the jump pad, maybe even holding the
1711 /* Do any necessary step collect actions. */
1712 tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc);
1714 tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc);
1716 /* See if we just hit a tracepoint and do its main collect
1718 tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc);
1722 gdb_assert (lwp->suspended == 0);
1723 gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint);
1725 if (tpoint_related_event)
1728 debug_printf ("got a tracepoint event\n");
1735 /* Convenience wrapper. Returns true if LWP is presently collecting a
1739 linux_fast_tracepoint_collecting (struct lwp_info *lwp,
1740 struct fast_tpoint_collect_status *status)
1742 CORE_ADDR thread_area;
1743 struct thread_info *thread = get_lwp_thread (lwp);
1745 if (the_low_target.get_thread_area == NULL)
1748 /* Get the thread area address. This is used to recognize which
1749 thread is which when tracing with the in-process agent library.
1750 We don't read anything from the address, and treat it as opaque;
1751 it's the address itself that we assume is unique per-thread. */
1752 if ((*the_low_target.get_thread_area) (lwpid_of (thread), &thread_area) == -1)
1755 return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status);
1758 /* The reason we resume in the caller, is because we want to be able
1759 to pass lwp->status_pending as WSTAT, and we need to clear
1760 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1761 refuses to resume. */
1764 maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat)
1766 struct thread_info *saved_thread;
1768 saved_thread = current_thread;
1769 current_thread = get_lwp_thread (lwp);
1772 || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP))
1773 && supports_fast_tracepoints ()
1774 && agent_loaded_p ())
1776 struct fast_tpoint_collect_status status;
1780 debug_printf ("Checking whether LWP %ld needs to move out of the "
1782 lwpid_of (current_thread));
1784 r = linux_fast_tracepoint_collecting (lwp, &status);
1787 || (WSTOPSIG (*wstat) != SIGILL
1788 && WSTOPSIG (*wstat) != SIGFPE
1789 && WSTOPSIG (*wstat) != SIGSEGV
1790 && WSTOPSIG (*wstat) != SIGBUS))
1792 lwp->collecting_fast_tracepoint = r;
1796 if (r == 1 && lwp->exit_jump_pad_bkpt == NULL)
1798 /* Haven't executed the original instruction yet.
1799 Set breakpoint there, and wait till it's hit,
1800 then single-step until exiting the jump pad. */
1801 lwp->exit_jump_pad_bkpt
1802 = set_breakpoint_at (status.adjusted_insn_addr, NULL);
1806 debug_printf ("Checking whether LWP %ld needs to move out of "
1807 "the jump pad...it does\n",
1808 lwpid_of (current_thread));
1809 current_thread = saved_thread;
1816 /* If we get a synchronous signal while collecting, *and*
1817 while executing the (relocated) original instruction,
1818 reset the PC to point at the tpoint address, before
1819 reporting to GDB. Otherwise, it's an IPA lib bug: just
1820 report the signal to GDB, and pray for the best. */
1822 lwp->collecting_fast_tracepoint = 0;
1825 && (status.adjusted_insn_addr <= lwp->stop_pc
1826 && lwp->stop_pc < status.adjusted_insn_addr_end))
1829 struct regcache *regcache;
1831 /* The si_addr on a few signals references the address
1832 of the faulting instruction. Adjust that as
1834 if ((WSTOPSIG (*wstat) == SIGILL
1835 || WSTOPSIG (*wstat) == SIGFPE
1836 || WSTOPSIG (*wstat) == SIGBUS
1837 || WSTOPSIG (*wstat) == SIGSEGV)
1838 && ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread),
1839 (PTRACE_TYPE_ARG3) 0, &info) == 0
1840 /* Final check just to make sure we don't clobber
1841 the siginfo of non-kernel-sent signals. */
1842 && (uintptr_t) info.si_addr == lwp->stop_pc)
1844 info.si_addr = (void *) (uintptr_t) status.tpoint_addr;
1845 ptrace (PTRACE_SETSIGINFO, lwpid_of (current_thread),
1846 (PTRACE_TYPE_ARG3) 0, &info);
1849 regcache = get_thread_regcache (current_thread, 1);
1850 (*the_low_target.set_pc) (regcache, status.tpoint_addr);
1851 lwp->stop_pc = status.tpoint_addr;
1853 /* Cancel any fast tracepoint lock this thread was
1855 force_unlock_trace_buffer ();
1858 if (lwp->exit_jump_pad_bkpt != NULL)
1861 debug_printf ("Cancelling fast exit-jump-pad: removing bkpt. "
1862 "stopping all threads momentarily.\n");
1864 stop_all_lwps (1, lwp);
1866 delete_breakpoint (lwp->exit_jump_pad_bkpt);
1867 lwp->exit_jump_pad_bkpt = NULL;
1869 unstop_all_lwps (1, lwp);
1871 gdb_assert (lwp->suspended >= 0);
1877 debug_printf ("Checking whether LWP %ld needs to move out of the "
1879 lwpid_of (current_thread));
1881 current_thread = saved_thread;
1885 /* Enqueue one signal in the "signals to report later when out of the
1889 enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1891 struct pending_signals *p_sig;
1892 struct thread_info *thread = get_lwp_thread (lwp);
1895 debug_printf ("Deferring signal %d for LWP %ld.\n",
1896 WSTOPSIG (*wstat), lwpid_of (thread));
1900 struct pending_signals *sig;
1902 for (sig = lwp->pending_signals_to_report;
1905 debug_printf (" Already queued %d\n",
1908 debug_printf (" (no more currently queued signals)\n");
1911 /* Don't enqueue non-RT signals if they are already in the deferred
1912 queue. (SIGSTOP being the easiest signal to see ending up here
1914 if (WSTOPSIG (*wstat) < __SIGRTMIN)
1916 struct pending_signals *sig;
1918 for (sig = lwp->pending_signals_to_report;
1922 if (sig->signal == WSTOPSIG (*wstat))
1925 debug_printf ("Not requeuing already queued non-RT signal %d"
1934 p_sig = xmalloc (sizeof (*p_sig));
1935 p_sig->prev = lwp->pending_signals_to_report;
1936 p_sig->signal = WSTOPSIG (*wstat);
1937 memset (&p_sig->info, 0, sizeof (siginfo_t));
1938 ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
1941 lwp->pending_signals_to_report = p_sig;
1944 /* Dequeue one signal from the "signals to report later when out of
1945 the jump pad" list. */
1948 dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1950 struct thread_info *thread = get_lwp_thread (lwp);
1952 if (lwp->pending_signals_to_report != NULL)
1954 struct pending_signals **p_sig;
1956 p_sig = &lwp->pending_signals_to_report;
1957 while ((*p_sig)->prev != NULL)
1958 p_sig = &(*p_sig)->prev;
1960 *wstat = W_STOPCODE ((*p_sig)->signal);
1961 if ((*p_sig)->info.si_signo != 0)
1962 ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
1968 debug_printf ("Reporting deferred signal %d for LWP %ld.\n",
1969 WSTOPSIG (*wstat), lwpid_of (thread));
1973 struct pending_signals *sig;
1975 for (sig = lwp->pending_signals_to_report;
1978 debug_printf (" Still queued %d\n",
1981 debug_printf (" (no more queued signals)\n");
1990 /* Fetch the possibly triggered data watchpoint info and store it in
1993 On some archs, like x86, that use debug registers to set
1994 watchpoints, it's possible that the way to know which watched
1995 address trapped, is to check the register that is used to select
1996 which address to watch. Problem is, between setting the watchpoint
1997 and reading back which data address trapped, the user may change
1998 the set of watchpoints, and, as a consequence, GDB changes the
1999 debug registers in the inferior. To avoid reading back a stale
2000 stopped-data-address when that happens, we cache in LP the fact
2001 that a watchpoint trapped, and the corresponding data address, as
2002 soon as we see CHILD stop with a SIGTRAP. If GDB changes the debug
2003 registers meanwhile, we have the cached data we can rely on. */
2006 check_stopped_by_watchpoint (struct lwp_info *child)
2008 if (the_low_target.stopped_by_watchpoint != NULL)
2010 struct thread_info *saved_thread;
2012 saved_thread = current_thread;
2013 current_thread = get_lwp_thread (child);
2015 if (the_low_target.stopped_by_watchpoint ())
2017 child->stop_reason = TARGET_STOPPED_BY_WATCHPOINT;
2019 if (the_low_target.stopped_data_address != NULL)
2020 child->stopped_data_address
2021 = the_low_target.stopped_data_address ();
2023 child->stopped_data_address = 0;
2026 current_thread = saved_thread;
2029 return child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2032 /* Return the ptrace options that we want to try to enable. */
2035 linux_low_ptrace_options (int attached)
2040 options |= PTRACE_O_EXITKILL;
2042 if (report_fork_events)
2043 options |= PTRACE_O_TRACEFORK;
2045 if (report_vfork_events)
2046 options |= (PTRACE_O_TRACEVFORK | PTRACE_O_TRACEVFORKDONE);
2051 /* Do low-level handling of the event, and check if we should go on
2052 and pass it to caller code. Return the affected lwp if we are, or
2055 static struct lwp_info *
2056 linux_low_filter_event (int lwpid, int wstat)
2058 struct lwp_info *child;
2059 struct thread_info *thread;
2060 int have_stop_pc = 0;
2062 child = find_lwp_pid (pid_to_ptid (lwpid));
2064 /* If we didn't find a process, one of two things presumably happened:
2065 - A process we started and then detached from has exited. Ignore it.
2066 - A process we are controlling has forked and the new child's stop
2067 was reported to us by the kernel. Save its PID. */
2068 if (child == NULL && WIFSTOPPED (wstat))
2070 add_to_pid_list (&stopped_pids, lwpid, wstat);
2073 else if (child == NULL)
2076 thread = get_lwp_thread (child);
2080 child->last_status = wstat;
2082 /* Check if the thread has exited. */
2083 if ((WIFEXITED (wstat) || WIFSIGNALED (wstat)))
2086 debug_printf ("LLFE: %d exited.\n", lwpid);
2087 if (num_lwps (pid_of (thread)) > 1)
2090 /* If there is at least one more LWP, then the exit signal was
2091 not the end of the debugged application and should be
2098 /* This was the last lwp in the process. Since events are
2099 serialized to GDB core, and we can't report this one
2100 right now, but GDB core and the other target layers will
2101 want to be notified about the exit code/signal, leave the
2102 status pending for the next time we're able to report
2104 mark_lwp_dead (child, wstat);
2109 gdb_assert (WIFSTOPPED (wstat));
2111 if (WIFSTOPPED (wstat))
2113 struct process_info *proc;
2115 /* Architecture-specific setup after inferior is running. */
2116 proc = find_process_pid (pid_of (thread));
2117 if (proc->tdesc == NULL)
2121 struct thread_info *saved_thread;
2123 /* This needs to happen after we have attached to the
2124 inferior and it is stopped for the first time, but
2125 before we access any inferior registers. */
2126 saved_thread = current_thread;
2127 current_thread = thread;
2129 the_low_target.arch_setup ();
2131 current_thread = saved_thread;
2135 /* The process is started, but GDBserver will do
2136 architecture-specific setup after the program stops at
2137 the first instruction. */
2138 child->status_pending_p = 1;
2139 child->status_pending = wstat;
2145 if (WIFSTOPPED (wstat) && child->must_set_ptrace_flags)
2147 struct process_info *proc = find_process_pid (pid_of (thread));
2148 int options = linux_low_ptrace_options (proc->attached);
2150 linux_enable_event_reporting (lwpid, options);
2151 child->must_set_ptrace_flags = 0;
2154 /* Be careful to not overwrite stop_pc until
2155 check_stopped_by_breakpoint is called. */
2156 if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
2157 && linux_is_extended_waitstatus (wstat))
2159 child->stop_pc = get_pc (child);
2160 if (handle_extended_wait (child, wstat))
2162 /* The event has been handled, so just return without
2168 /* Check first whether this was a SW/HW breakpoint before checking
2169 watchpoints, because at least s390 can't tell the data address of
2170 hardware watchpoint hits, and returns stopped-by-watchpoint as
2171 long as there's a watchpoint set. */
2172 if (WIFSTOPPED (wstat) && linux_wstatus_maybe_breakpoint (wstat))
2174 if (check_stopped_by_breakpoint (child))
2178 /* Note that TRAP_HWBKPT can indicate either a hardware breakpoint
2179 or hardware watchpoint. Check which is which if we got
2180 TARGET_STOPPED_BY_HW_BREAKPOINT. */
2181 if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
2182 && (child->stop_reason == TARGET_STOPPED_BY_NO_REASON
2183 || child->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
2184 check_stopped_by_watchpoint (child);
2187 child->stop_pc = get_pc (child);
2189 if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGSTOP
2190 && child->stop_expected)
2193 debug_printf ("Expected stop.\n");
2194 child->stop_expected = 0;
2196 if (thread->last_resume_kind == resume_stop)
2198 /* We want to report the stop to the core. Treat the
2199 SIGSTOP as a normal event. */
2201 debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n",
2202 target_pid_to_str (ptid_of (thread)));
2204 else if (stopping_threads != NOT_STOPPING_THREADS)
2206 /* Stopping threads. We don't want this SIGSTOP to end up
2209 debug_printf ("LLW: SIGSTOP caught for %s "
2210 "while stopping threads.\n",
2211 target_pid_to_str (ptid_of (thread)));
2216 /* This is a delayed SIGSTOP. Filter out the event. */
2218 debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
2219 child->stepping ? "step" : "continue",
2220 target_pid_to_str (ptid_of (thread)));
2222 linux_resume_one_lwp (child, child->stepping, 0, NULL);
2227 child->status_pending_p = 1;
2228 child->status_pending = wstat;
2232 /* Resume LWPs that are currently stopped without any pending status
2233 to report, but are resumed from the core's perspective. */
2236 resume_stopped_resumed_lwps (struct inferior_list_entry *entry)
2238 struct thread_info *thread = (struct thread_info *) entry;
2239 struct lwp_info *lp = get_thread_lwp (thread);
2242 && !lp->status_pending_p
2243 && thread->last_resume_kind != resume_stop
2244 && thread->last_status.kind == TARGET_WAITKIND_IGNORE)
2246 int step = thread->last_resume_kind == resume_step;
2249 debug_printf ("RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
2250 target_pid_to_str (ptid_of (thread)),
2251 paddress (lp->stop_pc),
2254 linux_resume_one_lwp (lp, step, GDB_SIGNAL_0, NULL);
2258 /* Wait for an event from child(ren) WAIT_PTID, and return any that
2259 match FILTER_PTID (leaving others pending). The PTIDs can be:
2260 minus_one_ptid, to specify any child; a pid PTID, specifying all
2261 lwps of a thread group; or a PTID representing a single lwp. Store
2262 the stop status through the status pointer WSTAT. OPTIONS is
2263 passed to the waitpid call. Return 0 if no event was found and
2264 OPTIONS contains WNOHANG. Return -1 if no unwaited-for children
2265 was found. Return the PID of the stopped child otherwise. */
2268 linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
2269 int *wstatp, int options)
2271 struct thread_info *event_thread;
2272 struct lwp_info *event_child, *requested_child;
2273 sigset_t block_mask, prev_mask;
2276 /* N.B. event_thread points to the thread_info struct that contains
2277 event_child. Keep them in sync. */
2278 event_thread = NULL;
2280 requested_child = NULL;
2282 /* Check for a lwp with a pending status. */
2284 if (ptid_equal (filter_ptid, minus_one_ptid) || ptid_is_pid (filter_ptid))
2286 event_thread = (struct thread_info *)
2287 find_inferior (&all_threads, status_pending_p_callback, &filter_ptid);
2288 if (event_thread != NULL)
2289 event_child = get_thread_lwp (event_thread);
2290 if (debug_threads && event_thread)
2291 debug_printf ("Got a pending child %ld\n", lwpid_of (event_thread));
2293 else if (!ptid_equal (filter_ptid, null_ptid))
2295 requested_child = find_lwp_pid (filter_ptid);
2297 if (stopping_threads == NOT_STOPPING_THREADS
2298 && requested_child->status_pending_p
2299 && requested_child->collecting_fast_tracepoint)
2301 enqueue_one_deferred_signal (requested_child,
2302 &requested_child->status_pending);
2303 requested_child->status_pending_p = 0;
2304 requested_child->status_pending = 0;
2305 linux_resume_one_lwp (requested_child, 0, 0, NULL);
2308 if (requested_child->suspended
2309 && requested_child->status_pending_p)
2311 internal_error (__FILE__, __LINE__,
2312 "requesting an event out of a"
2313 " suspended child?");
2316 if (requested_child->status_pending_p)
2318 event_child = requested_child;
2319 event_thread = get_lwp_thread (event_child);
2323 if (event_child != NULL)
2326 debug_printf ("Got an event from pending child %ld (%04x)\n",
2327 lwpid_of (event_thread), event_child->status_pending);
2328 *wstatp = event_child->status_pending;
2329 event_child->status_pending_p = 0;
2330 event_child->status_pending = 0;
2331 current_thread = event_thread;
2332 return lwpid_of (event_thread);
2335 /* But if we don't find a pending event, we'll have to wait.
2337 We only enter this loop if no process has a pending wait status.
2338 Thus any action taken in response to a wait status inside this
2339 loop is responding as soon as we detect the status, not after any
2342 /* Make sure SIGCHLD is blocked until the sigsuspend below. Block
2343 all signals while here. */
2344 sigfillset (&block_mask);
2345 sigprocmask (SIG_BLOCK, &block_mask, &prev_mask);
2347 /* Always pull all events out of the kernel. We'll randomly select
2348 an event LWP out of all that have events, to prevent
2350 while (event_child == NULL)
2354 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
2357 - If the thread group leader exits while other threads in the
2358 thread group still exist, waitpid(TGID, ...) hangs. That
2359 waitpid won't return an exit status until the other threads
2360 in the group are reaped.
2362 - When a non-leader thread execs, that thread just vanishes
2363 without reporting an exit (so we'd hang if we waited for it
2364 explicitly in that case). The exec event is reported to
2365 the TGID pid (although we don't currently enable exec
2368 ret = my_waitpid (-1, wstatp, options | WNOHANG);
2371 debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n",
2372 ret, errno ? strerror (errno) : "ERRNO-OK");
2378 debug_printf ("LLW: waitpid %ld received %s\n",
2379 (long) ret, status_to_str (*wstatp));
2382 /* Filter all events. IOW, leave all events pending. We'll
2383 randomly select an event LWP out of all that have events
2385 linux_low_filter_event (ret, *wstatp);
2386 /* Retry until nothing comes out of waitpid. A single
2387 SIGCHLD can indicate more than one child stopped. */
2391 /* Now that we've pulled all events out of the kernel, resume
2392 LWPs that don't have an interesting event to report. */
2393 if (stopping_threads == NOT_STOPPING_THREADS)
2394 for_each_inferior (&all_threads, resume_stopped_resumed_lwps);
2396 /* ... and find an LWP with a status to report to the core, if
2398 event_thread = (struct thread_info *)
2399 find_inferior (&all_threads, status_pending_p_callback, &filter_ptid);
2400 if (event_thread != NULL)
2402 event_child = get_thread_lwp (event_thread);
2403 *wstatp = event_child->status_pending;
2404 event_child->status_pending_p = 0;
2405 event_child->status_pending = 0;
2409 /* Check for zombie thread group leaders. Those can't be reaped
2410 until all other threads in the thread group are. */
2411 check_zombie_leaders ();
2413 /* If there are no resumed children left in the set of LWPs we
2414 want to wait for, bail. We can't just block in
2415 waitpid/sigsuspend, because lwps might have been left stopped
2416 in trace-stop state, and we'd be stuck forever waiting for
2417 their status to change (which would only happen if we resumed
2418 them). Even if WNOHANG is set, this return code is preferred
2419 over 0 (below), as it is more detailed. */
2420 if ((find_inferior (&all_threads,
2421 not_stopped_callback,
2422 &wait_ptid) == NULL))
2425 debug_printf ("LLW: exit (no unwaited-for LWP)\n");
2426 sigprocmask (SIG_SETMASK, &prev_mask, NULL);
2430 /* No interesting event to report to the caller. */
2431 if ((options & WNOHANG))
2434 debug_printf ("WNOHANG set, no event found\n");
2436 sigprocmask (SIG_SETMASK, &prev_mask, NULL);
2440 /* Block until we get an event reported with SIGCHLD. */
2442 debug_printf ("sigsuspend'ing\n");
2444 sigsuspend (&prev_mask);
2445 sigprocmask (SIG_SETMASK, &prev_mask, NULL);
2449 sigprocmask (SIG_SETMASK, &prev_mask, NULL);
2451 current_thread = event_thread;
2453 /* Check for thread exit. */
2454 if (! WIFSTOPPED (*wstatp))
2456 gdb_assert (last_thread_of_process_p (pid_of (event_thread)));
2459 debug_printf ("LWP %d is the last lwp of process. "
2460 "Process %ld exiting.\n",
2461 pid_of (event_thread), lwpid_of (event_thread));
2462 return lwpid_of (event_thread);
2465 return lwpid_of (event_thread);
2468 /* Wait for an event from child(ren) PTID. PTIDs can be:
2469 minus_one_ptid, to specify any child; a pid PTID, specifying all
2470 lwps of a thread group; or a PTID representing a single lwp. Store
2471 the stop status through the status pointer WSTAT. OPTIONS is
2472 passed to the waitpid call. Return 0 if no event was found and
2473 OPTIONS contains WNOHANG. Return -1 if no unwaited-for children
2474 was found. Return the PID of the stopped child otherwise. */
2477 linux_wait_for_event (ptid_t ptid, int *wstatp, int options)
2479 return linux_wait_for_event_filtered (ptid, ptid, wstatp, options);
2482 /* Count the LWP's that have had events. */
2485 count_events_callback (struct inferior_list_entry *entry, void *data)
2487 struct thread_info *thread = (struct thread_info *) entry;
2488 struct lwp_info *lp = get_thread_lwp (thread);
2491 gdb_assert (count != NULL);
2493 /* Count only resumed LWPs that have an event pending. */
2494 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
2495 && lp->status_pending_p)
2501 /* Select the LWP (if any) that is currently being single-stepped. */
2504 select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data)
2506 struct thread_info *thread = (struct thread_info *) entry;
2507 struct lwp_info *lp = get_thread_lwp (thread);
2509 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
2510 && thread->last_resume_kind == resume_step
2511 && lp->status_pending_p)
2517 /* Select the Nth LWP that has had an event. */
2520 select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
2522 struct thread_info *thread = (struct thread_info *) entry;
2523 struct lwp_info *lp = get_thread_lwp (thread);
2524 int *selector = data;
2526 gdb_assert (selector != NULL);
2528 /* Select only resumed LWPs that have an event pending. */
2529 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
2530 && lp->status_pending_p)
2531 if ((*selector)-- == 0)
2537 /* Select one LWP out of those that have events pending. */
2540 select_event_lwp (struct lwp_info **orig_lp)
2543 int random_selector;
2544 struct thread_info *event_thread = NULL;
2546 /* In all-stop, give preference to the LWP that is being
2547 single-stepped. There will be at most one, and it's the LWP that
2548 the core is most interested in. If we didn't do this, then we'd
2549 have to handle pending step SIGTRAPs somehow in case the core
2550 later continues the previously-stepped thread, otherwise we'd
2551 report the pending SIGTRAP, and the core, not having stepped the
2552 thread, wouldn't understand what the trap was for, and therefore
2553 would report it to the user as a random signal. */
2557 = (struct thread_info *) find_inferior (&all_threads,
2558 select_singlestep_lwp_callback,
2560 if (event_thread != NULL)
2563 debug_printf ("SEL: Select single-step %s\n",
2564 target_pid_to_str (ptid_of (event_thread)));
2567 if (event_thread == NULL)
2569 /* No single-stepping LWP. Select one at random, out of those
2570 which have had events. */
2572 /* First see how many events we have. */
2573 find_inferior (&all_threads, count_events_callback, &num_events);
2574 gdb_assert (num_events > 0);
2576 /* Now randomly pick a LWP out of those that have had
2578 random_selector = (int)
2579 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2581 if (debug_threads && num_events > 1)
2582 debug_printf ("SEL: Found %d SIGTRAP events, selecting #%d\n",
2583 num_events, random_selector);
2586 = (struct thread_info *) find_inferior (&all_threads,
2587 select_event_lwp_callback,
2591 if (event_thread != NULL)
2593 struct lwp_info *event_lp = get_thread_lwp (event_thread);
2595 /* Switch the event LWP. */
2596 *orig_lp = event_lp;
2600 /* Decrement the suspend count of an LWP. */
2603 unsuspend_one_lwp (struct inferior_list_entry *entry, void *except)
2605 struct thread_info *thread = (struct thread_info *) entry;
2606 struct lwp_info *lwp = get_thread_lwp (thread);
2608 /* Ignore EXCEPT. */
2614 gdb_assert (lwp->suspended >= 0);
2618 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
2622 unsuspend_all_lwps (struct lwp_info *except)
2624 find_inferior (&all_threads, unsuspend_one_lwp, except);
2627 static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry);
2628 static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry,
2630 static int lwp_running (struct inferior_list_entry *entry, void *data);
2631 static ptid_t linux_wait_1 (ptid_t ptid,
2632 struct target_waitstatus *ourstatus,
2633 int target_options);
2635 /* Stabilize threads (move out of jump pads).
2637 If a thread is midway collecting a fast tracepoint, we need to
2638 finish the collection and move it out of the jump pad before
2639 reporting the signal.
2641 This avoids recursion while collecting (when a signal arrives
2642 midway, and the signal handler itself collects), which would trash
2643 the trace buffer. In case the user set a breakpoint in a signal
2644 handler, this avoids the backtrace showing the jump pad, etc..
2645 Most importantly, there are certain things we can't do safely if
2646 threads are stopped in a jump pad (or in its callee's). For
2649 - starting a new trace run. A thread still collecting the
2650 previous run, could trash the trace buffer when resumed. The trace
2651 buffer control structures would have been reset but the thread had
2652 no way to tell. The thread could even midway memcpy'ing to the
2653 buffer, which would mean that when resumed, it would clobber the
2654 trace buffer that had been set for a new run.
2656 - we can't rewrite/reuse the jump pads for new tracepoints
2657 safely. Say you do tstart while a thread is stopped midway while
2658 collecting. When the thread is later resumed, it finishes the
2659 collection, and returns to the jump pad, to execute the original
2660 instruction that was under the tracepoint jump at the time the
2661 older run had been started. If the jump pad had been rewritten
2662 since for something else in the new run, the thread would now
2663 execute the wrong / random instructions. */
2666 linux_stabilize_threads (void)
2668 struct thread_info *saved_thread;
2669 struct thread_info *thread_stuck;
2672 = (struct thread_info *) find_inferior (&all_threads,
2673 stuck_in_jump_pad_callback,
2675 if (thread_stuck != NULL)
2678 debug_printf ("can't stabilize, LWP %ld is stuck in jump pad\n",
2679 lwpid_of (thread_stuck));
2683 saved_thread = current_thread;
2685 stabilizing_threads = 1;
2688 for_each_inferior (&all_threads, move_out_of_jump_pad_callback);
2690 /* Loop until all are stopped out of the jump pads. */
2691 while (find_inferior (&all_threads, lwp_running, NULL) != NULL)
2693 struct target_waitstatus ourstatus;
2694 struct lwp_info *lwp;
2697 /* Note that we go through the full wait even loop. While
2698 moving threads out of jump pad, we need to be able to step
2699 over internal breakpoints and such. */
2700 linux_wait_1 (minus_one_ptid, &ourstatus, 0);
2702 if (ourstatus.kind == TARGET_WAITKIND_STOPPED)
2704 lwp = get_thread_lwp (current_thread);
2709 if (ourstatus.value.sig != GDB_SIGNAL_0
2710 || current_thread->last_resume_kind == resume_stop)
2712 wstat = W_STOPCODE (gdb_signal_to_host (ourstatus.value.sig));
2713 enqueue_one_deferred_signal (lwp, &wstat);
2718 find_inferior (&all_threads, unsuspend_one_lwp, NULL);
2720 stabilizing_threads = 0;
2722 current_thread = saved_thread;
2727 = (struct thread_info *) find_inferior (&all_threads,
2728 stuck_in_jump_pad_callback,
2730 if (thread_stuck != NULL)
2731 debug_printf ("couldn't stabilize, LWP %ld got stuck in jump pad\n",
2732 lwpid_of (thread_stuck));
2736 static void async_file_mark (void);
2738 /* Convenience function that is called when the kernel reports an
2739 event that is not passed out to GDB. */
2742 ignore_event (struct target_waitstatus *ourstatus)
2744 /* If we got an event, there may still be others, as a single
2745 SIGCHLD can indicate more than one child stopped. This forces
2746 another target_wait call. */
2749 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2753 /* Return non-zero if WAITSTATUS reflects an extended linux
2754 event. Otherwise, return zero. */
2757 extended_event_reported (const struct target_waitstatus *waitstatus)
2759 if (waitstatus == NULL)
2762 return (waitstatus->kind == TARGET_WAITKIND_FORKED
2763 || waitstatus->kind == TARGET_WAITKIND_VFORKED
2764 || waitstatus->kind == TARGET_WAITKIND_VFORK_DONE);
2767 /* Wait for process, returns status. */
2770 linux_wait_1 (ptid_t ptid,
2771 struct target_waitstatus *ourstatus, int target_options)
2774 struct lwp_info *event_child;
2777 int step_over_finished;
2778 int bp_explains_trap;
2779 int maybe_internal_trap;
2787 debug_printf ("linux_wait_1: [%s]\n", target_pid_to_str (ptid));
2790 /* Translate generic target options into linux options. */
2792 if (target_options & TARGET_WNOHANG)
2795 bp_explains_trap = 0;
2798 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2800 if (ptid_equal (step_over_bkpt, null_ptid))
2801 pid = linux_wait_for_event (ptid, &w, options);
2805 debug_printf ("step_over_bkpt set [%s], doing a blocking wait\n",
2806 target_pid_to_str (step_over_bkpt));
2807 pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
2812 gdb_assert (target_options & TARGET_WNOHANG);
2816 debug_printf ("linux_wait_1 ret = null_ptid, "
2817 "TARGET_WAITKIND_IGNORE\n");
2821 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2828 debug_printf ("linux_wait_1 ret = null_ptid, "
2829 "TARGET_WAITKIND_NO_RESUMED\n");
2833 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
2837 event_child = get_thread_lwp (current_thread);
2839 /* linux_wait_for_event only returns an exit status for the last
2840 child of a process. Report it. */
2841 if (WIFEXITED (w) || WIFSIGNALED (w))
2845 ourstatus->kind = TARGET_WAITKIND_EXITED;
2846 ourstatus->value.integer = WEXITSTATUS (w);
2850 debug_printf ("linux_wait_1 ret = %s, exited with "
2852 target_pid_to_str (ptid_of (current_thread)),
2859 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
2860 ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (w));
2864 debug_printf ("linux_wait_1 ret = %s, terminated with "
2866 target_pid_to_str (ptid_of (current_thread)),
2872 return ptid_of (current_thread);
2875 /* If step-over executes a breakpoint instruction, it means a
2876 gdb/gdbserver breakpoint had been planted on top of a permanent
2877 breakpoint. The PC has been adjusted by
2878 check_stopped_by_breakpoint to point at the breakpoint address.
2879 Advance the PC manually past the breakpoint, otherwise the
2880 program would keep trapping the permanent breakpoint forever. */
2881 if (!ptid_equal (step_over_bkpt, null_ptid)
2882 && event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT)
2884 unsigned int increment_pc = the_low_target.breakpoint_len;
2888 debug_printf ("step-over for %s executed software breakpoint\n",
2889 target_pid_to_str (ptid_of (current_thread)));
2892 if (increment_pc != 0)
2894 struct regcache *regcache
2895 = get_thread_regcache (current_thread, 1);
2897 event_child->stop_pc += increment_pc;
2898 (*the_low_target.set_pc) (regcache, event_child->stop_pc);
2900 if (!(*the_low_target.breakpoint_at) (event_child->stop_pc))
2901 event_child->stop_reason = TARGET_STOPPED_BY_NO_REASON;
2905 /* If this event was not handled before, and is not a SIGTRAP, we
2906 report it. SIGILL and SIGSEGV are also treated as traps in case
2907 a breakpoint is inserted at the current PC. If this target does
2908 not support internal breakpoints at all, we also report the
2909 SIGTRAP without further processing; it's of no concern to us. */
2911 = (supports_breakpoints ()
2912 && (WSTOPSIG (w) == SIGTRAP
2913 || ((WSTOPSIG (w) == SIGILL
2914 || WSTOPSIG (w) == SIGSEGV)
2915 && (*the_low_target.breakpoint_at) (event_child->stop_pc))));
2917 if (maybe_internal_trap)
2919 /* Handle anything that requires bookkeeping before deciding to
2920 report the event or continue waiting. */
2922 /* First check if we can explain the SIGTRAP with an internal
2923 breakpoint, or if we should possibly report the event to GDB.
2924 Do this before anything that may remove or insert a
2926 bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc);
2928 /* We have a SIGTRAP, possibly a step-over dance has just
2929 finished. If so, tweak the state machine accordingly,
2930 reinsert breakpoints and delete any reinsert (software
2931 single-step) breakpoints. */
2932 step_over_finished = finish_step_over (event_child);
2934 /* Now invoke the callbacks of any internal breakpoints there. */
2935 check_breakpoints (event_child->stop_pc);
2937 /* Handle tracepoint data collecting. This may overflow the
2938 trace buffer, and cause a tracing stop, removing
2940 trace_event = handle_tracepoints (event_child);
2942 if (bp_explains_trap)
2944 /* If we stepped or ran into an internal breakpoint, we've
2945 already handled it. So next time we resume (from this
2946 PC), we should step over it. */
2948 debug_printf ("Hit a gdbserver breakpoint.\n");
2950 if (breakpoint_here (event_child->stop_pc))
2951 event_child->need_step_over = 1;
2956 /* We have some other signal, possibly a step-over dance was in
2957 progress, and it should be cancelled too. */
2958 step_over_finished = finish_step_over (event_child);
2961 /* We have all the data we need. Either report the event to GDB, or
2962 resume threads and keep waiting for more. */
2964 /* If we're collecting a fast tracepoint, finish the collection and
2965 move out of the jump pad before delivering a signal. See
2966 linux_stabilize_threads. */
2969 && WSTOPSIG (w) != SIGTRAP
2970 && supports_fast_tracepoints ()
2971 && agent_loaded_p ())
2974 debug_printf ("Got signal %d for LWP %ld. Check if we need "
2975 "to defer or adjust it.\n",
2976 WSTOPSIG (w), lwpid_of (current_thread));
2978 /* Allow debugging the jump pad itself. */
2979 if (current_thread->last_resume_kind != resume_step
2980 && maybe_move_out_of_jump_pad (event_child, &w))
2982 enqueue_one_deferred_signal (event_child, &w);
2985 debug_printf ("Signal %d for LWP %ld deferred (in jump pad)\n",
2986 WSTOPSIG (w), lwpid_of (current_thread));
2988 linux_resume_one_lwp (event_child, 0, 0, NULL);
2990 return ignore_event (ourstatus);
2994 if (event_child->collecting_fast_tracepoint)
2997 debug_printf ("LWP %ld was trying to move out of the jump pad (%d). "
2998 "Check if we're already there.\n",
2999 lwpid_of (current_thread),
3000 event_child->collecting_fast_tracepoint);
3004 event_child->collecting_fast_tracepoint
3005 = linux_fast_tracepoint_collecting (event_child, NULL);
3007 if (event_child->collecting_fast_tracepoint != 1)
3009 /* No longer need this breakpoint. */
3010 if (event_child->exit_jump_pad_bkpt != NULL)
3013 debug_printf ("No longer need exit-jump-pad bkpt; removing it."
3014 "stopping all threads momentarily.\n");
3016 /* Other running threads could hit this breakpoint.
3017 We don't handle moribund locations like GDB does,
3018 instead we always pause all threads when removing
3019 breakpoints, so that any step-over or
3020 decr_pc_after_break adjustment is always taken
3021 care of while the breakpoint is still
3023 stop_all_lwps (1, event_child);
3025 delete_breakpoint (event_child->exit_jump_pad_bkpt);
3026 event_child->exit_jump_pad_bkpt = NULL;
3028 unstop_all_lwps (1, event_child);
3030 gdb_assert (event_child->suspended >= 0);
3034 if (event_child->collecting_fast_tracepoint == 0)
3037 debug_printf ("fast tracepoint finished "
3038 "collecting successfully.\n");
3040 /* We may have a deferred signal to report. */
3041 if (dequeue_one_deferred_signal (event_child, &w))
3044 debug_printf ("dequeued one signal.\n");
3049 debug_printf ("no deferred signals.\n");
3051 if (stabilizing_threads)
3053 ourstatus->kind = TARGET_WAITKIND_STOPPED;
3054 ourstatus->value.sig = GDB_SIGNAL_0;
3058 debug_printf ("linux_wait_1 ret = %s, stopped "
3059 "while stabilizing threads\n",
3060 target_pid_to_str (ptid_of (current_thread)));
3064 return ptid_of (current_thread);
3070 /* Check whether GDB would be interested in this event. */
3072 /* If GDB is not interested in this signal, don't stop other
3073 threads, and don't report it to GDB. Just resume the inferior
3074 right away. We do this for threading-related signals as well as
3075 any that GDB specifically requested we ignore. But never ignore
3076 SIGSTOP if we sent it ourselves, and do not ignore signals when
3077 stepping - they may require special handling to skip the signal
3078 handler. Also never ignore signals that could be caused by a
3080 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
3083 && current_thread->last_resume_kind != resume_step
3085 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
3086 (current_process ()->priv->thread_db != NULL
3087 && (WSTOPSIG (w) == __SIGRTMIN
3088 || WSTOPSIG (w) == __SIGRTMIN + 1))
3091 (pass_signals[gdb_signal_from_host (WSTOPSIG (w))]
3092 && !(WSTOPSIG (w) == SIGSTOP
3093 && current_thread->last_resume_kind == resume_stop)
3094 && !linux_wstatus_maybe_breakpoint (w))))
3096 siginfo_t info, *info_p;
3099 debug_printf ("Ignored signal %d for LWP %ld.\n",
3100 WSTOPSIG (w), lwpid_of (current_thread));
3102 if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread),
3103 (PTRACE_TYPE_ARG3) 0, &info) == 0)
3107 linux_resume_one_lwp (event_child, event_child->stepping,
3108 WSTOPSIG (w), info_p);
3109 return ignore_event (ourstatus);
3112 /* Note that all addresses are always "out of the step range" when
3113 there's no range to begin with. */
3114 in_step_range = lwp_in_step_range (event_child);
3116 /* If GDB wanted this thread to single step, and the thread is out
3117 of the step range, we always want to report the SIGTRAP, and let
3118 GDB handle it. Watchpoints should always be reported. So should
3119 signals we can't explain. A SIGTRAP we can't explain could be a
3120 GDB breakpoint --- we may or not support Z0 breakpoints. If we
3121 do, we're be able to handle GDB breakpoints on top of internal
3122 breakpoints, by handling the internal breakpoint and still
3123 reporting the event to GDB. If we don't, we're out of luck, GDB
3124 won't see the breakpoint hit. */
3125 report_to_gdb = (!maybe_internal_trap
3126 || (current_thread->last_resume_kind == resume_step
3128 || event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT
3129 || (!step_over_finished && !in_step_range
3130 && !bp_explains_trap && !trace_event)
3131 || (gdb_breakpoint_here (event_child->stop_pc)
3132 && gdb_condition_true_at_breakpoint (event_child->stop_pc)
3133 && gdb_no_commands_at_breakpoint (event_child->stop_pc))
3134 || extended_event_reported (&event_child->waitstatus));
3136 run_breakpoint_commands (event_child->stop_pc);
3138 /* We found no reason GDB would want us to stop. We either hit one
3139 of our own breakpoints, or finished an internal step GDB
3140 shouldn't know about. */
3145 if (bp_explains_trap)
3146 debug_printf ("Hit a gdbserver breakpoint.\n");
3147 if (step_over_finished)
3148 debug_printf ("Step-over finished.\n");
3150 debug_printf ("Tracepoint event.\n");
3151 if (lwp_in_step_range (event_child))
3152 debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).\n",
3153 paddress (event_child->stop_pc),
3154 paddress (event_child->step_range_start),
3155 paddress (event_child->step_range_end));
3156 if (extended_event_reported (&event_child->waitstatus))
3158 char *str = target_waitstatus_to_string (ourstatus);
3159 debug_printf ("LWP %ld: extended event with waitstatus %s\n",
3160 lwpid_of (get_lwp_thread (event_child)), str);
3165 /* We're not reporting this breakpoint to GDB, so apply the
3166 decr_pc_after_break adjustment to the inferior's regcache
3169 if (the_low_target.set_pc != NULL)
3171 struct regcache *regcache
3172 = get_thread_regcache (current_thread, 1);
3173 (*the_low_target.set_pc) (regcache, event_child->stop_pc);
3176 /* We may have finished stepping over a breakpoint. If so,
3177 we've stopped and suspended all LWPs momentarily except the
3178 stepping one. This is where we resume them all again. We're
3179 going to keep waiting, so use proceed, which handles stepping
3180 over the next breakpoint. */
3182 debug_printf ("proceeding all threads.\n");
3184 if (step_over_finished)
3185 unsuspend_all_lwps (event_child);
3187 proceed_all_lwps ();
3188 return ignore_event (ourstatus);
3193 if (current_thread->last_resume_kind == resume_step)
3195 if (event_child->step_range_start == event_child->step_range_end)
3196 debug_printf ("GDB wanted to single-step, reporting event.\n");
3197 else if (!lwp_in_step_range (event_child))
3198 debug_printf ("Out of step range, reporting event.\n");
3200 if (event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT)
3201 debug_printf ("Stopped by watchpoint.\n");
3202 else if (gdb_breakpoint_here (event_child->stop_pc))
3203 debug_printf ("Stopped by GDB breakpoint.\n");
3205 debug_printf ("Hit a non-gdbserver trap event.\n");
3208 /* Alright, we're going to report a stop. */
3210 if (!stabilizing_threads)
3212 /* In all-stop, stop all threads. */
3214 stop_all_lwps (0, NULL);
3216 /* If we're not waiting for a specific LWP, choose an event LWP
3217 from among those that have had events. Giving equal priority
3218 to all LWPs that have had events helps prevent
3220 if (ptid_equal (ptid, minus_one_ptid))
3222 event_child->status_pending_p = 1;
3223 event_child->status_pending = w;
3225 select_event_lwp (&event_child);
3227 /* current_thread and event_child must stay in sync. */
3228 current_thread = get_lwp_thread (event_child);
3230 event_child->status_pending_p = 0;
3231 w = event_child->status_pending;
3234 if (step_over_finished)
3238 /* If we were doing a step-over, all other threads but
3239 the stepping one had been paused in start_step_over,
3240 with their suspend counts incremented. We don't want
3241 to do a full unstop/unpause, because we're in
3242 all-stop mode (so we want threads stopped), but we
3243 still need to unsuspend the other threads, to
3244 decrement their `suspended' count back. */
3245 unsuspend_all_lwps (event_child);
3249 /* If we just finished a step-over, then all threads had
3250 been momentarily paused. In all-stop, that's fine,
3251 we want threads stopped by now anyway. In non-stop,
3252 we need to re-resume threads that GDB wanted to be
3254 unstop_all_lwps (1, event_child);
3258 /* Stabilize threads (move out of jump pads). */
3260 stabilize_threads ();
3264 /* If we just finished a step-over, then all threads had been
3265 momentarily paused. In all-stop, that's fine, we want
3266 threads stopped by now anyway. In non-stop, we need to
3267 re-resume threads that GDB wanted to be running. */
3268 if (step_over_finished)
3269 unstop_all_lwps (1, event_child);
3272 if (extended_event_reported (&event_child->waitstatus))
3274 /* If the reported event is a fork, vfork or exec, let GDB know. */
3275 ourstatus->kind = event_child->waitstatus.kind;
3276 ourstatus->value = event_child->waitstatus.value;
3278 /* Clear the event lwp's waitstatus since we handled it already. */
3279 event_child->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3282 ourstatus->kind = TARGET_WAITKIND_STOPPED;
3284 /* Now that we've selected our final event LWP, un-adjust its PC if
3285 it was a software breakpoint, and the client doesn't know we can
3286 adjust the breakpoint ourselves. */
3287 if (event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3288 && !swbreak_feature)
3290 int decr_pc = the_low_target.decr_pc_after_break;
3294 struct regcache *regcache
3295 = get_thread_regcache (current_thread, 1);
3296 (*the_low_target.set_pc) (regcache, event_child->stop_pc + decr_pc);
3300 if (current_thread->last_resume_kind == resume_stop
3301 && WSTOPSIG (w) == SIGSTOP)
3303 /* A thread that has been requested to stop by GDB with vCont;t,
3304 and it stopped cleanly, so report as SIG0. The use of
3305 SIGSTOP is an implementation detail. */
3306 ourstatus->value.sig = GDB_SIGNAL_0;
3308 else if (current_thread->last_resume_kind == resume_stop
3309 && WSTOPSIG (w) != SIGSTOP)
3311 /* A thread that has been requested to stop by GDB with vCont;t,
3312 but, it stopped for other reasons. */
3313 ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
3315 else if (ourstatus->kind == TARGET_WAITKIND_STOPPED)
3317 ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
3320 gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
3324 debug_printf ("linux_wait_1 ret = %s, %d, %d\n",
3325 target_pid_to_str (ptid_of (current_thread)),
3326 ourstatus->kind, ourstatus->value.sig);
3330 return ptid_of (current_thread);
3333 /* Get rid of any pending event in the pipe. */
3335 async_file_flush (void)
3341 ret = read (linux_event_pipe[0], &buf, 1);
3342 while (ret >= 0 || (ret == -1 && errno == EINTR));
3345 /* Put something in the pipe, so the event loop wakes up. */
3347 async_file_mark (void)
3351 async_file_flush ();
3354 ret = write (linux_event_pipe[1], "+", 1);
3355 while (ret == 0 || (ret == -1 && errno == EINTR));
3357 /* Ignore EAGAIN. If the pipe is full, the event loop will already
3358 be awakened anyway. */
3362 linux_wait (ptid_t ptid,
3363 struct target_waitstatus *ourstatus, int target_options)
3367 /* Flush the async file first. */
3368 if (target_is_async_p ())
3369 async_file_flush ();
3373 event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
3375 while ((target_options & TARGET_WNOHANG) == 0
3376 && ptid_equal (event_ptid, null_ptid)
3377 && ourstatus->kind == TARGET_WAITKIND_IGNORE);
3379 /* If at least one stop was reported, there may be more. A single
3380 SIGCHLD can signal more than one child stop. */
3381 if (target_is_async_p ()
3382 && (target_options & TARGET_WNOHANG) != 0
3383 && !ptid_equal (event_ptid, null_ptid))
3389 /* Send a signal to an LWP. */
3392 kill_lwp (unsigned long lwpid, int signo)
3394 /* Use tkill, if possible, in case we are using nptl threads. If tkill
3395 fails, then we are not using nptl threads and we should be using kill. */
3399 static int tkill_failed;
3406 ret = syscall (__NR_tkill, lwpid, signo);
3407 if (errno != ENOSYS)
3414 return kill (lwpid, signo);
3418 linux_stop_lwp (struct lwp_info *lwp)
3424 send_sigstop (struct lwp_info *lwp)
3428 pid = lwpid_of (get_lwp_thread (lwp));
3430 /* If we already have a pending stop signal for this process, don't
3432 if (lwp->stop_expected)
3435 debug_printf ("Have pending sigstop for lwp %d\n", pid);
3441 debug_printf ("Sending sigstop to lwp %d\n", pid);
3443 lwp->stop_expected = 1;
3444 kill_lwp (pid, SIGSTOP);
3448 send_sigstop_callback (struct inferior_list_entry *entry, void *except)
3450 struct thread_info *thread = (struct thread_info *) entry;
3451 struct lwp_info *lwp = get_thread_lwp (thread);
3453 /* Ignore EXCEPT. */
3464 /* Increment the suspend count of an LWP, and stop it, if not stopped
3467 suspend_and_send_sigstop_callback (struct inferior_list_entry *entry,
3470 struct thread_info *thread = (struct thread_info *) entry;
3471 struct lwp_info *lwp = get_thread_lwp (thread);
3473 /* Ignore EXCEPT. */
3479 return send_sigstop_callback (entry, except);
3483 mark_lwp_dead (struct lwp_info *lwp, int wstat)
3485 /* It's dead, really. */
3488 /* Store the exit status for later. */
3489 lwp->status_pending_p = 1;
3490 lwp->status_pending = wstat;
3492 /* Prevent trying to stop it. */
3495 /* No further stops are expected from a dead lwp. */
3496 lwp->stop_expected = 0;
3499 /* Wait for all children to stop for the SIGSTOPs we just queued. */
3502 wait_for_sigstop (void)
3504 struct thread_info *saved_thread;
3509 saved_thread = current_thread;
3510 if (saved_thread != NULL)
3511 saved_tid = saved_thread->entry.id;
3513 saved_tid = null_ptid; /* avoid bogus unused warning */
3516 debug_printf ("wait_for_sigstop: pulling events\n");
3518 /* Passing NULL_PTID as filter indicates we want all events to be
3519 left pending. Eventually this returns when there are no
3520 unwaited-for children left. */
3521 ret = linux_wait_for_event_filtered (minus_one_ptid, null_ptid,
3523 gdb_assert (ret == -1);
3525 if (saved_thread == NULL || linux_thread_alive (saved_tid))
3526 current_thread = saved_thread;
3530 debug_printf ("Previously current thread died.\n");
3534 /* We can't change the current inferior behind GDB's back,
3535 otherwise, a subsequent command may apply to the wrong
3537 current_thread = NULL;
3541 /* Set a valid thread as current. */
3542 set_desired_thread (0);
3547 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
3548 move it out, because we need to report the stop event to GDB. For
3549 example, if the user puts a breakpoint in the jump pad, it's
3550 because she wants to debug it. */
3553 stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data)
3555 struct thread_info *thread = (struct thread_info *) entry;
3556 struct lwp_info *lwp = get_thread_lwp (thread);
3558 gdb_assert (lwp->suspended == 0);
3559 gdb_assert (lwp->stopped);
3561 /* Allow debugging the jump pad, gdb_collect, etc.. */
3562 return (supports_fast_tracepoints ()
3563 && agent_loaded_p ()
3564 && (gdb_breakpoint_here (lwp->stop_pc)
3565 || lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT
3566 || thread->last_resume_kind == resume_step)
3567 && linux_fast_tracepoint_collecting (lwp, NULL));
3571 move_out_of_jump_pad_callback (struct inferior_list_entry *entry)
3573 struct thread_info *thread = (struct thread_info *) entry;
3574 struct lwp_info *lwp = get_thread_lwp (thread);
3577 gdb_assert (lwp->suspended == 0);
3578 gdb_assert (lwp->stopped);
3580 wstat = lwp->status_pending_p ? &lwp->status_pending : NULL;
3582 /* Allow debugging the jump pad, gdb_collect, etc. */
3583 if (!gdb_breakpoint_here (lwp->stop_pc)
3584 && lwp->stop_reason != TARGET_STOPPED_BY_WATCHPOINT
3585 && thread->last_resume_kind != resume_step
3586 && maybe_move_out_of_jump_pad (lwp, wstat))
3589 debug_printf ("LWP %ld needs stabilizing (in jump pad)\n",
3594 lwp->status_pending_p = 0;
3595 enqueue_one_deferred_signal (lwp, wstat);
3598 debug_printf ("Signal %d for LWP %ld deferred "
3600 WSTOPSIG (*wstat), lwpid_of (thread));
3603 linux_resume_one_lwp (lwp, 0, 0, NULL);
3610 lwp_running (struct inferior_list_entry *entry, void *data)
3612 struct thread_info *thread = (struct thread_info *) entry;
3613 struct lwp_info *lwp = get_thread_lwp (thread);
3622 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
3623 If SUSPEND, then also increase the suspend count of every LWP,
3627 stop_all_lwps (int suspend, struct lwp_info *except)
3629 /* Should not be called recursively. */
3630 gdb_assert (stopping_threads == NOT_STOPPING_THREADS);
3635 debug_printf ("stop_all_lwps (%s, except=%s)\n",
3636 suspend ? "stop-and-suspend" : "stop",
3638 ? target_pid_to_str (ptid_of (get_lwp_thread (except)))
3642 stopping_threads = (suspend
3643 ? STOPPING_AND_SUSPENDING_THREADS
3644 : STOPPING_THREADS);
3647 find_inferior (&all_threads, suspend_and_send_sigstop_callback, except);
3649 find_inferior (&all_threads, send_sigstop_callback, except);
3650 wait_for_sigstop ();
3651 stopping_threads = NOT_STOPPING_THREADS;
3655 debug_printf ("stop_all_lwps done, setting stopping_threads "
3656 "back to !stopping\n");
3661 /* Resume execution of LWP. If STEP is nonzero, single-step it. If
3662 SIGNAL is nonzero, give it that signal. */
3665 linux_resume_one_lwp_throw (struct lwp_info *lwp,
3666 int step, int signal, siginfo_t *info)
3668 struct thread_info *thread = get_lwp_thread (lwp);
3669 struct thread_info *saved_thread;
3670 int fast_tp_collecting;
3671 struct process_info *proc = get_thread_process (thread);
3673 /* Note that target description may not be initialised
3674 (proc->tdesc == NULL) at this point because the program hasn't
3675 stopped at the first instruction yet. It means GDBserver skips
3676 the extra traps from the wrapper program (see option --wrapper).
3677 Code in this function that requires register access should be
3678 guarded by proc->tdesc == NULL or something else. */
3680 if (lwp->stopped == 0)
3683 fast_tp_collecting = lwp->collecting_fast_tracepoint;
3685 gdb_assert (!stabilizing_threads || fast_tp_collecting);
3687 /* Cancel actions that rely on GDB not changing the PC (e.g., the
3688 user used the "jump" command, or "set $pc = foo"). */
3689 if (thread->while_stepping != NULL && lwp->stop_pc != get_pc (lwp))
3691 /* Collecting 'while-stepping' actions doesn't make sense
3693 release_while_stepping_state_list (thread);
3696 /* If we have pending signals or status, and a new signal, enqueue the
3697 signal. Also enqueue the signal if we are waiting to reinsert a
3698 breakpoint; it will be picked up again below. */
3700 && (lwp->status_pending_p
3701 || lwp->pending_signals != NULL
3702 || lwp->bp_reinsert != 0
3703 || fast_tp_collecting))
3705 struct pending_signals *p_sig;
3706 p_sig = xmalloc (sizeof (*p_sig));
3707 p_sig->prev = lwp->pending_signals;
3708 p_sig->signal = signal;
3710 memset (&p_sig->info, 0, sizeof (siginfo_t));
3712 memcpy (&p_sig->info, info, sizeof (siginfo_t));
3713 lwp->pending_signals = p_sig;
3716 if (lwp->status_pending_p)
3719 debug_printf ("Not resuming lwp %ld (%s, signal %d, stop %s);"
3720 " has pending status\n",
3721 lwpid_of (thread), step ? "step" : "continue", signal,
3722 lwp->stop_expected ? "expected" : "not expected");
3726 saved_thread = current_thread;
3727 current_thread = thread;
3730 debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n",
3731 lwpid_of (thread), step ? "step" : "continue", signal,
3732 lwp->stop_expected ? "expected" : "not expected");
3734 /* This bit needs some thinking about. If we get a signal that
3735 we must report while a single-step reinsert is still pending,
3736 we often end up resuming the thread. It might be better to
3737 (ew) allow a stack of pending events; then we could be sure that
3738 the reinsert happened right away and not lose any signals.
3740 Making this stack would also shrink the window in which breakpoints are
3741 uninserted (see comment in linux_wait_for_lwp) but not enough for
3742 complete correctness, so it won't solve that problem. It may be
3743 worthwhile just to solve this one, however. */
3744 if (lwp->bp_reinsert != 0)
3747 debug_printf (" pending reinsert at 0x%s\n",
3748 paddress (lwp->bp_reinsert));
3750 if (can_hardware_single_step ())
3752 if (fast_tp_collecting == 0)
3755 fprintf (stderr, "BAD - reinserting but not stepping.\n");
3757 fprintf (stderr, "BAD - reinserting and suspended(%d).\n",
3764 /* Postpone any pending signal. It was enqueued above. */
3768 if (fast_tp_collecting == 1)
3771 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
3772 " (exit-jump-pad-bkpt)\n",
3775 /* Postpone any pending signal. It was enqueued above. */
3778 else if (fast_tp_collecting == 2)
3781 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
3782 " single-stepping\n",
3785 if (can_hardware_single_step ())
3789 internal_error (__FILE__, __LINE__,
3790 "moving out of jump pad single-stepping"
3791 " not implemented on this target");
3794 /* Postpone any pending signal. It was enqueued above. */
3798 /* If we have while-stepping actions in this thread set it stepping.
3799 If we have a signal to deliver, it may or may not be set to
3800 SIG_IGN, we don't know. Assume so, and allow collecting
3801 while-stepping into a signal handler. A possible smart thing to
3802 do would be to set an internal breakpoint at the signal return
3803 address, continue, and carry on catching this while-stepping
3804 action only when that breakpoint is hit. A future
3806 if (thread->while_stepping != NULL
3807 && can_hardware_single_step ())
3810 debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n",
3815 if (proc->tdesc != NULL && the_low_target.get_pc != NULL)
3817 struct regcache *regcache = get_thread_regcache (current_thread, 1);
3819 lwp->stop_pc = (*the_low_target.get_pc) (regcache);
3823 debug_printf (" %s from pc 0x%lx\n", step ? "step" : "continue",
3824 (long) lwp->stop_pc);
3828 /* If we have pending signals, consume one unless we are trying to
3829 reinsert a breakpoint or we're trying to finish a fast tracepoint
3831 if (lwp->pending_signals != NULL
3832 && lwp->bp_reinsert == 0
3833 && fast_tp_collecting == 0)
3835 struct pending_signals **p_sig;
3837 p_sig = &lwp->pending_signals;
3838 while ((*p_sig)->prev != NULL)
3839 p_sig = &(*p_sig)->prev;
3841 signal = (*p_sig)->signal;
3842 if ((*p_sig)->info.si_signo != 0)
3843 ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
3850 if (the_low_target.prepare_to_resume != NULL)
3851 the_low_target.prepare_to_resume (lwp);
3853 regcache_invalidate_thread (thread);
3855 lwp->stepping = step;
3856 ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (thread),
3857 (PTRACE_TYPE_ARG3) 0,
3858 /* Coerce to a uintptr_t first to avoid potential gcc warning
3859 of coercing an 8 byte integer to a 4 byte pointer. */
3860 (PTRACE_TYPE_ARG4) (uintptr_t) signal);
3862 current_thread = saved_thread;
3864 perror_with_name ("resuming thread");
3866 /* Successfully resumed. Clear state that no longer makes sense,
3867 and mark the LWP as running. Must not do this before resuming
3868 otherwise if that fails other code will be confused. E.g., we'd
3869 later try to stop the LWP and hang forever waiting for a stop
3870 status. Note that we must not throw after this is cleared,
3871 otherwise handle_zombie_lwp_error would get confused. */
3873 lwp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
3876 /* Called when we try to resume a stopped LWP and that errors out. If
3877 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
3878 or about to become), discard the error, clear any pending status
3879 the LWP may have, and return true (we'll collect the exit status
3880 soon enough). Otherwise, return false. */
3883 check_ptrace_stopped_lwp_gone (struct lwp_info *lp)
3885 struct thread_info *thread = get_lwp_thread (lp);
3887 /* If we get an error after resuming the LWP successfully, we'd
3888 confuse !T state for the LWP being gone. */
3889 gdb_assert (lp->stopped);
3891 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
3892 because even if ptrace failed with ESRCH, the tracee may be "not
3893 yet fully dead", but already refusing ptrace requests. In that
3894 case the tracee has 'R (Running)' state for a little bit
3895 (observed in Linux 3.18). See also the note on ESRCH in the
3896 ptrace(2) man page. Instead, check whether the LWP has any state
3897 other than ptrace-stopped. */
3899 /* Don't assume anything if /proc/PID/status can't be read. */
3900 if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread)) == 0)
3902 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
3903 lp->status_pending_p = 0;
3909 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
3910 disappears while we try to resume it. */
3913 linux_resume_one_lwp (struct lwp_info *lwp,
3914 int step, int signal, siginfo_t *info)
3918 linux_resume_one_lwp_throw (lwp, step, signal, info);
3920 CATCH (ex, RETURN_MASK_ERROR)
3922 if (!check_ptrace_stopped_lwp_gone (lwp))
3923 throw_exception (ex);
3928 struct thread_resume_array
3930 struct thread_resume *resume;
3934 /* This function is called once per thread via find_inferior.
3935 ARG is a pointer to a thread_resume_array struct.
3936 We look up the thread specified by ENTRY in ARG, and mark the thread
3937 with a pointer to the appropriate resume request.
3939 This algorithm is O(threads * resume elements), but resume elements
3940 is small (and will remain small at least until GDB supports thread
3944 linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
3946 struct thread_info *thread = (struct thread_info *) entry;
3947 struct lwp_info *lwp = get_thread_lwp (thread);
3949 struct thread_resume_array *r;
3953 for (ndx = 0; ndx < r->n; ndx++)
3955 ptid_t ptid = r->resume[ndx].thread;
3956 if (ptid_equal (ptid, minus_one_ptid)
3957 || ptid_equal (ptid, entry->id)
3958 /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads
3960 || (ptid_get_pid (ptid) == pid_of (thread)
3961 && (ptid_is_pid (ptid)
3962 || ptid_get_lwp (ptid) == -1)))
3964 if (r->resume[ndx].kind == resume_stop
3965 && thread->last_resume_kind == resume_stop)
3968 debug_printf ("already %s LWP %ld at GDB's request\n",
3969 (thread->last_status.kind
3970 == TARGET_WAITKIND_STOPPED)
3978 lwp->resume = &r->resume[ndx];
3979 thread->last_resume_kind = lwp->resume->kind;
3981 lwp->step_range_start = lwp->resume->step_range_start;
3982 lwp->step_range_end = lwp->resume->step_range_end;
3984 /* If we had a deferred signal to report, dequeue one now.
3985 This can happen if LWP gets more than one signal while
3986 trying to get out of a jump pad. */
3988 && !lwp->status_pending_p
3989 && dequeue_one_deferred_signal (lwp, &lwp->status_pending))
3991 lwp->status_pending_p = 1;
3994 debug_printf ("Dequeueing deferred signal %d for LWP %ld, "
3995 "leaving status pending.\n",
3996 WSTOPSIG (lwp->status_pending),
4004 /* No resume action for this thread. */
4010 /* find_inferior callback for linux_resume.
4011 Set *FLAG_P if this lwp has an interesting status pending. */
4014 resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
4016 struct thread_info *thread = (struct thread_info *) entry;
4017 struct lwp_info *lwp = get_thread_lwp (thread);
4019 /* LWPs which will not be resumed are not interesting, because
4020 we might not wait for them next time through linux_wait. */
4021 if (lwp->resume == NULL)
4024 if (thread_still_has_status_pending_p (thread))
4025 * (int *) flag_p = 1;
4030 /* Return 1 if this lwp that GDB wants running is stopped at an
4031 internal breakpoint that we need to step over. It assumes that any
4032 required STOP_PC adjustment has already been propagated to the
4033 inferior's regcache. */
4036 need_step_over_p (struct inferior_list_entry *entry, void *dummy)
4038 struct thread_info *thread = (struct thread_info *) entry;
4039 struct lwp_info *lwp = get_thread_lwp (thread);
4040 struct thread_info *saved_thread;
4042 struct process_info *proc = get_thread_process (thread);
4044 /* GDBserver is skipping the extra traps from the wrapper program,
4045 don't have to do step over. */
4046 if (proc->tdesc == NULL)
4049 /* LWPs which will not be resumed are not interesting, because we
4050 might not wait for them next time through linux_wait. */
4055 debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped\n",
4060 if (thread->last_resume_kind == resume_stop)
4063 debug_printf ("Need step over [LWP %ld]? Ignoring, should remain"
4069 gdb_assert (lwp->suspended >= 0);
4074 debug_printf ("Need step over [LWP %ld]? Ignoring, suspended\n",
4079 if (!lwp->need_step_over)
4082 debug_printf ("Need step over [LWP %ld]? No\n", lwpid_of (thread));
4085 if (lwp->status_pending_p)
4088 debug_printf ("Need step over [LWP %ld]? Ignoring, has pending"
4094 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
4098 /* If the PC has changed since we stopped, then don't do anything,
4099 and let the breakpoint/tracepoint be hit. This happens if, for
4100 instance, GDB handled the decr_pc_after_break subtraction itself,
4101 GDB is OOL stepping this thread, or the user has issued a "jump"
4102 command, or poked thread's registers herself. */
4103 if (pc != lwp->stop_pc)
4106 debug_printf ("Need step over [LWP %ld]? Cancelling, PC was changed. "
4107 "Old stop_pc was 0x%s, PC is now 0x%s\n",
4109 paddress (lwp->stop_pc), paddress (pc));
4111 lwp->need_step_over = 0;
4115 saved_thread = current_thread;
4116 current_thread = thread;
4118 /* We can only step over breakpoints we know about. */
4119 if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc))
4121 /* Don't step over a breakpoint that GDB expects to hit
4122 though. If the condition is being evaluated on the target's side
4123 and it evaluate to false, step over this breakpoint as well. */
4124 if (gdb_breakpoint_here (pc)
4125 && gdb_condition_true_at_breakpoint (pc)
4126 && gdb_no_commands_at_breakpoint (pc))
4129 debug_printf ("Need step over [LWP %ld]? yes, but found"
4130 " GDB breakpoint at 0x%s; skipping step over\n",
4131 lwpid_of (thread), paddress (pc));
4133 current_thread = saved_thread;
4139 debug_printf ("Need step over [LWP %ld]? yes, "
4140 "found breakpoint at 0x%s\n",
4141 lwpid_of (thread), paddress (pc));
4143 /* We've found an lwp that needs stepping over --- return 1 so
4144 that find_inferior stops looking. */
4145 current_thread = saved_thread;
4147 /* If the step over is cancelled, this is set again. */
4148 lwp->need_step_over = 0;
4153 current_thread = saved_thread;
4156 debug_printf ("Need step over [LWP %ld]? No, no breakpoint found"
4158 lwpid_of (thread), paddress (pc));
4163 /* Start a step-over operation on LWP. When LWP stopped at a
4164 breakpoint, to make progress, we need to remove the breakpoint out
4165 of the way. If we let other threads run while we do that, they may
4166 pass by the breakpoint location and miss hitting it. To avoid
4167 that, a step-over momentarily stops all threads while LWP is
4168 single-stepped while the breakpoint is temporarily uninserted from
4169 the inferior. When the single-step finishes, we reinsert the
4170 breakpoint, and let all threads that are supposed to be running,
4173 On targets that don't support hardware single-step, we don't
4174 currently support full software single-stepping. Instead, we only
4175 support stepping over the thread event breakpoint, by asking the
4176 low target where to place a reinsert breakpoint. Since this
4177 routine assumes the breakpoint being stepped over is a thread event
4178 breakpoint, it usually assumes the return address of the current
4179 function is a good enough place to set the reinsert breakpoint. */
4182 start_step_over (struct lwp_info *lwp)
4184 struct thread_info *thread = get_lwp_thread (lwp);
4185 struct thread_info *saved_thread;
4190 debug_printf ("Starting step-over on LWP %ld. Stopping all threads\n",
4193 stop_all_lwps (1, lwp);
4194 gdb_assert (lwp->suspended == 0);
4197 debug_printf ("Done stopping all threads for step-over.\n");
4199 /* Note, we should always reach here with an already adjusted PC,
4200 either by GDB (if we're resuming due to GDB's request), or by our
4201 caller, if we just finished handling an internal breakpoint GDB
4202 shouldn't care about. */
4205 saved_thread = current_thread;
4206 current_thread = thread;
4208 lwp->bp_reinsert = pc;
4209 uninsert_breakpoints_at (pc);
4210 uninsert_fast_tracepoint_jumps_at (pc);
4212 if (can_hardware_single_step ())
4218 CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
4219 set_reinsert_breakpoint (raddr);
4223 current_thread = saved_thread;
4225 linux_resume_one_lwp (lwp, step, 0, NULL);
4227 /* Require next event from this LWP. */
4228 step_over_bkpt = thread->entry.id;
4232 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
4233 start_step_over, if still there, and delete any reinsert
4234 breakpoints we've set, on non hardware single-step targets. */
4237 finish_step_over (struct lwp_info *lwp)
4239 if (lwp->bp_reinsert != 0)
4242 debug_printf ("Finished step over.\n");
4244 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
4245 may be no breakpoint to reinsert there by now. */
4246 reinsert_breakpoints_at (lwp->bp_reinsert);
4247 reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert);
4249 lwp->bp_reinsert = 0;
4251 /* Delete any software-single-step reinsert breakpoints. No
4252 longer needed. We don't have to worry about other threads
4253 hitting this trap, and later not being able to explain it,
4254 because we were stepping over a breakpoint, and we hold all
4255 threads but LWP stopped while doing that. */
4256 if (!can_hardware_single_step ())
4257 delete_reinsert_breakpoints ();
4259 step_over_bkpt = null_ptid;
4266 /* This function is called once per thread. We check the thread's resume
4267 request, which will tell us whether to resume, step, or leave the thread
4268 stopped; and what signal, if any, it should be sent.
4270 For threads which we aren't explicitly told otherwise, we preserve
4271 the stepping flag; this is used for stepping over gdbserver-placed
4274 If pending_flags was set in any thread, we queue any needed
4275 signals, since we won't actually resume. We already have a pending
4276 event to report, so we don't need to preserve any step requests;
4277 they should be re-issued if necessary. */
4280 linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
4282 struct thread_info *thread = (struct thread_info *) entry;
4283 struct lwp_info *lwp = get_thread_lwp (thread);
4285 int leave_all_stopped = * (int *) arg;
4288 if (lwp->resume == NULL)
4291 if (lwp->resume->kind == resume_stop)
4294 debug_printf ("resume_stop request for LWP %ld\n", lwpid_of (thread));
4299 debug_printf ("stopping LWP %ld\n", lwpid_of (thread));
4301 /* Stop the thread, and wait for the event asynchronously,
4302 through the event loop. */
4308 debug_printf ("already stopped LWP %ld\n",
4311 /* The LWP may have been stopped in an internal event that
4312 was not meant to be notified back to GDB (e.g., gdbserver
4313 breakpoint), so we should be reporting a stop event in
4316 /* If the thread already has a pending SIGSTOP, this is a
4317 no-op. Otherwise, something later will presumably resume
4318 the thread and this will cause it to cancel any pending
4319 operation, due to last_resume_kind == resume_stop. If
4320 the thread already has a pending status to report, we
4321 will still report it the next time we wait - see
4322 status_pending_p_callback. */
4324 /* If we already have a pending signal to report, then
4325 there's no need to queue a SIGSTOP, as this means we're
4326 midway through moving the LWP out of the jumppad, and we
4327 will report the pending signal as soon as that is
4329 if (lwp->pending_signals_to_report == NULL)
4333 /* For stop requests, we're done. */
4335 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
4339 /* If this thread which is about to be resumed has a pending status,
4340 then don't resume any threads - we can just report the pending
4341 status. Make sure to queue any signals that would otherwise be
4342 sent. In all-stop mode, we do this decision based on if *any*
4343 thread has a pending status. If there's a thread that needs the
4344 step-over-breakpoint dance, then don't resume any other thread
4345 but that particular one. */
4346 leave_pending = (lwp->status_pending_p || leave_all_stopped);
4351 debug_printf ("resuming LWP %ld\n", lwpid_of (thread));
4353 step = (lwp->resume->kind == resume_step);
4354 linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
4359 debug_printf ("leaving LWP %ld stopped\n", lwpid_of (thread));
4361 /* If we have a new signal, enqueue the signal. */
4362 if (lwp->resume->sig != 0)
4364 struct pending_signals *p_sig;
4365 p_sig = xmalloc (sizeof (*p_sig));
4366 p_sig->prev = lwp->pending_signals;
4367 p_sig->signal = lwp->resume->sig;
4368 memset (&p_sig->info, 0, sizeof (siginfo_t));
4370 /* If this is the same signal we were previously stopped by,
4371 make sure to queue its siginfo. We can ignore the return
4372 value of ptrace; if it fails, we'll skip
4373 PTRACE_SETSIGINFO. */
4374 if (WIFSTOPPED (lwp->last_status)
4375 && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
4376 ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
4379 lwp->pending_signals = p_sig;
4383 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
4389 linux_resume (struct thread_resume *resume_info, size_t n)
4391 struct thread_resume_array array = { resume_info, n };
4392 struct thread_info *need_step_over = NULL;
4394 int leave_all_stopped;
4399 debug_printf ("linux_resume:\n");
4402 find_inferior (&all_threads, linux_set_resume_request, &array);
4404 /* If there is a thread which would otherwise be resumed, which has
4405 a pending status, then don't resume any threads - we can just
4406 report the pending status. Make sure to queue any signals that
4407 would otherwise be sent. In non-stop mode, we'll apply this
4408 logic to each thread individually. We consume all pending events
4409 before considering to start a step-over (in all-stop). */
4412 find_inferior (&all_threads, resume_status_pending_p, &any_pending);
4414 /* If there is a thread which would otherwise be resumed, which is
4415 stopped at a breakpoint that needs stepping over, then don't
4416 resume any threads - have it step over the breakpoint with all
4417 other threads stopped, then resume all threads again. Make sure
4418 to queue any signals that would otherwise be delivered or
4420 if (!any_pending && supports_breakpoints ())
4422 = (struct thread_info *) find_inferior (&all_threads,
4423 need_step_over_p, NULL);
4425 leave_all_stopped = (need_step_over != NULL || any_pending);
4429 if (need_step_over != NULL)
4430 debug_printf ("Not resuming all, need step over\n");
4431 else if (any_pending)
4432 debug_printf ("Not resuming, all-stop and found "
4433 "an LWP with pending status\n");
4435 debug_printf ("Resuming, no pending status or step over needed\n");
4438 /* Even if we're leaving threads stopped, queue all signals we'd
4439 otherwise deliver. */
4440 find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped);
4443 start_step_over (get_thread_lwp (need_step_over));
4447 debug_printf ("linux_resume done\n");
4452 /* This function is called once per thread. We check the thread's
4453 last resume request, which will tell us whether to resume, step, or
4454 leave the thread stopped. Any signal the client requested to be
4455 delivered has already been enqueued at this point.
4457 If any thread that GDB wants running is stopped at an internal
4458 breakpoint that needs stepping over, we start a step-over operation
4459 on that particular thread, and leave all others stopped. */
4462 proceed_one_lwp (struct inferior_list_entry *entry, void *except)
4464 struct thread_info *thread = (struct thread_info *) entry;
4465 struct lwp_info *lwp = get_thread_lwp (thread);
4472 debug_printf ("proceed_one_lwp: lwp %ld\n", lwpid_of (thread));
4477 debug_printf (" LWP %ld already running\n", lwpid_of (thread));
4481 if (thread->last_resume_kind == resume_stop
4482 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
4485 debug_printf (" client wants LWP to remain %ld stopped\n",
4490 if (lwp->status_pending_p)
4493 debug_printf (" LWP %ld has pending status, leaving stopped\n",
4498 gdb_assert (lwp->suspended >= 0);
4503 debug_printf (" LWP %ld is suspended\n", lwpid_of (thread));
4507 if (thread->last_resume_kind == resume_stop
4508 && lwp->pending_signals_to_report == NULL
4509 && lwp->collecting_fast_tracepoint == 0)
4511 /* We haven't reported this LWP as stopped yet (otherwise, the
4512 last_status.kind check above would catch it, and we wouldn't
4513 reach here. This LWP may have been momentarily paused by a
4514 stop_all_lwps call while handling for example, another LWP's
4515 step-over. In that case, the pending expected SIGSTOP signal
4516 that was queued at vCont;t handling time will have already
4517 been consumed by wait_for_sigstop, and so we need to requeue
4518 another one here. Note that if the LWP already has a SIGSTOP
4519 pending, this is a no-op. */
4522 debug_printf ("Client wants LWP %ld to stop. "
4523 "Making sure it has a SIGSTOP pending\n",
4529 step = thread->last_resume_kind == resume_step;
4530 linux_resume_one_lwp (lwp, step, 0, NULL);
4535 unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except)
4537 struct thread_info *thread = (struct thread_info *) entry;
4538 struct lwp_info *lwp = get_thread_lwp (thread);
4544 gdb_assert (lwp->suspended >= 0);
4546 return proceed_one_lwp (entry, except);
4549 /* When we finish a step-over, set threads running again. If there's
4550 another thread that may need a step-over, now's the time to start
4551 it. Eventually, we'll move all threads past their breakpoints. */
4554 proceed_all_lwps (void)
4556 struct thread_info *need_step_over;
4558 /* If there is a thread which would otherwise be resumed, which is
4559 stopped at a breakpoint that needs stepping over, then don't
4560 resume any threads - have it step over the breakpoint with all
4561 other threads stopped, then resume all threads again. */
4563 if (supports_breakpoints ())
4566 = (struct thread_info *) find_inferior (&all_threads,
4567 need_step_over_p, NULL);
4569 if (need_step_over != NULL)
4572 debug_printf ("proceed_all_lwps: found "
4573 "thread %ld needing a step-over\n",
4574 lwpid_of (need_step_over));
4576 start_step_over (get_thread_lwp (need_step_over));
4582 debug_printf ("Proceeding, no step-over needed\n");
4584 find_inferior (&all_threads, proceed_one_lwp, NULL);
4587 /* Stopped LWPs that the client wanted to be running, that don't have
4588 pending statuses, are set to run again, except for EXCEPT, if not
4589 NULL. This undoes a stop_all_lwps call. */
4592 unstop_all_lwps (int unsuspend, struct lwp_info *except)
4598 debug_printf ("unstopping all lwps, except=(LWP %ld)\n",
4599 lwpid_of (get_lwp_thread (except)));
4601 debug_printf ("unstopping all lwps\n");
4605 find_inferior (&all_threads, unsuspend_and_proceed_one_lwp, except);
4607 find_inferior (&all_threads, proceed_one_lwp, except);
4611 debug_printf ("unstop_all_lwps done\n");
4617 #ifdef HAVE_LINUX_REGSETS
4619 #define use_linux_regsets 1
4621 /* Returns true if REGSET has been disabled. */
4624 regset_disabled (struct regsets_info *info, struct regset_info *regset)
4626 return (info->disabled_regsets != NULL
4627 && info->disabled_regsets[regset - info->regsets]);
4630 /* Disable REGSET. */
4633 disable_regset (struct regsets_info *info, struct regset_info *regset)
4637 dr_offset = regset - info->regsets;
4638 if (info->disabled_regsets == NULL)
4639 info->disabled_regsets = xcalloc (1, info->num_regsets);
4640 info->disabled_regsets[dr_offset] = 1;
4644 regsets_fetch_inferior_registers (struct regsets_info *regsets_info,
4645 struct regcache *regcache)
4647 struct regset_info *regset;
4648 int saw_general_regs = 0;
4652 pid = lwpid_of (current_thread);
4653 for (regset = regsets_info->regsets; regset->size >= 0; regset++)
4658 if (regset->size == 0 || regset_disabled (regsets_info, regset))
4661 buf = xmalloc (regset->size);
4663 nt_type = regset->nt_type;
4667 iov.iov_len = regset->size;
4668 data = (void *) &iov;
4674 res = ptrace (regset->get_request, pid,
4675 (PTRACE_TYPE_ARG3) (long) nt_type, data);
4677 res = ptrace (regset->get_request, pid, data, nt_type);
4683 /* If we get EIO on a regset, do not try it again for
4684 this process mode. */
4685 disable_regset (regsets_info, regset);
4687 else if (errno == ENODATA)
4689 /* ENODATA may be returned if the regset is currently
4690 not "active". This can happen in normal operation,
4691 so suppress the warning in this case. */
4696 sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
4703 if (regset->type == GENERAL_REGS)
4704 saw_general_regs = 1;
4705 regset->store_function (regcache, buf);
4709 if (saw_general_regs)
4716 regsets_store_inferior_registers (struct regsets_info *regsets_info,
4717 struct regcache *regcache)
4719 struct regset_info *regset;
4720 int saw_general_regs = 0;
4724 pid = lwpid_of (current_thread);
4725 for (regset = regsets_info->regsets; regset->size >= 0; regset++)
4730 if (regset->size == 0 || regset_disabled (regsets_info, regset)
4731 || regset->fill_function == NULL)
4734 buf = xmalloc (regset->size);
4736 /* First fill the buffer with the current register set contents,
4737 in case there are any items in the kernel's regset that are
4738 not in gdbserver's regcache. */
4740 nt_type = regset->nt_type;
4744 iov.iov_len = regset->size;
4745 data = (void *) &iov;
4751 res = ptrace (regset->get_request, pid,
4752 (PTRACE_TYPE_ARG3) (long) nt_type, data);
4754 res = ptrace (regset->get_request, pid, data, nt_type);
4759 /* Then overlay our cached registers on that. */
4760 regset->fill_function (regcache, buf);
4762 /* Only now do we write the register set. */
4764 res = ptrace (regset->set_request, pid,
4765 (PTRACE_TYPE_ARG3) (long) nt_type, data);
4767 res = ptrace (regset->set_request, pid, data, nt_type);
4775 /* If we get EIO on a regset, do not try it again for
4776 this process mode. */
4777 disable_regset (regsets_info, regset);
4779 else if (errno == ESRCH)
4781 /* At this point, ESRCH should mean the process is
4782 already gone, in which case we simply ignore attempts
4783 to change its registers. See also the related
4784 comment in linux_resume_one_lwp. */
4790 perror ("Warning: ptrace(regsets_store_inferior_registers)");
4793 else if (regset->type == GENERAL_REGS)
4794 saw_general_regs = 1;
4797 if (saw_general_regs)
4803 #else /* !HAVE_LINUX_REGSETS */
4805 #define use_linux_regsets 0
4806 #define regsets_fetch_inferior_registers(regsets_info, regcache) 1
4807 #define regsets_store_inferior_registers(regsets_info, regcache) 1
4811 /* Return 1 if register REGNO is supported by one of the regset ptrace
4812 calls or 0 if it has to be transferred individually. */
4815 linux_register_in_regsets (const struct regs_info *regs_info, int regno)
4817 unsigned char mask = 1 << (regno % 8);
4818 size_t index = regno / 8;
4820 return (use_linux_regsets
4821 && (regs_info->regset_bitmap == NULL
4822 || (regs_info->regset_bitmap[index] & mask) != 0));
4825 #ifdef HAVE_LINUX_USRREGS
4828 register_addr (const struct usrregs_info *usrregs, int regnum)
4832 if (regnum < 0 || regnum >= usrregs->num_regs)
4833 error ("Invalid register number %d.", regnum);
4835 addr = usrregs->regmap[regnum];
4840 /* Fetch one register. */
4842 fetch_register (const struct usrregs_info *usrregs,
4843 struct regcache *regcache, int regno)
4850 if (regno >= usrregs->num_regs)
4852 if ((*the_low_target.cannot_fetch_register) (regno))
4855 regaddr = register_addr (usrregs, regno);
4859 size = ((register_size (regcache->tdesc, regno)
4860 + sizeof (PTRACE_XFER_TYPE) - 1)
4861 & -sizeof (PTRACE_XFER_TYPE));
4862 buf = alloca (size);
4864 pid = lwpid_of (current_thread);
4865 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
4868 *(PTRACE_XFER_TYPE *) (buf + i) =
4869 ptrace (PTRACE_PEEKUSER, pid,
4870 /* Coerce to a uintptr_t first to avoid potential gcc warning
4871 of coercing an 8 byte integer to a 4 byte pointer. */
4872 (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, (PTRACE_TYPE_ARG4) 0);
4873 regaddr += sizeof (PTRACE_XFER_TYPE);
4875 error ("reading register %d: %s", regno, strerror (errno));
4878 if (the_low_target.supply_ptrace_register)
4879 the_low_target.supply_ptrace_register (regcache, regno, buf);
4881 supply_register (regcache, regno, buf);
4884 /* Store one register. */
4886 store_register (const struct usrregs_info *usrregs,
4887 struct regcache *regcache, int regno)
4894 if (regno >= usrregs->num_regs)
4896 if ((*the_low_target.cannot_store_register) (regno))
4899 regaddr = register_addr (usrregs, regno);
4903 size = ((register_size (regcache->tdesc, regno)
4904 + sizeof (PTRACE_XFER_TYPE) - 1)
4905 & -sizeof (PTRACE_XFER_TYPE));
4906 buf = alloca (size);
4907 memset (buf, 0, size);
4909 if (the_low_target.collect_ptrace_register)
4910 the_low_target.collect_ptrace_register (regcache, regno, buf);
4912 collect_register (regcache, regno, buf);
4914 pid = lwpid_of (current_thread);
4915 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
4918 ptrace (PTRACE_POKEUSER, pid,
4919 /* Coerce to a uintptr_t first to avoid potential gcc warning
4920 about coercing an 8 byte integer to a 4 byte pointer. */
4921 (PTRACE_TYPE_ARG3) (uintptr_t) regaddr,
4922 (PTRACE_TYPE_ARG4) *(PTRACE_XFER_TYPE *) (buf + i));
4925 /* At this point, ESRCH should mean the process is
4926 already gone, in which case we simply ignore attempts
4927 to change its registers. See also the related
4928 comment in linux_resume_one_lwp. */
4932 if ((*the_low_target.cannot_store_register) (regno) == 0)
4933 error ("writing register %d: %s", regno, strerror (errno));
4935 regaddr += sizeof (PTRACE_XFER_TYPE);
4939 /* Fetch all registers, or just one, from the child process.
4940 If REGNO is -1, do this for all registers, skipping any that are
4941 assumed to have been retrieved by regsets_fetch_inferior_registers,
4942 unless ALL is non-zero.
4943 Otherwise, REGNO specifies which register (so we can save time). */
4945 usr_fetch_inferior_registers (const struct regs_info *regs_info,
4946 struct regcache *regcache, int regno, int all)
4948 struct usrregs_info *usr = regs_info->usrregs;
4952 for (regno = 0; regno < usr->num_regs; regno++)
4953 if (all || !linux_register_in_regsets (regs_info, regno))
4954 fetch_register (usr, regcache, regno);
4957 fetch_register (usr, regcache, regno);
4960 /* Store our register values back into the inferior.
4961 If REGNO is -1, do this for all registers, skipping any that are
4962 assumed to have been saved by regsets_store_inferior_registers,
4963 unless ALL is non-zero.
4964 Otherwise, REGNO specifies which register (so we can save time). */
4966 usr_store_inferior_registers (const struct regs_info *regs_info,
4967 struct regcache *regcache, int regno, int all)
4969 struct usrregs_info *usr = regs_info->usrregs;
4973 for (regno = 0; regno < usr->num_regs; regno++)
4974 if (all || !linux_register_in_regsets (regs_info, regno))
4975 store_register (usr, regcache, regno);
4978 store_register (usr, regcache, regno);
4981 #else /* !HAVE_LINUX_USRREGS */
4983 #define usr_fetch_inferior_registers(regs_info, regcache, regno, all) do {} while (0)
4984 #define usr_store_inferior_registers(regs_info, regcache, regno, all) do {} while (0)
4990 linux_fetch_registers (struct regcache *regcache, int regno)
4994 const struct regs_info *regs_info = (*the_low_target.regs_info) ();
4998 if (the_low_target.fetch_register != NULL
4999 && regs_info->usrregs != NULL)
5000 for (regno = 0; regno < regs_info->usrregs->num_regs; regno++)
5001 (*the_low_target.fetch_register) (regcache, regno);
5003 all = regsets_fetch_inferior_registers (regs_info->regsets_info, regcache);
5004 if (regs_info->usrregs != NULL)
5005 usr_fetch_inferior_registers (regs_info, regcache, -1, all);
5009 if (the_low_target.fetch_register != NULL
5010 && (*the_low_target.fetch_register) (regcache, regno))
5013 use_regsets = linux_register_in_regsets (regs_info, regno);
5015 all = regsets_fetch_inferior_registers (regs_info->regsets_info,
5017 if ((!use_regsets || all) && regs_info->usrregs != NULL)
5018 usr_fetch_inferior_registers (regs_info, regcache, regno, 1);
5023 linux_store_registers (struct regcache *regcache, int regno)
5027 const struct regs_info *regs_info = (*the_low_target.regs_info) ();
5031 all = regsets_store_inferior_registers (regs_info->regsets_info,
5033 if (regs_info->usrregs != NULL)
5034 usr_store_inferior_registers (regs_info, regcache, regno, all);
5038 use_regsets = linux_register_in_regsets (regs_info, regno);
5040 all = regsets_store_inferior_registers (regs_info->regsets_info,
5042 if ((!use_regsets || all) && regs_info->usrregs != NULL)
5043 usr_store_inferior_registers (regs_info, regcache, regno, 1);
5048 /* Copy LEN bytes from inferior's memory starting at MEMADDR
5049 to debugger memory starting at MYADDR. */
5052 linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
5054 int pid = lwpid_of (current_thread);
5055 register PTRACE_XFER_TYPE *buffer;
5056 register CORE_ADDR addr;
5063 /* Try using /proc. Don't bother for one word. */
5064 if (len >= 3 * sizeof (long))
5068 /* We could keep this file open and cache it - possibly one per
5069 thread. That requires some juggling, but is even faster. */
5070 sprintf (filename, "/proc/%d/mem", pid);
5071 fd = open (filename, O_RDONLY | O_LARGEFILE);
5075 /* If pread64 is available, use it. It's faster if the kernel
5076 supports it (only one syscall), and it's 64-bit safe even on
5077 32-bit platforms (for instance, SPARC debugging a SPARC64
5080 bytes = pread64 (fd, myaddr, len, memaddr);
5083 if (lseek (fd, memaddr, SEEK_SET) != -1)
5084 bytes = read (fd, myaddr, len);
5091 /* Some data was read, we'll try to get the rest with ptrace. */
5101 /* Round starting address down to longword boundary. */
5102 addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
5103 /* Round ending address up; get number of longwords that makes. */
5104 count = ((((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
5105 / sizeof (PTRACE_XFER_TYPE));
5106 /* Allocate buffer of that many longwords. */
5107 buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
5109 /* Read all the longwords */
5111 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
5113 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
5114 about coercing an 8 byte integer to a 4 byte pointer. */
5115 buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
5116 (PTRACE_TYPE_ARG3) (uintptr_t) addr,
5117 (PTRACE_TYPE_ARG4) 0);
5123 /* Copy appropriate bytes out of the buffer. */
5126 i *= sizeof (PTRACE_XFER_TYPE);
5127 i -= memaddr & (sizeof (PTRACE_XFER_TYPE) - 1);
5129 (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
5136 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
5137 memory at MEMADDR. On failure (cannot write to the inferior)
5138 returns the value of errno. Always succeeds if LEN is zero. */
5141 linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
5144 /* Round starting address down to longword boundary. */
5145 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
5146 /* Round ending address up; get number of longwords that makes. */
5148 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
5149 / sizeof (PTRACE_XFER_TYPE);
5151 /* Allocate buffer of that many longwords. */
5152 register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *)
5153 alloca (count * sizeof (PTRACE_XFER_TYPE));
5155 int pid = lwpid_of (current_thread);
5159 /* Zero length write always succeeds. */
5165 /* Dump up to four bytes. */
5166 unsigned int val = * (unsigned int *) myaddr;
5172 val = val & 0xffffff;
5173 debug_printf ("Writing %0*x to 0x%08lx in process %d\n",
5174 2 * ((len < 4) ? len : 4), val, (long)memaddr, pid);
5177 /* Fill start and end extra bytes of buffer with existing memory data. */
5180 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
5181 about coercing an 8 byte integer to a 4 byte pointer. */
5182 buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
5183 (PTRACE_TYPE_ARG3) (uintptr_t) addr,
5184 (PTRACE_TYPE_ARG4) 0);
5192 = ptrace (PTRACE_PEEKTEXT, pid,
5193 /* Coerce to a uintptr_t first to avoid potential gcc warning
5194 about coercing an 8 byte integer to a 4 byte pointer. */
5195 (PTRACE_TYPE_ARG3) (uintptr_t) (addr + (count - 1)
5196 * sizeof (PTRACE_XFER_TYPE)),
5197 (PTRACE_TYPE_ARG4) 0);
5202 /* Copy data to be written over corresponding part of buffer. */
5204 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
5207 /* Write the entire buffer. */
5209 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
5212 ptrace (PTRACE_POKETEXT, pid,
5213 /* Coerce to a uintptr_t first to avoid potential gcc warning
5214 about coercing an 8 byte integer to a 4 byte pointer. */
5215 (PTRACE_TYPE_ARG3) (uintptr_t) addr,
5216 (PTRACE_TYPE_ARG4) buffer[i]);
5225 linux_look_up_symbols (void)
5227 #ifdef USE_THREAD_DB
5228 struct process_info *proc = current_process ();
5230 if (proc->priv->thread_db != NULL)
5233 /* If the kernel supports tracing clones, then we don't need to
5234 use the magic thread event breakpoint to learn about
5236 thread_db_init (!linux_supports_traceclone ());
5241 linux_request_interrupt (void)
5243 extern unsigned long signal_pid;
5245 /* Send a SIGINT to the process group. This acts just like the user
5246 typed a ^C on the controlling terminal. */
5247 kill (-signal_pid, SIGINT);
5250 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
5251 to debugger memory starting at MYADDR. */
5254 linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
5256 char filename[PATH_MAX];
5258 int pid = lwpid_of (current_thread);
5260 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
5262 fd = open (filename, O_RDONLY);
5266 if (offset != (CORE_ADDR) 0
5267 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
5270 n = read (fd, myaddr, len);
5277 /* These breakpoint and watchpoint related wrapper functions simply
5278 pass on the function call if the target has registered a
5279 corresponding function. */
5282 linux_supports_z_point_type (char z_type)
5284 return (the_low_target.supports_z_point_type != NULL
5285 && the_low_target.supports_z_point_type (z_type));
5289 linux_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
5290 int size, struct raw_breakpoint *bp)
5292 if (type == raw_bkpt_type_sw)
5293 return insert_memory_breakpoint (bp);
5294 else if (the_low_target.insert_point != NULL)
5295 return the_low_target.insert_point (type, addr, size, bp);
5297 /* Unsupported (see target.h). */
5302 linux_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
5303 int size, struct raw_breakpoint *bp)
5305 if (type == raw_bkpt_type_sw)
5306 return remove_memory_breakpoint (bp);
5307 else if (the_low_target.remove_point != NULL)
5308 return the_low_target.remove_point (type, addr, size, bp);
5310 /* Unsupported (see target.h). */
5314 /* Implement the to_stopped_by_sw_breakpoint target_ops
5318 linux_stopped_by_sw_breakpoint (void)
5320 struct lwp_info *lwp = get_thread_lwp (current_thread);
5322 return (lwp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT);
5325 /* Implement the to_supports_stopped_by_sw_breakpoint target_ops
5329 linux_supports_stopped_by_sw_breakpoint (void)
5331 return USE_SIGTRAP_SIGINFO;
5334 /* Implement the to_stopped_by_hw_breakpoint target_ops
5338 linux_stopped_by_hw_breakpoint (void)
5340 struct lwp_info *lwp = get_thread_lwp (current_thread);
5342 return (lwp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT);
5345 /* Implement the to_supports_stopped_by_hw_breakpoint target_ops
5349 linux_supports_stopped_by_hw_breakpoint (void)
5351 return USE_SIGTRAP_SIGINFO;
5354 /* Implement the supports_conditional_breakpoints target_ops
5358 linux_supports_conditional_breakpoints (void)
5360 /* GDBserver needs to step over the breakpoint if the condition is
5361 false. GDBserver software single step is too simple, so disable
5362 conditional breakpoints if the target doesn't have hardware single
5364 return can_hardware_single_step ();
5368 linux_stopped_by_watchpoint (void)
5370 struct lwp_info *lwp = get_thread_lwp (current_thread);
5372 return lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
5376 linux_stopped_data_address (void)
5378 struct lwp_info *lwp = get_thread_lwp (current_thread);
5380 return lwp->stopped_data_address;
5383 #if defined(__UCLIBC__) && defined(HAS_NOMMU) \
5384 && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
5385 && defined(PT_TEXT_END_ADDR)
5387 /* This is only used for targets that define PT_TEXT_ADDR,
5388 PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly
5389 the target has different ways of acquiring this information, like
5392 /* Under uClinux, programs are loaded at non-zero offsets, which we need
5393 to tell gdb about. */
5396 linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
5398 unsigned long text, text_end, data;
5399 int pid = lwpid_of (current_thread);
5403 text = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_ADDR,
5404 (PTRACE_TYPE_ARG4) 0);
5405 text_end = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_END_ADDR,
5406 (PTRACE_TYPE_ARG4) 0);
5407 data = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_DATA_ADDR,
5408 (PTRACE_TYPE_ARG4) 0);
5412 /* Both text and data offsets produced at compile-time (and so
5413 used by gdb) are relative to the beginning of the program,
5414 with the data segment immediately following the text segment.
5415 However, the actual runtime layout in memory may put the data
5416 somewhere else, so when we send gdb a data base-address, we
5417 use the real data base address and subtract the compile-time
5418 data base-address from it (which is just the length of the
5419 text segment). BSS immediately follows data in both
5422 *data_p = data - (text_end - text);
5431 linux_qxfer_osdata (const char *annex,
5432 unsigned char *readbuf, unsigned const char *writebuf,
5433 CORE_ADDR offset, int len)
5435 return linux_common_xfer_osdata (annex, readbuf, offset, len);
5438 /* Convert a native/host siginfo object, into/from the siginfo in the
5439 layout of the inferiors' architecture. */
5442 siginfo_fixup (siginfo_t *siginfo, void *inf_siginfo, int direction)
5446 if (the_low_target.siginfo_fixup != NULL)
5447 done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
5449 /* If there was no callback, or the callback didn't do anything,
5450 then just do a straight memcpy. */
5454 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
5456 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
5461 linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
5462 unsigned const char *writebuf, CORE_ADDR offset, int len)
5466 char inf_siginfo[sizeof (siginfo_t)];
5468 if (current_thread == NULL)
5471 pid = lwpid_of (current_thread);
5474 debug_printf ("%s siginfo for lwp %d.\n",
5475 readbuf != NULL ? "Reading" : "Writing",
5478 if (offset >= sizeof (siginfo))
5481 if (ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0)
5484 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
5485 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
5486 inferior with a 64-bit GDBSERVER should look the same as debugging it
5487 with a 32-bit GDBSERVER, we need to convert it. */
5488 siginfo_fixup (&siginfo, inf_siginfo, 0);
5490 if (offset + len > sizeof (siginfo))
5491 len = sizeof (siginfo) - offset;
5493 if (readbuf != NULL)
5494 memcpy (readbuf, inf_siginfo + offset, len);
5497 memcpy (inf_siginfo + offset, writebuf, len);
5499 /* Convert back to ptrace layout before flushing it out. */
5500 siginfo_fixup (&siginfo, inf_siginfo, 1);
5502 if (ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0)
5509 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
5510 so we notice when children change state; as the handler for the
5511 sigsuspend in my_waitpid. */
5514 sigchld_handler (int signo)
5516 int old_errno = errno;
5522 /* fprintf is not async-signal-safe, so call write
5524 if (write (2, "sigchld_handler\n",
5525 sizeof ("sigchld_handler\n") - 1) < 0)
5526 break; /* just ignore */
5530 if (target_is_async_p ())
5531 async_file_mark (); /* trigger a linux_wait */
5537 linux_supports_non_stop (void)
5543 linux_async (int enable)
5545 int previous = target_is_async_p ();
5548 debug_printf ("linux_async (%d), previous=%d\n",
5551 if (previous != enable)
5554 sigemptyset (&mask);
5555 sigaddset (&mask, SIGCHLD);
5557 sigprocmask (SIG_BLOCK, &mask, NULL);
5561 if (pipe (linux_event_pipe) == -1)
5563 linux_event_pipe[0] = -1;
5564 linux_event_pipe[1] = -1;
5565 sigprocmask (SIG_UNBLOCK, &mask, NULL);
5567 warning ("creating event pipe failed.");
5571 fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
5572 fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
5574 /* Register the event loop handler. */
5575 add_file_handler (linux_event_pipe[0],
5576 handle_target_event, NULL);
5578 /* Always trigger a linux_wait. */
5583 delete_file_handler (linux_event_pipe[0]);
5585 close (linux_event_pipe[0]);
5586 close (linux_event_pipe[1]);
5587 linux_event_pipe[0] = -1;
5588 linux_event_pipe[1] = -1;
5591 sigprocmask (SIG_UNBLOCK, &mask, NULL);
5598 linux_start_non_stop (int nonstop)
5600 /* Register or unregister from event-loop accordingly. */
5601 linux_async (nonstop);
5603 if (target_is_async_p () != (nonstop != 0))
5610 linux_supports_multi_process (void)
5615 /* Check if fork events are supported. */
5618 linux_supports_fork_events (void)
5620 return linux_supports_tracefork ();
5623 /* Check if vfork events are supported. */
5626 linux_supports_vfork_events (void)
5628 return linux_supports_tracefork ();
5631 /* Callback for 'find_inferior'. Set the (possibly changed) ptrace
5632 options for the specified lwp. */
5635 reset_lwp_ptrace_options_callback (struct inferior_list_entry *entry,
5638 struct thread_info *thread = (struct thread_info *) entry;
5639 struct lwp_info *lwp = get_thread_lwp (thread);
5643 /* Stop the lwp so we can modify its ptrace options. */
5644 lwp->must_set_ptrace_flags = 1;
5645 linux_stop_lwp (lwp);
5649 /* Already stopped; go ahead and set the ptrace options. */
5650 struct process_info *proc = find_process_pid (pid_of (thread));
5651 int options = linux_low_ptrace_options (proc->attached);
5653 linux_enable_event_reporting (lwpid_of (thread), options);
5654 lwp->must_set_ptrace_flags = 0;
5660 /* Target hook for 'handle_new_gdb_connection'. Causes a reset of the
5661 ptrace flags for all inferiors. This is in case the new GDB connection
5662 doesn't support the same set of events that the previous one did. */
5665 linux_handle_new_gdb_connection (void)
5669 /* Request that all the lwps reset their ptrace options. */
5670 find_inferior (&all_threads, reset_lwp_ptrace_options_callback , &pid);
5674 linux_supports_disable_randomization (void)
5676 #ifdef HAVE_PERSONALITY
5684 linux_supports_agent (void)
5690 linux_supports_range_stepping (void)
5692 if (*the_low_target.supports_range_stepping == NULL)
5695 return (*the_low_target.supports_range_stepping) ();
5698 /* Enumerate spufs IDs for process PID. */
5700 spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
5706 struct dirent *entry;
5708 sprintf (path, "/proc/%ld/fd", pid);
5709 dir = opendir (path);
5714 while ((entry = readdir (dir)) != NULL)
5720 fd = atoi (entry->d_name);
5724 sprintf (path, "/proc/%ld/fd/%d", pid, fd);
5725 if (stat (path, &st) != 0)
5727 if (!S_ISDIR (st.st_mode))
5730 if (statfs (path, &stfs) != 0)
5732 if (stfs.f_type != SPUFS_MAGIC)
5735 if (pos >= offset && pos + 4 <= offset + len)
5737 *(unsigned int *)(buf + pos - offset) = fd;
5747 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
5748 object type, using the /proc file system. */
5750 linux_qxfer_spu (const char *annex, unsigned char *readbuf,
5751 unsigned const char *writebuf,
5752 CORE_ADDR offset, int len)
5754 long pid = lwpid_of (current_thread);
5759 if (!writebuf && !readbuf)
5767 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
5770 sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
5771 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
5776 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
5783 ret = write (fd, writebuf, (size_t) len);
5785 ret = read (fd, readbuf, (size_t) len);
5791 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
5792 struct target_loadseg
5794 /* Core address to which the segment is mapped. */
5796 /* VMA recorded in the program header. */
5798 /* Size of this segment in memory. */
5802 # if defined PT_GETDSBT
5803 struct target_loadmap
5805 /* Protocol version number, must be zero. */
5807 /* Pointer to the DSBT table, its size, and the DSBT index. */
5808 unsigned *dsbt_table;
5809 unsigned dsbt_size, dsbt_index;
5810 /* Number of segments in this map. */
5812 /* The actual memory map. */
5813 struct target_loadseg segs[/*nsegs*/];
5815 # define LINUX_LOADMAP PT_GETDSBT
5816 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
5817 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
5819 struct target_loadmap
5821 /* Protocol version number, must be zero. */
5823 /* Number of segments in this map. */
5825 /* The actual memory map. */
5826 struct target_loadseg segs[/*nsegs*/];
5828 # define LINUX_LOADMAP PTRACE_GETFDPIC
5829 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
5830 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
5834 linux_read_loadmap (const char *annex, CORE_ADDR offset,
5835 unsigned char *myaddr, unsigned int len)
5837 int pid = lwpid_of (current_thread);
5839 struct target_loadmap *data = NULL;
5840 unsigned int actual_length, copy_length;
5842 if (strcmp (annex, "exec") == 0)
5843 addr = (int) LINUX_LOADMAP_EXEC;
5844 else if (strcmp (annex, "interp") == 0)
5845 addr = (int) LINUX_LOADMAP_INTERP;
5849 if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0)
5855 actual_length = sizeof (struct target_loadmap)
5856 + sizeof (struct target_loadseg) * data->nsegs;
5858 if (offset < 0 || offset > actual_length)
5861 copy_length = actual_length - offset < len ? actual_length - offset : len;
5862 memcpy (myaddr, (char *) data + offset, copy_length);
5866 # define linux_read_loadmap NULL
5867 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
5870 linux_process_qsupported (const char *query)
5872 if (the_low_target.process_qsupported != NULL)
5873 the_low_target.process_qsupported (query);
5877 linux_supports_tracepoints (void)
5879 if (*the_low_target.supports_tracepoints == NULL)
5882 return (*the_low_target.supports_tracepoints) ();
5886 linux_read_pc (struct regcache *regcache)
5888 if (the_low_target.get_pc == NULL)
5891 return (*the_low_target.get_pc) (regcache);
5895 linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
5897 gdb_assert (the_low_target.set_pc != NULL);
5899 (*the_low_target.set_pc) (regcache, pc);
5903 linux_thread_stopped (struct thread_info *thread)
5905 return get_thread_lwp (thread)->stopped;
5908 /* This exposes stop-all-threads functionality to other modules. */
5911 linux_pause_all (int freeze)
5913 stop_all_lwps (freeze, NULL);
5916 /* This exposes unstop-all-threads functionality to other gdbserver
5920 linux_unpause_all (int unfreeze)
5922 unstop_all_lwps (unfreeze, NULL);
5926 linux_prepare_to_access_memory (void)
5928 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5931 linux_pause_all (1);
5936 linux_done_accessing_memory (void)
5938 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5941 linux_unpause_all (1);
5945 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
5946 CORE_ADDR collector,
5949 CORE_ADDR *jump_entry,
5950 CORE_ADDR *trampoline,
5951 ULONGEST *trampoline_size,
5952 unsigned char *jjump_pad_insn,
5953 ULONGEST *jjump_pad_insn_size,
5954 CORE_ADDR *adjusted_insn_addr,
5955 CORE_ADDR *adjusted_insn_addr_end,
5958 return (*the_low_target.install_fast_tracepoint_jump_pad)
5959 (tpoint, tpaddr, collector, lockaddr, orig_size,
5960 jump_entry, trampoline, trampoline_size,
5961 jjump_pad_insn, jjump_pad_insn_size,
5962 adjusted_insn_addr, adjusted_insn_addr_end,
5966 static struct emit_ops *
5967 linux_emit_ops (void)
5969 if (the_low_target.emit_ops != NULL)
5970 return (*the_low_target.emit_ops) ();
5976 linux_get_min_fast_tracepoint_insn_len (void)
5978 return (*the_low_target.get_min_fast_tracepoint_insn_len) ();
5981 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
5984 get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64,
5985 CORE_ADDR *phdr_memaddr, int *num_phdr)
5987 char filename[PATH_MAX];
5989 const int auxv_size = is_elf64
5990 ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t);
5991 char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */
5993 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
5995 fd = open (filename, O_RDONLY);
6001 while (read (fd, buf, auxv_size) == auxv_size
6002 && (*phdr_memaddr == 0 || *num_phdr == 0))
6006 Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf;
6008 switch (aux->a_type)
6011 *phdr_memaddr = aux->a_un.a_val;
6014 *num_phdr = aux->a_un.a_val;
6020 Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf;
6022 switch (aux->a_type)
6025 *phdr_memaddr = aux->a_un.a_val;
6028 *num_phdr = aux->a_un.a_val;
6036 if (*phdr_memaddr == 0 || *num_phdr == 0)
6038 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
6039 "phdr_memaddr = %ld, phdr_num = %d",
6040 (long) *phdr_memaddr, *num_phdr);
6047 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
6050 get_dynamic (const int pid, const int is_elf64)
6052 CORE_ADDR phdr_memaddr, relocation;
6054 unsigned char *phdr_buf;
6055 const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr);
6057 if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr))
6060 gdb_assert (num_phdr < 100); /* Basic sanity check. */
6061 phdr_buf = alloca (num_phdr * phdr_size);
6063 if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size))
6066 /* Compute relocation: it is expected to be 0 for "regular" executables,
6067 non-zero for PIE ones. */
6069 for (i = 0; relocation == -1 && i < num_phdr; i++)
6072 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
6074 if (p->p_type == PT_PHDR)
6075 relocation = phdr_memaddr - p->p_vaddr;
6079 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
6081 if (p->p_type == PT_PHDR)
6082 relocation = phdr_memaddr - p->p_vaddr;
6085 if (relocation == -1)
6087 /* PT_PHDR is optional, but necessary for PIE in general. Fortunately
6088 any real world executables, including PIE executables, have always
6089 PT_PHDR present. PT_PHDR is not present in some shared libraries or
6090 in fpc (Free Pascal 2.4) binaries but neither of those have a need for
6091 or present DT_DEBUG anyway (fpc binaries are statically linked).
6093 Therefore if there exists DT_DEBUG there is always also PT_PHDR.
6095 GDB could find RELOCATION also from AT_ENTRY - e_entry. */
6100 for (i = 0; i < num_phdr; i++)
6104 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
6106 if (p->p_type == PT_DYNAMIC)
6107 return p->p_vaddr + relocation;
6111 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
6113 if (p->p_type == PT_DYNAMIC)
6114 return p->p_vaddr + relocation;
6121 /* Return &_r_debug in the inferior, or -1 if not present. Return value
6122 can be 0 if the inferior does not yet have the library list initialized.
6123 We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of
6124 DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */
6127 get_r_debug (const int pid, const int is_elf64)
6129 CORE_ADDR dynamic_memaddr;
6130 const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn);
6131 unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */
6134 dynamic_memaddr = get_dynamic (pid, is_elf64);
6135 if (dynamic_memaddr == 0)
6138 while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0)
6142 Elf64_Dyn *const dyn = (Elf64_Dyn *) buf;
6143 #ifdef DT_MIPS_RLD_MAP
6147 unsigned char buf[sizeof (Elf64_Xword)];
6151 if (dyn->d_tag == DT_MIPS_RLD_MAP)
6153 if (linux_read_memory (dyn->d_un.d_val,
6154 rld_map.buf, sizeof (rld_map.buf)) == 0)
6159 #endif /* DT_MIPS_RLD_MAP */
6161 if (dyn->d_tag == DT_DEBUG && map == -1)
6162 map = dyn->d_un.d_val;
6164 if (dyn->d_tag == DT_NULL)
6169 Elf32_Dyn *const dyn = (Elf32_Dyn *) buf;
6170 #ifdef DT_MIPS_RLD_MAP
6174 unsigned char buf[sizeof (Elf32_Word)];
6178 if (dyn->d_tag == DT_MIPS_RLD_MAP)
6180 if (linux_read_memory (dyn->d_un.d_val,
6181 rld_map.buf, sizeof (rld_map.buf)) == 0)
6186 #endif /* DT_MIPS_RLD_MAP */
6188 if (dyn->d_tag == DT_DEBUG && map == -1)
6189 map = dyn->d_un.d_val;
6191 if (dyn->d_tag == DT_NULL)
6195 dynamic_memaddr += dyn_size;
6201 /* Read one pointer from MEMADDR in the inferior. */
6204 read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size)
6208 /* Go through a union so this works on either big or little endian
6209 hosts, when the inferior's pointer size is smaller than the size
6210 of CORE_ADDR. It is assumed the inferior's endianness is the
6211 same of the superior's. */
6214 CORE_ADDR core_addr;
6219 ret = linux_read_memory (memaddr, &addr.uc, ptr_size);
6222 if (ptr_size == sizeof (CORE_ADDR))
6223 *ptr = addr.core_addr;
6224 else if (ptr_size == sizeof (unsigned int))
6227 gdb_assert_not_reached ("unhandled pointer size");
6232 struct link_map_offsets
6234 /* Offset and size of r_debug.r_version. */
6235 int r_version_offset;
6237 /* Offset and size of r_debug.r_map. */
6240 /* Offset to l_addr field in struct link_map. */
6243 /* Offset to l_name field in struct link_map. */
6246 /* Offset to l_ld field in struct link_map. */
6249 /* Offset to l_next field in struct link_map. */
6252 /* Offset to l_prev field in struct link_map. */
6256 /* Construct qXfer:libraries-svr4:read reply. */
6259 linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf,
6260 unsigned const char *writebuf,
6261 CORE_ADDR offset, int len)
6264 unsigned document_len;
6265 struct process_info_private *const priv = current_process ()->priv;
6266 char filename[PATH_MAX];
6269 static const struct link_map_offsets lmo_32bit_offsets =
6271 0, /* r_version offset. */
6272 4, /* r_debug.r_map offset. */
6273 0, /* l_addr offset in link_map. */
6274 4, /* l_name offset in link_map. */
6275 8, /* l_ld offset in link_map. */
6276 12, /* l_next offset in link_map. */
6277 16 /* l_prev offset in link_map. */
6280 static const struct link_map_offsets lmo_64bit_offsets =
6282 0, /* r_version offset. */
6283 8, /* r_debug.r_map offset. */
6284 0, /* l_addr offset in link_map. */
6285 8, /* l_name offset in link_map. */
6286 16, /* l_ld offset in link_map. */
6287 24, /* l_next offset in link_map. */
6288 32 /* l_prev offset in link_map. */
6290 const struct link_map_offsets *lmo;
6291 unsigned int machine;
6293 CORE_ADDR lm_addr = 0, lm_prev = 0;
6294 int allocated = 1024;
6296 CORE_ADDR l_name, l_addr, l_ld, l_next, l_prev;
6297 int header_done = 0;
6299 if (writebuf != NULL)
6301 if (readbuf == NULL)
6304 pid = lwpid_of (current_thread);
6305 xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid);
6306 is_elf64 = elf_64_file_p (filename, &machine);
6307 lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets;
6308 ptr_size = is_elf64 ? 8 : 4;
6310 while (annex[0] != '\0')
6316 sep = strchr (annex, '=');
6321 if (len == 5 && startswith (annex, "start"))
6323 else if (len == 4 && startswith (annex, "prev"))
6327 annex = strchr (sep, ';');
6334 annex = decode_address_to_semicolon (addrp, sep + 1);
6341 if (priv->r_debug == 0)
6342 priv->r_debug = get_r_debug (pid, is_elf64);
6344 /* We failed to find DT_DEBUG. Such situation will not change
6345 for this inferior - do not retry it. Report it to GDB as
6346 E01, see for the reasons at the GDB solib-svr4.c side. */
6347 if (priv->r_debug == (CORE_ADDR) -1)
6350 if (priv->r_debug != 0)
6352 if (linux_read_memory (priv->r_debug + lmo->r_version_offset,
6353 (unsigned char *) &r_version,
6354 sizeof (r_version)) != 0
6357 warning ("unexpected r_debug version %d", r_version);
6359 else if (read_one_ptr (priv->r_debug + lmo->r_map_offset,
6360 &lm_addr, ptr_size) != 0)
6362 warning ("unable to read r_map from 0x%lx",
6363 (long) priv->r_debug + lmo->r_map_offset);
6368 document = xmalloc (allocated);
6369 strcpy (document, "<library-list-svr4 version=\"1.0\"");
6370 p = document + strlen (document);
6373 && read_one_ptr (lm_addr + lmo->l_name_offset,
6374 &l_name, ptr_size) == 0
6375 && read_one_ptr (lm_addr + lmo->l_addr_offset,
6376 &l_addr, ptr_size) == 0
6377 && read_one_ptr (lm_addr + lmo->l_ld_offset,
6378 &l_ld, ptr_size) == 0
6379 && read_one_ptr (lm_addr + lmo->l_prev_offset,
6380 &l_prev, ptr_size) == 0
6381 && read_one_ptr (lm_addr + lmo->l_next_offset,
6382 &l_next, ptr_size) == 0)
6384 unsigned char libname[PATH_MAX];
6386 if (lm_prev != l_prev)
6388 warning ("Corrupted shared library list: 0x%lx != 0x%lx",
6389 (long) lm_prev, (long) l_prev);
6393 /* Ignore the first entry even if it has valid name as the first entry
6394 corresponds to the main executable. The first entry should not be
6395 skipped if the dynamic loader was loaded late by a static executable
6396 (see solib-svr4.c parameter ignore_first). But in such case the main
6397 executable does not have PT_DYNAMIC present and this function already
6398 exited above due to failed get_r_debug. */
6401 sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr);
6406 /* Not checking for error because reading may stop before
6407 we've got PATH_MAX worth of characters. */
6409 linux_read_memory (l_name, libname, sizeof (libname) - 1);
6410 libname[sizeof (libname) - 1] = '\0';
6411 if (libname[0] != '\0')
6413 /* 6x the size for xml_escape_text below. */
6414 size_t len = 6 * strlen ((char *) libname);
6419 /* Terminate `<library-list-svr4'. */
6424 while (allocated < p - document + len + 200)
6426 /* Expand to guarantee sufficient storage. */
6427 uintptr_t document_len = p - document;
6429 document = xrealloc (document, 2 * allocated);
6431 p = document + document_len;
6434 name = xml_escape_text ((char *) libname);
6435 p += sprintf (p, "<library name=\"%s\" lm=\"0x%lx\" "
6436 "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
6437 name, (unsigned long) lm_addr,
6438 (unsigned long) l_addr, (unsigned long) l_ld);
6449 /* Empty list; terminate `<library-list-svr4'. */
6453 strcpy (p, "</library-list-svr4>");
6455 document_len = strlen (document);
6456 if (offset < document_len)
6457 document_len -= offset;
6460 if (len > document_len)
6463 memcpy (readbuf, document + offset, len);
6469 #ifdef HAVE_LINUX_BTRACE
6471 /* See to_enable_btrace target method. */
6473 static struct btrace_target_info *
6474 linux_low_enable_btrace (ptid_t ptid, const struct btrace_config *conf)
6476 struct btrace_target_info *tinfo;
6478 tinfo = linux_enable_btrace (ptid, conf);
6480 if (tinfo != NULL && tinfo->ptr_bits == 0)
6482 struct thread_info *thread = find_thread_ptid (ptid);
6483 struct regcache *regcache = get_thread_regcache (thread, 0);
6485 tinfo->ptr_bits = register_size (regcache->tdesc, 0) * 8;
6491 /* See to_disable_btrace target method. */
6494 linux_low_disable_btrace (struct btrace_target_info *tinfo)
6496 enum btrace_error err;
6498 err = linux_disable_btrace (tinfo);
6499 return (err == BTRACE_ERR_NONE ? 0 : -1);
6502 /* Encode an Intel(R) Processor Trace configuration. */
6505 linux_low_encode_pt_config (struct buffer *buffer,
6506 const struct btrace_data_pt_config *config)
6508 buffer_grow_str (buffer, "<pt-config>\n");
6510 switch (config->cpu.vendor)
6513 buffer_xml_printf (buffer, "<cpu vendor=\"GenuineIntel\" family=\"%u\" "
6514 "model=\"%u\" stepping=\"%u\"/>\n",
6515 config->cpu.family, config->cpu.model,
6516 config->cpu.stepping);
6523 buffer_grow_str (buffer, "</pt-config>\n");
6526 /* Encode a raw buffer. */
6529 linux_low_encode_raw (struct buffer *buffer, const gdb_byte *data,
6535 /* We use hex encoding - see common/rsp-low.h. */
6536 buffer_grow_str (buffer, "<raw>\n");
6542 elem[0] = tohex ((*data >> 4) & 0xf);
6543 elem[1] = tohex (*data++ & 0xf);
6545 buffer_grow (buffer, elem, 2);
6548 buffer_grow_str (buffer, "</raw>\n");
6551 /* See to_read_btrace target method. */
6554 linux_low_read_btrace (struct btrace_target_info *tinfo, struct buffer *buffer,
6557 struct btrace_data btrace;
6558 struct btrace_block *block;
6559 enum btrace_error err;
6562 btrace_data_init (&btrace);
6564 err = linux_read_btrace (&btrace, tinfo, type);
6565 if (err != BTRACE_ERR_NONE)
6567 if (err == BTRACE_ERR_OVERFLOW)
6568 buffer_grow_str0 (buffer, "E.Overflow.");
6570 buffer_grow_str0 (buffer, "E.Generic Error.");
6575 switch (btrace.format)
6577 case BTRACE_FORMAT_NONE:
6578 buffer_grow_str0 (buffer, "E.No Trace.");
6581 case BTRACE_FORMAT_BTS:
6582 buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n");
6583 buffer_grow_str (buffer, "<btrace version=\"1.0\">\n");
6586 VEC_iterate (btrace_block_s, btrace.variant.bts.blocks, i, block);
6588 buffer_xml_printf (buffer, "<block begin=\"0x%s\" end=\"0x%s\"/>\n",
6589 paddress (block->begin), paddress (block->end));
6591 buffer_grow_str0 (buffer, "</btrace>\n");
6594 case BTRACE_FORMAT_PT:
6595 buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n");
6596 buffer_grow_str (buffer, "<btrace version=\"1.0\">\n");
6597 buffer_grow_str (buffer, "<pt>\n");
6599 linux_low_encode_pt_config (buffer, &btrace.variant.pt.config);
6601 linux_low_encode_raw (buffer, btrace.variant.pt.data,
6602 btrace.variant.pt.size);
6604 buffer_grow_str (buffer, "</pt>\n");
6605 buffer_grow_str0 (buffer, "</btrace>\n");
6609 buffer_grow_str0 (buffer, "E.Unsupported Trace Format.");
6613 btrace_data_fini (&btrace);
6617 btrace_data_fini (&btrace);
6621 /* See to_btrace_conf target method. */
6624 linux_low_btrace_conf (const struct btrace_target_info *tinfo,
6625 struct buffer *buffer)
6627 const struct btrace_config *conf;
6629 buffer_grow_str (buffer, "<!DOCTYPE btrace-conf SYSTEM \"btrace-conf.dtd\">\n");
6630 buffer_grow_str (buffer, "<btrace-conf version=\"1.0\">\n");
6632 conf = linux_btrace_conf (tinfo);
6635 switch (conf->format)
6637 case BTRACE_FORMAT_NONE:
6640 case BTRACE_FORMAT_BTS:
6641 buffer_xml_printf (buffer, "<bts");
6642 buffer_xml_printf (buffer, " size=\"0x%x\"", conf->bts.size);
6643 buffer_xml_printf (buffer, " />\n");
6646 case BTRACE_FORMAT_PT:
6647 buffer_xml_printf (buffer, "<pt");
6648 buffer_xml_printf (buffer, " size=\"0x%x\"", conf->pt.size);
6649 buffer_xml_printf (buffer, "/>\n");
6654 buffer_grow_str0 (buffer, "</btrace-conf>\n");
6657 #endif /* HAVE_LINUX_BTRACE */
6659 /* See nat/linux-nat.h. */
6662 current_lwp_ptid (void)
6664 return ptid_of (current_thread);
6667 static struct target_ops linux_target_ops = {
6668 linux_create_inferior,
6678 linux_fetch_registers,
6679 linux_store_registers,
6680 linux_prepare_to_access_memory,
6681 linux_done_accessing_memory,
6684 linux_look_up_symbols,
6685 linux_request_interrupt,
6687 linux_supports_z_point_type,
6690 linux_stopped_by_sw_breakpoint,
6691 linux_supports_stopped_by_sw_breakpoint,
6692 linux_stopped_by_hw_breakpoint,
6693 linux_supports_stopped_by_hw_breakpoint,
6694 linux_supports_conditional_breakpoints,
6695 linux_stopped_by_watchpoint,
6696 linux_stopped_data_address,
6697 #if defined(__UCLIBC__) && defined(HAS_NOMMU) \
6698 && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
6699 && defined(PT_TEXT_END_ADDR)
6704 #ifdef USE_THREAD_DB
6705 thread_db_get_tls_address,
6710 hostio_last_error_from_errno,
6713 linux_supports_non_stop,
6715 linux_start_non_stop,
6716 linux_supports_multi_process,
6717 linux_supports_fork_events,
6718 linux_supports_vfork_events,
6719 linux_handle_new_gdb_connection,
6720 #ifdef USE_THREAD_DB
6721 thread_db_handle_monitor_command,
6725 linux_common_core_of_thread,
6727 linux_process_qsupported,
6728 linux_supports_tracepoints,
6731 linux_thread_stopped,
6735 linux_stabilize_threads,
6736 linux_install_fast_tracepoint_jump_pad,
6738 linux_supports_disable_randomization,
6739 linux_get_min_fast_tracepoint_insn_len,
6740 linux_qxfer_libraries_svr4,
6741 linux_supports_agent,
6742 #ifdef HAVE_LINUX_BTRACE
6743 linux_supports_btrace,
6744 linux_low_enable_btrace,
6745 linux_low_disable_btrace,
6746 linux_low_read_btrace,
6747 linux_low_btrace_conf,
6755 linux_supports_range_stepping,
6756 linux_proc_pid_to_exec_file,
6757 linux_mntns_open_cloexec,
6759 linux_mntns_readlink,
6763 linux_init_signals ()
6765 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
6766 to find what the cancel signal actually is. */
6767 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
6768 signal (__SIGRTMIN+1, SIG_IGN);
6772 #ifdef HAVE_LINUX_REGSETS
6774 initialize_regsets_info (struct regsets_info *info)
6776 for (info->num_regsets = 0;
6777 info->regsets[info->num_regsets].size >= 0;
6778 info->num_regsets++)
6784 initialize_low (void)
6786 struct sigaction sigchld_action;
6787 memset (&sigchld_action, 0, sizeof (sigchld_action));
6788 set_target_ops (&linux_target_ops);
6789 set_breakpoint_data (the_low_target.breakpoint,
6790 the_low_target.breakpoint_len);
6791 linux_init_signals ();
6792 linux_ptrace_init_warnings ();
6794 sigchld_action.sa_handler = sigchld_handler;
6795 sigemptyset (&sigchld_action.sa_mask);
6796 sigchld_action.sa_flags = SA_RESTART;
6797 sigaction (SIGCHLD, &sigchld_action, NULL);
6799 initialize_low_arch ();
6801 linux_check_ptrace_features ();