1 /* Native-dependent code for FreeBSD.
3 Copyright (C) 2002-2018 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "byte-vector.h"
27 #include "gdbthread.h"
29 #include <sys/types.h>
30 #include <sys/procfs.h>
31 #include <sys/ptrace.h>
32 #include <sys/signal.h>
33 #include <sys/sysctl.h>
35 #ifdef HAVE_KINFO_GETVMMAP
38 #include "filestuff.h"
46 /* Return the name of a file that can be opened to get the symbols for
47 the child process identified by PID. */
50 fbsd_pid_to_exec_file (struct target_ops *self, int pid)
53 static char buf[PATH_MAX];
56 #ifdef KERN_PROC_PATHNAME
62 mib[2] = KERN_PROC_PATHNAME;
65 if (sysctl (mib, 4, buf, &buflen, NULL, 0) == 0)
66 /* The kern.proc.pathname.<pid> sysctl returns a length of zero
67 for processes without an associated executable such as kernel
69 return buflen == 0 ? NULL : buf;
72 xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid);
73 len = readlink (name, buf, PATH_MAX - 1);
83 #ifdef HAVE_KINFO_GETVMMAP
84 /* Deleter for std::unique_ptr that invokes free. */
89 void operator() (T *ptr) const { free (ptr); }
92 /* Iterate over all the memory regions in the current inferior,
93 calling FUNC for each memory region. OBFD is passed as the last
97 fbsd_find_memory_regions (struct target_ops *self,
98 find_memory_region_ftype func, void *obfd)
100 pid_t pid = ptid_get_pid (inferior_ptid);
101 struct kinfo_vmentry *kve;
105 std::unique_ptr<struct kinfo_vmentry, free_deleter<struct kinfo_vmentry>>
106 vmentl (kinfo_getvmmap (pid, &nitems));
108 perror_with_name (_("Couldn't fetch VM map entries."));
110 for (i = 0, kve = vmentl.get (); i < nitems; i++, kve++)
112 /* Skip unreadable segments and those where MAP_NOCORE has been set. */
113 if (!(kve->kve_protection & KVME_PROT_READ)
114 || kve->kve_flags & KVME_FLAG_NOCOREDUMP)
117 /* Skip segments with an invalid type. */
118 if (kve->kve_type != KVME_TYPE_DEFAULT
119 && kve->kve_type != KVME_TYPE_VNODE
120 && kve->kve_type != KVME_TYPE_SWAP
121 && kve->kve_type != KVME_TYPE_PHYS)
124 size = kve->kve_end - kve->kve_start;
127 fprintf_filtered (gdb_stdout,
128 "Save segment, %ld bytes at %s (%c%c%c)\n",
130 paddress (target_gdbarch (), kve->kve_start),
131 kve->kve_protection & KVME_PROT_READ ? 'r' : '-',
132 kve->kve_protection & KVME_PROT_WRITE ? 'w' : '-',
133 kve->kve_protection & KVME_PROT_EXEC ? 'x' : '-');
136 /* Invoke the callback function to create the corefile segment.
137 Pass MODIFIED as true, we do not know the real modification state. */
138 func (kve->kve_start, size, kve->kve_protection & KVME_PROT_READ,
139 kve->kve_protection & KVME_PROT_WRITE,
140 kve->kve_protection & KVME_PROT_EXEC, 1, obfd);
146 fbsd_read_mapping (FILE *mapfile, unsigned long *start, unsigned long *end,
149 /* FreeBSD 5.1-RELEASE uses a 256-byte buffer. */
151 int resident, privateresident;
155 /* As of FreeBSD 5.0-RELEASE, the layout is described in
156 /usr/src/sys/fs/procfs/procfs_map.c. Somewhere in 5.1-CURRENT a
157 new column was added to the procfs map. Therefore we can't use
158 fscanf since we need to support older releases too. */
159 if (fgets (buf, sizeof buf, mapfile) != NULL)
160 ret = sscanf (buf, "%lx %lx %d %d %lx %s", start, end,
161 &resident, &privateresident, &obj, protection);
163 return (ret != 0 && ret != EOF);
166 /* Iterate over all the memory regions in the current inferior,
167 calling FUNC for each memory region. OBFD is passed as the last
171 fbsd_find_memory_regions (struct target_ops *self,
172 find_memory_region_ftype func, void *obfd)
174 pid_t pid = ptid_get_pid (inferior_ptid);
175 unsigned long start, end, size;
177 int read, write, exec;
179 std::string mapfilename = string_printf ("/proc/%ld/map", (long) pid);
180 gdb_file_up mapfile (fopen (mapfilename.c_str (), "r"));
182 error (_("Couldn't open %s."), mapfilename.c_str ());
185 fprintf_filtered (gdb_stdout,
186 "Reading memory regions from %s\n", mapfilename.c_str ());
188 /* Now iterate until end-of-file. */
189 while (fbsd_read_mapping (mapfile.get (), &start, &end, &protection[0]))
193 read = (strchr (protection, 'r') != 0);
194 write = (strchr (protection, 'w') != 0);
195 exec = (strchr (protection, 'x') != 0);
199 fprintf_filtered (gdb_stdout,
200 "Save segment, %ld bytes at %s (%c%c%c)\n",
201 size, paddress (target_gdbarch (), start),
207 /* Invoke the callback function to create the corefile segment.
208 Pass MODIFIED as true, we do not know the real modification state. */
209 func (start, size, read, write, exec, 1, obfd);
216 #ifdef KERN_PROC_AUXV
217 static enum target_xfer_status (*super_xfer_partial) (struct target_ops *ops,
218 enum target_object object,
221 const gdb_byte *writebuf,
224 ULONGEST *xfered_len);
227 /* Return the size of siginfo for the current inferior. */
235 /* This structure matches the naming and layout of `siginfo_t' in
236 <sys/signal.h>. In particular, the `si_foo' macros defined in that
237 header can be used with both types to copy fields in the `_reason'
249 union sigval32 si_value;
282 struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
284 /* Is the inferior 32-bit? If so, use the 32-bit siginfo size. */
285 if (gdbarch_long_bit (gdbarch) == 32)
286 return sizeof (struct siginfo32);
288 return sizeof (siginfo_t);
291 /* Convert a native 64-bit siginfo object to a 32-bit object. Note
292 that FreeBSD doesn't support writing to $_siginfo, so this only
293 needs to convert one way. */
296 fbsd_convert_siginfo (siginfo_t *si)
299 struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
301 /* Is the inferior 32-bit? If not, nothing to do. */
302 if (gdbarch_long_bit (gdbarch) != 32)
305 struct siginfo32 si32;
307 si32.si_signo = si->si_signo;
308 si32.si_errno = si->si_errno;
309 si32.si_code = si->si_code;
310 si32.si_pid = si->si_pid;
311 si32.si_uid = si->si_uid;
312 si32.si_status = si->si_status;
313 si32.si_addr = (uintptr_t) si->si_addr;
315 /* If sival_ptr is being used instead of sival_int on a big-endian
316 platform, then sival_int will be zero since it holds the upper
317 32-bits of the pointer value. */
318 #if _BYTE_ORDER == _BIG_ENDIAN
319 if (si->si_value.sival_int == 0)
320 si32.si_value.sival_ptr = (uintptr_t) si->si_value.sival_ptr;
322 si32.si_value.sival_int = si->si_value.sival_int;
324 si32.si_value.sival_int = si->si_value.sival_int;
327 /* Always copy the spare fields and then possibly overwrite them for
328 signal-specific or code-specific fields. */
329 si32._reason.__spare__.__spare1__ = si->_reason.__spare__.__spare1__;
330 for (int i = 0; i < 7; i++)
331 si32._reason.__spare__.__spare2__[i] = si->_reason.__spare__.__spare2__[i];
332 switch (si->si_signo) {
337 si32.si_trapno = si->si_trapno;
340 switch (si->si_code) {
342 si32.si_timerid = si->si_timerid;
343 si32.si_overrun = si->si_overrun;
346 si32.si_mqd = si->si_mqd;
350 memcpy(si, &si32, sizeof (si32));
355 /* Implement the "to_xfer_partial target_ops" method. */
357 static enum target_xfer_status
358 fbsd_xfer_partial (struct target_ops *ops, enum target_object object,
359 const char *annex, gdb_byte *readbuf,
360 const gdb_byte *writebuf,
361 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
363 pid_t pid = ptid_get_pid (inferior_ptid);
368 case TARGET_OBJECT_SIGNAL_INFO:
370 struct ptrace_lwpinfo pl;
373 /* FreeBSD doesn't support writing to $_siginfo. */
374 if (writebuf != NULL)
375 return TARGET_XFER_E_IO;
377 if (inferior_ptid.lwp_p ())
378 pid = inferior_ptid.lwp ();
380 siginfo_size = fbsd_siginfo_size ();
381 if (offset > siginfo_size)
382 return TARGET_XFER_E_IO;
384 if (ptrace (PT_LWPINFO, pid, (PTRACE_TYPE_ARG3) &pl, sizeof (pl)) == -1)
385 return TARGET_XFER_E_IO;
387 if (!(pl.pl_flags & PL_FLAG_SI))
388 return TARGET_XFER_E_IO;
390 fbsd_convert_siginfo (&pl.pl_siginfo);
391 if (offset + len > siginfo_size)
392 len = siginfo_size - offset;
394 memcpy (readbuf, ((gdb_byte *) &pl.pl_siginfo) + offset, len);
396 return TARGET_XFER_OK;
399 case TARGET_OBJECT_AUXV:
401 gdb::byte_vector buf_storage;
406 if (writebuf != NULL)
407 return TARGET_XFER_E_IO;
410 mib[2] = KERN_PROC_AUXV;
419 buflen = offset + len;
420 buf_storage.resize (buflen);
421 buf = buf_storage.data ();
423 if (sysctl (mib, 4, buf, &buflen, NULL, 0) == 0)
430 memcpy (readbuf, buf + offset, buflen);
435 *xfered_len = buflen;
436 return (buflen == 0) ? TARGET_XFER_EOF : TARGET_XFER_OK;
438 return TARGET_XFER_E_IO;
441 return super_xfer_partial (ops, object, annex, readbuf, writebuf, offset,
448 static int debug_fbsd_lwp;
450 static void (*super_resume) (struct target_ops *,
454 static ptid_t (*super_wait) (struct target_ops *,
456 struct target_waitstatus *,
460 show_fbsd_lwp_debug (struct ui_file *file, int from_tty,
461 struct cmd_list_element *c, const char *value)
463 fprintf_filtered (file, _("Debugging of FreeBSD lwp module is %s.\n"), value);
466 #if defined(TDP_RFPPWAIT) || defined(HAVE_STRUCT_PTRACE_LWPINFO_PL_TDNAME)
467 /* Fetch the external variant of the kernel's internal process
468 structure for the process PID into KP. */
471 fbsd_fetch_kinfo_proc (pid_t pid, struct kinfo_proc *kp)
479 mib[2] = KERN_PROC_PID;
481 if (sysctl (mib, 4, kp, &len, NULL, 0) == -1)
482 perror_with_name (("sysctl"));
487 FreeBSD's first thread support was via a "reentrant" version of libc
488 (libc_r) that first shipped in 2.2.7. This library multiplexed all
489 of the threads in a process onto a single kernel thread. This
490 library was supported via the bsd-uthread target.
492 FreeBSD 5.1 introduced two new threading libraries that made use of
493 multiple kernel threads. The first (libkse) scheduled M user
494 threads onto N (<= M) kernel threads (LWPs). The second (libthr)
495 bound each user thread to a dedicated kernel thread. libkse shipped
496 as the default threading library (libpthread).
498 FreeBSD 5.3 added a libthread_db to abstract the interface across
499 the various thread libraries (libc_r, libkse, and libthr).
501 FreeBSD 7.0 switched the default threading library from from libkse
502 to libpthread and removed libc_r.
504 FreeBSD 8.0 removed libkse and the in-kernel support for it. The
505 only threading library supported by 8.0 and later is libthr which
506 ties each user thread directly to an LWP. To simplify the
507 implementation, this target only supports LWP-backed threads using
508 ptrace directly rather than libthread_db.
510 FreeBSD 11.0 introduced LWP event reporting via PT_LWP_EVENTS.
513 /* Return true if PTID is still active in the inferior. */
516 fbsd_thread_alive (struct target_ops *ops, ptid_t ptid)
518 if (ptid_lwp_p (ptid))
520 struct ptrace_lwpinfo pl;
522 if (ptrace (PT_LWPINFO, ptid_get_lwp (ptid), (caddr_t) &pl, sizeof pl)
525 #ifdef PL_FLAG_EXITED
526 if (pl.pl_flags & PL_FLAG_EXITED)
534 /* Convert PTID to a string. Returns the string in a static
538 fbsd_pid_to_str (struct target_ops *ops, ptid_t ptid)
542 lwp = ptid_get_lwp (ptid);
546 int pid = ptid_get_pid (ptid);
548 xsnprintf (buf, sizeof buf, "LWP %d of process %d", lwp, pid);
552 return normal_pid_to_str (ptid);
555 #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_TDNAME
556 /* Return the name assigned to a thread by an application. Returns
557 the string in a static buffer. */
560 fbsd_thread_name (struct target_ops *self, struct thread_info *thr)
562 struct ptrace_lwpinfo pl;
563 struct kinfo_proc kp;
564 int pid = ptid_get_pid (thr->ptid);
565 long lwp = ptid_get_lwp (thr->ptid);
566 static char buf[sizeof pl.pl_tdname + 1];
568 /* Note that ptrace_lwpinfo returns the process command in pl_tdname
569 if a name has not been set explicitly. Return a NULL name in
571 fbsd_fetch_kinfo_proc (pid, &kp);
572 if (ptrace (PT_LWPINFO, lwp, (caddr_t) &pl, sizeof pl) == -1)
573 perror_with_name (("ptrace"));
574 if (strcmp (kp.ki_comm, pl.pl_tdname) == 0)
576 xsnprintf (buf, sizeof buf, "%s", pl.pl_tdname);
581 /* Enable additional event reporting on new processes.
583 To catch fork events, PTRACE_FORK is set on every traced process
584 to enable stops on returns from fork or vfork. Note that both the
585 parent and child will always stop, even if system call stops are
588 To catch LWP events, PTRACE_EVENTS is set on every traced process.
589 This enables stops on the birth for new LWPs (excluding the "main" LWP)
590 and the death of LWPs (excluding the last LWP in a process). Note
591 that unlike fork events, the LWP that creates a new LWP does not
595 fbsd_enable_proc_events (pid_t pid)
597 #ifdef PT_GET_EVENT_MASK
600 if (ptrace (PT_GET_EVENT_MASK, pid, (PTRACE_TYPE_ARG3)&events,
601 sizeof (events)) == -1)
602 perror_with_name (("ptrace"));
603 events |= PTRACE_FORK | PTRACE_LWP;
605 events |= PTRACE_VFORK;
607 if (ptrace (PT_SET_EVENT_MASK, pid, (PTRACE_TYPE_ARG3)&events,
608 sizeof (events)) == -1)
609 perror_with_name (("ptrace"));
612 if (ptrace (PT_FOLLOW_FORK, pid, (PTRACE_TYPE_ARG3)0, 1) == -1)
613 perror_with_name (("ptrace"));
616 if (ptrace (PT_LWP_EVENTS, pid, (PTRACE_TYPE_ARG3)0, 1) == -1)
617 perror_with_name (("ptrace"));
622 /* Add threads for any new LWPs in a process.
624 When LWP events are used, this function is only used to detect existing
625 threads when attaching to a process. On older systems, this function is
626 called to discover new threads each time the thread list is updated. */
629 fbsd_add_threads (pid_t pid)
633 gdb_assert (!in_thread_list (pid_to_ptid (pid)));
634 nlwps = ptrace (PT_GETNUMLWPS, pid, NULL, 0);
636 perror_with_name (("ptrace"));
638 gdb::unique_xmalloc_ptr<lwpid_t[]> lwps (XCNEWVEC (lwpid_t, nlwps));
640 nlwps = ptrace (PT_GETLWPLIST, pid, (caddr_t) lwps.get (), nlwps);
642 perror_with_name (("ptrace"));
644 for (i = 0; i < nlwps; i++)
646 ptid_t ptid = ptid_build (pid, lwps[i], 0);
648 if (!in_thread_list (ptid))
651 struct ptrace_lwpinfo pl;
653 /* Don't add exited threads. Note that this is only called
654 when attaching to a multi-threaded process. */
655 if (ptrace (PT_LWPINFO, lwps[i], (caddr_t) &pl, sizeof pl) == -1)
656 perror_with_name (("ptrace"));
657 if (pl.pl_flags & PL_FLAG_EXITED)
661 fprintf_unfiltered (gdb_stdlog,
662 "FLWP: adding thread for LWP %u\n",
669 /* Implement the "to_update_thread_list" target_ops method. */
672 fbsd_update_thread_list (struct target_ops *ops)
675 /* With support for thread events, threads are added/deleted from the
676 list as events are reported, so just try deleting exited threads. */
677 delete_exited_threads ();
681 fbsd_add_threads (ptid_get_pid (inferior_ptid));
687 To catch fork events, PT_FOLLOW_FORK is set on every traced process
688 to enable stops on returns from fork or vfork. Note that both the
689 parent and child will always stop, even if system call stops are not
692 After a fork, both the child and parent process will stop and report
693 an event. However, there is no guarantee of order. If the parent
694 reports its stop first, then fbsd_wait explicitly waits for the new
695 child before returning. If the child reports its stop first, then
696 the event is saved on a list and ignored until the parent's stop is
697 reported. fbsd_wait could have been changed to fetch the parent PID
698 of the new child and used that to wait for the parent explicitly.
699 However, if two threads in the parent fork at the same time, then
700 the wait on the parent might return the "wrong" fork event.
702 The initial version of PT_FOLLOW_FORK did not set PL_FLAG_CHILD for
703 the new child process. This flag could be inferred by treating any
704 events for an unknown pid as a new child.
706 In addition, the initial version of PT_FOLLOW_FORK did not report a
707 stop event for the parent process of a vfork until after the child
708 process executed a new program or exited. The kernel was changed to
709 defer the wait for exit or exec of the child until after posting the
710 stop event shortly after the change to introduce PL_FLAG_CHILD.
711 This could be worked around by reporting a vfork event when the
712 child event posted and ignoring the subsequent event from the
715 This implementation requires both of these fixes for simplicity's
716 sake. FreeBSD versions newer than 9.1 contain both fixes.
719 static std::list<ptid_t> fbsd_pending_children;
721 /* Record a new child process event that is reported before the
722 corresponding fork event in the parent. */
725 fbsd_remember_child (ptid_t pid)
727 fbsd_pending_children.push_front (pid);
730 /* Check for a previously-recorded new child process event for PID.
731 If one is found, remove it from the list and return the PTID. */
734 fbsd_is_child_pending (pid_t pid)
736 for (auto it = fbsd_pending_children.begin ();
737 it != fbsd_pending_children.end (); it++)
738 if (it->pid () == pid)
741 fbsd_pending_children.erase (it);
748 static std::forward_list<ptid_t> fbsd_pending_vfork_done;
750 /* Record a pending vfork done event. */
753 fbsd_add_vfork_done (ptid_t pid)
755 fbsd_pending_vfork_done.push_front (pid);
758 /* Check for a pending vfork done event for a specific PID. */
761 fbsd_is_vfork_done_pending (pid_t pid)
763 for (auto it = fbsd_pending_vfork_done.begin ();
764 it != fbsd_pending_vfork_done.end (); it++)
765 if (it->pid () == pid)
770 /* Check for a pending vfork done event. If one is found, remove it
771 from the list and return the PTID. */
774 fbsd_next_vfork_done (void)
776 if (!fbsd_pending_vfork_done.empty ())
778 ptid_t ptid = fbsd_pending_vfork_done.front ();
779 fbsd_pending_vfork_done.pop_front ();
787 /* Implement the "to_resume" target_ops method. */
790 fbsd_resume (struct target_ops *ops,
791 ptid_t ptid, int step, enum gdb_signal signo)
793 #if defined(TDP_RFPPWAIT) && !defined(PTRACE_VFORK)
796 /* Don't PT_CONTINUE a process which has a pending vfork done event. */
797 if (ptid_equal (minus_one_ptid, ptid))
798 pid = ptid_get_pid (inferior_ptid);
800 pid = ptid_get_pid (ptid);
801 if (fbsd_is_vfork_done_pending (pid))
806 fprintf_unfiltered (gdb_stdlog,
807 "FLWP: fbsd_resume for ptid (%d, %ld, %ld)\n",
808 ptid_get_pid (ptid), ptid_get_lwp (ptid),
809 ptid_get_tid (ptid));
810 if (ptid_lwp_p (ptid))
812 /* If ptid is a specific LWP, suspend all other LWPs in the process. */
813 struct thread_info *tp;
816 ALL_NON_EXITED_THREADS (tp)
818 if (ptid_get_pid (tp->ptid) != ptid_get_pid (ptid))
821 if (ptid_get_lwp (tp->ptid) == ptid_get_lwp (ptid))
824 request = PT_SUSPEND;
826 if (ptrace (request, ptid_get_lwp (tp->ptid), NULL, 0) == -1)
827 perror_with_name (("ptrace"));
832 /* If ptid is a wildcard, resume all matching threads (they won't run
833 until the process is continued however). */
834 struct thread_info *tp;
836 ALL_NON_EXITED_THREADS (tp)
838 if (!ptid_match (tp->ptid, ptid))
841 if (ptrace (PT_RESUME, ptid_get_lwp (tp->ptid), NULL, 0) == -1)
842 perror_with_name (("ptrace"));
844 ptid = inferior_ptid;
846 super_resume (ops, ptid, step, signo);
849 /* Wait for the child specified by PTID to do something. Return the
850 process ID of the child, or MINUS_ONE_PTID in case of error; store
851 the status in *OURSTATUS. */
854 fbsd_wait (struct target_ops *ops,
855 ptid_t ptid, struct target_waitstatus *ourstatus,
863 wptid = fbsd_next_vfork_done ();
864 if (!ptid_equal (wptid, null_ptid))
866 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
870 wptid = super_wait (ops, ptid, ourstatus, target_options);
871 if (ourstatus->kind == TARGET_WAITKIND_STOPPED)
873 struct ptrace_lwpinfo pl;
877 pid = ptid_get_pid (wptid);
878 if (ptrace (PT_LWPINFO, pid, (caddr_t) &pl, sizeof pl) == -1)
879 perror_with_name (("ptrace"));
881 wptid = ptid_build (pid, pl.pl_lwpid, 0);
884 if (pl.pl_flags & PL_FLAG_EXITED)
886 /* If GDB attaches to a multi-threaded process, exiting
887 threads might be skipped during fbsd_post_attach that
888 have not yet reported their PL_FLAG_EXITED event.
889 Ignore EXITED events for an unknown LWP. */
890 if (in_thread_list (wptid))
893 fprintf_unfiltered (gdb_stdlog,
894 "FLWP: deleting thread for LWP %u\n",
896 if (print_thread_events)
897 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str
899 delete_thread (wptid);
901 if (ptrace (PT_CONTINUE, pid, (caddr_t) 1, 0) == -1)
902 perror_with_name (("ptrace"));
907 /* Switch to an LWP PTID on the first stop in a new process.
908 This is done after handling PL_FLAG_EXITED to avoid
909 switching to an exited LWP. It is done before checking
910 PL_FLAG_BORN in case the first stop reported after
911 attaching to an existing process is a PL_FLAG_BORN
913 if (in_thread_list (pid_to_ptid (pid)))
916 fprintf_unfiltered (gdb_stdlog,
917 "FLWP: using LWP %u for first thread\n",
919 thread_change_ptid (pid_to_ptid (pid), wptid);
923 if (pl.pl_flags & PL_FLAG_BORN)
925 /* If GDB attaches to a multi-threaded process, newborn
926 threads might be added by fbsd_add_threads that have
927 not yet reported their PL_FLAG_BORN event. Ignore
928 BORN events for an already-known LWP. */
929 if (!in_thread_list (wptid))
932 fprintf_unfiltered (gdb_stdlog,
933 "FLWP: adding thread for LWP %u\n",
937 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
943 if (pl.pl_flags & PL_FLAG_FORKED)
946 struct kinfo_proc kp;
951 child = pl.pl_child_pid;
952 ourstatus->kind = TARGET_WAITKIND_FORKED;
954 if (pl.pl_flags & PL_FLAG_VFORKED)
955 ourstatus->kind = TARGET_WAITKIND_VFORKED;
958 /* Make sure the other end of the fork is stopped too. */
959 child_ptid = fbsd_is_child_pending (child);
960 if (ptid_equal (child_ptid, null_ptid))
962 pid = waitpid (child, &status, 0);
964 perror_with_name (("waitpid"));
966 gdb_assert (pid == child);
968 if (ptrace (PT_LWPINFO, child, (caddr_t)&pl, sizeof pl) == -1)
969 perror_with_name (("ptrace"));
971 gdb_assert (pl.pl_flags & PL_FLAG_CHILD);
972 child_ptid = ptid_build (child, pl.pl_lwpid, 0);
975 /* Enable additional events on the child process. */
976 fbsd_enable_proc_events (ptid_get_pid (child_ptid));
979 /* For vfork, the child process will have the P_PPWAIT
981 fbsd_fetch_kinfo_proc (child, &kp);
982 if (kp.ki_flag & P_PPWAIT)
983 ourstatus->kind = TARGET_WAITKIND_VFORKED;
985 ourstatus->value.related_pid = child_ptid;
990 if (pl.pl_flags & PL_FLAG_CHILD)
992 /* Remember that this child forked, but do not report it
993 until the parent reports its corresponding fork
995 fbsd_remember_child (wptid);
1000 if (pl.pl_flags & PL_FLAG_VFORK_DONE)
1002 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
1009 if (pl.pl_flags & PL_FLAG_EXEC)
1011 ourstatus->kind = TARGET_WAITKIND_EXECD;
1012 ourstatus->value.execd_pathname
1013 = xstrdup (fbsd_pid_to_exec_file (NULL, pid));
1018 /* Note that PL_FLAG_SCE is set for any event reported while
1019 a thread is executing a system call in the kernel. In
1020 particular, signals that interrupt a sleep in a system
1021 call will report this flag as part of their event. Stops
1022 explicitly for system call entry and exit always use
1023 SIGTRAP, so only treat SIGTRAP events as system call
1024 entry/exit events. */
1025 if (pl.pl_flags & (PL_FLAG_SCE | PL_FLAG_SCX)
1026 && ourstatus->value.sig == SIGTRAP)
1028 #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE
1029 if (catch_syscall_enabled ())
1031 if (catching_syscall_number (pl.pl_syscall_code))
1033 if (pl.pl_flags & PL_FLAG_SCE)
1034 ourstatus->kind = TARGET_WAITKIND_SYSCALL_ENTRY;
1036 ourstatus->kind = TARGET_WAITKIND_SYSCALL_RETURN;
1037 ourstatus->value.syscall_number = pl.pl_syscall_code;
1042 /* If the core isn't interested in this event, just
1043 continue the process explicitly and wait for another
1044 event. Note that PT_SYSCALL is "sticky" on FreeBSD
1045 and once system call stops are enabled on a process
1046 it stops for all system call entries and exits. */
1047 if (ptrace (PT_CONTINUE, pid, (caddr_t) 1, 0) == -1)
1048 perror_with_name (("ptrace"));
1057 /* Target hook for follow_fork. On entry and at return inferior_ptid is
1058 the ptid of the followed inferior. */
1061 fbsd_follow_fork (struct target_ops *ops, int follow_child,
1064 if (!follow_child && detach_fork)
1066 struct thread_info *tp = inferior_thread ();
1067 pid_t child_pid = ptid_get_pid (tp->pending_follow.value.related_pid);
1069 /* Breakpoints have already been detached from the child by
1072 if (ptrace (PT_DETACH, child_pid, (PTRACE_TYPE_ARG3)1, 0) == -1)
1073 perror_with_name (("ptrace"));
1075 #ifndef PTRACE_VFORK
1076 if (tp->pending_follow.kind == TARGET_WAITKIND_VFORKED)
1078 /* We can't insert breakpoints until the child process has
1079 finished with the shared memory region. The parent
1080 process doesn't wait for the child process to exit or
1081 exec until after it has been resumed from the ptrace stop
1082 to report the fork. Once it has been resumed it doesn't
1083 stop again before returning to userland, so there is no
1084 reliable way to wait on the parent.
1086 We can't stay attached to the child to wait for an exec
1087 or exit because it may invoke ptrace(PT_TRACE_ME)
1088 (e.g. if the parent process is a debugger forking a new
1091 In the end, the best we can do is to make sure it runs
1092 for a little while. Hopefully it will be out of range of
1093 any breakpoints we reinsert. Usually this is only the
1094 single-step breakpoint at vfork's return point. */
1098 /* Schedule a fake VFORK_DONE event to report on the next
1100 fbsd_add_vfork_done (inferior_ptid);
1109 fbsd_insert_fork_catchpoint (struct target_ops *self, int pid)
1115 fbsd_remove_fork_catchpoint (struct target_ops *self, int pid)
1121 fbsd_insert_vfork_catchpoint (struct target_ops *self, int pid)
1127 fbsd_remove_vfork_catchpoint (struct target_ops *self, int pid)
1133 /* Implement the "to_post_startup_inferior" target_ops method. */
1136 fbsd_post_startup_inferior (struct target_ops *self, ptid_t pid)
1138 fbsd_enable_proc_events (ptid_get_pid (pid));
1141 /* Implement the "to_post_attach" target_ops method. */
1144 fbsd_post_attach (struct target_ops *self, int pid)
1146 fbsd_enable_proc_events (pid);
1147 fbsd_add_threads (pid);
1151 /* If the FreeBSD kernel supports PL_FLAG_EXEC, then traced processes
1152 will always stop after exec. */
1155 fbsd_insert_exec_catchpoint (struct target_ops *self, int pid)
1161 fbsd_remove_exec_catchpoint (struct target_ops *self, int pid)
1167 #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE
1169 fbsd_set_syscall_catchpoint (struct target_ops *self, int pid, bool needed,
1171 gdb::array_view<const int> syscall_counts)
1174 /* Ignore the arguments. inf-ptrace.c will use PT_SYSCALL which
1175 will catch all system call entries and exits. The system calls
1176 are filtered by GDB rather than the kernel. */
1183 fbsd_nat_add_target (struct target_ops *t)
1185 t->to_pid_to_exec_file = fbsd_pid_to_exec_file;
1186 t->to_find_memory_regions = fbsd_find_memory_regions;
1187 #ifdef KERN_PROC_AUXV
1188 super_xfer_partial = t->to_xfer_partial;
1189 t->to_xfer_partial = fbsd_xfer_partial;
1192 t->to_thread_alive = fbsd_thread_alive;
1193 t->to_pid_to_str = fbsd_pid_to_str;
1194 #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_TDNAME
1195 t->to_thread_name = fbsd_thread_name;
1197 t->to_update_thread_list = fbsd_update_thread_list;
1198 t->to_has_thread_control = tc_schedlock;
1199 super_resume = t->to_resume;
1200 t->to_resume = fbsd_resume;
1201 super_wait = t->to_wait;
1202 t->to_wait = fbsd_wait;
1203 t->to_post_startup_inferior = fbsd_post_startup_inferior;
1204 t->to_post_attach = fbsd_post_attach;
1206 t->to_follow_fork = fbsd_follow_fork;
1207 t->to_insert_fork_catchpoint = fbsd_insert_fork_catchpoint;
1208 t->to_remove_fork_catchpoint = fbsd_remove_fork_catchpoint;
1209 t->to_insert_vfork_catchpoint = fbsd_insert_vfork_catchpoint;
1210 t->to_remove_vfork_catchpoint = fbsd_remove_vfork_catchpoint;
1213 t->to_insert_exec_catchpoint = fbsd_insert_exec_catchpoint;
1214 t->to_remove_exec_catchpoint = fbsd_remove_exec_catchpoint;
1216 #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE
1217 t->to_set_syscall_catchpoint = fbsd_set_syscall_catchpoint;
1224 _initialize_fbsd_nat (void)
1227 add_setshow_boolean_cmd ("fbsd-lwp", class_maintenance,
1228 &debug_fbsd_lwp, _("\
1229 Set debugging of FreeBSD lwp module."), _("\
1230 Show debugging of FreeBSD lwp module."), _("\
1231 Enables printf debugging output."),
1233 &show_fbsd_lwp_debug,
1234 &setdebuglist, &showdebuglist);