xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/fbsd-nat.c (revision 122b5006ee1bd67145794b4cde92f4fe4781a5ec)
1 /* Native-dependent code for FreeBSD.
2 
3    Copyright (C) 2002-2019 Free Software Foundation, Inc.
4 
5    This file is part of GDB.
6 
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.
11 
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.
16 
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/>.  */
19 
20 #include "defs.h"
21 #include "common/byte-vector.h"
22 #include "gdbcore.h"
23 #include "inferior.h"
24 #include "regcache.h"
25 #include "regset.h"
26 #include "gdbcmd.h"
27 #include "gdbthread.h"
28 #include "common/gdb_wait.h"
29 #include "inf-ptrace.h"
30 #include <sys/types.h>
31 #include <sys/procfs.h>
32 #include <sys/ptrace.h>
33 #include <sys/signal.h>
34 #include <sys/sysctl.h>
35 #include <sys/user.h>
36 #if defined(HAVE_KINFO_GETFILE) || defined(HAVE_KINFO_GETVMMAP)
37 #include <libutil.h>
38 #endif
39 #if !defined(HAVE_KINFO_GETVMMAP)
40 #include "common/filestuff.h"
41 #endif
42 
43 #include "elf-bfd.h"
44 #include "fbsd-nat.h"
45 #include "fbsd-tdep.h"
46 
47 #include <list>
48 
49 /* Return the name of a file that can be opened to get the symbols for
50    the child process identified by PID.  */
51 
52 char *
53 fbsd_nat_target::pid_to_exec_file (int pid)
54 {
55   ssize_t len;
56   static char buf[PATH_MAX];
57   char name[PATH_MAX];
58 
59 #ifdef KERN_PROC_PATHNAME
60   size_t buflen;
61   int mib[4];
62 
63   mib[0] = CTL_KERN;
64   mib[1] = KERN_PROC;
65   mib[2] = KERN_PROC_PATHNAME;
66   mib[3] = pid;
67   buflen = sizeof buf;
68   if (sysctl (mib, 4, buf, &buflen, NULL, 0) == 0)
69     /* The kern.proc.pathname.<pid> sysctl returns a length of zero
70        for processes without an associated executable such as kernel
71        processes.  */
72     return buflen == 0 ? NULL : buf;
73 #endif
74 
75   xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid);
76   len = readlink (name, buf, PATH_MAX - 1);
77   if (len != -1)
78     {
79       buf[len] = '\0';
80       return buf;
81     }
82 
83   return NULL;
84 }
85 
86 #ifdef HAVE_KINFO_GETVMMAP
87 /* Iterate over all the memory regions in the current inferior,
88    calling FUNC for each memory region.  OBFD is passed as the last
89    argument to FUNC.  */
90 
91 int
92 fbsd_nat_target::find_memory_regions (find_memory_region_ftype func,
93 				      void *obfd)
94 {
95   pid_t pid = inferior_ptid.pid ();
96   struct kinfo_vmentry *kve;
97   uint64_t size;
98   int i, nitems;
99 
100   gdb::unique_xmalloc_ptr<struct kinfo_vmentry>
101     vmentl (kinfo_getvmmap (pid, &nitems));
102   if (vmentl == NULL)
103     perror_with_name (_("Couldn't fetch VM map entries."));
104 
105   for (i = 0, kve = vmentl.get (); i < nitems; i++, kve++)
106     {
107       /* Skip unreadable segments and those where MAP_NOCORE has been set.  */
108       if (!(kve->kve_protection & KVME_PROT_READ)
109 	  || kve->kve_flags & KVME_FLAG_NOCOREDUMP)
110 	continue;
111 
112       /* Skip segments with an invalid type.  */
113       if (kve->kve_type != KVME_TYPE_DEFAULT
114 	  && kve->kve_type != KVME_TYPE_VNODE
115 	  && kve->kve_type != KVME_TYPE_SWAP
116 	  && kve->kve_type != KVME_TYPE_PHYS)
117 	continue;
118 
119       size = kve->kve_end - kve->kve_start;
120       if (info_verbose)
121 	{
122 	  fprintf_filtered (gdb_stdout,
123 			    "Save segment, %ld bytes at %s (%c%c%c)\n",
124 			    (long) size,
125 			    paddress (target_gdbarch (), kve->kve_start),
126 			    kve->kve_protection & KVME_PROT_READ ? 'r' : '-',
127 			    kve->kve_protection & KVME_PROT_WRITE ? 'w' : '-',
128 			    kve->kve_protection & KVME_PROT_EXEC ? 'x' : '-');
129 	}
130 
131       /* Invoke the callback function to create the corefile segment.
132 	 Pass MODIFIED as true, we do not know the real modification state.  */
133       func (kve->kve_start, size, kve->kve_protection & KVME_PROT_READ,
134 	    kve->kve_protection & KVME_PROT_WRITE,
135 	    kve->kve_protection & KVME_PROT_EXEC, 1, obfd);
136     }
137   return 0;
138 }
139 #else
140 static int
141 fbsd_read_mapping (FILE *mapfile, unsigned long *start, unsigned long *end,
142 		   char *protection)
143 {
144   /* FreeBSD 5.1-RELEASE uses a 256-byte buffer.  */
145   char buf[256];
146   int resident, privateresident;
147   unsigned long obj;
148   int ret = EOF;
149 
150   /* As of FreeBSD 5.0-RELEASE, the layout is described in
151      /usr/src/sys/fs/procfs/procfs_map.c.  Somewhere in 5.1-CURRENT a
152      new column was added to the procfs map.  Therefore we can't use
153      fscanf since we need to support older releases too.  */
154   if (fgets (buf, sizeof buf, mapfile) != NULL)
155     ret = sscanf (buf, "%lx %lx %d %d %lx %s", start, end,
156 		  &resident, &privateresident, &obj, protection);
157 
158   return (ret != 0 && ret != EOF);
159 }
160 
161 /* Iterate over all the memory regions in the current inferior,
162    calling FUNC for each memory region.  OBFD is passed as the last
163    argument to FUNC.  */
164 
165 int
166 fbsd_nat_target::find_memory_regions (find_memory_region_ftype func,
167 				      void *obfd)
168 {
169   pid_t pid = inferior_ptid.pid ();
170   unsigned long start, end, size;
171   char protection[4];
172   int read, write, exec;
173 
174   std::string mapfilename = string_printf ("/proc/%ld/map", (long) pid);
175   gdb_file_up mapfile (fopen (mapfilename.c_str (), "r"));
176   if (mapfile == NULL)
177     error (_("Couldn't open %s."), mapfilename.c_str ());
178 
179   if (info_verbose)
180     fprintf_filtered (gdb_stdout,
181 		      "Reading memory regions from %s\n", mapfilename.c_str ());
182 
183   /* Now iterate until end-of-file.  */
184   while (fbsd_read_mapping (mapfile.get (), &start, &end, &protection[0]))
185     {
186       size = end - start;
187 
188       read = (strchr (protection, 'r') != 0);
189       write = (strchr (protection, 'w') != 0);
190       exec = (strchr (protection, 'x') != 0);
191 
192       if (info_verbose)
193 	{
194 	  fprintf_filtered (gdb_stdout,
195 			    "Save segment, %ld bytes at %s (%c%c%c)\n",
196 			    size, paddress (target_gdbarch (), start),
197 			    read ? 'r' : '-',
198 			    write ? 'w' : '-',
199 			    exec ? 'x' : '-');
200 	}
201 
202       /* Invoke the callback function to create the corefile segment.
203 	 Pass MODIFIED as true, we do not know the real modification state.  */
204       func (start, size, read, write, exec, 1, obfd);
205     }
206 
207   return 0;
208 }
209 #endif
210 
211 /* Fetch the command line for a running process.  */
212 
213 static gdb::unique_xmalloc_ptr<char>
214 fbsd_fetch_cmdline (pid_t pid)
215 {
216   size_t len;
217   int mib[4];
218 
219   len = 0;
220   mib[0] = CTL_KERN;
221   mib[1] = KERN_PROC;
222   mib[2] = KERN_PROC_ARGS;
223   mib[3] = pid;
224   if (sysctl (mib, 4, NULL, &len, NULL, 0) == -1)
225     return nullptr;
226 
227   if (len == 0)
228     return nullptr;
229 
230   gdb::unique_xmalloc_ptr<char> cmdline ((char *) xmalloc (len));
231   if (sysctl (mib, 4, cmdline.get (), &len, NULL, 0) == -1)
232     return nullptr;
233 
234   /* Join the arguments with spaces to form a single string.  */
235   char *cp = cmdline.get ();
236   for (size_t i = 0; i < len - 1; i++)
237     if (cp[i] == '\0')
238       cp[i] = ' ';
239   cp[len - 1] = '\0';
240 
241   return cmdline;
242 }
243 
244 /* Fetch the external variant of the kernel's internal process
245    structure for the process PID into KP.  */
246 
247 static bool
248 fbsd_fetch_kinfo_proc (pid_t pid, struct kinfo_proc *kp)
249 {
250   size_t len;
251   int mib[4];
252 
253   len = sizeof *kp;
254   mib[0] = CTL_KERN;
255   mib[1] = KERN_PROC;
256   mib[2] = KERN_PROC_PID;
257   mib[3] = pid;
258   return (sysctl (mib, 4, kp, &len, NULL, 0) == 0);
259 }
260 
261 /* Implement the "info_proc" target_ops method.  */
262 
263 bool
264 fbsd_nat_target::info_proc (const char *args, enum info_proc_what what)
265 {
266 #ifdef HAVE_KINFO_GETFILE
267   gdb::unique_xmalloc_ptr<struct kinfo_file> fdtbl;
268   int nfd = 0;
269 #endif
270   struct kinfo_proc kp;
271   pid_t pid;
272   bool do_cmdline = false;
273   bool do_cwd = false;
274   bool do_exe = false;
275 #ifdef HAVE_KINFO_GETFILE
276   bool do_files = false;
277 #endif
278 #ifdef HAVE_KINFO_GETVMMAP
279   bool do_mappings = false;
280 #endif
281   bool do_status = false;
282 
283   switch (what)
284     {
285     case IP_MINIMAL:
286       do_cmdline = true;
287       do_cwd = true;
288       do_exe = true;
289       break;
290 #ifdef HAVE_KINFO_GETVMMAP
291     case IP_MAPPINGS:
292       do_mappings = true;
293       break;
294 #endif
295     case IP_STATUS:
296     case IP_STAT:
297       do_status = true;
298       break;
299     case IP_CMDLINE:
300       do_cmdline = true;
301       break;
302     case IP_EXE:
303       do_exe = true;
304       break;
305     case IP_CWD:
306       do_cwd = true;
307       break;
308 #ifdef HAVE_KINFO_GETFILE
309     case IP_FILES:
310       do_files = true;
311       break;
312 #endif
313     case IP_ALL:
314       do_cmdline = true;
315       do_cwd = true;
316       do_exe = true;
317 #ifdef HAVE_KINFO_GETFILE
318       do_files = true;
319 #endif
320 #ifdef HAVE_KINFO_GETVMMAP
321       do_mappings = true;
322 #endif
323       do_status = true;
324       break;
325     default:
326       error (_("Not supported on this target."));
327     }
328 
329   gdb_argv built_argv (args);
330   if (built_argv.count () == 0)
331     {
332       pid = inferior_ptid.pid ();
333       if (pid == 0)
334 	error (_("No current process: you must name one."));
335     }
336   else if (built_argv.count () == 1 && isdigit (built_argv[0][0]))
337     pid = strtol (built_argv[0], NULL, 10);
338   else
339     error (_("Invalid arguments."));
340 
341   printf_filtered (_("process %d\n"), pid);
342 #ifdef HAVE_KINFO_GETFILE
343   if (do_cwd || do_exe || do_files)
344     fdtbl.reset (kinfo_getfile (pid, &nfd));
345 #endif
346 
347   if (do_cmdline)
348     {
349       gdb::unique_xmalloc_ptr<char> cmdline = fbsd_fetch_cmdline (pid);
350       if (cmdline != nullptr)
351 	printf_filtered ("cmdline = '%s'\n", cmdline.get ());
352       else
353 	warning (_("unable to fetch command line"));
354     }
355   if (do_cwd)
356     {
357       const char *cwd = NULL;
358 #ifdef HAVE_KINFO_GETFILE
359       struct kinfo_file *kf = fdtbl.get ();
360       for (int i = 0; i < nfd; i++, kf++)
361 	{
362 	  if (kf->kf_type == KF_TYPE_VNODE && kf->kf_fd == KF_FD_TYPE_CWD)
363 	    {
364 	      cwd = kf->kf_path;
365 	      break;
366 	    }
367 	}
368 #endif
369       if (cwd != NULL)
370 	printf_filtered ("cwd = '%s'\n", cwd);
371       else
372 	warning (_("unable to fetch current working directory"));
373     }
374   if (do_exe)
375     {
376       const char *exe = NULL;
377 #ifdef HAVE_KINFO_GETFILE
378       struct kinfo_file *kf = fdtbl.get ();
379       for (int i = 0; i < nfd; i++, kf++)
380 	{
381 	  if (kf->kf_type == KF_TYPE_VNODE && kf->kf_fd == KF_FD_TYPE_TEXT)
382 	    {
383 	      exe = kf->kf_path;
384 	      break;
385 	    }
386 	}
387 #endif
388       if (exe == NULL)
389 	exe = pid_to_exec_file (pid);
390       if (exe != NULL)
391 	printf_filtered ("exe = '%s'\n", exe);
392       else
393 	warning (_("unable to fetch executable path name"));
394     }
395 #ifdef HAVE_KINFO_GETFILE
396   if (do_files)
397     {
398       struct kinfo_file *kf = fdtbl.get ();
399 
400       if (nfd > 0)
401 	{
402 	  fbsd_info_proc_files_header ();
403 	  for (int i = 0; i < nfd; i++, kf++)
404 	    fbsd_info_proc_files_entry (kf->kf_type, kf->kf_fd, kf->kf_flags,
405 					kf->kf_offset, kf->kf_vnode_type,
406 					kf->kf_sock_domain, kf->kf_sock_type,
407 					kf->kf_sock_protocol, &kf->kf_sa_local,
408 					&kf->kf_sa_peer, kf->kf_path);
409 	}
410       else
411 	warning (_("unable to fetch list of open files"));
412     }
413 #endif
414 #ifdef HAVE_KINFO_GETVMMAP
415   if (do_mappings)
416     {
417       int nvment;
418       gdb::unique_xmalloc_ptr<struct kinfo_vmentry>
419 	vmentl (kinfo_getvmmap (pid, &nvment));
420 
421       if (vmentl != nullptr)
422 	{
423 	  int addr_bit = TARGET_CHAR_BIT * sizeof (void *);
424 	  fbsd_info_proc_mappings_header (addr_bit);
425 
426 	  struct kinfo_vmentry *kve = vmentl.get ();
427 	  for (int i = 0; i < nvment; i++, kve++)
428 	    fbsd_info_proc_mappings_entry (addr_bit, kve->kve_start,
429 					   kve->kve_end, kve->kve_offset,
430 					   kve->kve_flags, kve->kve_protection,
431 					   kve->kve_path);
432 	}
433       else
434 	warning (_("unable to fetch virtual memory map"));
435     }
436 #endif
437   if (do_status)
438     {
439       if (!fbsd_fetch_kinfo_proc (pid, &kp))
440 	warning (_("Failed to fetch process information"));
441       else
442 	{
443 	  const char *state;
444 	  int pgtok;
445 
446 	  printf_filtered ("Name: %s\n", kp.ki_comm);
447 	  switch (kp.ki_stat)
448 	    {
449 	    case SIDL:
450 	      state = "I (idle)";
451 	      break;
452 	    case SRUN:
453 	      state = "R (running)";
454 	      break;
455 	    case SSTOP:
456 	      state = "T (stopped)";
457 	      break;
458 	    case SZOMB:
459 	      state = "Z (zombie)";
460 	      break;
461 	    case SSLEEP:
462 	      state = "S (sleeping)";
463 	      break;
464 	    case SWAIT:
465 	      state = "W (interrupt wait)";
466 	      break;
467 	    case SLOCK:
468 	      state = "L (blocked on lock)";
469 	      break;
470 	    default:
471 	      state = "? (unknown)";
472 	      break;
473 	    }
474 	  printf_filtered ("State: %s\n", state);
475 	  printf_filtered ("Parent process: %d\n", kp.ki_ppid);
476 	  printf_filtered ("Process group: %d\n", kp.ki_pgid);
477 	  printf_filtered ("Session id: %d\n", kp.ki_sid);
478 	  printf_filtered ("TTY: %ju\n", (uintmax_t) kp.ki_tdev);
479 	  printf_filtered ("TTY owner process group: %d\n", kp.ki_tpgid);
480 	  printf_filtered ("User IDs (real, effective, saved): %d %d %d\n",
481 			   kp.ki_ruid, kp.ki_uid, kp.ki_svuid);
482 	  printf_filtered ("Group IDs (real, effective, saved): %d %d %d\n",
483 			   kp.ki_rgid, kp.ki_groups[0], kp.ki_svgid);
484 	  printf_filtered ("Groups: ");
485 	  for (int i = 0; i < kp.ki_ngroups; i++)
486 	    printf_filtered ("%d ", kp.ki_groups[i]);
487 	  printf_filtered ("\n");
488 	  printf_filtered ("Minor faults (no memory page): %ld\n",
489 			   kp.ki_rusage.ru_minflt);
490 	  printf_filtered ("Minor faults, children: %ld\n",
491 			   kp.ki_rusage_ch.ru_minflt);
492 	  printf_filtered ("Major faults (memory page faults): %ld\n",
493 			   kp.ki_rusage.ru_majflt);
494 	  printf_filtered ("Major faults, children: %ld\n",
495 			   kp.ki_rusage_ch.ru_majflt);
496 	  printf_filtered ("utime: %jd.%06ld\n",
497 			   (intmax_t) kp.ki_rusage.ru_utime.tv_sec,
498 			   kp.ki_rusage.ru_utime.tv_usec);
499 	  printf_filtered ("stime: %jd.%06ld\n",
500 			   (intmax_t) kp.ki_rusage.ru_stime.tv_sec,
501 			   kp.ki_rusage.ru_stime.tv_usec);
502 	  printf_filtered ("utime, children: %jd.%06ld\n",
503 			   (intmax_t) kp.ki_rusage_ch.ru_utime.tv_sec,
504 			   kp.ki_rusage_ch.ru_utime.tv_usec);
505 	  printf_filtered ("stime, children: %jd.%06ld\n",
506 			   (intmax_t) kp.ki_rusage_ch.ru_stime.tv_sec,
507 			   kp.ki_rusage_ch.ru_stime.tv_usec);
508 	  printf_filtered ("'nice' value: %d\n", kp.ki_nice);
509 	  printf_filtered ("Start time: %jd.%06ld\n", kp.ki_start.tv_sec,
510 			   kp.ki_start.tv_usec);
511 	  pgtok = getpagesize () / 1024;
512 	  printf_filtered ("Virtual memory size: %ju kB\n",
513 			   (uintmax_t) kp.ki_size / 1024);
514 	  printf_filtered ("Data size: %ju kB\n",
515 			   (uintmax_t) kp.ki_dsize * pgtok);
516 	  printf_filtered ("Stack size: %ju kB\n",
517 			   (uintmax_t) kp.ki_ssize * pgtok);
518 	  printf_filtered ("Text size: %ju kB\n",
519 			   (uintmax_t) kp.ki_tsize * pgtok);
520 	  printf_filtered ("Resident set size: %ju kB\n",
521 			   (uintmax_t) kp.ki_rssize * pgtok);
522 	  printf_filtered ("Maximum RSS: %ju kB\n",
523 			   (uintmax_t) kp.ki_rusage.ru_maxrss);
524 	  printf_filtered ("Pending Signals: ");
525 	  for (int i = 0; i < _SIG_WORDS; i++)
526 	    printf_filtered ("%08x ", kp.ki_siglist.__bits[i]);
527 	  printf_filtered ("\n");
528 	  printf_filtered ("Ignored Signals: ");
529 	  for (int i = 0; i < _SIG_WORDS; i++)
530 	    printf_filtered ("%08x ", kp.ki_sigignore.__bits[i]);
531 	  printf_filtered ("\n");
532 	  printf_filtered ("Caught Signals: ");
533 	  for (int i = 0; i < _SIG_WORDS; i++)
534 	    printf_filtered ("%08x ", kp.ki_sigcatch.__bits[i]);
535 	  printf_filtered ("\n");
536 	}
537     }
538 
539   return true;
540 }
541 
542 /*
543  * The current layout of siginfo_t on FreeBSD was adopted in SVN
544  * revision 153154 which shipped in FreeBSD versions 7.0 and later.
545  * Don't bother supporting the older layout on older kernels.  The
546  * older format was also never used in core dump notes.
547  */
548 #if __FreeBSD_version >= 700009
549 #define USE_SIGINFO
550 #endif
551 
552 #ifdef USE_SIGINFO
553 /* Return the size of siginfo for the current inferior.  */
554 
555 #ifdef __LP64__
556 union sigval32 {
557   int sival_int;
558   uint32_t sival_ptr;
559 };
560 
561 /* This structure matches the naming and layout of `siginfo_t' in
562    <sys/signal.h>.  In particular, the `si_foo' macros defined in that
563    header can be used with both types to copy fields in the `_reason'
564    union.  */
565 
566 struct siginfo32
567 {
568   int si_signo;
569   int si_errno;
570   int si_code;
571   __pid_t si_pid;
572   __uid_t si_uid;
573   int si_status;
574   uint32_t si_addr;
575   union sigval32 si_value;
576   union
577   {
578     struct
579     {
580       int _trapno;
581     } _fault;
582     struct
583     {
584       int _timerid;
585       int _overrun;
586     } _timer;
587     struct
588     {
589       int _mqd;
590     } _mesgq;
591     struct
592     {
593       int32_t _band;
594     } _poll;
595     struct
596     {
597       int32_t __spare1__;
598       int __spare2__[7];
599     } __spare__;
600   } _reason;
601 };
602 #endif
603 
604 static size_t
605 fbsd_siginfo_size ()
606 {
607 #ifdef __LP64__
608   struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
609 
610   /* Is the inferior 32-bit?  If so, use the 32-bit siginfo size.  */
611   if (gdbarch_long_bit (gdbarch) == 32)
612     return sizeof (struct siginfo32);
613 #endif
614   return sizeof (siginfo_t);
615 }
616 
617 /* Convert a native 64-bit siginfo object to a 32-bit object.  Note
618    that FreeBSD doesn't support writing to $_siginfo, so this only
619    needs to convert one way.  */
620 
621 static void
622 fbsd_convert_siginfo (siginfo_t *si)
623 {
624 #ifdef __LP64__
625   struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
626 
627   /* Is the inferior 32-bit?  If not, nothing to do.  */
628   if (gdbarch_long_bit (gdbarch) != 32)
629     return;
630 
631   struct siginfo32 si32;
632 
633   si32.si_signo = si->si_signo;
634   si32.si_errno = si->si_errno;
635   si32.si_code = si->si_code;
636   si32.si_pid = si->si_pid;
637   si32.si_uid = si->si_uid;
638   si32.si_status = si->si_status;
639   si32.si_addr = (uintptr_t) si->si_addr;
640 
641   /* If sival_ptr is being used instead of sival_int on a big-endian
642      platform, then sival_int will be zero since it holds the upper
643      32-bits of the pointer value.  */
644 #if _BYTE_ORDER == _BIG_ENDIAN
645   if (si->si_value.sival_int == 0)
646     si32.si_value.sival_ptr = (uintptr_t) si->si_value.sival_ptr;
647   else
648     si32.si_value.sival_int = si->si_value.sival_int;
649 #else
650   si32.si_value.sival_int = si->si_value.sival_int;
651 #endif
652 
653   /* Always copy the spare fields and then possibly overwrite them for
654      signal-specific or code-specific fields.  */
655   si32._reason.__spare__.__spare1__ = si->_reason.__spare__.__spare1__;
656   for (int i = 0; i < 7; i++)
657     si32._reason.__spare__.__spare2__[i] = si->_reason.__spare__.__spare2__[i];
658   switch (si->si_signo) {
659   case SIGILL:
660   case SIGFPE:
661   case SIGSEGV:
662   case SIGBUS:
663     si32.si_trapno = si->si_trapno;
664     break;
665   }
666   switch (si->si_code) {
667   case SI_TIMER:
668     si32.si_timerid = si->si_timerid;
669     si32.si_overrun = si->si_overrun;
670     break;
671   case SI_MESGQ:
672     si32.si_mqd = si->si_mqd;
673     break;
674   }
675 
676   memcpy(si, &si32, sizeof (si32));
677 #endif
678 }
679 #endif
680 
681 /* Implement the "xfer_partial" target_ops method.  */
682 
683 enum target_xfer_status
684 fbsd_nat_target::xfer_partial (enum target_object object,
685 			       const char *annex, gdb_byte *readbuf,
686 			       const gdb_byte *writebuf,
687 			       ULONGEST offset, ULONGEST len,
688 			       ULONGEST *xfered_len)
689 {
690   pid_t pid = inferior_ptid.pid ();
691 
692   switch (object)
693     {
694 #ifdef USE_SIGINFO
695     case TARGET_OBJECT_SIGNAL_INFO:
696       {
697 	struct ptrace_lwpinfo pl;
698 	size_t siginfo_size;
699 
700 	/* FreeBSD doesn't support writing to $_siginfo.  */
701 	if (writebuf != NULL)
702 	  return TARGET_XFER_E_IO;
703 
704 	if (inferior_ptid.lwp_p ())
705 	  pid = inferior_ptid.lwp ();
706 
707 	siginfo_size = fbsd_siginfo_size ();
708 	if (offset > siginfo_size)
709 	  return TARGET_XFER_E_IO;
710 
711 	if (ptrace (PT_LWPINFO, pid, (PTRACE_TYPE_ARG3) &pl, sizeof (pl)) == -1)
712 	  return TARGET_XFER_E_IO;
713 
714 	if (!(pl.pl_flags & PL_FLAG_SI))
715 	  return TARGET_XFER_E_IO;
716 
717 	fbsd_convert_siginfo (&pl.pl_siginfo);
718 	if (offset + len > siginfo_size)
719 	  len = siginfo_size - offset;
720 
721 	memcpy (readbuf, ((gdb_byte *) &pl.pl_siginfo) + offset, len);
722 	*xfered_len = len;
723 	return TARGET_XFER_OK;
724       }
725 #endif
726 #ifdef KERN_PROC_AUXV
727     case TARGET_OBJECT_AUXV:
728       {
729 	gdb::byte_vector buf_storage;
730 	gdb_byte *buf;
731 	size_t buflen;
732 	int mib[4];
733 
734 	if (writebuf != NULL)
735 	  return TARGET_XFER_E_IO;
736 	mib[0] = CTL_KERN;
737 	mib[1] = KERN_PROC;
738 	mib[2] = KERN_PROC_AUXV;
739 	mib[3] = pid;
740 	if (offset == 0)
741 	  {
742 	    buf = readbuf;
743 	    buflen = len;
744 	  }
745 	else
746 	  {
747 	    buflen = offset + len;
748 	    buf_storage.resize (buflen);
749 	    buf = buf_storage.data ();
750 	  }
751 	if (sysctl (mib, 4, buf, &buflen, NULL, 0) == 0)
752 	  {
753 	    if (offset != 0)
754 	      {
755 		if (buflen > offset)
756 		  {
757 		    buflen -= offset;
758 		    memcpy (readbuf, buf + offset, buflen);
759 		  }
760 		else
761 		  buflen = 0;
762 	      }
763 	    *xfered_len = buflen;
764 	    return (buflen == 0) ? TARGET_XFER_EOF : TARGET_XFER_OK;
765 	  }
766 	return TARGET_XFER_E_IO;
767       }
768 #endif
769 #if defined(KERN_PROC_VMMAP) && defined(KERN_PROC_PS_STRINGS)
770     case TARGET_OBJECT_FREEBSD_VMMAP:
771     case TARGET_OBJECT_FREEBSD_PS_STRINGS:
772       {
773 	gdb::byte_vector buf_storage;
774 	gdb_byte *buf;
775 	size_t buflen;
776 	int mib[4];
777 
778 	int proc_target;
779 	uint32_t struct_size;
780 	switch (object)
781 	  {
782 	  case TARGET_OBJECT_FREEBSD_VMMAP:
783 	    proc_target = KERN_PROC_VMMAP;
784 	    struct_size = sizeof (struct kinfo_vmentry);
785 	    break;
786 	  case TARGET_OBJECT_FREEBSD_PS_STRINGS:
787 	    proc_target = KERN_PROC_PS_STRINGS;
788 	    struct_size = sizeof (void *);
789 	    break;
790 	  }
791 
792 	if (writebuf != NULL)
793 	  return TARGET_XFER_E_IO;
794 
795 	mib[0] = CTL_KERN;
796 	mib[1] = KERN_PROC;
797 	mib[2] = proc_target;
798 	mib[3] = pid;
799 
800 	if (sysctl (mib, 4, NULL, &buflen, NULL, 0) != 0)
801 	  return TARGET_XFER_E_IO;
802 	buflen += sizeof (struct_size);
803 
804 	if (offset >= buflen)
805 	  {
806 	    *xfered_len = 0;
807 	    return TARGET_XFER_EOF;
808 	  }
809 
810 	buf_storage.resize (buflen);
811 	buf = buf_storage.data ();
812 
813 	memcpy (buf, &struct_size, sizeof (struct_size));
814 	buflen -= sizeof (struct_size);
815 	if (sysctl (mib, 4, buf + sizeof (struct_size), &buflen, NULL, 0) != 0)
816 	  return TARGET_XFER_E_IO;
817 	buflen += sizeof (struct_size);
818 
819 	if (buflen - offset < len)
820 	  len = buflen - offset;
821 	memcpy (readbuf, buf + offset, len);
822 	*xfered_len = len;
823 	return TARGET_XFER_OK;
824       }
825 #endif
826     default:
827       return inf_ptrace_target::xfer_partial (object, annex,
828 					      readbuf, writebuf, offset,
829 					      len, xfered_len);
830     }
831 }
832 
833 #ifdef PT_LWPINFO
834 static int debug_fbsd_lwp;
835 static int debug_fbsd_nat;
836 
837 static void
838 show_fbsd_lwp_debug (struct ui_file *file, int from_tty,
839 		     struct cmd_list_element *c, const char *value)
840 {
841   fprintf_filtered (file, _("Debugging of FreeBSD lwp module is %s.\n"), value);
842 }
843 
844 static void
845 show_fbsd_nat_debug (struct ui_file *file, int from_tty,
846 		     struct cmd_list_element *c, const char *value)
847 {
848   fprintf_filtered (file, _("Debugging of FreeBSD native target is %s.\n"),
849 		    value);
850 }
851 
852 /*
853   FreeBSD's first thread support was via a "reentrant" version of libc
854   (libc_r) that first shipped in 2.2.7.  This library multiplexed all
855   of the threads in a process onto a single kernel thread.  This
856   library was supported via the bsd-uthread target.
857 
858   FreeBSD 5.1 introduced two new threading libraries that made use of
859   multiple kernel threads.  The first (libkse) scheduled M user
860   threads onto N (<= M) kernel threads (LWPs).  The second (libthr)
861   bound each user thread to a dedicated kernel thread.  libkse shipped
862   as the default threading library (libpthread).
863 
864   FreeBSD 5.3 added a libthread_db to abstract the interface across
865   the various thread libraries (libc_r, libkse, and libthr).
866 
867   FreeBSD 7.0 switched the default threading library from from libkse
868   to libpthread and removed libc_r.
869 
870   FreeBSD 8.0 removed libkse and the in-kernel support for it.  The
871   only threading library supported by 8.0 and later is libthr which
872   ties each user thread directly to an LWP.  To simplify the
873   implementation, this target only supports LWP-backed threads using
874   ptrace directly rather than libthread_db.
875 
876   FreeBSD 11.0 introduced LWP event reporting via PT_LWP_EVENTS.
877 */
878 
879 /* Return true if PTID is still active in the inferior.  */
880 
881 bool
882 fbsd_nat_target::thread_alive (ptid_t ptid)
883 {
884   if (ptid.lwp_p ())
885     {
886       struct ptrace_lwpinfo pl;
887 
888       if (ptrace (PT_LWPINFO, ptid.lwp (), (caddr_t) &pl, sizeof pl)
889 	  == -1)
890 	return false;
891 #ifdef PL_FLAG_EXITED
892       if (pl.pl_flags & PL_FLAG_EXITED)
893 	return false;
894 #endif
895     }
896 
897   return true;
898 }
899 
900 /* Convert PTID to a string.  Returns the string in a static
901    buffer.  */
902 
903 const char *
904 fbsd_nat_target::pid_to_str (ptid_t ptid)
905 {
906   lwpid_t lwp;
907 
908   lwp = ptid.lwp ();
909   if (lwp != 0)
910     {
911       static char buf[64];
912       int pid = ptid.pid ();
913 
914       xsnprintf (buf, sizeof buf, "LWP %d of process %d", lwp, pid);
915       return buf;
916     }
917 
918   return normal_pid_to_str (ptid);
919 }
920 
921 #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_TDNAME
922 /* Return the name assigned to a thread by an application.  Returns
923    the string in a static buffer.  */
924 
925 const char *
926 fbsd_nat_target::thread_name (struct thread_info *thr)
927 {
928   struct ptrace_lwpinfo pl;
929   struct kinfo_proc kp;
930   int pid = thr->ptid.pid ();
931   long lwp = thr->ptid.lwp ();
932   static char buf[sizeof pl.pl_tdname + 1];
933 
934   /* Note that ptrace_lwpinfo returns the process command in pl_tdname
935      if a name has not been set explicitly.  Return a NULL name in
936      that case.  */
937   if (!fbsd_fetch_kinfo_proc (pid, &kp))
938     perror_with_name (_("Failed to fetch process information"));
939   if (ptrace (PT_LWPINFO, lwp, (caddr_t) &pl, sizeof pl) == -1)
940     perror_with_name (("ptrace"));
941   if (strcmp (kp.ki_comm, pl.pl_tdname) == 0)
942     return NULL;
943   xsnprintf (buf, sizeof buf, "%s", pl.pl_tdname);
944   return buf;
945 }
946 #endif
947 
948 /* Enable additional event reporting on new processes.
949 
950    To catch fork events, PTRACE_FORK is set on every traced process
951    to enable stops on returns from fork or vfork.  Note that both the
952    parent and child will always stop, even if system call stops are
953    not enabled.
954 
955    To catch LWP events, PTRACE_EVENTS is set on every traced process.
956    This enables stops on the birth for new LWPs (excluding the "main" LWP)
957    and the death of LWPs (excluding the last LWP in a process).  Note
958    that unlike fork events, the LWP that creates a new LWP does not
959    report an event.  */
960 
961 static void
962 fbsd_enable_proc_events (pid_t pid)
963 {
964 #ifdef PT_GET_EVENT_MASK
965   int events;
966 
967   if (ptrace (PT_GET_EVENT_MASK, pid, (PTRACE_TYPE_ARG3)&events,
968 	      sizeof (events)) == -1)
969     perror_with_name (("ptrace"));
970   events |= PTRACE_FORK | PTRACE_LWP;
971 #ifdef PTRACE_VFORK
972   events |= PTRACE_VFORK;
973 #endif
974   if (ptrace (PT_SET_EVENT_MASK, pid, (PTRACE_TYPE_ARG3)&events,
975 	      sizeof (events)) == -1)
976     perror_with_name (("ptrace"));
977 #else
978 #ifdef TDP_RFPPWAIT
979   if (ptrace (PT_FOLLOW_FORK, pid, (PTRACE_TYPE_ARG3)0, 1) == -1)
980     perror_with_name (("ptrace"));
981 #endif
982 #ifdef PT_LWP_EVENTS
983   if (ptrace (PT_LWP_EVENTS, pid, (PTRACE_TYPE_ARG3)0, 1) == -1)
984     perror_with_name (("ptrace"));
985 #endif
986 #endif
987 }
988 
989 /* Add threads for any new LWPs in a process.
990 
991    When LWP events are used, this function is only used to detect existing
992    threads when attaching to a process.  On older systems, this function is
993    called to discover new threads each time the thread list is updated.  */
994 
995 static void
996 fbsd_add_threads (pid_t pid)
997 {
998   int i, nlwps;
999 
1000   gdb_assert (!in_thread_list (ptid_t (pid)));
1001   nlwps = ptrace (PT_GETNUMLWPS, pid, NULL, 0);
1002   if (nlwps == -1)
1003     perror_with_name (("ptrace"));
1004 
1005   gdb::unique_xmalloc_ptr<lwpid_t[]> lwps (XCNEWVEC (lwpid_t, nlwps));
1006 
1007   nlwps = ptrace (PT_GETLWPLIST, pid, (caddr_t) lwps.get (), nlwps);
1008   if (nlwps == -1)
1009     perror_with_name (("ptrace"));
1010 
1011   for (i = 0; i < nlwps; i++)
1012     {
1013       ptid_t ptid = ptid_t (pid, lwps[i], 0);
1014 
1015       if (!in_thread_list (ptid))
1016 	{
1017 #ifdef PT_LWP_EVENTS
1018 	  struct ptrace_lwpinfo pl;
1019 
1020 	  /* Don't add exited threads.  Note that this is only called
1021 	     when attaching to a multi-threaded process.  */
1022 	  if (ptrace (PT_LWPINFO, lwps[i], (caddr_t) &pl, sizeof pl) == -1)
1023 	    perror_with_name (("ptrace"));
1024 	  if (pl.pl_flags & PL_FLAG_EXITED)
1025 	    continue;
1026 #endif
1027 	  if (debug_fbsd_lwp)
1028 	    fprintf_unfiltered (gdb_stdlog,
1029 				"FLWP: adding thread for LWP %u\n",
1030 				lwps[i]);
1031 	  add_thread (ptid);
1032 	}
1033     }
1034 }
1035 
1036 /* Implement the "update_thread_list" target_ops method.  */
1037 
1038 void
1039 fbsd_nat_target::update_thread_list ()
1040 {
1041 #ifdef PT_LWP_EVENTS
1042   /* With support for thread events, threads are added/deleted from the
1043      list as events are reported, so just try deleting exited threads.  */
1044   delete_exited_threads ();
1045 #else
1046   prune_threads ();
1047 
1048   fbsd_add_threads (inferior_ptid.pid ());
1049 #endif
1050 }
1051 
1052 #ifdef TDP_RFPPWAIT
1053 /*
1054   To catch fork events, PT_FOLLOW_FORK is set on every traced process
1055   to enable stops on returns from fork or vfork.  Note that both the
1056   parent and child will always stop, even if system call stops are not
1057   enabled.
1058 
1059   After a fork, both the child and parent process will stop and report
1060   an event.  However, there is no guarantee of order.  If the parent
1061   reports its stop first, then fbsd_wait explicitly waits for the new
1062   child before returning.  If the child reports its stop first, then
1063   the event is saved on a list and ignored until the parent's stop is
1064   reported.  fbsd_wait could have been changed to fetch the parent PID
1065   of the new child and used that to wait for the parent explicitly.
1066   However, if two threads in the parent fork at the same time, then
1067   the wait on the parent might return the "wrong" fork event.
1068 
1069   The initial version of PT_FOLLOW_FORK did not set PL_FLAG_CHILD for
1070   the new child process.  This flag could be inferred by treating any
1071   events for an unknown pid as a new child.
1072 
1073   In addition, the initial version of PT_FOLLOW_FORK did not report a
1074   stop event for the parent process of a vfork until after the child
1075   process executed a new program or exited.  The kernel was changed to
1076   defer the wait for exit or exec of the child until after posting the
1077   stop event shortly after the change to introduce PL_FLAG_CHILD.
1078   This could be worked around by reporting a vfork event when the
1079   child event posted and ignoring the subsequent event from the
1080   parent.
1081 
1082   This implementation requires both of these fixes for simplicity's
1083   sake.  FreeBSD versions newer than 9.1 contain both fixes.
1084 */
1085 
1086 static std::list<ptid_t> fbsd_pending_children;
1087 
1088 /* Record a new child process event that is reported before the
1089    corresponding fork event in the parent.  */
1090 
1091 static void
1092 fbsd_remember_child (ptid_t pid)
1093 {
1094   fbsd_pending_children.push_front (pid);
1095 }
1096 
1097 /* Check for a previously-recorded new child process event for PID.
1098    If one is found, remove it from the list and return the PTID.  */
1099 
1100 static ptid_t
1101 fbsd_is_child_pending (pid_t pid)
1102 {
1103   for (auto it = fbsd_pending_children.begin ();
1104        it != fbsd_pending_children.end (); it++)
1105     if (it->pid () == pid)
1106       {
1107 	ptid_t ptid = *it;
1108 	fbsd_pending_children.erase (it);
1109 	return ptid;
1110       }
1111   return null_ptid;
1112 }
1113 
1114 #ifndef PTRACE_VFORK
1115 static std::forward_list<ptid_t> fbsd_pending_vfork_done;
1116 
1117 /* Record a pending vfork done event.  */
1118 
1119 static void
1120 fbsd_add_vfork_done (ptid_t pid)
1121 {
1122   fbsd_pending_vfork_done.push_front (pid);
1123 }
1124 
1125 /* Check for a pending vfork done event for a specific PID.  */
1126 
1127 static int
1128 fbsd_is_vfork_done_pending (pid_t pid)
1129 {
1130   for (auto it = fbsd_pending_vfork_done.begin ();
1131        it != fbsd_pending_vfork_done.end (); it++)
1132     if (it->pid () == pid)
1133       return 1;
1134   return 0;
1135 }
1136 
1137 /* Check for a pending vfork done event.  If one is found, remove it
1138    from the list and return the PTID.  */
1139 
1140 static ptid_t
1141 fbsd_next_vfork_done (void)
1142 {
1143   if (!fbsd_pending_vfork_done.empty ())
1144     {
1145       ptid_t ptid = fbsd_pending_vfork_done.front ();
1146       fbsd_pending_vfork_done.pop_front ();
1147       return ptid;
1148     }
1149   return null_ptid;
1150 }
1151 #endif
1152 #endif
1153 
1154 /* Implement the "resume" target_ops method.  */
1155 
1156 void
1157 fbsd_nat_target::resume (ptid_t ptid, int step, enum gdb_signal signo)
1158 {
1159 #if defined(TDP_RFPPWAIT) && !defined(PTRACE_VFORK)
1160   pid_t pid;
1161 
1162   /* Don't PT_CONTINUE a process which has a pending vfork done event.  */
1163   if (minus_one_ptid == ptid)
1164     pid = inferior_ptid.pid ();
1165   else
1166     pid = ptid.pid ();
1167   if (fbsd_is_vfork_done_pending (pid))
1168     return;
1169 #endif
1170 
1171   if (debug_fbsd_lwp)
1172     fprintf_unfiltered (gdb_stdlog,
1173 			"FLWP: fbsd_resume for ptid (%d, %ld, %ld)\n",
1174 			ptid.pid (), ptid.lwp (),
1175 			ptid.tid ());
1176   if (ptid.lwp_p ())
1177     {
1178       /* If ptid is a specific LWP, suspend all other LWPs in the process.  */
1179       inferior *inf = find_inferior_ptid (ptid);
1180 
1181       for (thread_info *tp : inf->non_exited_threads ())
1182         {
1183 	  int request;
1184 
1185 	  if (tp->ptid.lwp () == ptid.lwp ())
1186 	    request = PT_RESUME;
1187 	  else
1188 	    request = PT_SUSPEND;
1189 
1190 	  if (ptrace (request, tp->ptid.lwp (), NULL, 0) == -1)
1191 	    perror_with_name (("ptrace"));
1192 	}
1193     }
1194   else
1195     {
1196       /* If ptid is a wildcard, resume all matching threads (they won't run
1197 	 until the process is continued however).  */
1198       for (thread_info *tp : all_non_exited_threads (ptid))
1199 	if (ptrace (PT_RESUME, tp->ptid.lwp (), NULL, 0) == -1)
1200 	  perror_with_name (("ptrace"));
1201       ptid = inferior_ptid;
1202     }
1203 
1204 #if __FreeBSD_version < 1200052
1205   /* When multiple threads within a process wish to report STOPPED
1206      events from wait(), the kernel picks one thread event as the
1207      thread event to report.  The chosen thread event is retrieved via
1208      PT_LWPINFO by passing the process ID as the request pid.  If
1209      multiple events are pending, then the subsequent wait() after
1210      resuming a process will report another STOPPED event after
1211      resuming the process to handle the next thread event and so on.
1212 
1213      A single thread event is cleared as a side effect of resuming the
1214      process with PT_CONTINUE, PT_STEP, etc.  In older kernels,
1215      however, the request pid was used to select which thread's event
1216      was cleared rather than always clearing the event that was just
1217      reported.  To avoid clearing the event of the wrong LWP, always
1218      pass the process ID instead of an LWP ID to PT_CONTINUE or
1219      PT_SYSCALL.
1220 
1221      In the case of stepping, the process ID cannot be used with
1222      PT_STEP since it would step the thread that reported an event
1223      which may not be the thread indicated by PTID.  For stepping, use
1224      PT_SETSTEP to enable stepping on the desired thread before
1225      resuming the process via PT_CONTINUE instead of using
1226      PT_STEP.  */
1227   if (step)
1228     {
1229       if (ptrace (PT_SETSTEP, get_ptrace_pid (ptid), NULL, 0) == -1)
1230 	perror_with_name (("ptrace"));
1231       step = 0;
1232     }
1233   ptid = ptid_t (ptid.pid ());
1234 #endif
1235   inf_ptrace_target::resume (ptid, step, signo);
1236 }
1237 
1238 #ifdef USE_SIGTRAP_SIGINFO
1239 /* Handle breakpoint and trace traps reported via SIGTRAP.  If the
1240    trap was a breakpoint or trace trap that should be reported to the
1241    core, return true.  */
1242 
1243 static bool
1244 fbsd_handle_debug_trap (ptid_t ptid, const struct ptrace_lwpinfo &pl)
1245 {
1246 
1247   /* Ignore traps without valid siginfo or for signals other than
1248      SIGTRAP.
1249 
1250      FreeBSD kernels prior to r341800 can return stale siginfo for at
1251      least some events, but those events can be identified by
1252      additional flags set in pl_flags.  True breakpoint and
1253      single-step traps should not have other flags set in
1254      pl_flags.  */
1255   if (pl.pl_flags != PL_FLAG_SI || pl.pl_siginfo.si_signo != SIGTRAP)
1256     return false;
1257 
1258   /* Trace traps are either a single step or a hardware watchpoint or
1259      breakpoint.  */
1260   if (pl.pl_siginfo.si_code == TRAP_TRACE)
1261     {
1262       if (debug_fbsd_nat)
1263 	fprintf_unfiltered (gdb_stdlog,
1264 			    "FNAT: trace trap for LWP %ld\n", ptid.lwp ());
1265       return true;
1266     }
1267 
1268   if (pl.pl_siginfo.si_code == TRAP_BRKPT)
1269     {
1270       /* Fixup PC for the software breakpoint.  */
1271       struct regcache *regcache = get_thread_regcache (ptid);
1272       struct gdbarch *gdbarch = regcache->arch ();
1273       int decr_pc = gdbarch_decr_pc_after_break (gdbarch);
1274 
1275       if (debug_fbsd_nat)
1276 	fprintf_unfiltered (gdb_stdlog,
1277 			    "FNAT: sw breakpoint trap for LWP %ld\n",
1278 			    ptid.lwp ());
1279       if (decr_pc != 0)
1280 	{
1281 	  CORE_ADDR pc;
1282 
1283 	  pc = regcache_read_pc (regcache);
1284 	  regcache_write_pc (regcache, pc - decr_pc);
1285 	}
1286       return true;
1287     }
1288 
1289   return false;
1290 }
1291 #endif
1292 
1293 /* Wait for the child specified by PTID to do something.  Return the
1294    process ID of the child, or MINUS_ONE_PTID in case of error; store
1295    the status in *OURSTATUS.  */
1296 
1297 ptid_t
1298 fbsd_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus,
1299 		       int target_options)
1300 {
1301   ptid_t wptid;
1302 
1303   while (1)
1304     {
1305 #ifndef PTRACE_VFORK
1306       wptid = fbsd_next_vfork_done ();
1307       if (wptid != null_ptid)
1308 	{
1309 	  ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
1310 	  return wptid;
1311 	}
1312 #endif
1313       wptid = inf_ptrace_target::wait (ptid, ourstatus, target_options);
1314       if (ourstatus->kind == TARGET_WAITKIND_STOPPED)
1315 	{
1316 	  struct ptrace_lwpinfo pl;
1317 	  pid_t pid;
1318 	  int status;
1319 
1320 	  pid = wptid.pid ();
1321 	  if (ptrace (PT_LWPINFO, pid, (caddr_t) &pl, sizeof pl) == -1)
1322 	    perror_with_name (("ptrace"));
1323 
1324 	  wptid = ptid_t (pid, pl.pl_lwpid, 0);
1325 
1326 	  if (debug_fbsd_nat)
1327 	    {
1328 	      fprintf_unfiltered (gdb_stdlog,
1329 				  "FNAT: stop for LWP %u event %d flags %#x\n",
1330 				  pl.pl_lwpid, pl.pl_event, pl.pl_flags);
1331 	      if (pl.pl_flags & PL_FLAG_SI)
1332 		fprintf_unfiltered (gdb_stdlog,
1333 				    "FNAT: si_signo %u si_code %u\n",
1334 				    pl.pl_siginfo.si_signo,
1335 				    pl.pl_siginfo.si_code);
1336 	    }
1337 
1338 #ifdef PT_LWP_EVENTS
1339 	  if (pl.pl_flags & PL_FLAG_EXITED)
1340 	    {
1341 	      /* If GDB attaches to a multi-threaded process, exiting
1342 		 threads might be skipped during post_attach that
1343 		 have not yet reported their PL_FLAG_EXITED event.
1344 		 Ignore EXITED events for an unknown LWP.  */
1345 	      thread_info *thr = find_thread_ptid (wptid);
1346 	      if (thr != nullptr)
1347 		{
1348 		  if (debug_fbsd_lwp)
1349 		    fprintf_unfiltered (gdb_stdlog,
1350 					"FLWP: deleting thread for LWP %u\n",
1351 					pl.pl_lwpid);
1352 		  if (print_thread_events)
1353 		    printf_unfiltered (_("[%s exited]\n"), target_pid_to_str
1354 				       (wptid));
1355 		  delete_thread (thr);
1356 		}
1357 	      if (ptrace (PT_CONTINUE, pid, (caddr_t) 1, 0) == -1)
1358 		perror_with_name (("ptrace"));
1359 	      continue;
1360 	    }
1361 #endif
1362 
1363 	  /* Switch to an LWP PTID on the first stop in a new process.
1364 	     This is done after handling PL_FLAG_EXITED to avoid
1365 	     switching to an exited LWP.  It is done before checking
1366 	     PL_FLAG_BORN in case the first stop reported after
1367 	     attaching to an existing process is a PL_FLAG_BORN
1368 	     event.  */
1369 	  if (in_thread_list (ptid_t (pid)))
1370 	    {
1371 	      if (debug_fbsd_lwp)
1372 		fprintf_unfiltered (gdb_stdlog,
1373 				    "FLWP: using LWP %u for first thread\n",
1374 				    pl.pl_lwpid);
1375 	      thread_change_ptid (ptid_t (pid), wptid);
1376 	    }
1377 
1378 #ifdef PT_LWP_EVENTS
1379 	  if (pl.pl_flags & PL_FLAG_BORN)
1380 	    {
1381 	      /* If GDB attaches to a multi-threaded process, newborn
1382 		 threads might be added by fbsd_add_threads that have
1383 		 not yet reported their PL_FLAG_BORN event.  Ignore
1384 		 BORN events for an already-known LWP.  */
1385 	      if (!in_thread_list (wptid))
1386 		{
1387 		  if (debug_fbsd_lwp)
1388 		    fprintf_unfiltered (gdb_stdlog,
1389 					"FLWP: adding thread for LWP %u\n",
1390 					pl.pl_lwpid);
1391 		  add_thread (wptid);
1392 		}
1393 	      ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
1394 	      return wptid;
1395 	    }
1396 #endif
1397 
1398 #ifdef TDP_RFPPWAIT
1399 	  if (pl.pl_flags & PL_FLAG_FORKED)
1400 	    {
1401 #ifndef PTRACE_VFORK
1402 	      struct kinfo_proc kp;
1403 #endif
1404 	      ptid_t child_ptid;
1405 	      pid_t child;
1406 
1407 	      child = pl.pl_child_pid;
1408 	      ourstatus->kind = TARGET_WAITKIND_FORKED;
1409 #ifdef PTRACE_VFORK
1410 	      if (pl.pl_flags & PL_FLAG_VFORKED)
1411 		ourstatus->kind = TARGET_WAITKIND_VFORKED;
1412 #endif
1413 
1414 	      /* Make sure the other end of the fork is stopped too.  */
1415 	      child_ptid = fbsd_is_child_pending (child);
1416 	      if (child_ptid == null_ptid)
1417 		{
1418 		  pid = waitpid (child, &status, 0);
1419 		  if (pid == -1)
1420 		    perror_with_name (("waitpid"));
1421 
1422 		  gdb_assert (pid == child);
1423 
1424 		  if (ptrace (PT_LWPINFO, child, (caddr_t)&pl, sizeof pl) == -1)
1425 		    perror_with_name (("ptrace"));
1426 
1427 		  gdb_assert (pl.pl_flags & PL_FLAG_CHILD);
1428 		  child_ptid = ptid_t (child, pl.pl_lwpid, 0);
1429 		}
1430 
1431 	      /* Enable additional events on the child process.  */
1432 	      fbsd_enable_proc_events (child_ptid.pid ());
1433 
1434 #ifndef PTRACE_VFORK
1435 	      /* For vfork, the child process will have the P_PPWAIT
1436 		 flag set.  */
1437 	      if (fbsd_fetch_kinfo_proc (child, &kp))
1438 		{
1439 		  if (kp.ki_flag & P_PPWAIT)
1440 		    ourstatus->kind = TARGET_WAITKIND_VFORKED;
1441 		}
1442 	      else
1443 		warning (_("Failed to fetch process information"));
1444 #endif
1445 	      ourstatus->value.related_pid = child_ptid;
1446 
1447 	      return wptid;
1448 	    }
1449 
1450 	  if (pl.pl_flags & PL_FLAG_CHILD)
1451 	    {
1452 	      /* Remember that this child forked, but do not report it
1453 		 until the parent reports its corresponding fork
1454 		 event.  */
1455 	      fbsd_remember_child (wptid);
1456 	      continue;
1457 	    }
1458 
1459 #ifdef PTRACE_VFORK
1460 	  if (pl.pl_flags & PL_FLAG_VFORK_DONE)
1461 	    {
1462 	      ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
1463 	      return wptid;
1464 	    }
1465 #endif
1466 #endif
1467 
1468 #ifdef PL_FLAG_EXEC
1469 	  if (pl.pl_flags & PL_FLAG_EXEC)
1470 	    {
1471 	      ourstatus->kind = TARGET_WAITKIND_EXECD;
1472 	      ourstatus->value.execd_pathname
1473 		= xstrdup (pid_to_exec_file (pid));
1474 	      return wptid;
1475 	    }
1476 #endif
1477 
1478 #ifdef USE_SIGTRAP_SIGINFO
1479 	  if (fbsd_handle_debug_trap (wptid, pl))
1480 	    return wptid;
1481 #endif
1482 
1483 	  /* Note that PL_FLAG_SCE is set for any event reported while
1484 	     a thread is executing a system call in the kernel.  In
1485 	     particular, signals that interrupt a sleep in a system
1486 	     call will report this flag as part of their event.  Stops
1487 	     explicitly for system call entry and exit always use
1488 	     SIGTRAP, so only treat SIGTRAP events as system call
1489 	     entry/exit events.  */
1490 	  if (pl.pl_flags & (PL_FLAG_SCE | PL_FLAG_SCX)
1491 	      && ourstatus->value.sig == SIGTRAP)
1492 	    {
1493 #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE
1494 	      if (catch_syscall_enabled ())
1495 		{
1496 		  if (catching_syscall_number (pl.pl_syscall_code))
1497 		    {
1498 		      if (pl.pl_flags & PL_FLAG_SCE)
1499 			ourstatus->kind = TARGET_WAITKIND_SYSCALL_ENTRY;
1500 		      else
1501 			ourstatus->kind = TARGET_WAITKIND_SYSCALL_RETURN;
1502 		      ourstatus->value.syscall_number = pl.pl_syscall_code;
1503 		      return wptid;
1504 		    }
1505 		}
1506 #endif
1507 	      /* If the core isn't interested in this event, just
1508 		 continue the process explicitly and wait for another
1509 		 event.  Note that PT_SYSCALL is "sticky" on FreeBSD
1510 		 and once system call stops are enabled on a process
1511 		 it stops for all system call entries and exits.  */
1512 	      if (ptrace (PT_CONTINUE, pid, (caddr_t) 1, 0) == -1)
1513 		perror_with_name (("ptrace"));
1514 	      continue;
1515 	    }
1516 	}
1517       return wptid;
1518     }
1519 }
1520 
1521 #ifdef USE_SIGTRAP_SIGINFO
1522 /* Implement the "stopped_by_sw_breakpoint" target_ops method.  */
1523 
1524 bool
1525 fbsd_nat_target::stopped_by_sw_breakpoint ()
1526 {
1527   struct ptrace_lwpinfo pl;
1528 
1529   if (ptrace (PT_LWPINFO, get_ptrace_pid (inferior_ptid), (caddr_t) &pl,
1530 	      sizeof pl) == -1)
1531     return false;
1532 
1533   return (pl.pl_flags == PL_FLAG_SI
1534 	  && pl.pl_siginfo.si_signo == SIGTRAP
1535 	  && pl.pl_siginfo.si_code == TRAP_BRKPT);
1536 }
1537 
1538 /* Implement the "supports_stopped_by_sw_breakpoint" target_ops
1539    method.  */
1540 
1541 bool
1542 fbsd_nat_target::supports_stopped_by_sw_breakpoint ()
1543 {
1544   return true;
1545 }
1546 #endif
1547 
1548 #ifdef TDP_RFPPWAIT
1549 /* Target hook for follow_fork.  On entry and at return inferior_ptid is
1550    the ptid of the followed inferior.  */
1551 
1552 int
1553 fbsd_nat_target::follow_fork (int follow_child, int detach_fork)
1554 {
1555   if (!follow_child && detach_fork)
1556     {
1557       struct thread_info *tp = inferior_thread ();
1558       pid_t child_pid = tp->pending_follow.value.related_pid.pid ();
1559 
1560       /* Breakpoints have already been detached from the child by
1561 	 infrun.c.  */
1562 
1563       if (ptrace (PT_DETACH, child_pid, (PTRACE_TYPE_ARG3)1, 0) == -1)
1564 	perror_with_name (("ptrace"));
1565 
1566 #ifndef PTRACE_VFORK
1567       if (tp->pending_follow.kind == TARGET_WAITKIND_VFORKED)
1568 	{
1569 	  /* We can't insert breakpoints until the child process has
1570 	     finished with the shared memory region.  The parent
1571 	     process doesn't wait for the child process to exit or
1572 	     exec until after it has been resumed from the ptrace stop
1573 	     to report the fork.  Once it has been resumed it doesn't
1574 	     stop again before returning to userland, so there is no
1575 	     reliable way to wait on the parent.
1576 
1577 	     We can't stay attached to the child to wait for an exec
1578 	     or exit because it may invoke ptrace(PT_TRACE_ME)
1579 	     (e.g. if the parent process is a debugger forking a new
1580 	     child process).
1581 
1582 	     In the end, the best we can do is to make sure it runs
1583 	     for a little while.  Hopefully it will be out of range of
1584 	     any breakpoints we reinsert.  Usually this is only the
1585 	     single-step breakpoint at vfork's return point.  */
1586 
1587 	  usleep (10000);
1588 
1589 	  /* Schedule a fake VFORK_DONE event to report on the next
1590 	     wait.  */
1591 	  fbsd_add_vfork_done (inferior_ptid);
1592 	}
1593 #endif
1594     }
1595 
1596   return 0;
1597 }
1598 
1599 int
1600 fbsd_nat_target::insert_fork_catchpoint (int pid)
1601 {
1602   return 0;
1603 }
1604 
1605 int
1606 fbsd_nat_target::remove_fork_catchpoint (int pid)
1607 {
1608   return 0;
1609 }
1610 
1611 int
1612 fbsd_nat_target::insert_vfork_catchpoint (int pid)
1613 {
1614   return 0;
1615 }
1616 
1617 int
1618 fbsd_nat_target::remove_vfork_catchpoint (int pid)
1619 {
1620   return 0;
1621 }
1622 #endif
1623 
1624 /* Implement the "post_startup_inferior" target_ops method.  */
1625 
1626 void
1627 fbsd_nat_target::post_startup_inferior (ptid_t pid)
1628 {
1629   fbsd_enable_proc_events (pid.pid ());
1630 }
1631 
1632 /* Implement the "post_attach" target_ops method.  */
1633 
1634 void
1635 fbsd_nat_target::post_attach (int pid)
1636 {
1637   fbsd_enable_proc_events (pid);
1638   fbsd_add_threads (pid);
1639 }
1640 
1641 #ifdef PL_FLAG_EXEC
1642 /* If the FreeBSD kernel supports PL_FLAG_EXEC, then traced processes
1643    will always stop after exec.  */
1644 
1645 int
1646 fbsd_nat_target::insert_exec_catchpoint (int pid)
1647 {
1648   return 0;
1649 }
1650 
1651 int
1652 fbsd_nat_target::remove_exec_catchpoint (int pid)
1653 {
1654   return 0;
1655 }
1656 #endif
1657 
1658 #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE
1659 int
1660 fbsd_nat_target::set_syscall_catchpoint (int pid, bool needed,
1661 					 int any_count,
1662 					 gdb::array_view<const int> syscall_counts)
1663 {
1664 
1665   /* Ignore the arguments.  inf-ptrace.c will use PT_SYSCALL which
1666      will catch all system call entries and exits.  The system calls
1667      are filtered by GDB rather than the kernel.  */
1668   return 0;
1669 }
1670 #endif
1671 #endif
1672 
1673 void
1674 _initialize_fbsd_nat (void)
1675 {
1676 #ifdef PT_LWPINFO
1677   add_setshow_boolean_cmd ("fbsd-lwp", class_maintenance,
1678 			   &debug_fbsd_lwp, _("\
1679 Set debugging of FreeBSD lwp module."), _("\
1680 Show debugging of FreeBSD lwp module."), _("\
1681 Enables printf debugging output."),
1682 			   NULL,
1683 			   &show_fbsd_lwp_debug,
1684 			   &setdebuglist, &showdebuglist);
1685   add_setshow_boolean_cmd ("fbsd-nat", class_maintenance,
1686 			   &debug_fbsd_nat, _("\
1687 Set debugging of FreeBSD native target."), _("\
1688 Show debugging of FreeBSD native target."), _("\
1689 Enables printf debugging output."),
1690 			   NULL,
1691 			   &show_fbsd_nat_debug,
1692 			   &setdebuglist, &showdebuglist);
1693 #endif
1694 }
1695