| 1 | /* Native-dependent code for FreeBSD. |
| 2 | |
| 3 | Copyright (C) 2002-2016 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 "gdbcore.h" |
| 22 | #include "inferior.h" |
| 23 | #include "regcache.h" |
| 24 | #include "regset.h" |
| 25 | #include "gdbcmd.h" |
| 26 | #include "gdbthread.h" |
| 27 | #include "gdb_wait.h" |
| 28 | #include <sys/types.h> |
| 29 | #include <sys/procfs.h> |
| 30 | #include <sys/ptrace.h> |
| 31 | #include <sys/sysctl.h> |
| 32 | #ifdef HAVE_KINFO_GETVMMAP |
| 33 | #include <sys/user.h> |
| 34 | #include <libutil.h> |
| 35 | #endif |
| 36 | |
| 37 | #include "elf-bfd.h" |
| 38 | #include "fbsd-nat.h" |
| 39 | |
| 40 | /* Return the name of a file that can be opened to get the symbols for |
| 41 | the child process identified by PID. */ |
| 42 | |
| 43 | static char * |
| 44 | fbsd_pid_to_exec_file (struct target_ops *self, int pid) |
| 45 | { |
| 46 | ssize_t len; |
| 47 | static char buf[PATH_MAX]; |
| 48 | char name[PATH_MAX]; |
| 49 | |
| 50 | #ifdef KERN_PROC_PATHNAME |
| 51 | size_t buflen; |
| 52 | int mib[4]; |
| 53 | |
| 54 | mib[0] = CTL_KERN; |
| 55 | mib[1] = KERN_PROC; |
| 56 | mib[2] = KERN_PROC_PATHNAME; |
| 57 | mib[3] = pid; |
| 58 | buflen = sizeof buf; |
| 59 | if (sysctl (mib, 4, buf, &buflen, NULL, 0) == 0) |
| 60 | return buf; |
| 61 | #endif |
| 62 | |
| 63 | xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid); |
| 64 | len = readlink (name, buf, PATH_MAX - 1); |
| 65 | if (len != -1) |
| 66 | { |
| 67 | buf[len] = '\0'; |
| 68 | return buf; |
| 69 | } |
| 70 | |
| 71 | return NULL; |
| 72 | } |
| 73 | |
| 74 | #ifdef HAVE_KINFO_GETVMMAP |
| 75 | /* Iterate over all the memory regions in the current inferior, |
| 76 | calling FUNC for each memory region. OBFD is passed as the last |
| 77 | argument to FUNC. */ |
| 78 | |
| 79 | static int |
| 80 | fbsd_find_memory_regions (struct target_ops *self, |
| 81 | find_memory_region_ftype func, void *obfd) |
| 82 | { |
| 83 | pid_t pid = ptid_get_pid (inferior_ptid); |
| 84 | struct kinfo_vmentry *vmentl, *kve; |
| 85 | uint64_t size; |
| 86 | struct cleanup *cleanup; |
| 87 | int i, nitems; |
| 88 | |
| 89 | vmentl = kinfo_getvmmap (pid, &nitems); |
| 90 | if (vmentl == NULL) |
| 91 | perror_with_name (_("Couldn't fetch VM map entries.")); |
| 92 | cleanup = make_cleanup (free, vmentl); |
| 93 | |
| 94 | for (i = 0; i < nitems; i++) |
| 95 | { |
| 96 | kve = &vmentl[i]; |
| 97 | |
| 98 | /* Skip unreadable segments and those where MAP_NOCORE has been set. */ |
| 99 | if (!(kve->kve_protection & KVME_PROT_READ) |
| 100 | || kve->kve_flags & KVME_FLAG_NOCOREDUMP) |
| 101 | continue; |
| 102 | |
| 103 | /* Skip segments with an invalid type. */ |
| 104 | if (kve->kve_type != KVME_TYPE_DEFAULT |
| 105 | && kve->kve_type != KVME_TYPE_VNODE |
| 106 | && kve->kve_type != KVME_TYPE_SWAP |
| 107 | && kve->kve_type != KVME_TYPE_PHYS) |
| 108 | continue; |
| 109 | |
| 110 | size = kve->kve_end - kve->kve_start; |
| 111 | if (info_verbose) |
| 112 | { |
| 113 | fprintf_filtered (gdb_stdout, |
| 114 | "Save segment, %ld bytes at %s (%c%c%c)\n", |
| 115 | (long) size, |
| 116 | paddress (target_gdbarch (), kve->kve_start), |
| 117 | kve->kve_protection & KVME_PROT_READ ? 'r' : '-', |
| 118 | kve->kve_protection & KVME_PROT_WRITE ? 'w' : '-', |
| 119 | kve->kve_protection & KVME_PROT_EXEC ? 'x' : '-'); |
| 120 | } |
| 121 | |
| 122 | /* Invoke the callback function to create the corefile segment. |
| 123 | Pass MODIFIED as true, we do not know the real modification state. */ |
| 124 | func (kve->kve_start, size, kve->kve_protection & KVME_PROT_READ, |
| 125 | kve->kve_protection & KVME_PROT_WRITE, |
| 126 | kve->kve_protection & KVME_PROT_EXEC, 1, obfd); |
| 127 | } |
| 128 | do_cleanups (cleanup); |
| 129 | return 0; |
| 130 | } |
| 131 | #else |
| 132 | static int |
| 133 | fbsd_read_mapping (FILE *mapfile, unsigned long *start, unsigned long *end, |
| 134 | char *protection) |
| 135 | { |
| 136 | /* FreeBSD 5.1-RELEASE uses a 256-byte buffer. */ |
| 137 | char buf[256]; |
| 138 | int resident, privateresident; |
| 139 | unsigned long obj; |
| 140 | int ret = EOF; |
| 141 | |
| 142 | /* As of FreeBSD 5.0-RELEASE, the layout is described in |
| 143 | /usr/src/sys/fs/procfs/procfs_map.c. Somewhere in 5.1-CURRENT a |
| 144 | new column was added to the procfs map. Therefore we can't use |
| 145 | fscanf since we need to support older releases too. */ |
| 146 | if (fgets (buf, sizeof buf, mapfile) != NULL) |
| 147 | ret = sscanf (buf, "%lx %lx %d %d %lx %s", start, end, |
| 148 | &resident, &privateresident, &obj, protection); |
| 149 | |
| 150 | return (ret != 0 && ret != EOF); |
| 151 | } |
| 152 | |
| 153 | /* Iterate over all the memory regions in the current inferior, |
| 154 | calling FUNC for each memory region. OBFD is passed as the last |
| 155 | argument to FUNC. */ |
| 156 | |
| 157 | static int |
| 158 | fbsd_find_memory_regions (struct target_ops *self, |
| 159 | find_memory_region_ftype func, void *obfd) |
| 160 | { |
| 161 | pid_t pid = ptid_get_pid (inferior_ptid); |
| 162 | char *mapfilename; |
| 163 | FILE *mapfile; |
| 164 | unsigned long start, end, size; |
| 165 | char protection[4]; |
| 166 | int read, write, exec; |
| 167 | struct cleanup *cleanup; |
| 168 | |
| 169 | mapfilename = xstrprintf ("/proc/%ld/map", (long) pid); |
| 170 | cleanup = make_cleanup (xfree, mapfilename); |
| 171 | mapfile = fopen (mapfilename, "r"); |
| 172 | if (mapfile == NULL) |
| 173 | error (_("Couldn't open %s."), mapfilename); |
| 174 | make_cleanup_fclose (mapfile); |
| 175 | |
| 176 | if (info_verbose) |
| 177 | fprintf_filtered (gdb_stdout, |
| 178 | "Reading memory regions from %s\n", mapfilename); |
| 179 | |
| 180 | /* Now iterate until end-of-file. */ |
| 181 | while (fbsd_read_mapping (mapfile, &start, &end, &protection[0])) |
| 182 | { |
| 183 | size = end - start; |
| 184 | |
| 185 | read = (strchr (protection, 'r') != 0); |
| 186 | write = (strchr (protection, 'w') != 0); |
| 187 | exec = (strchr (protection, 'x') != 0); |
| 188 | |
| 189 | if (info_verbose) |
| 190 | { |
| 191 | fprintf_filtered (gdb_stdout, |
| 192 | "Save segment, %ld bytes at %s (%c%c%c)\n", |
| 193 | size, paddress (target_gdbarch (), start), |
| 194 | read ? 'r' : '-', |
| 195 | write ? 'w' : '-', |
| 196 | exec ? 'x' : '-'); |
| 197 | } |
| 198 | |
| 199 | /* Invoke the callback function to create the corefile segment. |
| 200 | Pass MODIFIED as true, we do not know the real modification state. */ |
| 201 | func (start, size, read, write, exec, 1, obfd); |
| 202 | } |
| 203 | |
| 204 | do_cleanups (cleanup); |
| 205 | return 0; |
| 206 | } |
| 207 | #endif |
| 208 | |
| 209 | #ifdef KERN_PROC_AUXV |
| 210 | static enum target_xfer_status (*super_xfer_partial) (struct target_ops *ops, |
| 211 | enum target_object object, |
| 212 | const char *annex, |
| 213 | gdb_byte *readbuf, |
| 214 | const gdb_byte *writebuf, |
| 215 | ULONGEST offset, |
| 216 | ULONGEST len, |
| 217 | ULONGEST *xfered_len); |
| 218 | |
| 219 | /* Implement the "to_xfer_partial target_ops" method. */ |
| 220 | |
| 221 | static enum target_xfer_status |
| 222 | fbsd_xfer_partial (struct target_ops *ops, enum target_object object, |
| 223 | const char *annex, gdb_byte *readbuf, |
| 224 | const gdb_byte *writebuf, |
| 225 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
| 226 | { |
| 227 | pid_t pid = ptid_get_pid (inferior_ptid); |
| 228 | |
| 229 | switch (object) |
| 230 | { |
| 231 | case TARGET_OBJECT_AUXV: |
| 232 | { |
| 233 | struct cleanup *cleanup = make_cleanup (null_cleanup, NULL); |
| 234 | unsigned char *buf; |
| 235 | size_t buflen; |
| 236 | int mib[4]; |
| 237 | |
| 238 | if (writebuf != NULL) |
| 239 | return TARGET_XFER_E_IO; |
| 240 | mib[0] = CTL_KERN; |
| 241 | mib[1] = KERN_PROC; |
| 242 | mib[2] = KERN_PROC_AUXV; |
| 243 | mib[3] = pid; |
| 244 | if (offset == 0) |
| 245 | { |
| 246 | buf = readbuf; |
| 247 | buflen = len; |
| 248 | } |
| 249 | else |
| 250 | { |
| 251 | buflen = offset + len; |
| 252 | buf = XCNEWVEC (unsigned char, buflen); |
| 253 | cleanup = make_cleanup (xfree, buf); |
| 254 | } |
| 255 | if (sysctl (mib, 4, buf, &buflen, NULL, 0) == 0) |
| 256 | { |
| 257 | if (offset != 0) |
| 258 | { |
| 259 | if (buflen > offset) |
| 260 | { |
| 261 | buflen -= offset; |
| 262 | memcpy (readbuf, buf + offset, buflen); |
| 263 | } |
| 264 | else |
| 265 | buflen = 0; |
| 266 | } |
| 267 | do_cleanups (cleanup); |
| 268 | *xfered_len = buflen; |
| 269 | return (buflen == 0) ? TARGET_XFER_EOF : TARGET_XFER_OK; |
| 270 | } |
| 271 | do_cleanups (cleanup); |
| 272 | return TARGET_XFER_E_IO; |
| 273 | } |
| 274 | default: |
| 275 | return super_xfer_partial (ops, object, annex, readbuf, writebuf, offset, |
| 276 | len, xfered_len); |
| 277 | } |
| 278 | } |
| 279 | #endif |
| 280 | |
| 281 | #ifdef PT_LWPINFO |
| 282 | static int debug_fbsd_lwp; |
| 283 | |
| 284 | static ptid_t (*super_wait) (struct target_ops *, |
| 285 | ptid_t, |
| 286 | struct target_waitstatus *, |
| 287 | int); |
| 288 | |
| 289 | static void |
| 290 | show_fbsd_lwp_debug (struct ui_file *file, int from_tty, |
| 291 | struct cmd_list_element *c, const char *value) |
| 292 | { |
| 293 | fprintf_filtered (file, _("Debugging of FreeBSD lwp module is %s.\n"), value); |
| 294 | } |
| 295 | |
| 296 | #if defined(TDP_RFPPWAIT) || defined(HAVE_STRUCT_PTRACE_LWPINFO_PL_TDNAME) |
| 297 | /* Fetch the external variant of the kernel's internal process |
| 298 | structure for the process PID into KP. */ |
| 299 | |
| 300 | static void |
| 301 | fbsd_fetch_kinfo_proc (pid_t pid, struct kinfo_proc *kp) |
| 302 | { |
| 303 | size_t len; |
| 304 | int mib[4]; |
| 305 | |
| 306 | len = sizeof *kp; |
| 307 | mib[0] = CTL_KERN; |
| 308 | mib[1] = KERN_PROC; |
| 309 | mib[2] = KERN_PROC_PID; |
| 310 | mib[3] = pid; |
| 311 | if (sysctl (mib, 4, kp, &len, NULL, 0) == -1) |
| 312 | perror_with_name (("sysctl")); |
| 313 | } |
| 314 | #endif |
| 315 | |
| 316 | /* |
| 317 | FreeBSD's first thread support was via a "reentrant" version of libc |
| 318 | (libc_r) that first shipped in 2.2.7. This library multiplexed all |
| 319 | of the threads in a process onto a single kernel thread. This |
| 320 | library is supported via the bsd-uthread target. |
| 321 | |
| 322 | FreeBSD 5.1 introduced two new threading libraries that made use of |
| 323 | multiple kernel threads. The first (libkse) scheduled M user |
| 324 | threads onto N (<= M) kernel threads (LWPs). The second (libthr) |
| 325 | bound each user thread to a dedicated kernel thread. libkse shipped |
| 326 | as the default threading library (libpthread). |
| 327 | |
| 328 | FreeBSD 5.3 added a libthread_db to abstract the interface across |
| 329 | the various thread libraries (libc_r, libkse, and libthr). |
| 330 | |
| 331 | FreeBSD 7.0 switched the default threading library from from libkse |
| 332 | to libpthread and removed libc_r. |
| 333 | |
| 334 | FreeBSD 8.0 removed libkse and the in-kernel support for it. The |
| 335 | only threading library supported by 8.0 and later is libthr which |
| 336 | ties each user thread directly to an LWP. To simplify the |
| 337 | implementation, this target only supports LWP-backed threads using |
| 338 | ptrace directly rather than libthread_db. |
| 339 | |
| 340 | FreeBSD 11.0 introduced LWP event reporting via PT_LWP_EVENTS. |
| 341 | */ |
| 342 | |
| 343 | /* Return true if PTID is still active in the inferior. */ |
| 344 | |
| 345 | static int |
| 346 | fbsd_thread_alive (struct target_ops *ops, ptid_t ptid) |
| 347 | { |
| 348 | if (ptid_lwp_p (ptid)) |
| 349 | { |
| 350 | struct ptrace_lwpinfo pl; |
| 351 | |
| 352 | if (ptrace (PT_LWPINFO, ptid_get_lwp (ptid), (caddr_t) &pl, sizeof pl) |
| 353 | == -1) |
| 354 | return 0; |
| 355 | #ifdef PL_FLAG_EXITED |
| 356 | if (pl.pl_flags & PL_FLAG_EXITED) |
| 357 | return 0; |
| 358 | #endif |
| 359 | } |
| 360 | |
| 361 | return 1; |
| 362 | } |
| 363 | |
| 364 | /* Convert PTID to a string. Returns the string in a static |
| 365 | buffer. */ |
| 366 | |
| 367 | static char * |
| 368 | fbsd_pid_to_str (struct target_ops *ops, ptid_t ptid) |
| 369 | { |
| 370 | lwpid_t lwp; |
| 371 | |
| 372 | lwp = ptid_get_lwp (ptid); |
| 373 | if (lwp != 0) |
| 374 | { |
| 375 | static char buf[64]; |
| 376 | int pid = ptid_get_pid (ptid); |
| 377 | |
| 378 | xsnprintf (buf, sizeof buf, "LWP %d of process %d", lwp, pid); |
| 379 | return buf; |
| 380 | } |
| 381 | |
| 382 | return normal_pid_to_str (ptid); |
| 383 | } |
| 384 | |
| 385 | #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_TDNAME |
| 386 | /* Return the name assigned to a thread by an application. Returns |
| 387 | the string in a static buffer. */ |
| 388 | |
| 389 | static const char * |
| 390 | fbsd_thread_name (struct target_ops *self, struct thread_info *thr) |
| 391 | { |
| 392 | struct ptrace_lwpinfo pl; |
| 393 | struct kinfo_proc kp; |
| 394 | int pid = ptid_get_pid (thr->ptid); |
| 395 | long lwp = ptid_get_lwp (thr->ptid); |
| 396 | static char buf[sizeof pl.pl_tdname + 1]; |
| 397 | |
| 398 | /* Note that ptrace_lwpinfo returns the process command in pl_tdname |
| 399 | if a name has not been set explicitly. Return a NULL name in |
| 400 | that case. */ |
| 401 | fbsd_fetch_kinfo_proc (pid, &kp); |
| 402 | if (ptrace (PT_LWPINFO, lwp, (caddr_t) &pl, sizeof pl) == -1) |
| 403 | perror_with_name (("ptrace")); |
| 404 | if (strcmp (kp.ki_comm, pl.pl_tdname) == 0) |
| 405 | return NULL; |
| 406 | xsnprintf (buf, sizeof buf, "%s", pl.pl_tdname); |
| 407 | return buf; |
| 408 | } |
| 409 | #endif |
| 410 | |
| 411 | #ifdef PT_LWP_EVENTS |
| 412 | /* Enable LWP events for a specific process. |
| 413 | |
| 414 | To catch LWP events, PT_LWP_EVENTS is set on every traced process. |
| 415 | This enables stops on the birth for new LWPs (excluding the "main" LWP) |
| 416 | and the death of LWPs (excluding the last LWP in a process). Note |
| 417 | that unlike fork events, the LWP that creates a new LWP does not |
| 418 | report an event. */ |
| 419 | |
| 420 | static void |
| 421 | fbsd_enable_lwp_events (pid_t pid) |
| 422 | { |
| 423 | if (ptrace (PT_LWP_EVENTS, pid, (PTRACE_TYPE_ARG3)0, 1) == -1) |
| 424 | perror_with_name (("ptrace")); |
| 425 | } |
| 426 | #endif |
| 427 | |
| 428 | /* Add threads for any new LWPs in a process. |
| 429 | |
| 430 | When LWP events are used, this function is only used to detect existing |
| 431 | threads when attaching to a process. On older systems, this function is |
| 432 | called to discover new threads each time the thread list is updated. */ |
| 433 | |
| 434 | static void |
| 435 | fbsd_add_threads (pid_t pid) |
| 436 | { |
| 437 | struct cleanup *cleanup; |
| 438 | lwpid_t *lwps; |
| 439 | int i, nlwps; |
| 440 | |
| 441 | gdb_assert (!in_thread_list (pid_to_ptid (pid))); |
| 442 | nlwps = ptrace (PT_GETNUMLWPS, pid, NULL, 0); |
| 443 | if (nlwps == -1) |
| 444 | perror_with_name (("ptrace")); |
| 445 | |
| 446 | lwps = XCNEWVEC (lwpid_t, nlwps); |
| 447 | cleanup = make_cleanup (xfree, lwps); |
| 448 | |
| 449 | nlwps = ptrace (PT_GETLWPLIST, pid, (caddr_t) lwps, nlwps); |
| 450 | if (nlwps == -1) |
| 451 | perror_with_name (("ptrace")); |
| 452 | |
| 453 | for (i = 0; i < nlwps; i++) |
| 454 | { |
| 455 | ptid_t ptid = ptid_build (pid, lwps[i], 0); |
| 456 | |
| 457 | if (!in_thread_list (ptid)) |
| 458 | { |
| 459 | #ifdef PT_LWP_EVENTS |
| 460 | struct ptrace_lwpinfo pl; |
| 461 | |
| 462 | /* Don't add exited threads. Note that this is only called |
| 463 | when attaching to a multi-threaded process. */ |
| 464 | if (ptrace (PT_LWPINFO, lwps[i], (caddr_t) &pl, sizeof pl) == -1) |
| 465 | perror_with_name (("ptrace")); |
| 466 | if (pl.pl_flags & PL_FLAG_EXITED) |
| 467 | continue; |
| 468 | #endif |
| 469 | if (debug_fbsd_lwp) |
| 470 | fprintf_unfiltered (gdb_stdlog, |
| 471 | "FLWP: adding thread for LWP %u\n", |
| 472 | lwps[i]); |
| 473 | add_thread (ptid); |
| 474 | } |
| 475 | } |
| 476 | do_cleanups (cleanup); |
| 477 | } |
| 478 | |
| 479 | /* Implement the "to_update_thread_list" target_ops method. */ |
| 480 | |
| 481 | static void |
| 482 | fbsd_update_thread_list (struct target_ops *ops) |
| 483 | { |
| 484 | #ifdef PT_LWP_EVENTS |
| 485 | /* With support for thread events, threads are added/deleted from the |
| 486 | list as events are reported, so just try deleting exited threads. */ |
| 487 | delete_exited_threads (); |
| 488 | #else |
| 489 | prune_threads (); |
| 490 | |
| 491 | fbsd_add_threads (ptid_get_pid (inferior_ptid)); |
| 492 | #endif |
| 493 | } |
| 494 | |
| 495 | static void (*super_resume) (struct target_ops *, |
| 496 | ptid_t, |
| 497 | int, |
| 498 | enum gdb_signal); |
| 499 | |
| 500 | static int |
| 501 | resume_one_thread_cb (struct thread_info *tp, void *data) |
| 502 | { |
| 503 | ptid_t *ptid = (ptid_t *) data; |
| 504 | int request; |
| 505 | |
| 506 | if (ptid_get_pid (tp->ptid) != ptid_get_pid (*ptid)) |
| 507 | return 0; |
| 508 | |
| 509 | if (ptid_get_lwp (tp->ptid) == ptid_get_lwp (*ptid)) |
| 510 | request = PT_RESUME; |
| 511 | else |
| 512 | request = PT_SUSPEND; |
| 513 | |
| 514 | if (ptrace (request, ptid_get_lwp (tp->ptid), NULL, 0) == -1) |
| 515 | perror_with_name (("ptrace")); |
| 516 | return 0; |
| 517 | } |
| 518 | |
| 519 | static int |
| 520 | resume_all_threads_cb (struct thread_info *tp, void *data) |
| 521 | { |
| 522 | ptid_t *filter = (ptid_t *) data; |
| 523 | |
| 524 | if (!ptid_match (tp->ptid, *filter)) |
| 525 | return 0; |
| 526 | |
| 527 | if (ptrace (PT_RESUME, ptid_get_lwp (tp->ptid), NULL, 0) == -1) |
| 528 | perror_with_name (("ptrace")); |
| 529 | return 0; |
| 530 | } |
| 531 | |
| 532 | /* Implement the "to_resume" target_ops method. */ |
| 533 | |
| 534 | static void |
| 535 | fbsd_resume (struct target_ops *ops, |
| 536 | ptid_t ptid, int step, enum gdb_signal signo) |
| 537 | { |
| 538 | |
| 539 | if (debug_fbsd_lwp) |
| 540 | fprintf_unfiltered (gdb_stdlog, |
| 541 | "FLWP: fbsd_resume for ptid (%d, %ld, %ld)\n", |
| 542 | ptid_get_pid (ptid), ptid_get_lwp (ptid), |
| 543 | ptid_get_tid (ptid)); |
| 544 | if (ptid_lwp_p (ptid)) |
| 545 | { |
| 546 | /* If ptid is a specific LWP, suspend all other LWPs in the process. */ |
| 547 | iterate_over_threads (resume_one_thread_cb, &ptid); |
| 548 | } |
| 549 | else |
| 550 | { |
| 551 | /* If ptid is a wildcard, resume all matching threads (they won't run |
| 552 | until the process is continued however). */ |
| 553 | iterate_over_threads (resume_all_threads_cb, &ptid); |
| 554 | ptid = inferior_ptid; |
| 555 | } |
| 556 | super_resume (ops, ptid, step, signo); |
| 557 | } |
| 558 | |
| 559 | #ifdef TDP_RFPPWAIT |
| 560 | /* |
| 561 | To catch fork events, PT_FOLLOW_FORK is set on every traced process |
| 562 | to enable stops on returns from fork or vfork. Note that both the |
| 563 | parent and child will always stop, even if system call stops are not |
| 564 | enabled. |
| 565 | |
| 566 | After a fork, both the child and parent process will stop and report |
| 567 | an event. However, there is no guarantee of order. If the parent |
| 568 | reports its stop first, then fbsd_wait explicitly waits for the new |
| 569 | child before returning. If the child reports its stop first, then |
| 570 | the event is saved on a list and ignored until the parent's stop is |
| 571 | reported. fbsd_wait could have been changed to fetch the parent PID |
| 572 | of the new child and used that to wait for the parent explicitly. |
| 573 | However, if two threads in the parent fork at the same time, then |
| 574 | the wait on the parent might return the "wrong" fork event. |
| 575 | |
| 576 | The initial version of PT_FOLLOW_FORK did not set PL_FLAG_CHILD for |
| 577 | the new child process. This flag could be inferred by treating any |
| 578 | events for an unknown pid as a new child. |
| 579 | |
| 580 | In addition, the initial version of PT_FOLLOW_FORK did not report a |
| 581 | stop event for the parent process of a vfork until after the child |
| 582 | process executed a new program or exited. The kernel was changed to |
| 583 | defer the wait for exit or exec of the child until after posting the |
| 584 | stop event shortly after the change to introduce PL_FLAG_CHILD. |
| 585 | This could be worked around by reporting a vfork event when the |
| 586 | child event posted and ignoring the subsequent event from the |
| 587 | parent. |
| 588 | |
| 589 | This implementation requires both of these fixes for simplicity's |
| 590 | sake. FreeBSD versions newer than 9.1 contain both fixes. |
| 591 | */ |
| 592 | |
| 593 | struct fbsd_fork_child_info |
| 594 | { |
| 595 | struct fbsd_fork_child_info *next; |
| 596 | ptid_t child; /* Pid of new child. */ |
| 597 | }; |
| 598 | |
| 599 | static struct fbsd_fork_child_info *fbsd_pending_children; |
| 600 | |
| 601 | /* Record a new child process event that is reported before the |
| 602 | corresponding fork event in the parent. */ |
| 603 | |
| 604 | static void |
| 605 | fbsd_remember_child (ptid_t pid) |
| 606 | { |
| 607 | struct fbsd_fork_child_info *info = XCNEW (struct fbsd_fork_child_info); |
| 608 | |
| 609 | info->child = pid; |
| 610 | info->next = fbsd_pending_children; |
| 611 | fbsd_pending_children = info; |
| 612 | } |
| 613 | |
| 614 | /* Check for a previously-recorded new child process event for PID. |
| 615 | If one is found, remove it from the list and return the PTID. */ |
| 616 | |
| 617 | static ptid_t |
| 618 | fbsd_is_child_pending (pid_t pid) |
| 619 | { |
| 620 | struct fbsd_fork_child_info *info, *prev; |
| 621 | ptid_t ptid; |
| 622 | |
| 623 | prev = NULL; |
| 624 | for (info = fbsd_pending_children; info; prev = info, info = info->next) |
| 625 | { |
| 626 | if (ptid_get_pid (info->child) == pid) |
| 627 | { |
| 628 | if (prev == NULL) |
| 629 | fbsd_pending_children = info->next; |
| 630 | else |
| 631 | prev->next = info->next; |
| 632 | ptid = info->child; |
| 633 | xfree (info); |
| 634 | return ptid; |
| 635 | } |
| 636 | } |
| 637 | return null_ptid; |
| 638 | } |
| 639 | #endif |
| 640 | |
| 641 | /* Wait for the child specified by PTID to do something. Return the |
| 642 | process ID of the child, or MINUS_ONE_PTID in case of error; store |
| 643 | the status in *OURSTATUS. */ |
| 644 | |
| 645 | static ptid_t |
| 646 | fbsd_wait (struct target_ops *ops, |
| 647 | ptid_t ptid, struct target_waitstatus *ourstatus, |
| 648 | int target_options) |
| 649 | { |
| 650 | ptid_t wptid; |
| 651 | |
| 652 | while (1) |
| 653 | { |
| 654 | wptid = super_wait (ops, ptid, ourstatus, target_options); |
| 655 | if (ourstatus->kind == TARGET_WAITKIND_STOPPED) |
| 656 | { |
| 657 | struct ptrace_lwpinfo pl; |
| 658 | pid_t pid; |
| 659 | int status; |
| 660 | |
| 661 | pid = ptid_get_pid (wptid); |
| 662 | if (ptrace (PT_LWPINFO, pid, (caddr_t) &pl, sizeof pl) == -1) |
| 663 | perror_with_name (("ptrace")); |
| 664 | |
| 665 | wptid = ptid_build (pid, pl.pl_lwpid, 0); |
| 666 | |
| 667 | #ifdef PT_LWP_EVENTS |
| 668 | if (pl.pl_flags & PL_FLAG_EXITED) |
| 669 | { |
| 670 | /* If GDB attaches to a multi-threaded process, exiting |
| 671 | threads might be skipped during fbsd_post_attach that |
| 672 | have not yet reported their PL_FLAG_EXITED event. |
| 673 | Ignore EXITED events for an unknown LWP. */ |
| 674 | if (in_thread_list (wptid)) |
| 675 | { |
| 676 | if (debug_fbsd_lwp) |
| 677 | fprintf_unfiltered (gdb_stdlog, |
| 678 | "FLWP: deleting thread for LWP %u\n", |
| 679 | pl.pl_lwpid); |
| 680 | if (print_thread_events) |
| 681 | printf_unfiltered (_("[%s exited]\n"), target_pid_to_str |
| 682 | (wptid)); |
| 683 | delete_thread (wptid); |
| 684 | } |
| 685 | if (ptrace (PT_CONTINUE, pid, (caddr_t) 1, 0) == -1) |
| 686 | perror_with_name (("ptrace")); |
| 687 | continue; |
| 688 | } |
| 689 | #endif |
| 690 | |
| 691 | /* Switch to an LWP PTID on the first stop in a new process. |
| 692 | This is done after handling PL_FLAG_EXITED to avoid |
| 693 | switching to an exited LWP. It is done before checking |
| 694 | PL_FLAG_BORN in case the first stop reported after |
| 695 | attaching to an existing process is a PL_FLAG_BORN |
| 696 | event. */ |
| 697 | if (in_thread_list (pid_to_ptid (pid))) |
| 698 | { |
| 699 | if (debug_fbsd_lwp) |
| 700 | fprintf_unfiltered (gdb_stdlog, |
| 701 | "FLWP: using LWP %u for first thread\n", |
| 702 | pl.pl_lwpid); |
| 703 | thread_change_ptid (pid_to_ptid (pid), wptid); |
| 704 | } |
| 705 | |
| 706 | #ifdef PT_LWP_EVENTS |
| 707 | if (pl.pl_flags & PL_FLAG_BORN) |
| 708 | { |
| 709 | /* If GDB attaches to a multi-threaded process, newborn |
| 710 | threads might be added by fbsd_add_threads that have |
| 711 | not yet reported their PL_FLAG_BORN event. Ignore |
| 712 | BORN events for an already-known LWP. */ |
| 713 | if (!in_thread_list (wptid)) |
| 714 | { |
| 715 | if (debug_fbsd_lwp) |
| 716 | fprintf_unfiltered (gdb_stdlog, |
| 717 | "FLWP: adding thread for LWP %u\n", |
| 718 | pl.pl_lwpid); |
| 719 | add_thread (wptid); |
| 720 | } |
| 721 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; |
| 722 | return wptid; |
| 723 | } |
| 724 | #endif |
| 725 | |
| 726 | #ifdef TDP_RFPPWAIT |
| 727 | if (pl.pl_flags & PL_FLAG_FORKED) |
| 728 | { |
| 729 | struct kinfo_proc kp; |
| 730 | ptid_t child_ptid; |
| 731 | pid_t child; |
| 732 | |
| 733 | child = pl.pl_child_pid; |
| 734 | ourstatus->kind = TARGET_WAITKIND_FORKED; |
| 735 | |
| 736 | /* Make sure the other end of the fork is stopped too. */ |
| 737 | child_ptid = fbsd_is_child_pending (child); |
| 738 | if (ptid_equal (child_ptid, null_ptid)) |
| 739 | { |
| 740 | pid = waitpid (child, &status, 0); |
| 741 | if (pid == -1) |
| 742 | perror_with_name (("waitpid")); |
| 743 | |
| 744 | gdb_assert (pid == child); |
| 745 | |
| 746 | if (ptrace (PT_LWPINFO, child, (caddr_t)&pl, sizeof pl) == -1) |
| 747 | perror_with_name (("ptrace")); |
| 748 | |
| 749 | gdb_assert (pl.pl_flags & PL_FLAG_CHILD); |
| 750 | child_ptid = ptid_build (child, pl.pl_lwpid, 0); |
| 751 | } |
| 752 | |
| 753 | /* For vfork, the child process will have the P_PPWAIT |
| 754 | flag set. */ |
| 755 | fbsd_fetch_kinfo_proc (child, &kp); |
| 756 | if (kp.ki_flag & P_PPWAIT) |
| 757 | ourstatus->kind = TARGET_WAITKIND_VFORKED; |
| 758 | ourstatus->value.related_pid = child_ptid; |
| 759 | |
| 760 | return wptid; |
| 761 | } |
| 762 | |
| 763 | if (pl.pl_flags & PL_FLAG_CHILD) |
| 764 | { |
| 765 | /* Remember that this child forked, but do not report it |
| 766 | until the parent reports its corresponding fork |
| 767 | event. */ |
| 768 | fbsd_remember_child (wptid); |
| 769 | continue; |
| 770 | } |
| 771 | #endif |
| 772 | |
| 773 | #ifdef PL_FLAG_EXEC |
| 774 | if (pl.pl_flags & PL_FLAG_EXEC) |
| 775 | { |
| 776 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
| 777 | ourstatus->value.execd_pathname |
| 778 | = xstrdup (fbsd_pid_to_exec_file (NULL, pid)); |
| 779 | return wptid; |
| 780 | } |
| 781 | #endif |
| 782 | |
| 783 | /* Note that PL_FLAG_SCE is set for any event reported while |
| 784 | a thread is executing a system call in the kernel. In |
| 785 | particular, signals that interrupt a sleep in a system |
| 786 | call will report this flag as part of their event. Stops |
| 787 | explicitly for system call entry and exit always use |
| 788 | SIGTRAP, so only treat SIGTRAP events as system call |
| 789 | entry/exit events. */ |
| 790 | if (pl.pl_flags & (PL_FLAG_SCE | PL_FLAG_SCX) |
| 791 | && ourstatus->value.sig == SIGTRAP) |
| 792 | { |
| 793 | #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE |
| 794 | if (catch_syscall_enabled ()) |
| 795 | { |
| 796 | if (catching_syscall_number (pl.pl_syscall_code)) |
| 797 | { |
| 798 | if (pl.pl_flags & PL_FLAG_SCE) |
| 799 | ourstatus->kind = TARGET_WAITKIND_SYSCALL_ENTRY; |
| 800 | else |
| 801 | ourstatus->kind = TARGET_WAITKIND_SYSCALL_RETURN; |
| 802 | ourstatus->value.syscall_number = pl.pl_syscall_code; |
| 803 | return wptid; |
| 804 | } |
| 805 | } |
| 806 | #endif |
| 807 | /* If the core isn't interested in this event, just |
| 808 | continue the process explicitly and wait for another |
| 809 | event. Note that PT_SYSCALL is "sticky" on FreeBSD |
| 810 | and once system call stops are enabled on a process |
| 811 | it stops for all system call entries and exits. */ |
| 812 | if (ptrace (PT_CONTINUE, pid, (caddr_t) 1, 0) == -1) |
| 813 | perror_with_name (("ptrace")); |
| 814 | continue; |
| 815 | } |
| 816 | } |
| 817 | return wptid; |
| 818 | } |
| 819 | } |
| 820 | |
| 821 | #ifdef TDP_RFPPWAIT |
| 822 | /* Target hook for follow_fork. On entry and at return inferior_ptid is |
| 823 | the ptid of the followed inferior. */ |
| 824 | |
| 825 | static int |
| 826 | fbsd_follow_fork (struct target_ops *ops, int follow_child, |
| 827 | int detach_fork) |
| 828 | { |
| 829 | if (!follow_child) |
| 830 | { |
| 831 | struct thread_info *tp = inferior_thread (); |
| 832 | pid_t child_pid = ptid_get_pid (tp->pending_follow.value.related_pid); |
| 833 | |
| 834 | /* Breakpoints have already been detached from the child by |
| 835 | infrun.c. */ |
| 836 | |
| 837 | if (ptrace (PT_DETACH, child_pid, (PTRACE_TYPE_ARG3)1, 0) == -1) |
| 838 | perror_with_name (("ptrace")); |
| 839 | } |
| 840 | |
| 841 | return 0; |
| 842 | } |
| 843 | |
| 844 | static int |
| 845 | fbsd_insert_fork_catchpoint (struct target_ops *self, int pid) |
| 846 | { |
| 847 | return 0; |
| 848 | } |
| 849 | |
| 850 | static int |
| 851 | fbsd_remove_fork_catchpoint (struct target_ops *self, int pid) |
| 852 | { |
| 853 | return 0; |
| 854 | } |
| 855 | |
| 856 | static int |
| 857 | fbsd_insert_vfork_catchpoint (struct target_ops *self, int pid) |
| 858 | { |
| 859 | return 0; |
| 860 | } |
| 861 | |
| 862 | static int |
| 863 | fbsd_remove_vfork_catchpoint (struct target_ops *self, int pid) |
| 864 | { |
| 865 | return 0; |
| 866 | } |
| 867 | |
| 868 | /* Enable fork tracing for a specific process. |
| 869 | |
| 870 | To catch fork events, PT_FOLLOW_FORK is set on every traced process |
| 871 | to enable stops on returns from fork or vfork. Note that both the |
| 872 | parent and child will always stop, even if system call stops are |
| 873 | not enabled. */ |
| 874 | |
| 875 | static void |
| 876 | fbsd_enable_follow_fork (pid_t pid) |
| 877 | { |
| 878 | if (ptrace (PT_FOLLOW_FORK, pid, (PTRACE_TYPE_ARG3)0, 1) == -1) |
| 879 | perror_with_name (("ptrace")); |
| 880 | } |
| 881 | #endif |
| 882 | |
| 883 | /* Implement the "to_post_startup_inferior" target_ops method. */ |
| 884 | |
| 885 | static void |
| 886 | fbsd_post_startup_inferior (struct target_ops *self, ptid_t pid) |
| 887 | { |
| 888 | #ifdef TDP_RFPPWAIT |
| 889 | fbsd_enable_follow_fork (ptid_get_pid (pid)); |
| 890 | #endif |
| 891 | #ifdef PT_LWP_EVENTS |
| 892 | fbsd_enable_lwp_events (ptid_get_pid (pid)); |
| 893 | #endif |
| 894 | } |
| 895 | |
| 896 | /* Implement the "to_post_attach" target_ops method. */ |
| 897 | |
| 898 | static void |
| 899 | fbsd_post_attach (struct target_ops *self, int pid) |
| 900 | { |
| 901 | #ifdef TDP_RFPPWAIT |
| 902 | fbsd_enable_follow_fork (pid); |
| 903 | #endif |
| 904 | #ifdef PT_LWP_EVENTS |
| 905 | fbsd_enable_lwp_events (pid); |
| 906 | #endif |
| 907 | fbsd_add_threads (pid); |
| 908 | } |
| 909 | |
| 910 | #ifdef PL_FLAG_EXEC |
| 911 | /* If the FreeBSD kernel supports PL_FLAG_EXEC, then traced processes |
| 912 | will always stop after exec. */ |
| 913 | |
| 914 | static int |
| 915 | fbsd_insert_exec_catchpoint (struct target_ops *self, int pid) |
| 916 | { |
| 917 | return 0; |
| 918 | } |
| 919 | |
| 920 | static int |
| 921 | fbsd_remove_exec_catchpoint (struct target_ops *self, int pid) |
| 922 | { |
| 923 | return 0; |
| 924 | } |
| 925 | #endif |
| 926 | |
| 927 | #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE |
| 928 | static int |
| 929 | fbsd_set_syscall_catchpoint (struct target_ops *self, int pid, int needed, |
| 930 | int any_count, int table_size, int *table) |
| 931 | { |
| 932 | |
| 933 | /* Ignore the arguments. inf-ptrace.c will use PT_SYSCALL which |
| 934 | will catch all system call entries and exits. The system calls |
| 935 | are filtered by GDB rather than the kernel. */ |
| 936 | return 0; |
| 937 | } |
| 938 | #endif |
| 939 | #endif |
| 940 | |
| 941 | void |
| 942 | fbsd_nat_add_target (struct target_ops *t) |
| 943 | { |
| 944 | t->to_pid_to_exec_file = fbsd_pid_to_exec_file; |
| 945 | t->to_find_memory_regions = fbsd_find_memory_regions; |
| 946 | #ifdef KERN_PROC_AUXV |
| 947 | super_xfer_partial = t->to_xfer_partial; |
| 948 | t->to_xfer_partial = fbsd_xfer_partial; |
| 949 | #endif |
| 950 | #ifdef PT_LWPINFO |
| 951 | t->to_thread_alive = fbsd_thread_alive; |
| 952 | t->to_pid_to_str = fbsd_pid_to_str; |
| 953 | #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_TDNAME |
| 954 | t->to_thread_name = fbsd_thread_name; |
| 955 | #endif |
| 956 | t->to_update_thread_list = fbsd_update_thread_list; |
| 957 | t->to_has_thread_control = tc_schedlock; |
| 958 | super_resume = t->to_resume; |
| 959 | t->to_resume = fbsd_resume; |
| 960 | super_wait = t->to_wait; |
| 961 | t->to_wait = fbsd_wait; |
| 962 | t->to_post_startup_inferior = fbsd_post_startup_inferior; |
| 963 | t->to_post_attach = fbsd_post_attach; |
| 964 | #ifdef TDP_RFPPWAIT |
| 965 | t->to_follow_fork = fbsd_follow_fork; |
| 966 | t->to_insert_fork_catchpoint = fbsd_insert_fork_catchpoint; |
| 967 | t->to_remove_fork_catchpoint = fbsd_remove_fork_catchpoint; |
| 968 | t->to_insert_vfork_catchpoint = fbsd_insert_vfork_catchpoint; |
| 969 | t->to_remove_vfork_catchpoint = fbsd_remove_vfork_catchpoint; |
| 970 | #endif |
| 971 | #ifdef PL_FLAG_EXEC |
| 972 | t->to_insert_exec_catchpoint = fbsd_insert_exec_catchpoint; |
| 973 | t->to_remove_exec_catchpoint = fbsd_remove_exec_catchpoint; |
| 974 | #endif |
| 975 | #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE |
| 976 | t->to_set_syscall_catchpoint = fbsd_set_syscall_catchpoint; |
| 977 | #endif |
| 978 | #endif |
| 979 | add_target (t); |
| 980 | } |
| 981 | |
| 982 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 983 | extern initialize_file_ftype _initialize_fbsd_nat; |
| 984 | |
| 985 | void |
| 986 | _initialize_fbsd_nat (void) |
| 987 | { |
| 988 | #ifdef PT_LWPINFO |
| 989 | add_setshow_boolean_cmd ("fbsd-lwp", class_maintenance, |
| 990 | &debug_fbsd_lwp, _("\ |
| 991 | Set debugging of FreeBSD lwp module."), _("\ |
| 992 | Show debugging of FreeBSD lwp module."), _("\ |
| 993 | Enables printf debugging output."), |
| 994 | NULL, |
| 995 | &show_fbsd_lwp_debug, |
| 996 | &setdebuglist, &showdebuglist); |
| 997 | #endif |
| 998 | } |