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 <sys/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. */
144 /* See nat/linux-nat.h. */
147 ptid_of_lwp (struct lwp_info *lwp)
149 return ptid_of (get_lwp_thread (lwp));
152 /* See nat/linux-nat.h. */
155 lwp_set_arch_private_info (struct lwp_info *lwp,
156 struct arch_lwp_info *info)
158 lwp->arch_private = info;
161 /* See nat/linux-nat.h. */
163 struct arch_lwp_info *
164 lwp_arch_private_info (struct lwp_info *lwp)
166 return lwp->arch_private;
169 /* See nat/linux-nat.h. */
172 lwp_is_stopped (struct lwp_info *lwp)
177 /* See nat/linux-nat.h. */
179 enum target_stop_reason
180 lwp_stop_reason (struct lwp_info *lwp)
182 return lwp->stop_reason;
185 /* A list of all unknown processes which receive stop signals. Some
186 other process will presumably claim each of these as forked
187 children momentarily. */
189 struct simple_pid_list
191 /* The process ID. */
194 /* The status as reported by waitpid. */
198 struct simple_pid_list *next;
200 struct simple_pid_list *stopped_pids;
202 /* Trivial list manipulation functions to keep track of a list of new
203 stopped processes. */
206 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
208 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
211 new_pid->status = status;
212 new_pid->next = *listp;
217 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
219 struct simple_pid_list **p;
221 for (p = listp; *p != NULL; p = &(*p)->next)
222 if ((*p)->pid == pid)
224 struct simple_pid_list *next = (*p)->next;
226 *statusp = (*p)->status;
234 enum stopping_threads_kind
236 /* Not stopping threads presently. */
237 NOT_STOPPING_THREADS,
239 /* Stopping threads. */
242 /* Stopping and suspending threads. */
243 STOPPING_AND_SUSPENDING_THREADS
246 /* This is set while stop_all_lwps is in effect. */
247 enum stopping_threads_kind stopping_threads = NOT_STOPPING_THREADS;
249 /* FIXME make into a target method? */
250 int using_threads = 1;
252 /* True if we're presently stabilizing threads (moving them out of
254 static int stabilizing_threads;
256 static void linux_resume_one_lwp (struct lwp_info *lwp,
257 int step, int signal, siginfo_t *info);
258 static void linux_resume (struct thread_resume *resume_info, size_t n);
259 static void stop_all_lwps (int suspend, struct lwp_info *except);
260 static void unstop_all_lwps (int unsuspend, struct lwp_info *except);
261 static int linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
262 int *wstat, int options);
263 static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
264 static struct lwp_info *add_lwp (ptid_t ptid);
265 static int linux_stopped_by_watchpoint (void);
266 static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
267 static void proceed_all_lwps (void);
268 static int finish_step_over (struct lwp_info *lwp);
269 static int kill_lwp (unsigned long lwpid, int signo);
271 /* When the event-loop is doing a step-over, this points at the thread
273 ptid_t step_over_bkpt;
275 /* True if the low target can hardware single-step. Such targets
276 don't need a BREAKPOINT_REINSERT_ADDR callback. */
279 can_hardware_single_step (void)
281 return (the_low_target.breakpoint_reinsert_addr == NULL);
284 /* True if the low target supports memory breakpoints. If so, we'll
285 have a GET_PC implementation. */
288 supports_breakpoints (void)
290 return (the_low_target.get_pc != NULL);
293 /* Returns true if this target can support fast tracepoints. This
294 does not mean that the in-process agent has been loaded in the
298 supports_fast_tracepoints (void)
300 return the_low_target.install_fast_tracepoint_jump_pad != NULL;
303 /* True if LWP is stopped in its stepping range. */
306 lwp_in_step_range (struct lwp_info *lwp)
308 CORE_ADDR pc = lwp->stop_pc;
310 return (pc >= lwp->step_range_start && pc < lwp->step_range_end);
313 struct pending_signals
317 struct pending_signals *prev;
320 /* The read/write ends of the pipe registered as waitable file in the
322 static int linux_event_pipe[2] = { -1, -1 };
324 /* True if we're currently in async mode. */
325 #define target_is_async_p() (linux_event_pipe[0] != -1)
327 static void send_sigstop (struct lwp_info *lwp);
328 static void wait_for_sigstop (void);
330 /* Return non-zero if HEADER is a 64-bit ELF file. */
333 elf_64_header_p (const Elf64_Ehdr *header, unsigned int *machine)
335 if (header->e_ident[EI_MAG0] == ELFMAG0
336 && header->e_ident[EI_MAG1] == ELFMAG1
337 && header->e_ident[EI_MAG2] == ELFMAG2
338 && header->e_ident[EI_MAG3] == ELFMAG3)
340 *machine = header->e_machine;
341 return header->e_ident[EI_CLASS] == ELFCLASS64;
348 /* Return non-zero if FILE is a 64-bit ELF file,
349 zero if the file is not a 64-bit ELF file,
350 and -1 if the file is not accessible or doesn't exist. */
353 elf_64_file_p (const char *file, unsigned int *machine)
358 fd = open (file, O_RDONLY);
362 if (read (fd, &header, sizeof (header)) != sizeof (header))
369 return elf_64_header_p (&header, machine);
372 /* Accepts an integer PID; Returns true if the executable PID is
373 running is a 64-bit ELF file.. */
376 linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine)
380 sprintf (file, "/proc/%d/exe", pid);
381 return elf_64_file_p (file, machine);
385 delete_lwp (struct lwp_info *lwp)
387 struct thread_info *thr = get_lwp_thread (lwp);
390 debug_printf ("deleting %ld\n", lwpid_of (thr));
393 free (lwp->arch_private);
397 /* Add a process to the common process list, and set its private
400 static struct process_info *
401 linux_add_process (int pid, int attached)
403 struct process_info *proc;
405 proc = add_process (pid, attached);
406 proc->priv = xcalloc (1, sizeof (*proc->priv));
408 if (the_low_target.new_process != NULL)
409 proc->priv->arch_private = the_low_target.new_process ();
414 static CORE_ADDR get_pc (struct lwp_info *lwp);
416 /* Handle a GNU/Linux extended wait response. If we see a clone
417 event, we need to add the new LWP to our list (and return 0 so as
418 not to report the trap to higher layers). */
421 handle_extended_wait (struct lwp_info *event_lwp, int wstat)
423 int event = linux_ptrace_get_extended_event (wstat);
424 struct thread_info *event_thr = get_lwp_thread (event_lwp);
425 struct lwp_info *new_lwp;
427 if ((event == PTRACE_EVENT_FORK) || (event == PTRACE_EVENT_VFORK)
428 || (event == PTRACE_EVENT_CLONE))
431 unsigned long new_pid;
434 /* Get the pid of the new lwp. */
435 ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_thr), (PTRACE_TYPE_ARG3) 0,
438 /* If we haven't already seen the new PID stop, wait for it now. */
439 if (!pull_pid_from_list (&stopped_pids, new_pid, &status))
441 /* The new child has a pending SIGSTOP. We can't affect it until it
442 hits the SIGSTOP, but we're already attached. */
444 ret = my_waitpid (new_pid, &status, __WALL);
447 perror_with_name ("waiting for new child");
448 else if (ret != new_pid)
449 warning ("wait returned unexpected PID %d", ret);
450 else if (!WIFSTOPPED (status))
451 warning ("wait returned unexpected status 0x%x", status);
454 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK)
456 struct process_info *parent_proc;
457 struct process_info *child_proc;
458 struct lwp_info *child_lwp;
459 struct thread_info *child_thr;
460 struct target_desc *tdesc;
462 ptid = ptid_build (new_pid, new_pid, 0);
466 debug_printf ("HEW: Got fork event from LWP %ld, "
468 ptid_get_lwp (ptid_of (event_thr)),
469 ptid_get_pid (ptid));
472 /* Add the new process to the tables and clone the breakpoint
473 lists of the parent. We need to do this even if the new process
474 will be detached, since we will need the process object and the
475 breakpoints to remove any breakpoints from memory when we
476 detach, and the client side will access registers. */
477 child_proc = linux_add_process (new_pid, 0);
478 gdb_assert (child_proc != NULL);
479 child_lwp = add_lwp (ptid);
480 gdb_assert (child_lwp != NULL);
481 child_lwp->stopped = 1;
482 child_lwp->must_set_ptrace_flags = 1;
483 child_lwp->status_pending_p = 0;
484 child_thr = get_lwp_thread (child_lwp);
485 child_thr->last_resume_kind = resume_stop;
486 parent_proc = get_thread_process (event_thr);
487 child_proc->attached = parent_proc->attached;
488 clone_all_breakpoints (&child_proc->breakpoints,
489 &child_proc->raw_breakpoints,
490 parent_proc->breakpoints);
492 tdesc = xmalloc (sizeof (struct target_desc));
493 copy_target_description (tdesc, parent_proc->tdesc);
494 child_proc->tdesc = tdesc;
496 /* Clone arch-specific process data. */
497 if (the_low_target.new_fork != NULL)
498 the_low_target.new_fork (parent_proc, child_proc);
500 /* Save fork info in the parent thread. */
501 if (event == PTRACE_EVENT_FORK)
502 event_lwp->waitstatus.kind = TARGET_WAITKIND_FORKED;
503 else if (event == PTRACE_EVENT_VFORK)
504 event_lwp->waitstatus.kind = TARGET_WAITKIND_VFORKED;
506 event_lwp->waitstatus.value.related_pid = ptid;
508 /* The status_pending field contains bits denoting the
509 extended event, so when the pending event is handled,
510 the handler will look at lwp->waitstatus. */
511 event_lwp->status_pending_p = 1;
512 event_lwp->status_pending = wstat;
514 /* Report the event. */
519 debug_printf ("HEW: Got clone event "
520 "from LWP %ld, new child is LWP %ld\n",
521 lwpid_of (event_thr), new_pid);
523 ptid = ptid_build (pid_of (event_thr), new_pid, 0);
524 new_lwp = add_lwp (ptid);
526 /* Either we're going to immediately resume the new thread
527 or leave it stopped. linux_resume_one_lwp is a nop if it
528 thinks the thread is currently running, so set this first
529 before calling linux_resume_one_lwp. */
530 new_lwp->stopped = 1;
532 /* If we're suspending all threads, leave this one suspended
534 if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS)
535 new_lwp->suspended = 1;
537 /* Normally we will get the pending SIGSTOP. But in some cases
538 we might get another signal delivered to the group first.
539 If we do get another signal, be sure not to lose it. */
540 if (WSTOPSIG (status) != SIGSTOP)
542 new_lwp->stop_expected = 1;
543 new_lwp->status_pending_p = 1;
544 new_lwp->status_pending = status;
547 /* Don't report the event. */
550 else if (event == PTRACE_EVENT_VFORK_DONE)
552 event_lwp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
554 /* Report the event. */
558 internal_error (__FILE__, __LINE__, _("unknown ptrace event %d"), event);
561 /* Return the PC as read from the regcache of LWP, without any
565 get_pc (struct lwp_info *lwp)
567 struct thread_info *saved_thread;
568 struct regcache *regcache;
571 if (the_low_target.get_pc == NULL)
574 saved_thread = current_thread;
575 current_thread = get_lwp_thread (lwp);
577 regcache = get_thread_regcache (current_thread, 1);
578 pc = (*the_low_target.get_pc) (regcache);
581 debug_printf ("pc is 0x%lx\n", (long) pc);
583 current_thread = saved_thread;
587 /* This function should only be called if LWP got a SIGTRAP.
588 The SIGTRAP could mean several things.
590 On i386, where decr_pc_after_break is non-zero:
592 If we were single-stepping this process using PTRACE_SINGLESTEP, we
593 will get only the one SIGTRAP. The value of $eip will be the next
594 instruction. If the instruction we stepped over was a breakpoint,
595 we need to decrement the PC.
597 If we continue the process using PTRACE_CONT, we will get a
598 SIGTRAP when we hit a breakpoint. The value of $eip will be
599 the instruction after the breakpoint (i.e. needs to be
600 decremented). If we report the SIGTRAP to GDB, we must also
601 report the undecremented PC. If the breakpoint is removed, we
602 must resume at the decremented PC.
604 On a non-decr_pc_after_break machine with hardware or kernel
607 If we either single-step a breakpoint instruction, or continue and
608 hit a breakpoint instruction, our PC will point at the breakpoint
612 check_stopped_by_breakpoint (struct lwp_info *lwp)
615 CORE_ADDR sw_breakpoint_pc;
616 struct thread_info *saved_thread;
617 #if USE_SIGTRAP_SIGINFO
621 if (the_low_target.get_pc == NULL)
625 sw_breakpoint_pc = pc - the_low_target.decr_pc_after_break;
627 /* breakpoint_at reads from the current thread. */
628 saved_thread = current_thread;
629 current_thread = get_lwp_thread (lwp);
631 #if USE_SIGTRAP_SIGINFO
632 if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread),
633 (PTRACE_TYPE_ARG3) 0, &siginfo) == 0)
635 if (siginfo.si_signo == SIGTRAP)
637 if (siginfo.si_code == GDB_ARCH_TRAP_BRKPT)
641 struct thread_info *thr = get_lwp_thread (lwp);
643 debug_printf ("CSBB: %s stopped by software breakpoint\n",
644 target_pid_to_str (ptid_of (thr)));
647 /* Back up the PC if necessary. */
648 if (pc != sw_breakpoint_pc)
650 struct regcache *regcache
651 = get_thread_regcache (current_thread, 1);
652 (*the_low_target.set_pc) (regcache, sw_breakpoint_pc);
655 lwp->stop_pc = sw_breakpoint_pc;
656 lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
657 current_thread = saved_thread;
660 else if (siginfo.si_code == TRAP_HWBKPT)
664 struct thread_info *thr = get_lwp_thread (lwp);
666 debug_printf ("CSBB: %s stopped by hardware "
667 "breakpoint/watchpoint\n",
668 target_pid_to_str (ptid_of (thr)));
672 lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
673 current_thread = saved_thread;
676 else if (siginfo.si_code == TRAP_TRACE)
680 struct thread_info *thr = get_lwp_thread (lwp);
682 debug_printf ("CSBB: %s stopped by trace\n",
683 target_pid_to_str (ptid_of (thr)));
689 /* We may have just stepped a breakpoint instruction. E.g., in
690 non-stop mode, GDB first tells the thread A to step a range, and
691 then the user inserts a breakpoint inside the range. In that
692 case we need to report the breakpoint PC. */
693 if ((!lwp->stepping || lwp->stop_pc == sw_breakpoint_pc)
694 && (*the_low_target.breakpoint_at) (sw_breakpoint_pc))
698 struct thread_info *thr = get_lwp_thread (lwp);
700 debug_printf ("CSBB: %s stopped by software breakpoint\n",
701 target_pid_to_str (ptid_of (thr)));
704 /* Back up the PC if necessary. */
705 if (pc != sw_breakpoint_pc)
707 struct regcache *regcache
708 = get_thread_regcache (current_thread, 1);
709 (*the_low_target.set_pc) (regcache, sw_breakpoint_pc);
712 lwp->stop_pc = sw_breakpoint_pc;
713 lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
714 current_thread = saved_thread;
718 if (hardware_breakpoint_inserted_here (pc))
722 struct thread_info *thr = get_lwp_thread (lwp);
724 debug_printf ("CSBB: %s stopped by hardware breakpoint\n",
725 target_pid_to_str (ptid_of (thr)));
729 lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
730 current_thread = saved_thread;
735 current_thread = saved_thread;
739 static struct lwp_info *
740 add_lwp (ptid_t ptid)
742 struct lwp_info *lwp;
744 lwp = (struct lwp_info *) xmalloc (sizeof (*lwp));
745 memset (lwp, 0, sizeof (*lwp));
747 if (the_low_target.new_thread != NULL)
748 the_low_target.new_thread (lwp);
750 lwp->thread = add_thread (ptid, lwp);
755 /* Start an inferior process and returns its pid.
756 ALLARGS is a vector of program-name and args. */
759 linux_create_inferior (char *program, char **allargs)
761 struct lwp_info *new_lwp;
764 struct cleanup *restore_personality
765 = maybe_disable_address_space_randomization (disable_randomization);
766 struct process_info *proc;
768 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
774 perror_with_name ("fork");
779 ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0);
781 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
782 signal (__SIGRTMIN + 1, SIG_DFL);
787 /* If gdbserver is connected to gdb via stdio, redirect the inferior's
788 stdout to stderr so that inferior i/o doesn't corrupt the connection.
789 Also, redirect stdin to /dev/null. */
790 if (remote_connection_is_stdio ())
793 open ("/dev/null", O_RDONLY);
795 if (write (2, "stdin/stdout redirected\n",
796 sizeof ("stdin/stdout redirected\n") - 1) < 0)
798 /* Errors ignored. */;
802 execv (program, allargs);
804 execvp (program, allargs);
806 fprintf (stderr, "Cannot exec %s: %s.\n", program,
812 do_cleanups (restore_personality);
814 proc = linux_add_process (pid, 0);
815 /* Set the arch when the first LWP stops. */
816 proc->priv->new_inferior = 1;
818 ptid = ptid_build (pid, pid, 0);
819 new_lwp = add_lwp (ptid);
820 new_lwp->must_set_ptrace_flags = 1;
825 /* Implement the arch_setup target_ops method. */
828 linux_arch_setup (void)
830 the_low_target.arch_setup ();
833 /* Attach to an inferior process. Returns 0 on success, ERRNO on
837 linux_attach_lwp (ptid_t ptid)
839 struct lwp_info *new_lwp;
840 int lwpid = ptid_get_lwp (ptid);
842 if (ptrace (PTRACE_ATTACH, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0)
846 new_lwp = add_lwp (ptid);
848 /* We need to wait for SIGSTOP before being able to make the next
849 ptrace call on this LWP. */
850 new_lwp->must_set_ptrace_flags = 1;
852 if (linux_proc_pid_is_stopped (lwpid))
855 debug_printf ("Attached to a stopped process\n");
857 /* The process is definitely stopped. It is in a job control
858 stop, unless the kernel predates the TASK_STOPPED /
859 TASK_TRACED distinction, in which case it might be in a
860 ptrace stop. Make sure it is in a ptrace stop; from there we
861 can kill it, signal it, et cetera.
863 First make sure there is a pending SIGSTOP. Since we are
864 already attached, the process can not transition from stopped
865 to running without a PTRACE_CONT; so we know this signal will
866 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
867 probably already in the queue (unless this kernel is old
868 enough to use TASK_STOPPED for ptrace stops); but since
869 SIGSTOP is not an RT signal, it can only be queued once. */
870 kill_lwp (lwpid, SIGSTOP);
872 /* Finally, resume the stopped process. This will deliver the
873 SIGSTOP (or a higher priority signal, just like normal
874 PTRACE_ATTACH), which we'll catch later on. */
875 ptrace (PTRACE_CONT, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0);
878 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
881 There are several cases to consider here:
883 1) gdbserver has already attached to the process and is being notified
884 of a new thread that is being created.
885 In this case we should ignore that SIGSTOP and resume the
886 process. This is handled below by setting stop_expected = 1,
887 and the fact that add_thread sets last_resume_kind ==
890 2) This is the first thread (the process thread), and we're attaching
891 to it via attach_inferior.
892 In this case we want the process thread to stop.
893 This is handled by having linux_attach set last_resume_kind ==
894 resume_stop after we return.
896 If the pid we are attaching to is also the tgid, we attach to and
897 stop all the existing threads. Otherwise, we attach to pid and
898 ignore any other threads in the same group as this pid.
900 3) GDB is connecting to gdbserver and is requesting an enumeration of all
902 In this case we want the thread to stop.
903 FIXME: This case is currently not properly handled.
904 We should wait for the SIGSTOP but don't. Things work apparently
905 because enough time passes between when we ptrace (ATTACH) and when
906 gdb makes the next ptrace call on the thread.
908 On the other hand, if we are currently trying to stop all threads, we
909 should treat the new thread as if we had sent it a SIGSTOP. This works
910 because we are guaranteed that the add_lwp call above added us to the
911 end of the list, and so the new thread has not yet reached
912 wait_for_sigstop (but will). */
913 new_lwp->stop_expected = 1;
918 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
919 already attached. Returns true if a new LWP is found, false
923 attach_proc_task_lwp_callback (ptid_t ptid)
925 /* Is this a new thread? */
926 if (find_thread_ptid (ptid) == NULL)
928 int lwpid = ptid_get_lwp (ptid);
932 debug_printf ("Found new lwp %d\n", lwpid);
934 err = linux_attach_lwp (ptid);
936 /* Be quiet if we simply raced with the thread exiting. EPERM
937 is returned if the thread's task still exists, and is marked
938 as exited or zombie, as well as other conditions, so in that
939 case, confirm the status in /proc/PID/status. */
941 || (err == EPERM && linux_proc_pid_is_gone (lwpid)))
945 debug_printf ("Cannot attach to lwp %d: "
946 "thread is gone (%d: %s)\n",
947 lwpid, err, strerror (err));
952 warning (_("Cannot attach to lwp %d: %s"),
954 linux_ptrace_attach_fail_reason_string (ptid, err));
962 /* Attach to PID. If PID is the tgid, attach to it and all
966 linux_attach (unsigned long pid)
968 ptid_t ptid = ptid_build (pid, pid, 0);
970 struct process_info *proc;
972 /* Attach to PID. We will check for other threads
974 err = linux_attach_lwp (ptid);
976 error ("Cannot attach to process %ld: %s",
977 pid, linux_ptrace_attach_fail_reason_string (ptid, err));
979 proc = linux_add_process (pid, 1);
980 /* Set the arch when the first LWP stops. */
981 proc->priv->new_inferior = 1;
985 struct thread_info *thread;
987 /* Don't ignore the initial SIGSTOP if we just attached to this
988 process. It will be collected by wait shortly. */
989 thread = find_thread_ptid (ptid_build (pid, pid, 0));
990 thread->last_resume_kind = resume_stop;
993 /* We must attach to every LWP. If /proc is mounted, use that to
994 find them now. On the one hand, the inferior may be using raw
995 clone instead of using pthreads. On the other hand, even if it
996 is using pthreads, GDB may not be connected yet (thread_db needs
997 to do symbol lookups, through qSymbol). Also, thread_db walks
998 structures in the inferior's address space to find the list of
999 threads/LWPs, and those structures may well be corrupted. Note
1000 that once thread_db is loaded, we'll still use it to list threads
1001 and associate pthread info with each LWP. */
1002 linux_proc_attach_tgid_threads (pid, attach_proc_task_lwp_callback);
1013 second_thread_of_pid_p (struct inferior_list_entry *entry, void *args)
1015 struct counter *counter = args;
1017 if (ptid_get_pid (entry->id) == counter->pid)
1019 if (++counter->count > 1)
1027 last_thread_of_process_p (int pid)
1029 struct counter counter = { pid , 0 };
1031 return (find_inferior (&all_threads,
1032 second_thread_of_pid_p, &counter) == NULL);
1038 linux_kill_one_lwp (struct lwp_info *lwp)
1040 struct thread_info *thr = get_lwp_thread (lwp);
1041 int pid = lwpid_of (thr);
1043 /* PTRACE_KILL is unreliable. After stepping into a signal handler,
1044 there is no signal context, and ptrace(PTRACE_KILL) (or
1045 ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
1046 ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
1047 alternative is to kill with SIGKILL. We only need one SIGKILL
1048 per process, not one for each thread. But since we still support
1049 linuxthreads, and we also support debugging programs using raw
1050 clone without CLONE_THREAD, we send one for each thread. For
1051 years, we used PTRACE_KILL only, so we're being a bit paranoid
1052 about some old kernels where PTRACE_KILL might work better
1053 (dubious if there are any such, but that's why it's paranoia), so
1054 we try SIGKILL first, PTRACE_KILL second, and so we're fine
1058 kill_lwp (pid, SIGKILL);
1061 int save_errno = errno;
1063 debug_printf ("LKL: kill_lwp (SIGKILL) %s, 0, 0 (%s)\n",
1064 target_pid_to_str (ptid_of (thr)),
1065 save_errno ? strerror (save_errno) : "OK");
1069 ptrace (PTRACE_KILL, pid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0);
1072 int save_errno = errno;
1074 debug_printf ("LKL: PTRACE_KILL %s, 0, 0 (%s)\n",
1075 target_pid_to_str (ptid_of (thr)),
1076 save_errno ? strerror (save_errno) : "OK");
1080 /* Kill LWP and wait for it to die. */
1083 kill_wait_lwp (struct lwp_info *lwp)
1085 struct thread_info *thr = get_lwp_thread (lwp);
1086 int pid = ptid_get_pid (ptid_of (thr));
1087 int lwpid = ptid_get_lwp (ptid_of (thr));
1092 debug_printf ("kwl: killing lwp %d, for pid: %d\n", lwpid, pid);
1096 linux_kill_one_lwp (lwp);
1098 /* Make sure it died. Notes:
1100 - The loop is most likely unnecessary.
1102 - We don't use linux_wait_for_event as that could delete lwps
1103 while we're iterating over them. We're not interested in
1104 any pending status at this point, only in making sure all
1105 wait status on the kernel side are collected until the
1108 - We don't use __WALL here as the __WALL emulation relies on
1109 SIGCHLD, and killing a stopped process doesn't generate
1110 one, nor an exit status.
1112 res = my_waitpid (lwpid, &wstat, 0);
1113 if (res == -1 && errno == ECHILD)
1114 res = my_waitpid (lwpid, &wstat, __WCLONE);
1115 } while (res > 0 && WIFSTOPPED (wstat));
1117 /* Even if it was stopped, the child may have already disappeared.
1118 E.g., if it was killed by SIGKILL. */
1119 if (res < 0 && errno != ECHILD)
1120 perror_with_name ("kill_wait_lwp");
1123 /* Callback for `find_inferior'. Kills an lwp of a given process,
1124 except the leader. */
1127 kill_one_lwp_callback (struct inferior_list_entry *entry, void *args)
1129 struct thread_info *thread = (struct thread_info *) entry;
1130 struct lwp_info *lwp = get_thread_lwp (thread);
1131 int pid = * (int *) args;
1133 if (ptid_get_pid (entry->id) != pid)
1136 /* We avoid killing the first thread here, because of a Linux kernel (at
1137 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
1138 the children get a chance to be reaped, it will remain a zombie
1141 if (lwpid_of (thread) == pid)
1144 debug_printf ("lkop: is last of process %s\n",
1145 target_pid_to_str (entry->id));
1149 kill_wait_lwp (lwp);
1154 linux_kill (int pid)
1156 struct process_info *process;
1157 struct lwp_info *lwp;
1159 process = find_process_pid (pid);
1160 if (process == NULL)
1163 /* If we're killing a running inferior, make sure it is stopped
1164 first, as PTRACE_KILL will not work otherwise. */
1165 stop_all_lwps (0, NULL);
1167 find_inferior (&all_threads, kill_one_lwp_callback , &pid);
1169 /* See the comment in linux_kill_one_lwp. We did not kill the first
1170 thread in the list, so do so now. */
1171 lwp = find_lwp_pid (pid_to_ptid (pid));
1176 debug_printf ("lk_1: cannot find lwp for pid: %d\n",
1180 kill_wait_lwp (lwp);
1182 the_target->mourn (process);
1184 /* Since we presently can only stop all lwps of all processes, we
1185 need to unstop lwps of other processes. */
1186 unstop_all_lwps (0, NULL);
1190 /* Get pending signal of THREAD, for detaching purposes. This is the
1191 signal the thread last stopped for, which we need to deliver to the
1192 thread when detaching, otherwise, it'd be suppressed/lost. */
1195 get_detach_signal (struct thread_info *thread)
1197 enum gdb_signal signo = GDB_SIGNAL_0;
1199 struct lwp_info *lp = get_thread_lwp (thread);
1201 if (lp->status_pending_p)
1202 status = lp->status_pending;
1205 /* If the thread had been suspended by gdbserver, and it stopped
1206 cleanly, then it'll have stopped with SIGSTOP. But we don't
1207 want to deliver that SIGSTOP. */
1208 if (thread->last_status.kind != TARGET_WAITKIND_STOPPED
1209 || thread->last_status.value.sig == GDB_SIGNAL_0)
1212 /* Otherwise, we may need to deliver the signal we
1214 status = lp->last_status;
1217 if (!WIFSTOPPED (status))
1220 debug_printf ("GPS: lwp %s hasn't stopped: no pending signal\n",
1221 target_pid_to_str (ptid_of (thread)));
1225 /* Extended wait statuses aren't real SIGTRAPs. */
1226 if (WSTOPSIG (status) == SIGTRAP && linux_is_extended_waitstatus (status))
1229 debug_printf ("GPS: lwp %s had stopped with extended "
1230 "status: no pending signal\n",
1231 target_pid_to_str (ptid_of (thread)));
1235 signo = gdb_signal_from_host (WSTOPSIG (status));
1237 if (program_signals_p && !program_signals[signo])
1240 debug_printf ("GPS: lwp %s had signal %s, but it is in nopass state\n",
1241 target_pid_to_str (ptid_of (thread)),
1242 gdb_signal_to_string (signo));
1245 else if (!program_signals_p
1246 /* If we have no way to know which signals GDB does not
1247 want to have passed to the program, assume
1248 SIGTRAP/SIGINT, which is GDB's default. */
1249 && (signo == GDB_SIGNAL_TRAP || signo == GDB_SIGNAL_INT))
1252 debug_printf ("GPS: lwp %s had signal %s, "
1253 "but we don't know if we should pass it. "
1254 "Default to not.\n",
1255 target_pid_to_str (ptid_of (thread)),
1256 gdb_signal_to_string (signo));
1262 debug_printf ("GPS: lwp %s has pending signal %s: delivering it.\n",
1263 target_pid_to_str (ptid_of (thread)),
1264 gdb_signal_to_string (signo));
1266 return WSTOPSIG (status);
1271 linux_detach_one_lwp (struct inferior_list_entry *entry, void *args)
1273 struct thread_info *thread = (struct thread_info *) entry;
1274 struct lwp_info *lwp = get_thread_lwp (thread);
1275 int pid = * (int *) args;
1278 if (ptid_get_pid (entry->id) != pid)
1281 /* If there is a pending SIGSTOP, get rid of it. */
1282 if (lwp->stop_expected)
1285 debug_printf ("Sending SIGCONT to %s\n",
1286 target_pid_to_str (ptid_of (thread)));
1288 kill_lwp (lwpid_of (thread), SIGCONT);
1289 lwp->stop_expected = 0;
1292 /* Flush any pending changes to the process's registers. */
1293 regcache_invalidate_thread (thread);
1295 /* Pass on any pending signal for this thread. */
1296 sig = get_detach_signal (thread);
1298 /* Finally, let it resume. */
1299 if (the_low_target.prepare_to_resume != NULL)
1300 the_low_target.prepare_to_resume (lwp);
1301 if (ptrace (PTRACE_DETACH, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
1302 (PTRACE_TYPE_ARG4) (long) sig) < 0)
1303 error (_("Can't detach %s: %s"),
1304 target_pid_to_str (ptid_of (thread)),
1312 linux_detach (int pid)
1314 struct process_info *process;
1316 process = find_process_pid (pid);
1317 if (process == NULL)
1320 /* Stop all threads before detaching. First, ptrace requires that
1321 the thread is stopped to sucessfully detach. Second, thread_db
1322 may need to uninstall thread event breakpoints from memory, which
1323 only works with a stopped process anyway. */
1324 stop_all_lwps (0, NULL);
1326 #ifdef USE_THREAD_DB
1327 thread_db_detach (process);
1330 /* Stabilize threads (move out of jump pads). */
1331 stabilize_threads ();
1333 find_inferior (&all_threads, linux_detach_one_lwp, &pid);
1335 the_target->mourn (process);
1337 /* Since we presently can only stop all lwps of all processes, we
1338 need to unstop lwps of other processes. */
1339 unstop_all_lwps (0, NULL);
1343 /* Remove all LWPs that belong to process PROC from the lwp list. */
1346 delete_lwp_callback (struct inferior_list_entry *entry, void *proc)
1348 struct thread_info *thread = (struct thread_info *) entry;
1349 struct lwp_info *lwp = get_thread_lwp (thread);
1350 struct process_info *process = proc;
1352 if (pid_of (thread) == pid_of (process))
1359 linux_mourn (struct process_info *process)
1361 struct process_info_private *priv;
1363 #ifdef USE_THREAD_DB
1364 thread_db_mourn (process);
1367 find_inferior (&all_threads, delete_lwp_callback, process);
1369 /* Freeing all private data. */
1370 priv = process->priv;
1371 free (priv->arch_private);
1373 process->priv = NULL;
1375 remove_process (process);
1379 linux_join (int pid)
1384 ret = my_waitpid (pid, &status, 0);
1385 if (WIFEXITED (status) || WIFSIGNALED (status))
1387 } while (ret != -1 || errno != ECHILD);
1390 /* Return nonzero if the given thread is still alive. */
1392 linux_thread_alive (ptid_t ptid)
1394 struct lwp_info *lwp = find_lwp_pid (ptid);
1396 /* We assume we always know if a thread exits. If a whole process
1397 exited but we still haven't been able to report it to GDB, we'll
1398 hold on to the last lwp of the dead process. */
1405 /* Return 1 if this lwp still has an interesting status pending. If
1406 not (e.g., it had stopped for a breakpoint that is gone), return
1410 thread_still_has_status_pending_p (struct thread_info *thread)
1412 struct lwp_info *lp = get_thread_lwp (thread);
1414 if (!lp->status_pending_p)
1417 /* If we got a `vCont;t', but we haven't reported a stop yet, do
1418 report any status pending the LWP may have. */
1419 if (thread->last_resume_kind == resume_stop
1420 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
1423 if (thread->last_resume_kind != resume_stop
1424 && (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
1425 || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
1427 struct thread_info *saved_thread;
1431 gdb_assert (lp->last_status != 0);
1435 saved_thread = current_thread;
1436 current_thread = thread;
1438 if (pc != lp->stop_pc)
1441 debug_printf ("PC of %ld changed\n",
1446 #if !USE_SIGTRAP_SIGINFO
1447 else if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
1448 && !(*the_low_target.breakpoint_at) (pc))
1451 debug_printf ("previous SW breakpoint of %ld gone\n",
1455 else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT
1456 && !hardware_breakpoint_inserted_here (pc))
1459 debug_printf ("previous HW breakpoint of %ld gone\n",
1465 current_thread = saved_thread;
1470 debug_printf ("discarding pending breakpoint status\n");
1471 lp->status_pending_p = 0;
1479 /* Return 1 if this lwp has an interesting status pending. */
1481 status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
1483 struct thread_info *thread = (struct thread_info *) entry;
1484 struct lwp_info *lp = get_thread_lwp (thread);
1485 ptid_t ptid = * (ptid_t *) arg;
1487 /* Check if we're only interested in events from a specific process
1488 or a specific LWP. */
1489 if (!ptid_match (ptid_of (thread), ptid))
1492 if (lp->status_pending_p
1493 && !thread_still_has_status_pending_p (thread))
1495 linux_resume_one_lwp (lp, lp->stepping, GDB_SIGNAL_0, NULL);
1499 return lp->status_pending_p;
1503 same_lwp (struct inferior_list_entry *entry, void *data)
1505 ptid_t ptid = *(ptid_t *) data;
1508 if (ptid_get_lwp (ptid) != 0)
1509 lwp = ptid_get_lwp (ptid);
1511 lwp = ptid_get_pid (ptid);
1513 if (ptid_get_lwp (entry->id) == lwp)
1520 find_lwp_pid (ptid_t ptid)
1522 struct inferior_list_entry *thread
1523 = find_inferior (&all_threads, same_lwp, &ptid);
1528 return get_thread_lwp ((struct thread_info *) thread);
1531 /* Return the number of known LWPs in the tgid given by PID. */
1536 struct inferior_list_entry *inf, *tmp;
1539 ALL_INFERIORS (&all_threads, inf, tmp)
1541 if (ptid_get_pid (inf->id) == pid)
1548 /* The arguments passed to iterate_over_lwps. */
1550 struct iterate_over_lwps_args
1552 /* The FILTER argument passed to iterate_over_lwps. */
1555 /* The CALLBACK argument passed to iterate_over_lwps. */
1556 iterate_over_lwps_ftype *callback;
1558 /* The DATA argument passed to iterate_over_lwps. */
1562 /* Callback for find_inferior used by iterate_over_lwps to filter
1563 calls to the callback supplied to that function. Returning a
1564 nonzero value causes find_inferiors to stop iterating and return
1565 the current inferior_list_entry. Returning zero indicates that
1566 find_inferiors should continue iterating. */
1569 iterate_over_lwps_filter (struct inferior_list_entry *entry, void *args_p)
1571 struct iterate_over_lwps_args *args
1572 = (struct iterate_over_lwps_args *) args_p;
1574 if (ptid_match (entry->id, args->filter))
1576 struct thread_info *thr = (struct thread_info *) entry;
1577 struct lwp_info *lwp = get_thread_lwp (thr);
1579 return (*args->callback) (lwp, args->data);
1585 /* See nat/linux-nat.h. */
1588 iterate_over_lwps (ptid_t filter,
1589 iterate_over_lwps_ftype callback,
1592 struct iterate_over_lwps_args args = {filter, callback, data};
1593 struct inferior_list_entry *entry;
1595 entry = find_inferior (&all_threads, iterate_over_lwps_filter, &args);
1599 return get_thread_lwp ((struct thread_info *) entry);
1602 /* Detect zombie thread group leaders, and "exit" them. We can't reap
1603 their exits until all other threads in the group have exited. */
1606 check_zombie_leaders (void)
1608 struct process_info *proc, *tmp;
1610 ALL_PROCESSES (proc, tmp)
1612 pid_t leader_pid = pid_of (proc);
1613 struct lwp_info *leader_lp;
1615 leader_lp = find_lwp_pid (pid_to_ptid (leader_pid));
1618 debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, "
1619 "num_lwps=%d, zombie=%d\n",
1620 leader_pid, leader_lp!= NULL, num_lwps (leader_pid),
1621 linux_proc_pid_is_zombie (leader_pid));
1623 if (leader_lp != NULL
1624 /* Check if there are other threads in the group, as we may
1625 have raced with the inferior simply exiting. */
1626 && !last_thread_of_process_p (leader_pid)
1627 && linux_proc_pid_is_zombie (leader_pid))
1629 /* A leader zombie can mean one of two things:
1631 - It exited, and there's an exit status pending
1632 available, or only the leader exited (not the whole
1633 program). In the latter case, we can't waitpid the
1634 leader's exit status until all other threads are gone.
1636 - There are 3 or more threads in the group, and a thread
1637 other than the leader exec'd. On an exec, the Linux
1638 kernel destroys all other threads (except the execing
1639 one) in the thread group, and resets the execing thread's
1640 tid to the tgid. No exit notification is sent for the
1641 execing thread -- from the ptracer's perspective, it
1642 appears as though the execing thread just vanishes.
1643 Until we reap all other threads except the leader and the
1644 execing thread, the leader will be zombie, and the
1645 execing thread will be in `D (disc sleep)'. As soon as
1646 all other threads are reaped, the execing thread changes
1647 it's tid to the tgid, and the previous (zombie) leader
1648 vanishes, giving place to the "new" leader. We could try
1649 distinguishing the exit and exec cases, by waiting once
1650 more, and seeing if something comes out, but it doesn't
1651 sound useful. The previous leader _does_ go away, and
1652 we'll re-add the new one once we see the exec event
1653 (which is just the same as what would happen if the
1654 previous leader did exit voluntarily before some other
1659 "CZL: Thread group leader %d zombie "
1660 "(it exited, or another thread execd).\n",
1663 delete_lwp (leader_lp);
1668 /* Callback for `find_inferior'. Returns the first LWP that is not
1669 stopped. ARG is a PTID filter. */
1672 not_stopped_callback (struct inferior_list_entry *entry, void *arg)
1674 struct thread_info *thr = (struct thread_info *) entry;
1675 struct lwp_info *lwp;
1676 ptid_t filter = *(ptid_t *) arg;
1678 if (!ptid_match (ptid_of (thr), filter))
1681 lwp = get_thread_lwp (thr);
1688 /* This function should only be called if the LWP got a SIGTRAP.
1690 Handle any tracepoint steps or hits. Return true if a tracepoint
1691 event was handled, 0 otherwise. */
1694 handle_tracepoints (struct lwp_info *lwp)
1696 struct thread_info *tinfo = get_lwp_thread (lwp);
1697 int tpoint_related_event = 0;
1699 gdb_assert (lwp->suspended == 0);
1701 /* If this tracepoint hit causes a tracing stop, we'll immediately
1702 uninsert tracepoints. To do this, we temporarily pause all
1703 threads, unpatch away, and then unpause threads. We need to make
1704 sure the unpausing doesn't resume LWP too. */
1707 /* And we need to be sure that any all-threads-stopping doesn't try
1708 to move threads out of the jump pads, as it could deadlock the
1709 inferior (LWP could be in the jump pad, maybe even holding the
1712 /* Do any necessary step collect actions. */
1713 tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc);
1715 tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc);
1717 /* See if we just hit a tracepoint and do its main collect
1719 tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc);
1723 gdb_assert (lwp->suspended == 0);
1724 gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint);
1726 if (tpoint_related_event)
1729 debug_printf ("got a tracepoint event\n");
1736 /* Convenience wrapper. Returns true if LWP is presently collecting a
1740 linux_fast_tracepoint_collecting (struct lwp_info *lwp,
1741 struct fast_tpoint_collect_status *status)
1743 CORE_ADDR thread_area;
1744 struct thread_info *thread = get_lwp_thread (lwp);
1746 if (the_low_target.get_thread_area == NULL)
1749 /* Get the thread area address. This is used to recognize which
1750 thread is which when tracing with the in-process agent library.
1751 We don't read anything from the address, and treat it as opaque;
1752 it's the address itself that we assume is unique per-thread. */
1753 if ((*the_low_target.get_thread_area) (lwpid_of (thread), &thread_area) == -1)
1756 return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status);
1759 /* The reason we resume in the caller, is because we want to be able
1760 to pass lwp->status_pending as WSTAT, and we need to clear
1761 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1762 refuses to resume. */
1765 maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat)
1767 struct thread_info *saved_thread;
1769 saved_thread = current_thread;
1770 current_thread = get_lwp_thread (lwp);
1773 || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP))
1774 && supports_fast_tracepoints ()
1775 && agent_loaded_p ())
1777 struct fast_tpoint_collect_status status;
1781 debug_printf ("Checking whether LWP %ld needs to move out of the "
1783 lwpid_of (current_thread));
1785 r = linux_fast_tracepoint_collecting (lwp, &status);
1788 || (WSTOPSIG (*wstat) != SIGILL
1789 && WSTOPSIG (*wstat) != SIGFPE
1790 && WSTOPSIG (*wstat) != SIGSEGV
1791 && WSTOPSIG (*wstat) != SIGBUS))
1793 lwp->collecting_fast_tracepoint = r;
1797 if (r == 1 && lwp->exit_jump_pad_bkpt == NULL)
1799 /* Haven't executed the original instruction yet.
1800 Set breakpoint there, and wait till it's hit,
1801 then single-step until exiting the jump pad. */
1802 lwp->exit_jump_pad_bkpt
1803 = set_breakpoint_at (status.adjusted_insn_addr, NULL);
1807 debug_printf ("Checking whether LWP %ld needs to move out of "
1808 "the jump pad...it does\n",
1809 lwpid_of (current_thread));
1810 current_thread = saved_thread;
1817 /* If we get a synchronous signal while collecting, *and*
1818 while executing the (relocated) original instruction,
1819 reset the PC to point at the tpoint address, before
1820 reporting to GDB. Otherwise, it's an IPA lib bug: just
1821 report the signal to GDB, and pray for the best. */
1823 lwp->collecting_fast_tracepoint = 0;
1826 && (status.adjusted_insn_addr <= lwp->stop_pc
1827 && lwp->stop_pc < status.adjusted_insn_addr_end))
1830 struct regcache *regcache;
1832 /* The si_addr on a few signals references the address
1833 of the faulting instruction. Adjust that as
1835 if ((WSTOPSIG (*wstat) == SIGILL
1836 || WSTOPSIG (*wstat) == SIGFPE
1837 || WSTOPSIG (*wstat) == SIGBUS
1838 || WSTOPSIG (*wstat) == SIGSEGV)
1839 && ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread),
1840 (PTRACE_TYPE_ARG3) 0, &info) == 0
1841 /* Final check just to make sure we don't clobber
1842 the siginfo of non-kernel-sent signals. */
1843 && (uintptr_t) info.si_addr == lwp->stop_pc)
1845 info.si_addr = (void *) (uintptr_t) status.tpoint_addr;
1846 ptrace (PTRACE_SETSIGINFO, lwpid_of (current_thread),
1847 (PTRACE_TYPE_ARG3) 0, &info);
1850 regcache = get_thread_regcache (current_thread, 1);
1851 (*the_low_target.set_pc) (regcache, status.tpoint_addr);
1852 lwp->stop_pc = status.tpoint_addr;
1854 /* Cancel any fast tracepoint lock this thread was
1856 force_unlock_trace_buffer ();
1859 if (lwp->exit_jump_pad_bkpt != NULL)
1862 debug_printf ("Cancelling fast exit-jump-pad: removing bkpt. "
1863 "stopping all threads momentarily.\n");
1865 stop_all_lwps (1, lwp);
1867 delete_breakpoint (lwp->exit_jump_pad_bkpt);
1868 lwp->exit_jump_pad_bkpt = NULL;
1870 unstop_all_lwps (1, lwp);
1872 gdb_assert (lwp->suspended >= 0);
1878 debug_printf ("Checking whether LWP %ld needs to move out of the "
1880 lwpid_of (current_thread));
1882 current_thread = saved_thread;
1886 /* Enqueue one signal in the "signals to report later when out of the
1890 enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1892 struct pending_signals *p_sig;
1893 struct thread_info *thread = get_lwp_thread (lwp);
1896 debug_printf ("Deferring signal %d for LWP %ld.\n",
1897 WSTOPSIG (*wstat), lwpid_of (thread));
1901 struct pending_signals *sig;
1903 for (sig = lwp->pending_signals_to_report;
1906 debug_printf (" Already queued %d\n",
1909 debug_printf (" (no more currently queued signals)\n");
1912 /* Don't enqueue non-RT signals if they are already in the deferred
1913 queue. (SIGSTOP being the easiest signal to see ending up here
1915 if (WSTOPSIG (*wstat) < __SIGRTMIN)
1917 struct pending_signals *sig;
1919 for (sig = lwp->pending_signals_to_report;
1923 if (sig->signal == WSTOPSIG (*wstat))
1926 debug_printf ("Not requeuing already queued non-RT signal %d"
1935 p_sig = xmalloc (sizeof (*p_sig));
1936 p_sig->prev = lwp->pending_signals_to_report;
1937 p_sig->signal = WSTOPSIG (*wstat);
1938 memset (&p_sig->info, 0, sizeof (siginfo_t));
1939 ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
1942 lwp->pending_signals_to_report = p_sig;
1945 /* Dequeue one signal from the "signals to report later when out of
1946 the jump pad" list. */
1949 dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat)
1951 struct thread_info *thread = get_lwp_thread (lwp);
1953 if (lwp->pending_signals_to_report != NULL)
1955 struct pending_signals **p_sig;
1957 p_sig = &lwp->pending_signals_to_report;
1958 while ((*p_sig)->prev != NULL)
1959 p_sig = &(*p_sig)->prev;
1961 *wstat = W_STOPCODE ((*p_sig)->signal);
1962 if ((*p_sig)->info.si_signo != 0)
1963 ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
1969 debug_printf ("Reporting deferred signal %d for LWP %ld.\n",
1970 WSTOPSIG (*wstat), lwpid_of (thread));
1974 struct pending_signals *sig;
1976 for (sig = lwp->pending_signals_to_report;
1979 debug_printf (" Still queued %d\n",
1982 debug_printf (" (no more queued signals)\n");
1991 /* Fetch the possibly triggered data watchpoint info and store it in
1994 On some archs, like x86, that use debug registers to set
1995 watchpoints, it's possible that the way to know which watched
1996 address trapped, is to check the register that is used to select
1997 which address to watch. Problem is, between setting the watchpoint
1998 and reading back which data address trapped, the user may change
1999 the set of watchpoints, and, as a consequence, GDB changes the
2000 debug registers in the inferior. To avoid reading back a stale
2001 stopped-data-address when that happens, we cache in LP the fact
2002 that a watchpoint trapped, and the corresponding data address, as
2003 soon as we see CHILD stop with a SIGTRAP. If GDB changes the debug
2004 registers meanwhile, we have the cached data we can rely on. */
2007 check_stopped_by_watchpoint (struct lwp_info *child)
2009 if (the_low_target.stopped_by_watchpoint != NULL)
2011 struct thread_info *saved_thread;
2013 saved_thread = current_thread;
2014 current_thread = get_lwp_thread (child);
2016 if (the_low_target.stopped_by_watchpoint ())
2018 child->stop_reason = TARGET_STOPPED_BY_WATCHPOINT;
2020 if (the_low_target.stopped_data_address != NULL)
2021 child->stopped_data_address
2022 = the_low_target.stopped_data_address ();
2024 child->stopped_data_address = 0;
2027 current_thread = saved_thread;
2030 return child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2033 /* Return the ptrace options that we want to try to enable. */
2036 linux_low_ptrace_options (int attached)
2041 options |= PTRACE_O_EXITKILL;
2043 if (report_fork_events)
2044 options |= PTRACE_O_TRACEFORK;
2046 if (report_vfork_events)
2047 options |= (PTRACE_O_TRACEVFORK | PTRACE_O_TRACEVFORKDONE);
2052 /* Do low-level handling of the event, and check if we should go on
2053 and pass it to caller code. Return the affected lwp if we are, or
2056 static struct lwp_info *
2057 linux_low_filter_event (int lwpid, int wstat)
2059 struct lwp_info *child;
2060 struct thread_info *thread;
2061 int have_stop_pc = 0;
2063 child = find_lwp_pid (pid_to_ptid (lwpid));
2065 /* If we didn't find a process, one of two things presumably happened:
2066 - A process we started and then detached from has exited. Ignore it.
2067 - A process we are controlling has forked and the new child's stop
2068 was reported to us by the kernel. Save its PID. */
2069 if (child == NULL && WIFSTOPPED (wstat))
2071 add_to_pid_list (&stopped_pids, lwpid, wstat);
2074 else if (child == NULL)
2077 thread = get_lwp_thread (child);
2081 child->last_status = wstat;
2083 /* Check if the thread has exited. */
2084 if ((WIFEXITED (wstat) || WIFSIGNALED (wstat)))
2087 debug_printf ("LLFE: %d exited.\n", lwpid);
2088 if (num_lwps (pid_of (thread)) > 1)
2091 /* If there is at least one more LWP, then the exit signal was
2092 not the end of the debugged application and should be
2099 /* This was the last lwp in the process. Since events are
2100 serialized to GDB core, and we can't report this one
2101 right now, but GDB core and the other target layers will
2102 want to be notified about the exit code/signal, leave the
2103 status pending for the next time we're able to report
2105 mark_lwp_dead (child, wstat);
2110 gdb_assert (WIFSTOPPED (wstat));
2112 if (WIFSTOPPED (wstat))
2114 struct process_info *proc;
2116 /* Architecture-specific setup after inferior is running. */
2117 proc = find_process_pid (pid_of (thread));
2118 if (proc->tdesc == NULL)
2122 struct thread_info *saved_thread;
2124 /* This needs to happen after we have attached to the
2125 inferior and it is stopped for the first time, but
2126 before we access any inferior registers. */
2127 saved_thread = current_thread;
2128 current_thread = thread;
2130 the_low_target.arch_setup ();
2132 current_thread = saved_thread;
2134 proc->priv->new_inferior = 0;
2138 /* The process is started, but GDBserver will do
2139 architecture-specific setup after the program stops at
2140 the first instruction. */
2141 child->status_pending_p = 1;
2142 child->status_pending = wstat;
2148 if (WIFSTOPPED (wstat) && child->must_set_ptrace_flags)
2150 struct process_info *proc = find_process_pid (pid_of (thread));
2151 int options = linux_low_ptrace_options (proc->attached);
2153 linux_enable_event_reporting (lwpid, options);
2154 child->must_set_ptrace_flags = 0;
2157 /* Be careful to not overwrite stop_pc until
2158 check_stopped_by_breakpoint is called. */
2159 if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
2160 && linux_is_extended_waitstatus (wstat))
2162 child->stop_pc = get_pc (child);
2163 if (handle_extended_wait (child, wstat))
2165 /* The event has been handled, so just return without
2171 /* Check first whether this was a SW/HW breakpoint before checking
2172 watchpoints, because at least s390 can't tell the data address of
2173 hardware watchpoint hits, and returns stopped-by-watchpoint as
2174 long as there's a watchpoint set. */
2175 if (WIFSTOPPED (wstat) && linux_wstatus_maybe_breakpoint (wstat))
2177 if (check_stopped_by_breakpoint (child))
2181 /* Note that TRAP_HWBKPT can indicate either a hardware breakpoint
2182 or hardware watchpoint. Check which is which if we got
2183 TARGET_STOPPED_BY_HW_BREAKPOINT. */
2184 if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP
2185 && (child->stop_reason == TARGET_STOPPED_BY_NO_REASON
2186 || child->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
2187 check_stopped_by_watchpoint (child);
2190 child->stop_pc = get_pc (child);
2192 if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGSTOP
2193 && child->stop_expected)
2196 debug_printf ("Expected stop.\n");
2197 child->stop_expected = 0;
2199 if (thread->last_resume_kind == resume_stop)
2201 /* We want to report the stop to the core. Treat the
2202 SIGSTOP as a normal event. */
2204 debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n",
2205 target_pid_to_str (ptid_of (thread)));
2207 else if (stopping_threads != NOT_STOPPING_THREADS)
2209 /* Stopping threads. We don't want this SIGSTOP to end up
2212 debug_printf ("LLW: SIGSTOP caught for %s "
2213 "while stopping threads.\n",
2214 target_pid_to_str (ptid_of (thread)));
2219 /* This is a delayed SIGSTOP. Filter out the event. */
2221 debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
2222 child->stepping ? "step" : "continue",
2223 target_pid_to_str (ptid_of (thread)));
2225 linux_resume_one_lwp (child, child->stepping, 0, NULL);
2230 child->status_pending_p = 1;
2231 child->status_pending = wstat;
2235 /* Resume LWPs that are currently stopped without any pending status
2236 to report, but are resumed from the core's perspective. */
2239 resume_stopped_resumed_lwps (struct inferior_list_entry *entry)
2241 struct thread_info *thread = (struct thread_info *) entry;
2242 struct lwp_info *lp = get_thread_lwp (thread);
2245 && !lp->status_pending_p
2246 && thread->last_resume_kind != resume_stop
2247 && thread->last_status.kind == TARGET_WAITKIND_IGNORE)
2249 int step = thread->last_resume_kind == resume_step;
2252 debug_printf ("RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
2253 target_pid_to_str (ptid_of (thread)),
2254 paddress (lp->stop_pc),
2257 linux_resume_one_lwp (lp, step, GDB_SIGNAL_0, NULL);
2261 /* Wait for an event from child(ren) WAIT_PTID, and return any that
2262 match FILTER_PTID (leaving others pending). The PTIDs can be:
2263 minus_one_ptid, to specify any child; a pid PTID, specifying all
2264 lwps of a thread group; or a PTID representing a single lwp. Store
2265 the stop status through the status pointer WSTAT. OPTIONS is
2266 passed to the waitpid call. Return 0 if no event was found and
2267 OPTIONS contains WNOHANG. Return -1 if no unwaited-for children
2268 was found. Return the PID of the stopped child otherwise. */
2271 linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
2272 int *wstatp, int options)
2274 struct thread_info *event_thread;
2275 struct lwp_info *event_child, *requested_child;
2276 sigset_t block_mask, prev_mask;
2279 /* N.B. event_thread points to the thread_info struct that contains
2280 event_child. Keep them in sync. */
2281 event_thread = NULL;
2283 requested_child = NULL;
2285 /* Check for a lwp with a pending status. */
2287 if (ptid_equal (filter_ptid, minus_one_ptid) || ptid_is_pid (filter_ptid))
2289 event_thread = (struct thread_info *)
2290 find_inferior (&all_threads, status_pending_p_callback, &filter_ptid);
2291 if (event_thread != NULL)
2292 event_child = get_thread_lwp (event_thread);
2293 if (debug_threads && event_thread)
2294 debug_printf ("Got a pending child %ld\n", lwpid_of (event_thread));
2296 else if (!ptid_equal (filter_ptid, null_ptid))
2298 requested_child = find_lwp_pid (filter_ptid);
2300 if (stopping_threads == NOT_STOPPING_THREADS
2301 && requested_child->status_pending_p
2302 && requested_child->collecting_fast_tracepoint)
2304 enqueue_one_deferred_signal (requested_child,
2305 &requested_child->status_pending);
2306 requested_child->status_pending_p = 0;
2307 requested_child->status_pending = 0;
2308 linux_resume_one_lwp (requested_child, 0, 0, NULL);
2311 if (requested_child->suspended
2312 && requested_child->status_pending_p)
2314 internal_error (__FILE__, __LINE__,
2315 "requesting an event out of a"
2316 " suspended child?");
2319 if (requested_child->status_pending_p)
2321 event_child = requested_child;
2322 event_thread = get_lwp_thread (event_child);
2326 if (event_child != NULL)
2329 debug_printf ("Got an event from pending child %ld (%04x)\n",
2330 lwpid_of (event_thread), event_child->status_pending);
2331 *wstatp = event_child->status_pending;
2332 event_child->status_pending_p = 0;
2333 event_child->status_pending = 0;
2334 current_thread = event_thread;
2335 return lwpid_of (event_thread);
2338 /* But if we don't find a pending event, we'll have to wait.
2340 We only enter this loop if no process has a pending wait status.
2341 Thus any action taken in response to a wait status inside this
2342 loop is responding as soon as we detect the status, not after any
2345 /* Make sure SIGCHLD is blocked until the sigsuspend below. Block
2346 all signals while here. */
2347 sigfillset (&block_mask);
2348 sigprocmask (SIG_BLOCK, &block_mask, &prev_mask);
2350 /* Always pull all events out of the kernel. We'll randomly select
2351 an event LWP out of all that have events, to prevent
2353 while (event_child == NULL)
2357 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
2360 - If the thread group leader exits while other threads in the
2361 thread group still exist, waitpid(TGID, ...) hangs. That
2362 waitpid won't return an exit status until the other threads
2363 in the group are reaped.
2365 - When a non-leader thread execs, that thread just vanishes
2366 without reporting an exit (so we'd hang if we waited for it
2367 explicitly in that case). The exec event is reported to
2368 the TGID pid (although we don't currently enable exec
2371 ret = my_waitpid (-1, wstatp, options | WNOHANG);
2374 debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n",
2375 ret, errno ? strerror (errno) : "ERRNO-OK");
2381 debug_printf ("LLW: waitpid %ld received %s\n",
2382 (long) ret, status_to_str (*wstatp));
2385 /* Filter all events. IOW, leave all events pending. We'll
2386 randomly select an event LWP out of all that have events
2388 linux_low_filter_event (ret, *wstatp);
2389 /* Retry until nothing comes out of waitpid. A single
2390 SIGCHLD can indicate more than one child stopped. */
2394 /* Now that we've pulled all events out of the kernel, resume
2395 LWPs that don't have an interesting event to report. */
2396 if (stopping_threads == NOT_STOPPING_THREADS)
2397 for_each_inferior (&all_threads, resume_stopped_resumed_lwps);
2399 /* ... and find an LWP with a status to report to the core, if
2401 event_thread = (struct thread_info *)
2402 find_inferior (&all_threads, status_pending_p_callback, &filter_ptid);
2403 if (event_thread != NULL)
2405 event_child = get_thread_lwp (event_thread);
2406 *wstatp = event_child->status_pending;
2407 event_child->status_pending_p = 0;
2408 event_child->status_pending = 0;
2412 /* Check for zombie thread group leaders. Those can't be reaped
2413 until all other threads in the thread group are. */
2414 check_zombie_leaders ();
2416 /* If there are no resumed children left in the set of LWPs we
2417 want to wait for, bail. We can't just block in
2418 waitpid/sigsuspend, because lwps might have been left stopped
2419 in trace-stop state, and we'd be stuck forever waiting for
2420 their status to change (which would only happen if we resumed
2421 them). Even if WNOHANG is set, this return code is preferred
2422 over 0 (below), as it is more detailed. */
2423 if ((find_inferior (&all_threads,
2424 not_stopped_callback,
2425 &wait_ptid) == NULL))
2428 debug_printf ("LLW: exit (no unwaited-for LWP)\n");
2429 sigprocmask (SIG_SETMASK, &prev_mask, NULL);
2433 /* No interesting event to report to the caller. */
2434 if ((options & WNOHANG))
2437 debug_printf ("WNOHANG set, no event found\n");
2439 sigprocmask (SIG_SETMASK, &prev_mask, NULL);
2443 /* Block until we get an event reported with SIGCHLD. */
2445 debug_printf ("sigsuspend'ing\n");
2447 sigsuspend (&prev_mask);
2448 sigprocmask (SIG_SETMASK, &prev_mask, NULL);
2452 sigprocmask (SIG_SETMASK, &prev_mask, NULL);
2454 current_thread = event_thread;
2456 /* Check for thread exit. */
2457 if (! WIFSTOPPED (*wstatp))
2459 gdb_assert (last_thread_of_process_p (pid_of (event_thread)));
2462 debug_printf ("LWP %d is the last lwp of process. "
2463 "Process %ld exiting.\n",
2464 pid_of (event_thread), lwpid_of (event_thread));
2465 return lwpid_of (event_thread);
2468 return lwpid_of (event_thread);
2471 /* Wait for an event from child(ren) PTID. PTIDs can be:
2472 minus_one_ptid, to specify any child; a pid PTID, specifying all
2473 lwps of a thread group; or a PTID representing a single lwp. Store
2474 the stop status through the status pointer WSTAT. OPTIONS is
2475 passed to the waitpid call. Return 0 if no event was found and
2476 OPTIONS contains WNOHANG. Return -1 if no unwaited-for children
2477 was found. Return the PID of the stopped child otherwise. */
2480 linux_wait_for_event (ptid_t ptid, int *wstatp, int options)
2482 return linux_wait_for_event_filtered (ptid, ptid, wstatp, options);
2485 /* Count the LWP's that have had events. */
2488 count_events_callback (struct inferior_list_entry *entry, void *data)
2490 struct thread_info *thread = (struct thread_info *) entry;
2491 struct lwp_info *lp = get_thread_lwp (thread);
2494 gdb_assert (count != NULL);
2496 /* Count only resumed LWPs that have an event pending. */
2497 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
2498 && lp->status_pending_p)
2504 /* Select the LWP (if any) that is currently being single-stepped. */
2507 select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data)
2509 struct thread_info *thread = (struct thread_info *) entry;
2510 struct lwp_info *lp = get_thread_lwp (thread);
2512 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
2513 && thread->last_resume_kind == resume_step
2514 && lp->status_pending_p)
2520 /* Select the Nth LWP that has had an event. */
2523 select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
2525 struct thread_info *thread = (struct thread_info *) entry;
2526 struct lwp_info *lp = get_thread_lwp (thread);
2527 int *selector = data;
2529 gdb_assert (selector != NULL);
2531 /* Select only resumed LWPs that have an event pending. */
2532 if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
2533 && lp->status_pending_p)
2534 if ((*selector)-- == 0)
2540 /* Select one LWP out of those that have events pending. */
2543 select_event_lwp (struct lwp_info **orig_lp)
2546 int random_selector;
2547 struct thread_info *event_thread = NULL;
2549 /* In all-stop, give preference to the LWP that is being
2550 single-stepped. There will be at most one, and it's the LWP that
2551 the core is most interested in. If we didn't do this, then we'd
2552 have to handle pending step SIGTRAPs somehow in case the core
2553 later continues the previously-stepped thread, otherwise we'd
2554 report the pending SIGTRAP, and the core, not having stepped the
2555 thread, wouldn't understand what the trap was for, and therefore
2556 would report it to the user as a random signal. */
2560 = (struct thread_info *) find_inferior (&all_threads,
2561 select_singlestep_lwp_callback,
2563 if (event_thread != NULL)
2566 debug_printf ("SEL: Select single-step %s\n",
2567 target_pid_to_str (ptid_of (event_thread)));
2570 if (event_thread == NULL)
2572 /* No single-stepping LWP. Select one at random, out of those
2573 which have had events. */
2575 /* First see how many events we have. */
2576 find_inferior (&all_threads, count_events_callback, &num_events);
2577 gdb_assert (num_events > 0);
2579 /* Now randomly pick a LWP out of those that have had
2581 random_selector = (int)
2582 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2584 if (debug_threads && num_events > 1)
2585 debug_printf ("SEL: Found %d SIGTRAP events, selecting #%d\n",
2586 num_events, random_selector);
2589 = (struct thread_info *) find_inferior (&all_threads,
2590 select_event_lwp_callback,
2594 if (event_thread != NULL)
2596 struct lwp_info *event_lp = get_thread_lwp (event_thread);
2598 /* Switch the event LWP. */
2599 *orig_lp = event_lp;
2603 /* Decrement the suspend count of an LWP. */
2606 unsuspend_one_lwp (struct inferior_list_entry *entry, void *except)
2608 struct thread_info *thread = (struct thread_info *) entry;
2609 struct lwp_info *lwp = get_thread_lwp (thread);
2611 /* Ignore EXCEPT. */
2617 gdb_assert (lwp->suspended >= 0);
2621 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
2625 unsuspend_all_lwps (struct lwp_info *except)
2627 find_inferior (&all_threads, unsuspend_one_lwp, except);
2630 static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry);
2631 static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry,
2633 static int lwp_running (struct inferior_list_entry *entry, void *data);
2634 static ptid_t linux_wait_1 (ptid_t ptid,
2635 struct target_waitstatus *ourstatus,
2636 int target_options);
2638 /* Stabilize threads (move out of jump pads).
2640 If a thread is midway collecting a fast tracepoint, we need to
2641 finish the collection and move it out of the jump pad before
2642 reporting the signal.
2644 This avoids recursion while collecting (when a signal arrives
2645 midway, and the signal handler itself collects), which would trash
2646 the trace buffer. In case the user set a breakpoint in a signal
2647 handler, this avoids the backtrace showing the jump pad, etc..
2648 Most importantly, there are certain things we can't do safely if
2649 threads are stopped in a jump pad (or in its callee's). For
2652 - starting a new trace run. A thread still collecting the
2653 previous run, could trash the trace buffer when resumed. The trace
2654 buffer control structures would have been reset but the thread had
2655 no way to tell. The thread could even midway memcpy'ing to the
2656 buffer, which would mean that when resumed, it would clobber the
2657 trace buffer that had been set for a new run.
2659 - we can't rewrite/reuse the jump pads for new tracepoints
2660 safely. Say you do tstart while a thread is stopped midway while
2661 collecting. When the thread is later resumed, it finishes the
2662 collection, and returns to the jump pad, to execute the original
2663 instruction that was under the tracepoint jump at the time the
2664 older run had been started. If the jump pad had been rewritten
2665 since for something else in the new run, the thread would now
2666 execute the wrong / random instructions. */
2669 linux_stabilize_threads (void)
2671 struct thread_info *saved_thread;
2672 struct thread_info *thread_stuck;
2675 = (struct thread_info *) find_inferior (&all_threads,
2676 stuck_in_jump_pad_callback,
2678 if (thread_stuck != NULL)
2681 debug_printf ("can't stabilize, LWP %ld is stuck in jump pad\n",
2682 lwpid_of (thread_stuck));
2686 saved_thread = current_thread;
2688 stabilizing_threads = 1;
2691 for_each_inferior (&all_threads, move_out_of_jump_pad_callback);
2693 /* Loop until all are stopped out of the jump pads. */
2694 while (find_inferior (&all_threads, lwp_running, NULL) != NULL)
2696 struct target_waitstatus ourstatus;
2697 struct lwp_info *lwp;
2700 /* Note that we go through the full wait even loop. While
2701 moving threads out of jump pad, we need to be able to step
2702 over internal breakpoints and such. */
2703 linux_wait_1 (minus_one_ptid, &ourstatus, 0);
2705 if (ourstatus.kind == TARGET_WAITKIND_STOPPED)
2707 lwp = get_thread_lwp (current_thread);
2712 if (ourstatus.value.sig != GDB_SIGNAL_0
2713 || current_thread->last_resume_kind == resume_stop)
2715 wstat = W_STOPCODE (gdb_signal_to_host (ourstatus.value.sig));
2716 enqueue_one_deferred_signal (lwp, &wstat);
2721 find_inferior (&all_threads, unsuspend_one_lwp, NULL);
2723 stabilizing_threads = 0;
2725 current_thread = saved_thread;
2730 = (struct thread_info *) find_inferior (&all_threads,
2731 stuck_in_jump_pad_callback,
2733 if (thread_stuck != NULL)
2734 debug_printf ("couldn't stabilize, LWP %ld got stuck in jump pad\n",
2735 lwpid_of (thread_stuck));
2739 static void async_file_mark (void);
2741 /* Convenience function that is called when the kernel reports an
2742 event that is not passed out to GDB. */
2745 ignore_event (struct target_waitstatus *ourstatus)
2747 /* If we got an event, there may still be others, as a single
2748 SIGCHLD can indicate more than one child stopped. This forces
2749 another target_wait call. */
2752 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2756 /* Return non-zero if WAITSTATUS reflects an extended linux
2757 event. Otherwise, return zero. */
2760 extended_event_reported (const struct target_waitstatus *waitstatus)
2762 if (waitstatus == NULL)
2765 return (waitstatus->kind == TARGET_WAITKIND_FORKED
2766 || waitstatus->kind == TARGET_WAITKIND_VFORKED
2767 || waitstatus->kind == TARGET_WAITKIND_VFORK_DONE);
2770 /* Wait for process, returns status. */
2773 linux_wait_1 (ptid_t ptid,
2774 struct target_waitstatus *ourstatus, int target_options)
2777 struct lwp_info *event_child;
2780 int step_over_finished;
2781 int bp_explains_trap;
2782 int maybe_internal_trap;
2790 debug_printf ("linux_wait_1: [%s]\n", target_pid_to_str (ptid));
2793 /* Translate generic target options into linux options. */
2795 if (target_options & TARGET_WNOHANG)
2798 bp_explains_trap = 0;
2801 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2803 if (ptid_equal (step_over_bkpt, null_ptid))
2804 pid = linux_wait_for_event (ptid, &w, options);
2808 debug_printf ("step_over_bkpt set [%s], doing a blocking wait\n",
2809 target_pid_to_str (step_over_bkpt));
2810 pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
2815 gdb_assert (target_options & TARGET_WNOHANG);
2819 debug_printf ("linux_wait_1 ret = null_ptid, "
2820 "TARGET_WAITKIND_IGNORE\n");
2824 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2831 debug_printf ("linux_wait_1 ret = null_ptid, "
2832 "TARGET_WAITKIND_NO_RESUMED\n");
2836 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
2840 event_child = get_thread_lwp (current_thread);
2842 /* linux_wait_for_event only returns an exit status for the last
2843 child of a process. Report it. */
2844 if (WIFEXITED (w) || WIFSIGNALED (w))
2848 ourstatus->kind = TARGET_WAITKIND_EXITED;
2849 ourstatus->value.integer = WEXITSTATUS (w);
2853 debug_printf ("linux_wait_1 ret = %s, exited with "
2855 target_pid_to_str (ptid_of (current_thread)),
2862 ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
2863 ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (w));
2867 debug_printf ("linux_wait_1 ret = %s, terminated with "
2869 target_pid_to_str (ptid_of (current_thread)),
2875 return ptid_of (current_thread);
2878 /* If step-over executes a breakpoint instruction, it means a
2879 gdb/gdbserver breakpoint had been planted on top of a permanent
2880 breakpoint. The PC has been adjusted by
2881 check_stopped_by_breakpoint to point at the breakpoint address.
2882 Advance the PC manually past the breakpoint, otherwise the
2883 program would keep trapping the permanent breakpoint forever. */
2884 if (!ptid_equal (step_over_bkpt, null_ptid)
2885 && event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT)
2887 unsigned int increment_pc = the_low_target.breakpoint_len;
2891 debug_printf ("step-over for %s executed software breakpoint\n",
2892 target_pid_to_str (ptid_of (current_thread)));
2895 if (increment_pc != 0)
2897 struct regcache *regcache
2898 = get_thread_regcache (current_thread, 1);
2900 event_child->stop_pc += increment_pc;
2901 (*the_low_target.set_pc) (regcache, event_child->stop_pc);
2903 if (!(*the_low_target.breakpoint_at) (event_child->stop_pc))
2904 event_child->stop_reason = TARGET_STOPPED_BY_NO_REASON;
2908 /* If this event was not handled before, and is not a SIGTRAP, we
2909 report it. SIGILL and SIGSEGV are also treated as traps in case
2910 a breakpoint is inserted at the current PC. If this target does
2911 not support internal breakpoints at all, we also report the
2912 SIGTRAP without further processing; it's of no concern to us. */
2914 = (supports_breakpoints ()
2915 && (WSTOPSIG (w) == SIGTRAP
2916 || ((WSTOPSIG (w) == SIGILL
2917 || WSTOPSIG (w) == SIGSEGV)
2918 && (*the_low_target.breakpoint_at) (event_child->stop_pc))));
2920 if (maybe_internal_trap)
2922 /* Handle anything that requires bookkeeping before deciding to
2923 report the event or continue waiting. */
2925 /* First check if we can explain the SIGTRAP with an internal
2926 breakpoint, or if we should possibly report the event to GDB.
2927 Do this before anything that may remove or insert a
2929 bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc);
2931 /* We have a SIGTRAP, possibly a step-over dance has just
2932 finished. If so, tweak the state machine accordingly,
2933 reinsert breakpoints and delete any reinsert (software
2934 single-step) breakpoints. */
2935 step_over_finished = finish_step_over (event_child);
2937 /* Now invoke the callbacks of any internal breakpoints there. */
2938 check_breakpoints (event_child->stop_pc);
2940 /* Handle tracepoint data collecting. This may overflow the
2941 trace buffer, and cause a tracing stop, removing
2943 trace_event = handle_tracepoints (event_child);
2945 if (bp_explains_trap)
2947 /* If we stepped or ran into an internal breakpoint, we've
2948 already handled it. So next time we resume (from this
2949 PC), we should step over it. */
2951 debug_printf ("Hit a gdbserver breakpoint.\n");
2953 if (breakpoint_here (event_child->stop_pc))
2954 event_child->need_step_over = 1;
2959 /* We have some other signal, possibly a step-over dance was in
2960 progress, and it should be cancelled too. */
2961 step_over_finished = finish_step_over (event_child);
2964 /* We have all the data we need. Either report the event to GDB, or
2965 resume threads and keep waiting for more. */
2967 /* If we're collecting a fast tracepoint, finish the collection and
2968 move out of the jump pad before delivering a signal. See
2969 linux_stabilize_threads. */
2972 && WSTOPSIG (w) != SIGTRAP
2973 && supports_fast_tracepoints ()
2974 && agent_loaded_p ())
2977 debug_printf ("Got signal %d for LWP %ld. Check if we need "
2978 "to defer or adjust it.\n",
2979 WSTOPSIG (w), lwpid_of (current_thread));
2981 /* Allow debugging the jump pad itself. */
2982 if (current_thread->last_resume_kind != resume_step
2983 && maybe_move_out_of_jump_pad (event_child, &w))
2985 enqueue_one_deferred_signal (event_child, &w);
2988 debug_printf ("Signal %d for LWP %ld deferred (in jump pad)\n",
2989 WSTOPSIG (w), lwpid_of (current_thread));
2991 linux_resume_one_lwp (event_child, 0, 0, NULL);
2993 return ignore_event (ourstatus);
2997 if (event_child->collecting_fast_tracepoint)
3000 debug_printf ("LWP %ld was trying to move out of the jump pad (%d). "
3001 "Check if we're already there.\n",
3002 lwpid_of (current_thread),
3003 event_child->collecting_fast_tracepoint);
3007 event_child->collecting_fast_tracepoint
3008 = linux_fast_tracepoint_collecting (event_child, NULL);
3010 if (event_child->collecting_fast_tracepoint != 1)
3012 /* No longer need this breakpoint. */
3013 if (event_child->exit_jump_pad_bkpt != NULL)
3016 debug_printf ("No longer need exit-jump-pad bkpt; removing it."
3017 "stopping all threads momentarily.\n");
3019 /* Other running threads could hit this breakpoint.
3020 We don't handle moribund locations like GDB does,
3021 instead we always pause all threads when removing
3022 breakpoints, so that any step-over or
3023 decr_pc_after_break adjustment is always taken
3024 care of while the breakpoint is still
3026 stop_all_lwps (1, event_child);
3028 delete_breakpoint (event_child->exit_jump_pad_bkpt);
3029 event_child->exit_jump_pad_bkpt = NULL;
3031 unstop_all_lwps (1, event_child);
3033 gdb_assert (event_child->suspended >= 0);
3037 if (event_child->collecting_fast_tracepoint == 0)
3040 debug_printf ("fast tracepoint finished "
3041 "collecting successfully.\n");
3043 /* We may have a deferred signal to report. */
3044 if (dequeue_one_deferred_signal (event_child, &w))
3047 debug_printf ("dequeued one signal.\n");
3052 debug_printf ("no deferred signals.\n");
3054 if (stabilizing_threads)
3056 ourstatus->kind = TARGET_WAITKIND_STOPPED;
3057 ourstatus->value.sig = GDB_SIGNAL_0;
3061 debug_printf ("linux_wait_1 ret = %s, stopped "
3062 "while stabilizing threads\n",
3063 target_pid_to_str (ptid_of (current_thread)));
3067 return ptid_of (current_thread);
3073 /* Check whether GDB would be interested in this event. */
3075 /* If GDB is not interested in this signal, don't stop other
3076 threads, and don't report it to GDB. Just resume the inferior
3077 right away. We do this for threading-related signals as well as
3078 any that GDB specifically requested we ignore. But never ignore
3079 SIGSTOP if we sent it ourselves, and do not ignore signals when
3080 stepping - they may require special handling to skip the signal
3081 handler. Also never ignore signals that could be caused by a
3083 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
3086 && current_thread->last_resume_kind != resume_step
3088 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
3089 (current_process ()->priv->thread_db != NULL
3090 && (WSTOPSIG (w) == __SIGRTMIN
3091 || WSTOPSIG (w) == __SIGRTMIN + 1))
3094 (pass_signals[gdb_signal_from_host (WSTOPSIG (w))]
3095 && !(WSTOPSIG (w) == SIGSTOP
3096 && current_thread->last_resume_kind == resume_stop)
3097 && !linux_wstatus_maybe_breakpoint (w))))
3099 siginfo_t info, *info_p;
3102 debug_printf ("Ignored signal %d for LWP %ld.\n",
3103 WSTOPSIG (w), lwpid_of (current_thread));
3105 if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread),
3106 (PTRACE_TYPE_ARG3) 0, &info) == 0)
3110 linux_resume_one_lwp (event_child, event_child->stepping,
3111 WSTOPSIG (w), info_p);
3112 return ignore_event (ourstatus);
3115 /* Note that all addresses are always "out of the step range" when
3116 there's no range to begin with. */
3117 in_step_range = lwp_in_step_range (event_child);
3119 /* If GDB wanted this thread to single step, and the thread is out
3120 of the step range, we always want to report the SIGTRAP, and let
3121 GDB handle it. Watchpoints should always be reported. So should
3122 signals we can't explain. A SIGTRAP we can't explain could be a
3123 GDB breakpoint --- we may or not support Z0 breakpoints. If we
3124 do, we're be able to handle GDB breakpoints on top of internal
3125 breakpoints, by handling the internal breakpoint and still
3126 reporting the event to GDB. If we don't, we're out of luck, GDB
3127 won't see the breakpoint hit. */
3128 report_to_gdb = (!maybe_internal_trap
3129 || (current_thread->last_resume_kind == resume_step
3131 || event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT
3132 || (!step_over_finished && !in_step_range
3133 && !bp_explains_trap && !trace_event)
3134 || (gdb_breakpoint_here (event_child->stop_pc)
3135 && gdb_condition_true_at_breakpoint (event_child->stop_pc)
3136 && gdb_no_commands_at_breakpoint (event_child->stop_pc))
3137 || extended_event_reported (&event_child->waitstatus));
3139 run_breakpoint_commands (event_child->stop_pc);
3141 /* We found no reason GDB would want us to stop. We either hit one
3142 of our own breakpoints, or finished an internal step GDB
3143 shouldn't know about. */
3148 if (bp_explains_trap)
3149 debug_printf ("Hit a gdbserver breakpoint.\n");
3150 if (step_over_finished)
3151 debug_printf ("Step-over finished.\n");
3153 debug_printf ("Tracepoint event.\n");
3154 if (lwp_in_step_range (event_child))
3155 debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).\n",
3156 paddress (event_child->stop_pc),
3157 paddress (event_child->step_range_start),
3158 paddress (event_child->step_range_end));
3159 if (extended_event_reported (&event_child->waitstatus))
3161 char *str = target_waitstatus_to_string (ourstatus);
3162 debug_printf ("LWP %ld: extended event with waitstatus %s\n",
3163 lwpid_of (get_lwp_thread (event_child)), str);
3168 /* We're not reporting this breakpoint to GDB, so apply the
3169 decr_pc_after_break adjustment to the inferior's regcache
3172 if (the_low_target.set_pc != NULL)
3174 struct regcache *regcache
3175 = get_thread_regcache (current_thread, 1);
3176 (*the_low_target.set_pc) (regcache, event_child->stop_pc);
3179 /* We may have finished stepping over a breakpoint. If so,
3180 we've stopped and suspended all LWPs momentarily except the
3181 stepping one. This is where we resume them all again. We're
3182 going to keep waiting, so use proceed, which handles stepping
3183 over the next breakpoint. */
3185 debug_printf ("proceeding all threads.\n");
3187 if (step_over_finished)
3188 unsuspend_all_lwps (event_child);
3190 proceed_all_lwps ();
3191 return ignore_event (ourstatus);
3196 if (current_thread->last_resume_kind == resume_step)
3198 if (event_child->step_range_start == event_child->step_range_end)
3199 debug_printf ("GDB wanted to single-step, reporting event.\n");
3200 else if (!lwp_in_step_range (event_child))
3201 debug_printf ("Out of step range, reporting event.\n");
3203 if (event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT)
3204 debug_printf ("Stopped by watchpoint.\n");
3205 else if (gdb_breakpoint_here (event_child->stop_pc))
3206 debug_printf ("Stopped by GDB breakpoint.\n");
3208 debug_printf ("Hit a non-gdbserver trap event.\n");
3211 /* Alright, we're going to report a stop. */
3213 if (!stabilizing_threads)
3215 /* In all-stop, stop all threads. */
3217 stop_all_lwps (0, NULL);
3219 /* If we're not waiting for a specific LWP, choose an event LWP
3220 from among those that have had events. Giving equal priority
3221 to all LWPs that have had events helps prevent
3223 if (ptid_equal (ptid, minus_one_ptid))
3225 event_child->status_pending_p = 1;
3226 event_child->status_pending = w;
3228 select_event_lwp (&event_child);
3230 /* current_thread and event_child must stay in sync. */
3231 current_thread = get_lwp_thread (event_child);
3233 event_child->status_pending_p = 0;
3234 w = event_child->status_pending;
3237 if (step_over_finished)
3241 /* If we were doing a step-over, all other threads but
3242 the stepping one had been paused in start_step_over,
3243 with their suspend counts incremented. We don't want
3244 to do a full unstop/unpause, because we're in
3245 all-stop mode (so we want threads stopped), but we
3246 still need to unsuspend the other threads, to
3247 decrement their `suspended' count back. */
3248 unsuspend_all_lwps (event_child);
3252 /* If we just finished a step-over, then all threads had
3253 been momentarily paused. In all-stop, that's fine,
3254 we want threads stopped by now anyway. In non-stop,
3255 we need to re-resume threads that GDB wanted to be
3257 unstop_all_lwps (1, event_child);
3261 /* Stabilize threads (move out of jump pads). */
3263 stabilize_threads ();
3267 /* If we just finished a step-over, then all threads had been
3268 momentarily paused. In all-stop, that's fine, we want
3269 threads stopped by now anyway. In non-stop, we need to
3270 re-resume threads that GDB wanted to be running. */
3271 if (step_over_finished)
3272 unstop_all_lwps (1, event_child);
3275 if (extended_event_reported (&event_child->waitstatus))
3277 /* If the reported event is a fork, vfork or exec, let GDB know. */
3278 ourstatus->kind = event_child->waitstatus.kind;
3279 ourstatus->value = event_child->waitstatus.value;
3281 /* Clear the event lwp's waitstatus since we handled it already. */
3282 event_child->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3285 ourstatus->kind = TARGET_WAITKIND_STOPPED;
3287 /* Now that we've selected our final event LWP, un-adjust its PC if
3288 it was a software breakpoint, and the client doesn't know we can
3289 adjust the breakpoint ourselves. */
3290 if (event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3291 && !swbreak_feature)
3293 int decr_pc = the_low_target.decr_pc_after_break;
3297 struct regcache *regcache
3298 = get_thread_regcache (current_thread, 1);
3299 (*the_low_target.set_pc) (regcache, event_child->stop_pc + decr_pc);
3303 if (current_thread->last_resume_kind == resume_stop
3304 && WSTOPSIG (w) == SIGSTOP)
3306 /* A thread that has been requested to stop by GDB with vCont;t,
3307 and it stopped cleanly, so report as SIG0. The use of
3308 SIGSTOP is an implementation detail. */
3309 ourstatus->value.sig = GDB_SIGNAL_0;
3311 else if (current_thread->last_resume_kind == resume_stop
3312 && WSTOPSIG (w) != SIGSTOP)
3314 /* A thread that has been requested to stop by GDB with vCont;t,
3315 but, it stopped for other reasons. */
3316 ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
3318 else if (ourstatus->kind == TARGET_WAITKIND_STOPPED)
3320 ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
3323 gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
3327 debug_printf ("linux_wait_1 ret = %s, %d, %d\n",
3328 target_pid_to_str (ptid_of (current_thread)),
3329 ourstatus->kind, ourstatus->value.sig);
3333 return ptid_of (current_thread);
3336 /* Get rid of any pending event in the pipe. */
3338 async_file_flush (void)
3344 ret = read (linux_event_pipe[0], &buf, 1);
3345 while (ret >= 0 || (ret == -1 && errno == EINTR));
3348 /* Put something in the pipe, so the event loop wakes up. */
3350 async_file_mark (void)
3354 async_file_flush ();
3357 ret = write (linux_event_pipe[1], "+", 1);
3358 while (ret == 0 || (ret == -1 && errno == EINTR));
3360 /* Ignore EAGAIN. If the pipe is full, the event loop will already
3361 be awakened anyway. */
3365 linux_wait (ptid_t ptid,
3366 struct target_waitstatus *ourstatus, int target_options)
3370 /* Flush the async file first. */
3371 if (target_is_async_p ())
3372 async_file_flush ();
3376 event_ptid = linux_wait_1 (ptid, ourstatus, target_options);
3378 while ((target_options & TARGET_WNOHANG) == 0
3379 && ptid_equal (event_ptid, null_ptid)
3380 && ourstatus->kind == TARGET_WAITKIND_IGNORE);
3382 /* If at least one stop was reported, there may be more. A single
3383 SIGCHLD can signal more than one child stop. */
3384 if (target_is_async_p ()
3385 && (target_options & TARGET_WNOHANG) != 0
3386 && !ptid_equal (event_ptid, null_ptid))
3392 /* Send a signal to an LWP. */
3395 kill_lwp (unsigned long lwpid, int signo)
3397 /* Use tkill, if possible, in case we are using nptl threads. If tkill
3398 fails, then we are not using nptl threads and we should be using kill. */
3402 static int tkill_failed;
3409 ret = syscall (__NR_tkill, lwpid, signo);
3410 if (errno != ENOSYS)
3417 return kill (lwpid, signo);
3421 linux_stop_lwp (struct lwp_info *lwp)
3427 send_sigstop (struct lwp_info *lwp)
3431 pid = lwpid_of (get_lwp_thread (lwp));
3433 /* If we already have a pending stop signal for this process, don't
3435 if (lwp->stop_expected)
3438 debug_printf ("Have pending sigstop for lwp %d\n", pid);
3444 debug_printf ("Sending sigstop to lwp %d\n", pid);
3446 lwp->stop_expected = 1;
3447 kill_lwp (pid, SIGSTOP);
3451 send_sigstop_callback (struct inferior_list_entry *entry, void *except)
3453 struct thread_info *thread = (struct thread_info *) entry;
3454 struct lwp_info *lwp = get_thread_lwp (thread);
3456 /* Ignore EXCEPT. */
3467 /* Increment the suspend count of an LWP, and stop it, if not stopped
3470 suspend_and_send_sigstop_callback (struct inferior_list_entry *entry,
3473 struct thread_info *thread = (struct thread_info *) entry;
3474 struct lwp_info *lwp = get_thread_lwp (thread);
3476 /* Ignore EXCEPT. */
3482 return send_sigstop_callback (entry, except);
3486 mark_lwp_dead (struct lwp_info *lwp, int wstat)
3488 /* It's dead, really. */
3491 /* Store the exit status for later. */
3492 lwp->status_pending_p = 1;
3493 lwp->status_pending = wstat;
3495 /* Prevent trying to stop it. */
3498 /* No further stops are expected from a dead lwp. */
3499 lwp->stop_expected = 0;
3502 /* Wait for all children to stop for the SIGSTOPs we just queued. */
3505 wait_for_sigstop (void)
3507 struct thread_info *saved_thread;
3512 saved_thread = current_thread;
3513 if (saved_thread != NULL)
3514 saved_tid = saved_thread->entry.id;
3516 saved_tid = null_ptid; /* avoid bogus unused warning */
3519 debug_printf ("wait_for_sigstop: pulling events\n");
3521 /* Passing NULL_PTID as filter indicates we want all events to be
3522 left pending. Eventually this returns when there are no
3523 unwaited-for children left. */
3524 ret = linux_wait_for_event_filtered (minus_one_ptid, null_ptid,
3526 gdb_assert (ret == -1);
3528 if (saved_thread == NULL || linux_thread_alive (saved_tid))
3529 current_thread = saved_thread;
3533 debug_printf ("Previously current thread died.\n");
3537 /* We can't change the current inferior behind GDB's back,
3538 otherwise, a subsequent command may apply to the wrong
3540 current_thread = NULL;
3544 /* Set a valid thread as current. */
3545 set_desired_thread (0);
3550 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
3551 move it out, because we need to report the stop event to GDB. For
3552 example, if the user puts a breakpoint in the jump pad, it's
3553 because she wants to debug it. */
3556 stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data)
3558 struct thread_info *thread = (struct thread_info *) entry;
3559 struct lwp_info *lwp = get_thread_lwp (thread);
3561 gdb_assert (lwp->suspended == 0);
3562 gdb_assert (lwp->stopped);
3564 /* Allow debugging the jump pad, gdb_collect, etc.. */
3565 return (supports_fast_tracepoints ()
3566 && agent_loaded_p ()
3567 && (gdb_breakpoint_here (lwp->stop_pc)
3568 || lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT
3569 || thread->last_resume_kind == resume_step)
3570 && linux_fast_tracepoint_collecting (lwp, NULL));
3574 move_out_of_jump_pad_callback (struct inferior_list_entry *entry)
3576 struct thread_info *thread = (struct thread_info *) entry;
3577 struct lwp_info *lwp = get_thread_lwp (thread);
3580 gdb_assert (lwp->suspended == 0);
3581 gdb_assert (lwp->stopped);
3583 wstat = lwp->status_pending_p ? &lwp->status_pending : NULL;
3585 /* Allow debugging the jump pad, gdb_collect, etc. */
3586 if (!gdb_breakpoint_here (lwp->stop_pc)
3587 && lwp->stop_reason != TARGET_STOPPED_BY_WATCHPOINT
3588 && thread->last_resume_kind != resume_step
3589 && maybe_move_out_of_jump_pad (lwp, wstat))
3592 debug_printf ("LWP %ld needs stabilizing (in jump pad)\n",
3597 lwp->status_pending_p = 0;
3598 enqueue_one_deferred_signal (lwp, wstat);
3601 debug_printf ("Signal %d for LWP %ld deferred "
3603 WSTOPSIG (*wstat), lwpid_of (thread));
3606 linux_resume_one_lwp (lwp, 0, 0, NULL);
3613 lwp_running (struct inferior_list_entry *entry, void *data)
3615 struct thread_info *thread = (struct thread_info *) entry;
3616 struct lwp_info *lwp = get_thread_lwp (thread);
3625 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
3626 If SUSPEND, then also increase the suspend count of every LWP,
3630 stop_all_lwps (int suspend, struct lwp_info *except)
3632 /* Should not be called recursively. */
3633 gdb_assert (stopping_threads == NOT_STOPPING_THREADS);
3638 debug_printf ("stop_all_lwps (%s, except=%s)\n",
3639 suspend ? "stop-and-suspend" : "stop",
3641 ? target_pid_to_str (ptid_of (get_lwp_thread (except)))
3645 stopping_threads = (suspend
3646 ? STOPPING_AND_SUSPENDING_THREADS
3647 : STOPPING_THREADS);
3650 find_inferior (&all_threads, suspend_and_send_sigstop_callback, except);
3652 find_inferior (&all_threads, send_sigstop_callback, except);
3653 wait_for_sigstop ();
3654 stopping_threads = NOT_STOPPING_THREADS;
3658 debug_printf ("stop_all_lwps done, setting stopping_threads "
3659 "back to !stopping\n");
3664 /* Resume execution of LWP. If STEP is nonzero, single-step it. If
3665 SIGNAL is nonzero, give it that signal. */
3668 linux_resume_one_lwp_throw (struct lwp_info *lwp,
3669 int step, int signal, siginfo_t *info)
3671 struct thread_info *thread = get_lwp_thread (lwp);
3672 struct thread_info *saved_thread;
3673 int fast_tp_collecting;
3674 struct process_info *proc = get_thread_process (thread);
3676 /* Note that target description may not be initialised
3677 (proc->tdesc == NULL) at this point because the program hasn't
3678 stopped at the first instruction yet. It means GDBserver skips
3679 the extra traps from the wrapper program (see option --wrapper).
3680 Code in this function that requires register access should be
3681 guarded by proc->tdesc == NULL or something else. */
3683 if (lwp->stopped == 0)
3686 fast_tp_collecting = lwp->collecting_fast_tracepoint;
3688 gdb_assert (!stabilizing_threads || fast_tp_collecting);
3690 /* Cancel actions that rely on GDB not changing the PC (e.g., the
3691 user used the "jump" command, or "set $pc = foo"). */
3692 if (thread->while_stepping != NULL && lwp->stop_pc != get_pc (lwp))
3694 /* Collecting 'while-stepping' actions doesn't make sense
3696 release_while_stepping_state_list (thread);
3699 /* If we have pending signals or status, and a new signal, enqueue the
3700 signal. Also enqueue the signal if we are waiting to reinsert a
3701 breakpoint; it will be picked up again below. */
3703 && (lwp->status_pending_p
3704 || lwp->pending_signals != NULL
3705 || lwp->bp_reinsert != 0
3706 || fast_tp_collecting))
3708 struct pending_signals *p_sig;
3709 p_sig = xmalloc (sizeof (*p_sig));
3710 p_sig->prev = lwp->pending_signals;
3711 p_sig->signal = signal;
3713 memset (&p_sig->info, 0, sizeof (siginfo_t));
3715 memcpy (&p_sig->info, info, sizeof (siginfo_t));
3716 lwp->pending_signals = p_sig;
3719 if (lwp->status_pending_p)
3722 debug_printf ("Not resuming lwp %ld (%s, signal %d, stop %s);"
3723 " has pending status\n",
3724 lwpid_of (thread), step ? "step" : "continue", signal,
3725 lwp->stop_expected ? "expected" : "not expected");
3729 saved_thread = current_thread;
3730 current_thread = thread;
3733 debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n",
3734 lwpid_of (thread), step ? "step" : "continue", signal,
3735 lwp->stop_expected ? "expected" : "not expected");
3737 /* This bit needs some thinking about. If we get a signal that
3738 we must report while a single-step reinsert is still pending,
3739 we often end up resuming the thread. It might be better to
3740 (ew) allow a stack of pending events; then we could be sure that
3741 the reinsert happened right away and not lose any signals.
3743 Making this stack would also shrink the window in which breakpoints are
3744 uninserted (see comment in linux_wait_for_lwp) but not enough for
3745 complete correctness, so it won't solve that problem. It may be
3746 worthwhile just to solve this one, however. */
3747 if (lwp->bp_reinsert != 0)
3750 debug_printf (" pending reinsert at 0x%s\n",
3751 paddress (lwp->bp_reinsert));
3753 if (can_hardware_single_step ())
3755 if (fast_tp_collecting == 0)
3758 fprintf (stderr, "BAD - reinserting but not stepping.\n");
3760 fprintf (stderr, "BAD - reinserting and suspended(%d).\n",
3767 /* Postpone any pending signal. It was enqueued above. */
3771 if (fast_tp_collecting == 1)
3774 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
3775 " (exit-jump-pad-bkpt)\n",
3778 /* Postpone any pending signal. It was enqueued above. */
3781 else if (fast_tp_collecting == 2)
3784 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
3785 " single-stepping\n",
3788 if (can_hardware_single_step ())
3792 internal_error (__FILE__, __LINE__,
3793 "moving out of jump pad single-stepping"
3794 " not implemented on this target");
3797 /* Postpone any pending signal. It was enqueued above. */
3801 /* If we have while-stepping actions in this thread set it stepping.
3802 If we have a signal to deliver, it may or may not be set to
3803 SIG_IGN, we don't know. Assume so, and allow collecting
3804 while-stepping into a signal handler. A possible smart thing to
3805 do would be to set an internal breakpoint at the signal return
3806 address, continue, and carry on catching this while-stepping
3807 action only when that breakpoint is hit. A future
3809 if (thread->while_stepping != NULL
3810 && can_hardware_single_step ())
3813 debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n",
3818 if (proc->tdesc != NULL && the_low_target.get_pc != NULL)
3820 struct regcache *regcache = get_thread_regcache (current_thread, 1);
3822 lwp->stop_pc = (*the_low_target.get_pc) (regcache);
3826 debug_printf (" %s from pc 0x%lx\n", step ? "step" : "continue",
3827 (long) lwp->stop_pc);
3831 /* If we have pending signals, consume one unless we are trying to
3832 reinsert a breakpoint or we're trying to finish a fast tracepoint
3834 if (lwp->pending_signals != NULL
3835 && lwp->bp_reinsert == 0
3836 && fast_tp_collecting == 0)
3838 struct pending_signals **p_sig;
3840 p_sig = &lwp->pending_signals;
3841 while ((*p_sig)->prev != NULL)
3842 p_sig = &(*p_sig)->prev;
3844 signal = (*p_sig)->signal;
3845 if ((*p_sig)->info.si_signo != 0)
3846 ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
3853 if (the_low_target.prepare_to_resume != NULL)
3854 the_low_target.prepare_to_resume (lwp);
3856 regcache_invalidate_thread (thread);
3858 lwp->stepping = step;
3859 ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (thread),
3860 (PTRACE_TYPE_ARG3) 0,
3861 /* Coerce to a uintptr_t first to avoid potential gcc warning
3862 of coercing an 8 byte integer to a 4 byte pointer. */
3863 (PTRACE_TYPE_ARG4) (uintptr_t) signal);
3865 current_thread = saved_thread;
3867 perror_with_name ("resuming thread");
3869 /* Successfully resumed. Clear state that no longer makes sense,
3870 and mark the LWP as running. Must not do this before resuming
3871 otherwise if that fails other code will be confused. E.g., we'd
3872 later try to stop the LWP and hang forever waiting for a stop
3873 status. Note that we must not throw after this is cleared,
3874 otherwise handle_zombie_lwp_error would get confused. */
3876 lwp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
3879 /* Called when we try to resume a stopped LWP and that errors out. If
3880 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
3881 or about to become), discard the error, clear any pending status
3882 the LWP may have, and return true (we'll collect the exit status
3883 soon enough). Otherwise, return false. */
3886 check_ptrace_stopped_lwp_gone (struct lwp_info *lp)
3888 struct thread_info *thread = get_lwp_thread (lp);
3890 /* If we get an error after resuming the LWP successfully, we'd
3891 confuse !T state for the LWP being gone. */
3892 gdb_assert (lp->stopped);
3894 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
3895 because even if ptrace failed with ESRCH, the tracee may be "not
3896 yet fully dead", but already refusing ptrace requests. In that
3897 case the tracee has 'R (Running)' state for a little bit
3898 (observed in Linux 3.18). See also the note on ESRCH in the
3899 ptrace(2) man page. Instead, check whether the LWP has any state
3900 other than ptrace-stopped. */
3902 /* Don't assume anything if /proc/PID/status can't be read. */
3903 if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread)) == 0)
3905 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
3906 lp->status_pending_p = 0;
3912 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
3913 disappears while we try to resume it. */
3916 linux_resume_one_lwp (struct lwp_info *lwp,
3917 int step, int signal, siginfo_t *info)
3921 linux_resume_one_lwp_throw (lwp, step, signal, info);
3923 CATCH (ex, RETURN_MASK_ERROR)
3925 if (!check_ptrace_stopped_lwp_gone (lwp))
3926 throw_exception (ex);
3931 struct thread_resume_array
3933 struct thread_resume *resume;
3937 /* This function is called once per thread via find_inferior.
3938 ARG is a pointer to a thread_resume_array struct.
3939 We look up the thread specified by ENTRY in ARG, and mark the thread
3940 with a pointer to the appropriate resume request.
3942 This algorithm is O(threads * resume elements), but resume elements
3943 is small (and will remain small at least until GDB supports thread
3947 linux_set_resume_request (struct inferior_list_entry *entry, void *arg)
3949 struct thread_info *thread = (struct thread_info *) entry;
3950 struct lwp_info *lwp = get_thread_lwp (thread);
3952 struct thread_resume_array *r;
3956 for (ndx = 0; ndx < r->n; ndx++)
3958 ptid_t ptid = r->resume[ndx].thread;
3959 if (ptid_equal (ptid, minus_one_ptid)
3960 || ptid_equal (ptid, entry->id)
3961 /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads
3963 || (ptid_get_pid (ptid) == pid_of (thread)
3964 && (ptid_is_pid (ptid)
3965 || ptid_get_lwp (ptid) == -1)))
3967 if (r->resume[ndx].kind == resume_stop
3968 && thread->last_resume_kind == resume_stop)
3971 debug_printf ("already %s LWP %ld at GDB's request\n",
3972 (thread->last_status.kind
3973 == TARGET_WAITKIND_STOPPED)
3981 lwp->resume = &r->resume[ndx];
3982 thread->last_resume_kind = lwp->resume->kind;
3984 lwp->step_range_start = lwp->resume->step_range_start;
3985 lwp->step_range_end = lwp->resume->step_range_end;
3987 /* If we had a deferred signal to report, dequeue one now.
3988 This can happen if LWP gets more than one signal while
3989 trying to get out of a jump pad. */
3991 && !lwp->status_pending_p
3992 && dequeue_one_deferred_signal (lwp, &lwp->status_pending))
3994 lwp->status_pending_p = 1;
3997 debug_printf ("Dequeueing deferred signal %d for LWP %ld, "
3998 "leaving status pending.\n",
3999 WSTOPSIG (lwp->status_pending),
4007 /* No resume action for this thread. */
4013 /* find_inferior callback for linux_resume.
4014 Set *FLAG_P if this lwp has an interesting status pending. */
4017 resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
4019 struct thread_info *thread = (struct thread_info *) entry;
4020 struct lwp_info *lwp = get_thread_lwp (thread);
4022 /* LWPs which will not be resumed are not interesting, because
4023 we might not wait for them next time through linux_wait. */
4024 if (lwp->resume == NULL)
4027 if (thread_still_has_status_pending_p (thread))
4028 * (int *) flag_p = 1;
4033 /* Return 1 if this lwp that GDB wants running is stopped at an
4034 internal breakpoint that we need to step over. It assumes that any
4035 required STOP_PC adjustment has already been propagated to the
4036 inferior's regcache. */
4039 need_step_over_p (struct inferior_list_entry *entry, void *dummy)
4041 struct thread_info *thread = (struct thread_info *) entry;
4042 struct lwp_info *lwp = get_thread_lwp (thread);
4043 struct thread_info *saved_thread;
4045 struct process_info *proc = get_thread_process (thread);
4047 /* GDBserver is skipping the extra traps from the wrapper program,
4048 don't have to do step over. */
4049 if (proc->tdesc == NULL)
4052 /* LWPs which will not be resumed are not interesting, because we
4053 might not wait for them next time through linux_wait. */
4058 debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped\n",
4063 if (thread->last_resume_kind == resume_stop)
4066 debug_printf ("Need step over [LWP %ld]? Ignoring, should remain"
4072 gdb_assert (lwp->suspended >= 0);
4077 debug_printf ("Need step over [LWP %ld]? Ignoring, suspended\n",
4082 if (!lwp->need_step_over)
4085 debug_printf ("Need step over [LWP %ld]? No\n", lwpid_of (thread));
4088 if (lwp->status_pending_p)
4091 debug_printf ("Need step over [LWP %ld]? Ignoring, has pending"
4097 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
4101 /* If the PC has changed since we stopped, then don't do anything,
4102 and let the breakpoint/tracepoint be hit. This happens if, for
4103 instance, GDB handled the decr_pc_after_break subtraction itself,
4104 GDB is OOL stepping this thread, or the user has issued a "jump"
4105 command, or poked thread's registers herself. */
4106 if (pc != lwp->stop_pc)
4109 debug_printf ("Need step over [LWP %ld]? Cancelling, PC was changed. "
4110 "Old stop_pc was 0x%s, PC is now 0x%s\n",
4112 paddress (lwp->stop_pc), paddress (pc));
4114 lwp->need_step_over = 0;
4118 saved_thread = current_thread;
4119 current_thread = thread;
4121 /* We can only step over breakpoints we know about. */
4122 if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc))
4124 /* Don't step over a breakpoint that GDB expects to hit
4125 though. If the condition is being evaluated on the target's side
4126 and it evaluate to false, step over this breakpoint as well. */
4127 if (gdb_breakpoint_here (pc)
4128 && gdb_condition_true_at_breakpoint (pc)
4129 && gdb_no_commands_at_breakpoint (pc))
4132 debug_printf ("Need step over [LWP %ld]? yes, but found"
4133 " GDB breakpoint at 0x%s; skipping step over\n",
4134 lwpid_of (thread), paddress (pc));
4136 current_thread = saved_thread;
4142 debug_printf ("Need step over [LWP %ld]? yes, "
4143 "found breakpoint at 0x%s\n",
4144 lwpid_of (thread), paddress (pc));
4146 /* We've found an lwp that needs stepping over --- return 1 so
4147 that find_inferior stops looking. */
4148 current_thread = saved_thread;
4150 /* If the step over is cancelled, this is set again. */
4151 lwp->need_step_over = 0;
4156 current_thread = saved_thread;
4159 debug_printf ("Need step over [LWP %ld]? No, no breakpoint found"
4161 lwpid_of (thread), paddress (pc));
4166 /* Start a step-over operation on LWP. When LWP stopped at a
4167 breakpoint, to make progress, we need to remove the breakpoint out
4168 of the way. If we let other threads run while we do that, they may
4169 pass by the breakpoint location and miss hitting it. To avoid
4170 that, a step-over momentarily stops all threads while LWP is
4171 single-stepped while the breakpoint is temporarily uninserted from
4172 the inferior. When the single-step finishes, we reinsert the
4173 breakpoint, and let all threads that are supposed to be running,
4176 On targets that don't support hardware single-step, we don't
4177 currently support full software single-stepping. Instead, we only
4178 support stepping over the thread event breakpoint, by asking the
4179 low target where to place a reinsert breakpoint. Since this
4180 routine assumes the breakpoint being stepped over is a thread event
4181 breakpoint, it usually assumes the return address of the current
4182 function is a good enough place to set the reinsert breakpoint. */
4185 start_step_over (struct lwp_info *lwp)
4187 struct thread_info *thread = get_lwp_thread (lwp);
4188 struct thread_info *saved_thread;
4193 debug_printf ("Starting step-over on LWP %ld. Stopping all threads\n",
4196 stop_all_lwps (1, lwp);
4197 gdb_assert (lwp->suspended == 0);
4200 debug_printf ("Done stopping all threads for step-over.\n");
4202 /* Note, we should always reach here with an already adjusted PC,
4203 either by GDB (if we're resuming due to GDB's request), or by our
4204 caller, if we just finished handling an internal breakpoint GDB
4205 shouldn't care about. */
4208 saved_thread = current_thread;
4209 current_thread = thread;
4211 lwp->bp_reinsert = pc;
4212 uninsert_breakpoints_at (pc);
4213 uninsert_fast_tracepoint_jumps_at (pc);
4215 if (can_hardware_single_step ())
4221 CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
4222 set_reinsert_breakpoint (raddr);
4226 current_thread = saved_thread;
4228 linux_resume_one_lwp (lwp, step, 0, NULL);
4230 /* Require next event from this LWP. */
4231 step_over_bkpt = thread->entry.id;
4235 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
4236 start_step_over, if still there, and delete any reinsert
4237 breakpoints we've set, on non hardware single-step targets. */
4240 finish_step_over (struct lwp_info *lwp)
4242 if (lwp->bp_reinsert != 0)
4245 debug_printf ("Finished step over.\n");
4247 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
4248 may be no breakpoint to reinsert there by now. */
4249 reinsert_breakpoints_at (lwp->bp_reinsert);
4250 reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert);
4252 lwp->bp_reinsert = 0;
4254 /* Delete any software-single-step reinsert breakpoints. No
4255 longer needed. We don't have to worry about other threads
4256 hitting this trap, and later not being able to explain it,
4257 because we were stepping over a breakpoint, and we hold all
4258 threads but LWP stopped while doing that. */
4259 if (!can_hardware_single_step ())
4260 delete_reinsert_breakpoints ();
4262 step_over_bkpt = null_ptid;
4269 /* This function is called once per thread. We check the thread's resume
4270 request, which will tell us whether to resume, step, or leave the thread
4271 stopped; and what signal, if any, it should be sent.
4273 For threads which we aren't explicitly told otherwise, we preserve
4274 the stepping flag; this is used for stepping over gdbserver-placed
4277 If pending_flags was set in any thread, we queue any needed
4278 signals, since we won't actually resume. We already have a pending
4279 event to report, so we don't need to preserve any step requests;
4280 they should be re-issued if necessary. */
4283 linux_resume_one_thread (struct inferior_list_entry *entry, void *arg)
4285 struct thread_info *thread = (struct thread_info *) entry;
4286 struct lwp_info *lwp = get_thread_lwp (thread);
4288 int leave_all_stopped = * (int *) arg;
4291 if (lwp->resume == NULL)
4294 if (lwp->resume->kind == resume_stop)
4297 debug_printf ("resume_stop request for LWP %ld\n", lwpid_of (thread));
4302 debug_printf ("stopping LWP %ld\n", lwpid_of (thread));
4304 /* Stop the thread, and wait for the event asynchronously,
4305 through the event loop. */
4311 debug_printf ("already stopped LWP %ld\n",
4314 /* The LWP may have been stopped in an internal event that
4315 was not meant to be notified back to GDB (e.g., gdbserver
4316 breakpoint), so we should be reporting a stop event in
4319 /* If the thread already has a pending SIGSTOP, this is a
4320 no-op. Otherwise, something later will presumably resume
4321 the thread and this will cause it to cancel any pending
4322 operation, due to last_resume_kind == resume_stop. If
4323 the thread already has a pending status to report, we
4324 will still report it the next time we wait - see
4325 status_pending_p_callback. */
4327 /* If we already have a pending signal to report, then
4328 there's no need to queue a SIGSTOP, as this means we're
4329 midway through moving the LWP out of the jumppad, and we
4330 will report the pending signal as soon as that is
4332 if (lwp->pending_signals_to_report == NULL)
4336 /* For stop requests, we're done. */
4338 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
4342 /* If this thread which is about to be resumed has a pending status,
4343 then don't resume any threads - we can just report the pending
4344 status. Make sure to queue any signals that would otherwise be
4345 sent. In all-stop mode, we do this decision based on if *any*
4346 thread has a pending status. If there's a thread that needs the
4347 step-over-breakpoint dance, then don't resume any other thread
4348 but that particular one. */
4349 leave_pending = (lwp->status_pending_p || leave_all_stopped);
4354 debug_printf ("resuming LWP %ld\n", lwpid_of (thread));
4356 step = (lwp->resume->kind == resume_step);
4357 linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
4362 debug_printf ("leaving LWP %ld stopped\n", lwpid_of (thread));
4364 /* If we have a new signal, enqueue the signal. */
4365 if (lwp->resume->sig != 0)
4367 struct pending_signals *p_sig;
4368 p_sig = xmalloc (sizeof (*p_sig));
4369 p_sig->prev = lwp->pending_signals;
4370 p_sig->signal = lwp->resume->sig;
4371 memset (&p_sig->info, 0, sizeof (siginfo_t));
4373 /* If this is the same signal we were previously stopped by,
4374 make sure to queue its siginfo. We can ignore the return
4375 value of ptrace; if it fails, we'll skip
4376 PTRACE_SETSIGINFO. */
4377 if (WIFSTOPPED (lwp->last_status)
4378 && WSTOPSIG (lwp->last_status) == lwp->resume->sig)
4379 ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0,
4382 lwp->pending_signals = p_sig;
4386 thread->last_status.kind = TARGET_WAITKIND_IGNORE;
4392 linux_resume (struct thread_resume *resume_info, size_t n)
4394 struct thread_resume_array array = { resume_info, n };
4395 struct thread_info *need_step_over = NULL;
4397 int leave_all_stopped;
4402 debug_printf ("linux_resume:\n");
4405 find_inferior (&all_threads, linux_set_resume_request, &array);
4407 /* If there is a thread which would otherwise be resumed, which has
4408 a pending status, then don't resume any threads - we can just
4409 report the pending status. Make sure to queue any signals that
4410 would otherwise be sent. In non-stop mode, we'll apply this
4411 logic to each thread individually. We consume all pending events
4412 before considering to start a step-over (in all-stop). */
4415 find_inferior (&all_threads, resume_status_pending_p, &any_pending);
4417 /* If there is a thread which would otherwise be resumed, which is
4418 stopped at a breakpoint that needs stepping over, then don't
4419 resume any threads - have it step over the breakpoint with all
4420 other threads stopped, then resume all threads again. Make sure
4421 to queue any signals that would otherwise be delivered or
4423 if (!any_pending && supports_breakpoints ())
4425 = (struct thread_info *) find_inferior (&all_threads,
4426 need_step_over_p, NULL);
4428 leave_all_stopped = (need_step_over != NULL || any_pending);
4432 if (need_step_over != NULL)
4433 debug_printf ("Not resuming all, need step over\n");
4434 else if (any_pending)
4435 debug_printf ("Not resuming, all-stop and found "
4436 "an LWP with pending status\n");
4438 debug_printf ("Resuming, no pending status or step over needed\n");
4441 /* Even if we're leaving threads stopped, queue all signals we'd
4442 otherwise deliver. */
4443 find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped);
4446 start_step_over (get_thread_lwp (need_step_over));
4450 debug_printf ("linux_resume done\n");
4455 /* This function is called once per thread. We check the thread's
4456 last resume request, which will tell us whether to resume, step, or
4457 leave the thread stopped. Any signal the client requested to be
4458 delivered has already been enqueued at this point.
4460 If any thread that GDB wants running is stopped at an internal
4461 breakpoint that needs stepping over, we start a step-over operation
4462 on that particular thread, and leave all others stopped. */
4465 proceed_one_lwp (struct inferior_list_entry *entry, void *except)
4467 struct thread_info *thread = (struct thread_info *) entry;
4468 struct lwp_info *lwp = get_thread_lwp (thread);
4475 debug_printf ("proceed_one_lwp: lwp %ld\n", lwpid_of (thread));
4480 debug_printf (" LWP %ld already running\n", lwpid_of (thread));
4484 if (thread->last_resume_kind == resume_stop
4485 && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
4488 debug_printf (" client wants LWP to remain %ld stopped\n",
4493 if (lwp->status_pending_p)
4496 debug_printf (" LWP %ld has pending status, leaving stopped\n",
4501 gdb_assert (lwp->suspended >= 0);
4506 debug_printf (" LWP %ld is suspended\n", lwpid_of (thread));
4510 if (thread->last_resume_kind == resume_stop
4511 && lwp->pending_signals_to_report == NULL
4512 && lwp->collecting_fast_tracepoint == 0)
4514 /* We haven't reported this LWP as stopped yet (otherwise, the
4515 last_status.kind check above would catch it, and we wouldn't
4516 reach here. This LWP may have been momentarily paused by a
4517 stop_all_lwps call while handling for example, another LWP's
4518 step-over. In that case, the pending expected SIGSTOP signal
4519 that was queued at vCont;t handling time will have already
4520 been consumed by wait_for_sigstop, and so we need to requeue
4521 another one here. Note that if the LWP already has a SIGSTOP
4522 pending, this is a no-op. */
4525 debug_printf ("Client wants LWP %ld to stop. "
4526 "Making sure it has a SIGSTOP pending\n",
4532 step = thread->last_resume_kind == resume_step;
4533 linux_resume_one_lwp (lwp, step, 0, NULL);
4538 unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except)
4540 struct thread_info *thread = (struct thread_info *) entry;
4541 struct lwp_info *lwp = get_thread_lwp (thread);
4547 gdb_assert (lwp->suspended >= 0);
4549 return proceed_one_lwp (entry, except);
4552 /* When we finish a step-over, set threads running again. If there's
4553 another thread that may need a step-over, now's the time to start
4554 it. Eventually, we'll move all threads past their breakpoints. */
4557 proceed_all_lwps (void)
4559 struct thread_info *need_step_over;
4561 /* If there is a thread which would otherwise be resumed, which is
4562 stopped at a breakpoint that needs stepping over, then don't
4563 resume any threads - have it step over the breakpoint with all
4564 other threads stopped, then resume all threads again. */
4566 if (supports_breakpoints ())
4569 = (struct thread_info *) find_inferior (&all_threads,
4570 need_step_over_p, NULL);
4572 if (need_step_over != NULL)
4575 debug_printf ("proceed_all_lwps: found "
4576 "thread %ld needing a step-over\n",
4577 lwpid_of (need_step_over));
4579 start_step_over (get_thread_lwp (need_step_over));
4585 debug_printf ("Proceeding, no step-over needed\n");
4587 find_inferior (&all_threads, proceed_one_lwp, NULL);
4590 /* Stopped LWPs that the client wanted to be running, that don't have
4591 pending statuses, are set to run again, except for EXCEPT, if not
4592 NULL. This undoes a stop_all_lwps call. */
4595 unstop_all_lwps (int unsuspend, struct lwp_info *except)
4601 debug_printf ("unstopping all lwps, except=(LWP %ld)\n",
4602 lwpid_of (get_lwp_thread (except)));
4604 debug_printf ("unstopping all lwps\n");
4608 find_inferior (&all_threads, unsuspend_and_proceed_one_lwp, except);
4610 find_inferior (&all_threads, proceed_one_lwp, except);
4614 debug_printf ("unstop_all_lwps done\n");
4620 #ifdef HAVE_LINUX_REGSETS
4622 #define use_linux_regsets 1
4624 /* Returns true if REGSET has been disabled. */
4627 regset_disabled (struct regsets_info *info, struct regset_info *regset)
4629 return (info->disabled_regsets != NULL
4630 && info->disabled_regsets[regset - info->regsets]);
4633 /* Disable REGSET. */
4636 disable_regset (struct regsets_info *info, struct regset_info *regset)
4640 dr_offset = regset - info->regsets;
4641 if (info->disabled_regsets == NULL)
4642 info->disabled_regsets = xcalloc (1, info->num_regsets);
4643 info->disabled_regsets[dr_offset] = 1;
4647 regsets_fetch_inferior_registers (struct regsets_info *regsets_info,
4648 struct regcache *regcache)
4650 struct regset_info *regset;
4651 int saw_general_regs = 0;
4655 pid = lwpid_of (current_thread);
4656 for (regset = regsets_info->regsets; regset->size >= 0; regset++)
4661 if (regset->size == 0 || regset_disabled (regsets_info, regset))
4664 buf = xmalloc (regset->size);
4666 nt_type = regset->nt_type;
4670 iov.iov_len = regset->size;
4671 data = (void *) &iov;
4677 res = ptrace (regset->get_request, pid,
4678 (PTRACE_TYPE_ARG3) (long) nt_type, data);
4680 res = ptrace (regset->get_request, pid, data, nt_type);
4686 /* If we get EIO on a regset, do not try it again for
4687 this process mode. */
4688 disable_regset (regsets_info, regset);
4690 else if (errno == ENODATA)
4692 /* ENODATA may be returned if the regset is currently
4693 not "active". This can happen in normal operation,
4694 so suppress the warning in this case. */
4699 sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d",
4706 if (regset->type == GENERAL_REGS)
4707 saw_general_regs = 1;
4708 regset->store_function (regcache, buf);
4712 if (saw_general_regs)
4719 regsets_store_inferior_registers (struct regsets_info *regsets_info,
4720 struct regcache *regcache)
4722 struct regset_info *regset;
4723 int saw_general_regs = 0;
4727 pid = lwpid_of (current_thread);
4728 for (regset = regsets_info->regsets; regset->size >= 0; regset++)
4733 if (regset->size == 0 || regset_disabled (regsets_info, regset)
4734 || regset->fill_function == NULL)
4737 buf = xmalloc (regset->size);
4739 /* First fill the buffer with the current register set contents,
4740 in case there are any items in the kernel's regset that are
4741 not in gdbserver's regcache. */
4743 nt_type = regset->nt_type;
4747 iov.iov_len = regset->size;
4748 data = (void *) &iov;
4754 res = ptrace (regset->get_request, pid,
4755 (PTRACE_TYPE_ARG3) (long) nt_type, data);
4757 res = ptrace (regset->get_request, pid, data, nt_type);
4762 /* Then overlay our cached registers on that. */
4763 regset->fill_function (regcache, buf);
4765 /* Only now do we write the register set. */
4767 res = ptrace (regset->set_request, pid,
4768 (PTRACE_TYPE_ARG3) (long) nt_type, data);
4770 res = ptrace (regset->set_request, pid, data, nt_type);
4778 /* If we get EIO on a regset, do not try it again for
4779 this process mode. */
4780 disable_regset (regsets_info, regset);
4782 else if (errno == ESRCH)
4784 /* At this point, ESRCH should mean the process is
4785 already gone, in which case we simply ignore attempts
4786 to change its registers. See also the related
4787 comment in linux_resume_one_lwp. */
4793 perror ("Warning: ptrace(regsets_store_inferior_registers)");
4796 else if (regset->type == GENERAL_REGS)
4797 saw_general_regs = 1;
4800 if (saw_general_regs)
4806 #else /* !HAVE_LINUX_REGSETS */
4808 #define use_linux_regsets 0
4809 #define regsets_fetch_inferior_registers(regsets_info, regcache) 1
4810 #define regsets_store_inferior_registers(regsets_info, regcache) 1
4814 /* Return 1 if register REGNO is supported by one of the regset ptrace
4815 calls or 0 if it has to be transferred individually. */
4818 linux_register_in_regsets (const struct regs_info *regs_info, int regno)
4820 unsigned char mask = 1 << (regno % 8);
4821 size_t index = regno / 8;
4823 return (use_linux_regsets
4824 && (regs_info->regset_bitmap == NULL
4825 || (regs_info->regset_bitmap[index] & mask) != 0));
4828 #ifdef HAVE_LINUX_USRREGS
4831 register_addr (const struct usrregs_info *usrregs, int regnum)
4835 if (regnum < 0 || regnum >= usrregs->num_regs)
4836 error ("Invalid register number %d.", regnum);
4838 addr = usrregs->regmap[regnum];
4843 /* Fetch one register. */
4845 fetch_register (const struct usrregs_info *usrregs,
4846 struct regcache *regcache, int regno)
4853 if (regno >= usrregs->num_regs)
4855 if ((*the_low_target.cannot_fetch_register) (regno))
4858 regaddr = register_addr (usrregs, regno);
4862 size = ((register_size (regcache->tdesc, regno)
4863 + sizeof (PTRACE_XFER_TYPE) - 1)
4864 & -sizeof (PTRACE_XFER_TYPE));
4865 buf = alloca (size);
4867 pid = lwpid_of (current_thread);
4868 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
4871 *(PTRACE_XFER_TYPE *) (buf + i) =
4872 ptrace (PTRACE_PEEKUSER, pid,
4873 /* Coerce to a uintptr_t first to avoid potential gcc warning
4874 of coercing an 8 byte integer to a 4 byte pointer. */
4875 (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, (PTRACE_TYPE_ARG4) 0);
4876 regaddr += sizeof (PTRACE_XFER_TYPE);
4878 error ("reading register %d: %s", regno, strerror (errno));
4881 if (the_low_target.supply_ptrace_register)
4882 the_low_target.supply_ptrace_register (regcache, regno, buf);
4884 supply_register (regcache, regno, buf);
4887 /* Store one register. */
4889 store_register (const struct usrregs_info *usrregs,
4890 struct regcache *regcache, int regno)
4897 if (regno >= usrregs->num_regs)
4899 if ((*the_low_target.cannot_store_register) (regno))
4902 regaddr = register_addr (usrregs, regno);
4906 size = ((register_size (regcache->tdesc, regno)
4907 + sizeof (PTRACE_XFER_TYPE) - 1)
4908 & -sizeof (PTRACE_XFER_TYPE));
4909 buf = alloca (size);
4910 memset (buf, 0, size);
4912 if (the_low_target.collect_ptrace_register)
4913 the_low_target.collect_ptrace_register (regcache, regno, buf);
4915 collect_register (regcache, regno, buf);
4917 pid = lwpid_of (current_thread);
4918 for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
4921 ptrace (PTRACE_POKEUSER, pid,
4922 /* Coerce to a uintptr_t first to avoid potential gcc warning
4923 about coercing an 8 byte integer to a 4 byte pointer. */
4924 (PTRACE_TYPE_ARG3) (uintptr_t) regaddr,
4925 (PTRACE_TYPE_ARG4) *(PTRACE_XFER_TYPE *) (buf + i));
4928 /* At this point, ESRCH should mean the process is
4929 already gone, in which case we simply ignore attempts
4930 to change its registers. See also the related
4931 comment in linux_resume_one_lwp. */
4935 if ((*the_low_target.cannot_store_register) (regno) == 0)
4936 error ("writing register %d: %s", regno, strerror (errno));
4938 regaddr += sizeof (PTRACE_XFER_TYPE);
4942 /* Fetch all registers, or just one, from the child process.
4943 If REGNO is -1, do this for all registers, skipping any that are
4944 assumed to have been retrieved by regsets_fetch_inferior_registers,
4945 unless ALL is non-zero.
4946 Otherwise, REGNO specifies which register (so we can save time). */
4948 usr_fetch_inferior_registers (const struct regs_info *regs_info,
4949 struct regcache *regcache, int regno, int all)
4951 struct usrregs_info *usr = regs_info->usrregs;
4955 for (regno = 0; regno < usr->num_regs; regno++)
4956 if (all || !linux_register_in_regsets (regs_info, regno))
4957 fetch_register (usr, regcache, regno);
4960 fetch_register (usr, regcache, regno);
4963 /* Store our register values back into the inferior.
4964 If REGNO is -1, do this for all registers, skipping any that are
4965 assumed to have been saved by regsets_store_inferior_registers,
4966 unless ALL is non-zero.
4967 Otherwise, REGNO specifies which register (so we can save time). */
4969 usr_store_inferior_registers (const struct regs_info *regs_info,
4970 struct regcache *regcache, int regno, int all)
4972 struct usrregs_info *usr = regs_info->usrregs;
4976 for (regno = 0; regno < usr->num_regs; regno++)
4977 if (all || !linux_register_in_regsets (regs_info, regno))
4978 store_register (usr, regcache, regno);
4981 store_register (usr, regcache, regno);
4984 #else /* !HAVE_LINUX_USRREGS */
4986 #define usr_fetch_inferior_registers(regs_info, regcache, regno, all) do {} while (0)
4987 #define usr_store_inferior_registers(regs_info, regcache, regno, all) do {} while (0)
4993 linux_fetch_registers (struct regcache *regcache, int regno)
4997 const struct regs_info *regs_info = (*the_low_target.regs_info) ();
5001 if (the_low_target.fetch_register != NULL
5002 && regs_info->usrregs != NULL)
5003 for (regno = 0; regno < regs_info->usrregs->num_regs; regno++)
5004 (*the_low_target.fetch_register) (regcache, regno);
5006 all = regsets_fetch_inferior_registers (regs_info->regsets_info, regcache);
5007 if (regs_info->usrregs != NULL)
5008 usr_fetch_inferior_registers (regs_info, regcache, -1, all);
5012 if (the_low_target.fetch_register != NULL
5013 && (*the_low_target.fetch_register) (regcache, regno))
5016 use_regsets = linux_register_in_regsets (regs_info, regno);
5018 all = regsets_fetch_inferior_registers (regs_info->regsets_info,
5020 if ((!use_regsets || all) && regs_info->usrregs != NULL)
5021 usr_fetch_inferior_registers (regs_info, regcache, regno, 1);
5026 linux_store_registers (struct regcache *regcache, int regno)
5030 const struct regs_info *regs_info = (*the_low_target.regs_info) ();
5034 all = regsets_store_inferior_registers (regs_info->regsets_info,
5036 if (regs_info->usrregs != NULL)
5037 usr_store_inferior_registers (regs_info, regcache, regno, all);
5041 use_regsets = linux_register_in_regsets (regs_info, regno);
5043 all = regsets_store_inferior_registers (regs_info->regsets_info,
5045 if ((!use_regsets || all) && regs_info->usrregs != NULL)
5046 usr_store_inferior_registers (regs_info, regcache, regno, 1);
5051 /* Copy LEN bytes from inferior's memory starting at MEMADDR
5052 to debugger memory starting at MYADDR. */
5055 linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
5057 int pid = lwpid_of (current_thread);
5058 register PTRACE_XFER_TYPE *buffer;
5059 register CORE_ADDR addr;
5066 /* Try using /proc. Don't bother for one word. */
5067 if (len >= 3 * sizeof (long))
5071 /* We could keep this file open and cache it - possibly one per
5072 thread. That requires some juggling, but is even faster. */
5073 sprintf (filename, "/proc/%d/mem", pid);
5074 fd = open (filename, O_RDONLY | O_LARGEFILE);
5078 /* If pread64 is available, use it. It's faster if the kernel
5079 supports it (only one syscall), and it's 64-bit safe even on
5080 32-bit platforms (for instance, SPARC debugging a SPARC64
5083 bytes = pread64 (fd, myaddr, len, memaddr);
5086 if (lseek (fd, memaddr, SEEK_SET) != -1)
5087 bytes = read (fd, myaddr, len);
5094 /* Some data was read, we'll try to get the rest with ptrace. */
5104 /* Round starting address down to longword boundary. */
5105 addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
5106 /* Round ending address up; get number of longwords that makes. */
5107 count = ((((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
5108 / sizeof (PTRACE_XFER_TYPE));
5109 /* Allocate buffer of that many longwords. */
5110 buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
5112 /* Read all the longwords */
5114 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
5116 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
5117 about coercing an 8 byte integer to a 4 byte pointer. */
5118 buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
5119 (PTRACE_TYPE_ARG3) (uintptr_t) addr,
5120 (PTRACE_TYPE_ARG4) 0);
5126 /* Copy appropriate bytes out of the buffer. */
5129 i *= sizeof (PTRACE_XFER_TYPE);
5130 i -= memaddr & (sizeof (PTRACE_XFER_TYPE) - 1);
5132 (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
5139 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
5140 memory at MEMADDR. On failure (cannot write to the inferior)
5141 returns the value of errno. Always succeeds if LEN is zero. */
5144 linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
5147 /* Round starting address down to longword boundary. */
5148 register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
5149 /* Round ending address up; get number of longwords that makes. */
5151 = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
5152 / sizeof (PTRACE_XFER_TYPE);
5154 /* Allocate buffer of that many longwords. */
5155 register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *)
5156 alloca (count * sizeof (PTRACE_XFER_TYPE));
5158 int pid = lwpid_of (current_thread);
5162 /* Zero length write always succeeds. */
5168 /* Dump up to four bytes. */
5169 unsigned int val = * (unsigned int *) myaddr;
5175 val = val & 0xffffff;
5176 debug_printf ("Writing %0*x to 0x%08lx in process %d\n",
5177 2 * ((len < 4) ? len : 4), val, (long)memaddr, pid);
5180 /* Fill start and end extra bytes of buffer with existing memory data. */
5183 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
5184 about coercing an 8 byte integer to a 4 byte pointer. */
5185 buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
5186 (PTRACE_TYPE_ARG3) (uintptr_t) addr,
5187 (PTRACE_TYPE_ARG4) 0);
5195 = ptrace (PTRACE_PEEKTEXT, pid,
5196 /* Coerce to a uintptr_t first to avoid potential gcc warning
5197 about coercing an 8 byte integer to a 4 byte pointer. */
5198 (PTRACE_TYPE_ARG3) (uintptr_t) (addr + (count - 1)
5199 * sizeof (PTRACE_XFER_TYPE)),
5200 (PTRACE_TYPE_ARG4) 0);
5205 /* Copy data to be written over corresponding part of buffer. */
5207 memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
5210 /* Write the entire buffer. */
5212 for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
5215 ptrace (PTRACE_POKETEXT, pid,
5216 /* Coerce to a uintptr_t first to avoid potential gcc warning
5217 about coercing an 8 byte integer to a 4 byte pointer. */
5218 (PTRACE_TYPE_ARG3) (uintptr_t) addr,
5219 (PTRACE_TYPE_ARG4) buffer[i]);
5228 linux_look_up_symbols (void)
5230 #ifdef USE_THREAD_DB
5231 struct process_info *proc = current_process ();
5233 if (proc->priv->thread_db != NULL)
5236 /* If the kernel supports tracing clones, then we don't need to
5237 use the magic thread event breakpoint to learn about
5239 thread_db_init (!linux_supports_traceclone ());
5244 linux_request_interrupt (void)
5246 extern unsigned long signal_pid;
5248 /* Send a SIGINT to the process group. This acts just like the user
5249 typed a ^C on the controlling terminal. */
5250 kill (-signal_pid, SIGINT);
5253 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
5254 to debugger memory starting at MYADDR. */
5257 linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len)
5259 char filename[PATH_MAX];
5261 int pid = lwpid_of (current_thread);
5263 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
5265 fd = open (filename, O_RDONLY);
5269 if (offset != (CORE_ADDR) 0
5270 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
5273 n = read (fd, myaddr, len);
5280 /* These breakpoint and watchpoint related wrapper functions simply
5281 pass on the function call if the target has registered a
5282 corresponding function. */
5285 linux_supports_z_point_type (char z_type)
5287 return (the_low_target.supports_z_point_type != NULL
5288 && the_low_target.supports_z_point_type (z_type));
5292 linux_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
5293 int size, struct raw_breakpoint *bp)
5295 if (type == raw_bkpt_type_sw)
5296 return insert_memory_breakpoint (bp);
5297 else if (the_low_target.insert_point != NULL)
5298 return the_low_target.insert_point (type, addr, size, bp);
5300 /* Unsupported (see target.h). */
5305 linux_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
5306 int size, struct raw_breakpoint *bp)
5308 if (type == raw_bkpt_type_sw)
5309 return remove_memory_breakpoint (bp);
5310 else if (the_low_target.remove_point != NULL)
5311 return the_low_target.remove_point (type, addr, size, bp);
5313 /* Unsupported (see target.h). */
5317 /* Implement the to_stopped_by_sw_breakpoint target_ops
5321 linux_stopped_by_sw_breakpoint (void)
5323 struct lwp_info *lwp = get_thread_lwp (current_thread);
5325 return (lwp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT);
5328 /* Implement the to_supports_stopped_by_sw_breakpoint target_ops
5332 linux_supports_stopped_by_sw_breakpoint (void)
5334 return USE_SIGTRAP_SIGINFO;
5337 /* Implement the to_stopped_by_hw_breakpoint target_ops
5341 linux_stopped_by_hw_breakpoint (void)
5343 struct lwp_info *lwp = get_thread_lwp (current_thread);
5345 return (lwp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT);
5348 /* Implement the to_supports_stopped_by_hw_breakpoint target_ops
5352 linux_supports_stopped_by_hw_breakpoint (void)
5354 return USE_SIGTRAP_SIGINFO;
5357 /* Implement the supports_conditional_breakpoints target_ops
5361 linux_supports_conditional_breakpoints (void)
5363 /* GDBserver needs to step over the breakpoint if the condition is
5364 false. GDBserver software single step is too simple, so disable
5365 conditional breakpoints if the target doesn't have hardware single
5367 return can_hardware_single_step ();
5371 linux_stopped_by_watchpoint (void)
5373 struct lwp_info *lwp = get_thread_lwp (current_thread);
5375 return lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
5379 linux_stopped_data_address (void)
5381 struct lwp_info *lwp = get_thread_lwp (current_thread);
5383 return lwp->stopped_data_address;
5386 #if defined(__UCLIBC__) && defined(HAS_NOMMU) \
5387 && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
5388 && defined(PT_TEXT_END_ADDR)
5390 /* This is only used for targets that define PT_TEXT_ADDR,
5391 PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly
5392 the target has different ways of acquiring this information, like
5395 /* Under uClinux, programs are loaded at non-zero offsets, which we need
5396 to tell gdb about. */
5399 linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
5401 unsigned long text, text_end, data;
5402 int pid = lwpid_of (current_thread);
5406 text = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_ADDR,
5407 (PTRACE_TYPE_ARG4) 0);
5408 text_end = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_END_ADDR,
5409 (PTRACE_TYPE_ARG4) 0);
5410 data = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_DATA_ADDR,
5411 (PTRACE_TYPE_ARG4) 0);
5415 /* Both text and data offsets produced at compile-time (and so
5416 used by gdb) are relative to the beginning of the program,
5417 with the data segment immediately following the text segment.
5418 However, the actual runtime layout in memory may put the data
5419 somewhere else, so when we send gdb a data base-address, we
5420 use the real data base address and subtract the compile-time
5421 data base-address from it (which is just the length of the
5422 text segment). BSS immediately follows data in both
5425 *data_p = data - (text_end - text);
5434 linux_qxfer_osdata (const char *annex,
5435 unsigned char *readbuf, unsigned const char *writebuf,
5436 CORE_ADDR offset, int len)
5438 return linux_common_xfer_osdata (annex, readbuf, offset, len);
5441 /* Convert a native/host siginfo object, into/from the siginfo in the
5442 layout of the inferiors' architecture. */
5445 siginfo_fixup (siginfo_t *siginfo, void *inf_siginfo, int direction)
5449 if (the_low_target.siginfo_fixup != NULL)
5450 done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction);
5452 /* If there was no callback, or the callback didn't do anything,
5453 then just do a straight memcpy. */
5457 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
5459 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
5464 linux_xfer_siginfo (const char *annex, unsigned char *readbuf,
5465 unsigned const char *writebuf, CORE_ADDR offset, int len)
5469 char inf_siginfo[sizeof (siginfo_t)];
5471 if (current_thread == NULL)
5474 pid = lwpid_of (current_thread);
5477 debug_printf ("%s siginfo for lwp %d.\n",
5478 readbuf != NULL ? "Reading" : "Writing",
5481 if (offset >= sizeof (siginfo))
5484 if (ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0)
5487 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
5488 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
5489 inferior with a 64-bit GDBSERVER should look the same as debugging it
5490 with a 32-bit GDBSERVER, we need to convert it. */
5491 siginfo_fixup (&siginfo, inf_siginfo, 0);
5493 if (offset + len > sizeof (siginfo))
5494 len = sizeof (siginfo) - offset;
5496 if (readbuf != NULL)
5497 memcpy (readbuf, inf_siginfo + offset, len);
5500 memcpy (inf_siginfo + offset, writebuf, len);
5502 /* Convert back to ptrace layout before flushing it out. */
5503 siginfo_fixup (&siginfo, inf_siginfo, 1);
5505 if (ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0)
5512 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
5513 so we notice when children change state; as the handler for the
5514 sigsuspend in my_waitpid. */
5517 sigchld_handler (int signo)
5519 int old_errno = errno;
5525 /* fprintf is not async-signal-safe, so call write
5527 if (write (2, "sigchld_handler\n",
5528 sizeof ("sigchld_handler\n") - 1) < 0)
5529 break; /* just ignore */
5533 if (target_is_async_p ())
5534 async_file_mark (); /* trigger a linux_wait */
5540 linux_supports_non_stop (void)
5546 linux_async (int enable)
5548 int previous = target_is_async_p ();
5551 debug_printf ("linux_async (%d), previous=%d\n",
5554 if (previous != enable)
5557 sigemptyset (&mask);
5558 sigaddset (&mask, SIGCHLD);
5560 sigprocmask (SIG_BLOCK, &mask, NULL);
5564 if (pipe (linux_event_pipe) == -1)
5566 linux_event_pipe[0] = -1;
5567 linux_event_pipe[1] = -1;
5568 sigprocmask (SIG_UNBLOCK, &mask, NULL);
5570 warning ("creating event pipe failed.");
5574 fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
5575 fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
5577 /* Register the event loop handler. */
5578 add_file_handler (linux_event_pipe[0],
5579 handle_target_event, NULL);
5581 /* Always trigger a linux_wait. */
5586 delete_file_handler (linux_event_pipe[0]);
5588 close (linux_event_pipe[0]);
5589 close (linux_event_pipe[1]);
5590 linux_event_pipe[0] = -1;
5591 linux_event_pipe[1] = -1;
5594 sigprocmask (SIG_UNBLOCK, &mask, NULL);
5601 linux_start_non_stop (int nonstop)
5603 /* Register or unregister from event-loop accordingly. */
5604 linux_async (nonstop);
5606 if (target_is_async_p () != (nonstop != 0))
5613 linux_supports_multi_process (void)
5618 /* Check if fork events are supported. */
5621 linux_supports_fork_events (void)
5623 return linux_supports_tracefork ();
5626 /* Check if vfork events are supported. */
5629 linux_supports_vfork_events (void)
5631 return linux_supports_tracefork ();
5634 /* Callback for 'find_inferior'. Set the (possibly changed) ptrace
5635 options for the specified lwp. */
5638 reset_lwp_ptrace_options_callback (struct inferior_list_entry *entry,
5641 struct thread_info *thread = (struct thread_info *) entry;
5642 struct lwp_info *lwp = get_thread_lwp (thread);
5646 /* Stop the lwp so we can modify its ptrace options. */
5647 lwp->must_set_ptrace_flags = 1;
5648 linux_stop_lwp (lwp);
5652 /* Already stopped; go ahead and set the ptrace options. */
5653 struct process_info *proc = find_process_pid (pid_of (thread));
5654 int options = linux_low_ptrace_options (proc->attached);
5656 linux_enable_event_reporting (lwpid_of (thread), options);
5657 lwp->must_set_ptrace_flags = 0;
5663 /* Target hook for 'handle_new_gdb_connection'. Causes a reset of the
5664 ptrace flags for all inferiors. This is in case the new GDB connection
5665 doesn't support the same set of events that the previous one did. */
5668 linux_handle_new_gdb_connection (void)
5672 /* Request that all the lwps reset their ptrace options. */
5673 find_inferior (&all_threads, reset_lwp_ptrace_options_callback , &pid);
5677 linux_supports_disable_randomization (void)
5679 #ifdef HAVE_PERSONALITY
5687 linux_supports_agent (void)
5693 linux_supports_range_stepping (void)
5695 if (*the_low_target.supports_range_stepping == NULL)
5698 return (*the_low_target.supports_range_stepping) ();
5701 /* Enumerate spufs IDs for process PID. */
5703 spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
5709 struct dirent *entry;
5711 sprintf (path, "/proc/%ld/fd", pid);
5712 dir = opendir (path);
5717 while ((entry = readdir (dir)) != NULL)
5723 fd = atoi (entry->d_name);
5727 sprintf (path, "/proc/%ld/fd/%d", pid, fd);
5728 if (stat (path, &st) != 0)
5730 if (!S_ISDIR (st.st_mode))
5733 if (statfs (path, &stfs) != 0)
5735 if (stfs.f_type != SPUFS_MAGIC)
5738 if (pos >= offset && pos + 4 <= offset + len)
5740 *(unsigned int *)(buf + pos - offset) = fd;
5750 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
5751 object type, using the /proc file system. */
5753 linux_qxfer_spu (const char *annex, unsigned char *readbuf,
5754 unsigned const char *writebuf,
5755 CORE_ADDR offset, int len)
5757 long pid = lwpid_of (current_thread);
5762 if (!writebuf && !readbuf)
5770 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
5773 sprintf (buf, "/proc/%ld/fd/%s", pid, annex);
5774 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
5779 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
5786 ret = write (fd, writebuf, (size_t) len);
5788 ret = read (fd, readbuf, (size_t) len);
5794 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
5795 struct target_loadseg
5797 /* Core address to which the segment is mapped. */
5799 /* VMA recorded in the program header. */
5801 /* Size of this segment in memory. */
5805 # if defined PT_GETDSBT
5806 struct target_loadmap
5808 /* Protocol version number, must be zero. */
5810 /* Pointer to the DSBT table, its size, and the DSBT index. */
5811 unsigned *dsbt_table;
5812 unsigned dsbt_size, dsbt_index;
5813 /* Number of segments in this map. */
5815 /* The actual memory map. */
5816 struct target_loadseg segs[/*nsegs*/];
5818 # define LINUX_LOADMAP PT_GETDSBT
5819 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
5820 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
5822 struct target_loadmap
5824 /* Protocol version number, must be zero. */
5826 /* Number of segments in this map. */
5828 /* The actual memory map. */
5829 struct target_loadseg segs[/*nsegs*/];
5831 # define LINUX_LOADMAP PTRACE_GETFDPIC
5832 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
5833 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
5837 linux_read_loadmap (const char *annex, CORE_ADDR offset,
5838 unsigned char *myaddr, unsigned int len)
5840 int pid = lwpid_of (current_thread);
5842 struct target_loadmap *data = NULL;
5843 unsigned int actual_length, copy_length;
5845 if (strcmp (annex, "exec") == 0)
5846 addr = (int) LINUX_LOADMAP_EXEC;
5847 else if (strcmp (annex, "interp") == 0)
5848 addr = (int) LINUX_LOADMAP_INTERP;
5852 if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0)
5858 actual_length = sizeof (struct target_loadmap)
5859 + sizeof (struct target_loadseg) * data->nsegs;
5861 if (offset < 0 || offset > actual_length)
5864 copy_length = actual_length - offset < len ? actual_length - offset : len;
5865 memcpy (myaddr, (char *) data + offset, copy_length);
5869 # define linux_read_loadmap NULL
5870 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
5873 linux_process_qsupported (const char *query)
5875 if (the_low_target.process_qsupported != NULL)
5876 the_low_target.process_qsupported (query);
5880 linux_supports_tracepoints (void)
5882 if (*the_low_target.supports_tracepoints == NULL)
5885 return (*the_low_target.supports_tracepoints) ();
5889 linux_read_pc (struct regcache *regcache)
5891 if (the_low_target.get_pc == NULL)
5894 return (*the_low_target.get_pc) (regcache);
5898 linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
5900 gdb_assert (the_low_target.set_pc != NULL);
5902 (*the_low_target.set_pc) (regcache, pc);
5906 linux_thread_stopped (struct thread_info *thread)
5908 return get_thread_lwp (thread)->stopped;
5911 /* This exposes stop-all-threads functionality to other modules. */
5914 linux_pause_all (int freeze)
5916 stop_all_lwps (freeze, NULL);
5919 /* This exposes unstop-all-threads functionality to other gdbserver
5923 linux_unpause_all (int unfreeze)
5925 unstop_all_lwps (unfreeze, NULL);
5929 linux_prepare_to_access_memory (void)
5931 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5934 linux_pause_all (1);
5939 linux_done_accessing_memory (void)
5941 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
5944 linux_unpause_all (1);
5948 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
5949 CORE_ADDR collector,
5952 CORE_ADDR *jump_entry,
5953 CORE_ADDR *trampoline,
5954 ULONGEST *trampoline_size,
5955 unsigned char *jjump_pad_insn,
5956 ULONGEST *jjump_pad_insn_size,
5957 CORE_ADDR *adjusted_insn_addr,
5958 CORE_ADDR *adjusted_insn_addr_end,
5961 return (*the_low_target.install_fast_tracepoint_jump_pad)
5962 (tpoint, tpaddr, collector, lockaddr, orig_size,
5963 jump_entry, trampoline, trampoline_size,
5964 jjump_pad_insn, jjump_pad_insn_size,
5965 adjusted_insn_addr, adjusted_insn_addr_end,
5969 static struct emit_ops *
5970 linux_emit_ops (void)
5972 if (the_low_target.emit_ops != NULL)
5973 return (*the_low_target.emit_ops) ();
5979 linux_get_min_fast_tracepoint_insn_len (void)
5981 return (*the_low_target.get_min_fast_tracepoint_insn_len) ();
5984 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
5987 get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64,
5988 CORE_ADDR *phdr_memaddr, int *num_phdr)
5990 char filename[PATH_MAX];
5992 const int auxv_size = is_elf64
5993 ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t);
5994 char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */
5996 xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid);
5998 fd = open (filename, O_RDONLY);
6004 while (read (fd, buf, auxv_size) == auxv_size
6005 && (*phdr_memaddr == 0 || *num_phdr == 0))
6009 Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf;
6011 switch (aux->a_type)
6014 *phdr_memaddr = aux->a_un.a_val;
6017 *num_phdr = aux->a_un.a_val;
6023 Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf;
6025 switch (aux->a_type)
6028 *phdr_memaddr = aux->a_un.a_val;
6031 *num_phdr = aux->a_un.a_val;
6039 if (*phdr_memaddr == 0 || *num_phdr == 0)
6041 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
6042 "phdr_memaddr = %ld, phdr_num = %d",
6043 (long) *phdr_memaddr, *num_phdr);
6050 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
6053 get_dynamic (const int pid, const int is_elf64)
6055 CORE_ADDR phdr_memaddr, relocation;
6057 unsigned char *phdr_buf;
6058 const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr);
6060 if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr))
6063 gdb_assert (num_phdr < 100); /* Basic sanity check. */
6064 phdr_buf = alloca (num_phdr * phdr_size);
6066 if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size))
6069 /* Compute relocation: it is expected to be 0 for "regular" executables,
6070 non-zero for PIE ones. */
6072 for (i = 0; relocation == -1 && i < num_phdr; i++)
6075 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
6077 if (p->p_type == PT_PHDR)
6078 relocation = phdr_memaddr - p->p_vaddr;
6082 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
6084 if (p->p_type == PT_PHDR)
6085 relocation = phdr_memaddr - p->p_vaddr;
6088 if (relocation == -1)
6090 /* PT_PHDR is optional, but necessary for PIE in general. Fortunately
6091 any real world executables, including PIE executables, have always
6092 PT_PHDR present. PT_PHDR is not present in some shared libraries or
6093 in fpc (Free Pascal 2.4) binaries but neither of those have a need for
6094 or present DT_DEBUG anyway (fpc binaries are statically linked).
6096 Therefore if there exists DT_DEBUG there is always also PT_PHDR.
6098 GDB could find RELOCATION also from AT_ENTRY - e_entry. */
6103 for (i = 0; i < num_phdr; i++)
6107 Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size);
6109 if (p->p_type == PT_DYNAMIC)
6110 return p->p_vaddr + relocation;
6114 Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size);
6116 if (p->p_type == PT_DYNAMIC)
6117 return p->p_vaddr + relocation;
6124 /* Return &_r_debug in the inferior, or -1 if not present. Return value
6125 can be 0 if the inferior does not yet have the library list initialized.
6126 We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of
6127 DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */
6130 get_r_debug (const int pid, const int is_elf64)
6132 CORE_ADDR dynamic_memaddr;
6133 const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn);
6134 unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */
6137 dynamic_memaddr = get_dynamic (pid, is_elf64);
6138 if (dynamic_memaddr == 0)
6141 while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0)
6145 Elf64_Dyn *const dyn = (Elf64_Dyn *) buf;
6146 #ifdef DT_MIPS_RLD_MAP
6150 unsigned char buf[sizeof (Elf64_Xword)];
6154 if (dyn->d_tag == DT_MIPS_RLD_MAP)
6156 if (linux_read_memory (dyn->d_un.d_val,
6157 rld_map.buf, sizeof (rld_map.buf)) == 0)
6162 #endif /* DT_MIPS_RLD_MAP */
6164 if (dyn->d_tag == DT_DEBUG && map == -1)
6165 map = dyn->d_un.d_val;
6167 if (dyn->d_tag == DT_NULL)
6172 Elf32_Dyn *const dyn = (Elf32_Dyn *) buf;
6173 #ifdef DT_MIPS_RLD_MAP
6177 unsigned char buf[sizeof (Elf32_Word)];
6181 if (dyn->d_tag == DT_MIPS_RLD_MAP)
6183 if (linux_read_memory (dyn->d_un.d_val,
6184 rld_map.buf, sizeof (rld_map.buf)) == 0)
6189 #endif /* DT_MIPS_RLD_MAP */
6191 if (dyn->d_tag == DT_DEBUG && map == -1)
6192 map = dyn->d_un.d_val;
6194 if (dyn->d_tag == DT_NULL)
6198 dynamic_memaddr += dyn_size;
6204 /* Read one pointer from MEMADDR in the inferior. */
6207 read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size)
6211 /* Go through a union so this works on either big or little endian
6212 hosts, when the inferior's pointer size is smaller than the size
6213 of CORE_ADDR. It is assumed the inferior's endianness is the
6214 same of the superior's. */
6217 CORE_ADDR core_addr;
6222 ret = linux_read_memory (memaddr, &addr.uc, ptr_size);
6225 if (ptr_size == sizeof (CORE_ADDR))
6226 *ptr = addr.core_addr;
6227 else if (ptr_size == sizeof (unsigned int))
6230 gdb_assert_not_reached ("unhandled pointer size");
6235 struct link_map_offsets
6237 /* Offset and size of r_debug.r_version. */
6238 int r_version_offset;
6240 /* Offset and size of r_debug.r_map. */
6243 /* Offset to l_addr field in struct link_map. */
6246 /* Offset to l_name field in struct link_map. */
6249 /* Offset to l_ld field in struct link_map. */
6252 /* Offset to l_next field in struct link_map. */
6255 /* Offset to l_prev field in struct link_map. */
6259 /* Construct qXfer:libraries-svr4:read reply. */
6262 linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf,
6263 unsigned const char *writebuf,
6264 CORE_ADDR offset, int len)
6267 unsigned document_len;
6268 struct process_info_private *const priv = current_process ()->priv;
6269 char filename[PATH_MAX];
6272 static const struct link_map_offsets lmo_32bit_offsets =
6274 0, /* r_version offset. */
6275 4, /* r_debug.r_map offset. */
6276 0, /* l_addr offset in link_map. */
6277 4, /* l_name offset in link_map. */
6278 8, /* l_ld offset in link_map. */
6279 12, /* l_next offset in link_map. */
6280 16 /* l_prev offset in link_map. */
6283 static const struct link_map_offsets lmo_64bit_offsets =
6285 0, /* r_version offset. */
6286 8, /* r_debug.r_map offset. */
6287 0, /* l_addr offset in link_map. */
6288 8, /* l_name offset in link_map. */
6289 16, /* l_ld offset in link_map. */
6290 24, /* l_next offset in link_map. */
6291 32 /* l_prev offset in link_map. */
6293 const struct link_map_offsets *lmo;
6294 unsigned int machine;
6296 CORE_ADDR lm_addr = 0, lm_prev = 0;
6297 int allocated = 1024;
6299 CORE_ADDR l_name, l_addr, l_ld, l_next, l_prev;
6300 int header_done = 0;
6302 if (writebuf != NULL)
6304 if (readbuf == NULL)
6307 pid = lwpid_of (current_thread);
6308 xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid);
6309 is_elf64 = elf_64_file_p (filename, &machine);
6310 lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets;
6311 ptr_size = is_elf64 ? 8 : 4;
6313 while (annex[0] != '\0')
6319 sep = strchr (annex, '=');
6324 if (len == 5 && startswith (annex, "start"))
6326 else if (len == 4 && startswith (annex, "prev"))
6330 annex = strchr (sep, ';');
6337 annex = decode_address_to_semicolon (addrp, sep + 1);
6344 if (priv->r_debug == 0)
6345 priv->r_debug = get_r_debug (pid, is_elf64);
6347 /* We failed to find DT_DEBUG. Such situation will not change
6348 for this inferior - do not retry it. Report it to GDB as
6349 E01, see for the reasons at the GDB solib-svr4.c side. */
6350 if (priv->r_debug == (CORE_ADDR) -1)
6353 if (priv->r_debug != 0)
6355 if (linux_read_memory (priv->r_debug + lmo->r_version_offset,
6356 (unsigned char *) &r_version,
6357 sizeof (r_version)) != 0
6360 warning ("unexpected r_debug version %d", r_version);
6362 else if (read_one_ptr (priv->r_debug + lmo->r_map_offset,
6363 &lm_addr, ptr_size) != 0)
6365 warning ("unable to read r_map from 0x%lx",
6366 (long) priv->r_debug + lmo->r_map_offset);
6371 document = xmalloc (allocated);
6372 strcpy (document, "<library-list-svr4 version=\"1.0\"");
6373 p = document + strlen (document);
6376 && read_one_ptr (lm_addr + lmo->l_name_offset,
6377 &l_name, ptr_size) == 0
6378 && read_one_ptr (lm_addr + lmo->l_addr_offset,
6379 &l_addr, ptr_size) == 0
6380 && read_one_ptr (lm_addr + lmo->l_ld_offset,
6381 &l_ld, ptr_size) == 0
6382 && read_one_ptr (lm_addr + lmo->l_prev_offset,
6383 &l_prev, ptr_size) == 0
6384 && read_one_ptr (lm_addr + lmo->l_next_offset,
6385 &l_next, ptr_size) == 0)
6387 unsigned char libname[PATH_MAX];
6389 if (lm_prev != l_prev)
6391 warning ("Corrupted shared library list: 0x%lx != 0x%lx",
6392 (long) lm_prev, (long) l_prev);
6396 /* Ignore the first entry even if it has valid name as the first entry
6397 corresponds to the main executable. The first entry should not be
6398 skipped if the dynamic loader was loaded late by a static executable
6399 (see solib-svr4.c parameter ignore_first). But in such case the main
6400 executable does not have PT_DYNAMIC present and this function already
6401 exited above due to failed get_r_debug. */
6404 sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr);
6409 /* Not checking for error because reading may stop before
6410 we've got PATH_MAX worth of characters. */
6412 linux_read_memory (l_name, libname, sizeof (libname) - 1);
6413 libname[sizeof (libname) - 1] = '\0';
6414 if (libname[0] != '\0')
6416 /* 6x the size for xml_escape_text below. */
6417 size_t len = 6 * strlen ((char *) libname);
6422 /* Terminate `<library-list-svr4'. */
6427 while (allocated < p - document + len + 200)
6429 /* Expand to guarantee sufficient storage. */
6430 uintptr_t document_len = p - document;
6432 document = xrealloc (document, 2 * allocated);
6434 p = document + document_len;
6437 name = xml_escape_text ((char *) libname);
6438 p += sprintf (p, "<library name=\"%s\" lm=\"0x%lx\" "
6439 "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
6440 name, (unsigned long) lm_addr,
6441 (unsigned long) l_addr, (unsigned long) l_ld);
6452 /* Empty list; terminate `<library-list-svr4'. */
6456 strcpy (p, "</library-list-svr4>");
6458 document_len = strlen (document);
6459 if (offset < document_len)
6460 document_len -= offset;
6463 if (len > document_len)
6466 memcpy (readbuf, document + offset, len);
6472 #ifdef HAVE_LINUX_BTRACE
6474 /* See to_enable_btrace target method. */
6476 static struct btrace_target_info *
6477 linux_low_enable_btrace (ptid_t ptid, const struct btrace_config *conf)
6479 struct btrace_target_info *tinfo;
6481 tinfo = linux_enable_btrace (ptid, conf);
6483 if (tinfo != NULL && tinfo->ptr_bits == 0)
6485 struct thread_info *thread = find_thread_ptid (ptid);
6486 struct regcache *regcache = get_thread_regcache (thread, 0);
6488 tinfo->ptr_bits = register_size (regcache->tdesc, 0) * 8;
6494 /* See to_disable_btrace target method. */
6497 linux_low_disable_btrace (struct btrace_target_info *tinfo)
6499 enum btrace_error err;
6501 err = linux_disable_btrace (tinfo);
6502 return (err == BTRACE_ERR_NONE ? 0 : -1);
6505 /* Encode an Intel(R) Processor Trace configuration. */
6508 linux_low_encode_pt_config (struct buffer *buffer,
6509 const struct btrace_data_pt_config *config)
6511 buffer_grow_str (buffer, "<pt-config>\n");
6513 switch (config->cpu.vendor)
6516 buffer_xml_printf (buffer, "<cpu vendor=\"GenuineIntel\" family=\"%u\" "
6517 "model=\"%u\" stepping=\"%u\"/>\n",
6518 config->cpu.family, config->cpu.model,
6519 config->cpu.stepping);
6526 buffer_grow_str (buffer, "</pt-config>\n");
6529 /* Encode a raw buffer. */
6532 linux_low_encode_raw (struct buffer *buffer, const gdb_byte *data,
6538 /* We use hex encoding - see common/rsp-low.h. */
6539 buffer_grow_str (buffer, "<raw>\n");
6545 elem[0] = tohex ((*data >> 4) & 0xf);
6546 elem[1] = tohex (*data++ & 0xf);
6548 buffer_grow (buffer, elem, 2);
6551 buffer_grow_str (buffer, "</raw>\n");
6554 /* See to_read_btrace target method. */
6557 linux_low_read_btrace (struct btrace_target_info *tinfo, struct buffer *buffer,
6560 struct btrace_data btrace;
6561 struct btrace_block *block;
6562 enum btrace_error err;
6565 btrace_data_init (&btrace);
6567 err = linux_read_btrace (&btrace, tinfo, type);
6568 if (err != BTRACE_ERR_NONE)
6570 if (err == BTRACE_ERR_OVERFLOW)
6571 buffer_grow_str0 (buffer, "E.Overflow.");
6573 buffer_grow_str0 (buffer, "E.Generic Error.");
6578 switch (btrace.format)
6580 case BTRACE_FORMAT_NONE:
6581 buffer_grow_str0 (buffer, "E.No Trace.");
6584 case BTRACE_FORMAT_BTS:
6585 buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n");
6586 buffer_grow_str (buffer, "<btrace version=\"1.0\">\n");
6589 VEC_iterate (btrace_block_s, btrace.variant.bts.blocks, i, block);
6591 buffer_xml_printf (buffer, "<block begin=\"0x%s\" end=\"0x%s\"/>\n",
6592 paddress (block->begin), paddress (block->end));
6594 buffer_grow_str0 (buffer, "</btrace>\n");
6597 case BTRACE_FORMAT_PT:
6598 buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n");
6599 buffer_grow_str (buffer, "<btrace version=\"1.0\">\n");
6600 buffer_grow_str (buffer, "<pt>\n");
6602 linux_low_encode_pt_config (buffer, &btrace.variant.pt.config);
6604 linux_low_encode_raw (buffer, btrace.variant.pt.data,
6605 btrace.variant.pt.size);
6607 buffer_grow_str (buffer, "</pt>\n");
6608 buffer_grow_str0 (buffer, "</btrace>\n");
6612 buffer_grow_str0 (buffer, "E.Unsupported Trace Format.");
6616 btrace_data_fini (&btrace);
6620 btrace_data_fini (&btrace);
6624 /* See to_btrace_conf target method. */
6627 linux_low_btrace_conf (const struct btrace_target_info *tinfo,
6628 struct buffer *buffer)
6630 const struct btrace_config *conf;
6632 buffer_grow_str (buffer, "<!DOCTYPE btrace-conf SYSTEM \"btrace-conf.dtd\">\n");
6633 buffer_grow_str (buffer, "<btrace-conf version=\"1.0\">\n");
6635 conf = linux_btrace_conf (tinfo);
6638 switch (conf->format)
6640 case BTRACE_FORMAT_NONE:
6643 case BTRACE_FORMAT_BTS:
6644 buffer_xml_printf (buffer, "<bts");
6645 buffer_xml_printf (buffer, " size=\"0x%x\"", conf->bts.size);
6646 buffer_xml_printf (buffer, " />\n");
6649 case BTRACE_FORMAT_PT:
6650 buffer_xml_printf (buffer, "<pt");
6651 buffer_xml_printf (buffer, " size=\"0x%x\"", conf->pt.size);
6652 buffer_xml_printf (buffer, "/>\n");
6657 buffer_grow_str0 (buffer, "</btrace-conf>\n");
6660 #endif /* HAVE_LINUX_BTRACE */
6662 /* See nat/linux-nat.h. */
6665 current_lwp_ptid (void)
6667 return ptid_of (current_thread);
6670 static struct target_ops linux_target_ops = {
6671 linux_create_inferior,
6681 linux_fetch_registers,
6682 linux_store_registers,
6683 linux_prepare_to_access_memory,
6684 linux_done_accessing_memory,
6687 linux_look_up_symbols,
6688 linux_request_interrupt,
6690 linux_supports_z_point_type,
6693 linux_stopped_by_sw_breakpoint,
6694 linux_supports_stopped_by_sw_breakpoint,
6695 linux_stopped_by_hw_breakpoint,
6696 linux_supports_stopped_by_hw_breakpoint,
6697 linux_supports_conditional_breakpoints,
6698 linux_stopped_by_watchpoint,
6699 linux_stopped_data_address,
6700 #if defined(__UCLIBC__) && defined(HAS_NOMMU) \
6701 && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
6702 && defined(PT_TEXT_END_ADDR)
6707 #ifdef USE_THREAD_DB
6708 thread_db_get_tls_address,
6713 hostio_last_error_from_errno,
6716 linux_supports_non_stop,
6718 linux_start_non_stop,
6719 linux_supports_multi_process,
6720 linux_supports_fork_events,
6721 linux_supports_vfork_events,
6722 linux_handle_new_gdb_connection,
6723 #ifdef USE_THREAD_DB
6724 thread_db_handle_monitor_command,
6728 linux_common_core_of_thread,
6730 linux_process_qsupported,
6731 linux_supports_tracepoints,
6734 linux_thread_stopped,
6738 linux_stabilize_threads,
6739 linux_install_fast_tracepoint_jump_pad,
6741 linux_supports_disable_randomization,
6742 linux_get_min_fast_tracepoint_insn_len,
6743 linux_qxfer_libraries_svr4,
6744 linux_supports_agent,
6745 #ifdef HAVE_LINUX_BTRACE
6746 linux_supports_btrace,
6747 linux_low_enable_btrace,
6748 linux_low_disable_btrace,
6749 linux_low_read_btrace,
6750 linux_low_btrace_conf,
6758 linux_supports_range_stepping,
6759 linux_proc_pid_to_exec_file,
6760 linux_mntns_open_cloexec,
6762 linux_mntns_readlink,
6766 linux_init_signals ()
6768 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
6769 to find what the cancel signal actually is. */
6770 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
6771 signal (__SIGRTMIN+1, SIG_IGN);
6775 #ifdef HAVE_LINUX_REGSETS
6777 initialize_regsets_info (struct regsets_info *info)
6779 for (info->num_regsets = 0;
6780 info->regsets[info->num_regsets].size >= 0;
6781 info->num_regsets++)
6787 initialize_low (void)
6789 struct sigaction sigchld_action;
6790 memset (&sigchld_action, 0, sizeof (sigchld_action));
6791 set_target_ops (&linux_target_ops);
6792 set_breakpoint_data (the_low_target.breakpoint,
6793 the_low_target.breakpoint_len);
6794 linux_init_signals ();
6795 linux_ptrace_init_warnings ();
6797 sigchld_action.sa_handler = sigchld_handler;
6798 sigemptyset (&sigchld_action.sa_mask);
6799 sigchld_action.sa_flags = SA_RESTART;
6800 sigaction (SIGCHLD, &sigchld_action, NULL);
6802 initialize_low_arch ();
6804 linux_check_ptrace_features ();