| 1 | /* libthread_db assisted debugging support, generic parts. |
| 2 | |
| 3 | Copyright (C) 1999-2015 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 <dlfcn.h> |
| 22 | #include "gdb_proc_service.h" |
| 23 | #include "nat/gdb_thread_db.h" |
| 24 | #include "gdb_vecs.h" |
| 25 | #include "bfd.h" |
| 26 | #include "command.h" |
| 27 | #include "gdbcmd.h" |
| 28 | #include "gdbthread.h" |
| 29 | #include "inferior.h" |
| 30 | #include "infrun.h" |
| 31 | #include "symfile.h" |
| 32 | #include "objfiles.h" |
| 33 | #include "target.h" |
| 34 | #include "regcache.h" |
| 35 | #include "solib.h" |
| 36 | #include "solib-svr4.h" |
| 37 | #include "gdbcore.h" |
| 38 | #include "observer.h" |
| 39 | #include "linux-nat.h" |
| 40 | #include "nat/linux-procfs.h" |
| 41 | #include "nat/linux-ptrace.h" |
| 42 | #include "nat/linux-osdata.h" |
| 43 | #include "auto-load.h" |
| 44 | #include "cli/cli-utils.h" |
| 45 | |
| 46 | #include <signal.h> |
| 47 | #include <ctype.h> |
| 48 | |
| 49 | /* GNU/Linux libthread_db support. |
| 50 | |
| 51 | libthread_db is a library, provided along with libpthread.so, which |
| 52 | exposes the internals of the thread library to a debugger. It |
| 53 | allows GDB to find existing threads, new threads as they are |
| 54 | created, thread IDs (usually, the result of pthread_self), and |
| 55 | thread-local variables. |
| 56 | |
| 57 | The libthread_db interface originates on Solaris, where it is |
| 58 | both more powerful and more complicated. This implementation |
| 59 | only works for LinuxThreads and NPTL, the two glibc threading |
| 60 | libraries. It assumes that each thread is permanently assigned |
| 61 | to a single light-weight process (LWP). |
| 62 | |
| 63 | libthread_db-specific information is stored in the "private" field |
| 64 | of struct thread_info. When the field is NULL we do not yet have |
| 65 | information about the new thread; this could be temporary (created, |
| 66 | but the thread library's data structures do not reflect it yet) |
| 67 | or permanent (created using clone instead of pthread_create). |
| 68 | |
| 69 | Process IDs managed by linux-thread-db.c match those used by |
| 70 | linux-nat.c: a common PID for all processes, an LWP ID for each |
| 71 | thread, and no TID. We save the TID in private. Keeping it out |
| 72 | of the ptid_t prevents thread IDs changing when libpthread is |
| 73 | loaded or unloaded. */ |
| 74 | |
| 75 | static char *libthread_db_search_path; |
| 76 | |
| 77 | /* Set to non-zero if thread_db auto-loading is enabled |
| 78 | by the "set auto-load libthread-db" command. */ |
| 79 | static int auto_load_thread_db = 1; |
| 80 | |
| 81 | /* Returns true if we need to use thread_db thread create/death event |
| 82 | breakpoints to learn about threads. */ |
| 83 | |
| 84 | static int |
| 85 | thread_db_use_events (void) |
| 86 | { |
| 87 | /* Not necessary if the kernel supports clone events. */ |
| 88 | return !linux_supports_traceclone (); |
| 89 | } |
| 90 | |
| 91 | /* "show" command for the auto_load_thread_db configuration variable. */ |
| 92 | |
| 93 | static void |
| 94 | show_auto_load_thread_db (struct ui_file *file, int from_tty, |
| 95 | struct cmd_list_element *c, const char *value) |
| 96 | { |
| 97 | fprintf_filtered (file, _("Auto-loading of inferior specific libthread_db " |
| 98 | "is %s.\n"), |
| 99 | value); |
| 100 | } |
| 101 | |
| 102 | static void |
| 103 | set_libthread_db_search_path (char *ignored, int from_tty, |
| 104 | struct cmd_list_element *c) |
| 105 | { |
| 106 | if (*libthread_db_search_path == '\0') |
| 107 | { |
| 108 | xfree (libthread_db_search_path); |
| 109 | libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH); |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | /* If non-zero, print details of libthread_db processing. */ |
| 114 | |
| 115 | static unsigned int libthread_db_debug; |
| 116 | |
| 117 | static void |
| 118 | show_libthread_db_debug (struct ui_file *file, int from_tty, |
| 119 | struct cmd_list_element *c, const char *value) |
| 120 | { |
| 121 | fprintf_filtered (file, _("libthread-db debugging is %s.\n"), value); |
| 122 | } |
| 123 | |
| 124 | /* If we're running on GNU/Linux, we must explicitly attach to any new |
| 125 | threads. */ |
| 126 | |
| 127 | /* This module's target vector. */ |
| 128 | static struct target_ops thread_db_ops; |
| 129 | |
| 130 | /* Non-zero if we have determined the signals used by the threads |
| 131 | library. */ |
| 132 | static int thread_signals; |
| 133 | static sigset_t thread_stop_set; |
| 134 | static sigset_t thread_print_set; |
| 135 | |
| 136 | struct thread_db_info |
| 137 | { |
| 138 | struct thread_db_info *next; |
| 139 | |
| 140 | /* Process id this object refers to. */ |
| 141 | int pid; |
| 142 | |
| 143 | /* Handle from dlopen for libthread_db.so. */ |
| 144 | void *handle; |
| 145 | |
| 146 | /* Absolute pathname from gdb_realpath to disk file used for dlopen-ing |
| 147 | HANDLE. It may be NULL for system library. */ |
| 148 | char *filename; |
| 149 | |
| 150 | /* Structure that identifies the child process for the |
| 151 | <proc_service.h> interface. */ |
| 152 | struct ps_prochandle proc_handle; |
| 153 | |
| 154 | /* Connection to the libthread_db library. */ |
| 155 | td_thragent_t *thread_agent; |
| 156 | |
| 157 | /* True if we need to apply the workaround for glibc/BZ5983. When |
| 158 | we catch a PTRACE_O_TRACEFORK, and go query the child's thread |
| 159 | list, nptl_db returns the parent's threads in addition to the new |
| 160 | (single) child thread. If this flag is set, we do extra work to |
| 161 | be able to ignore such stale entries. */ |
| 162 | int need_stale_parent_threads_check; |
| 163 | |
| 164 | /* Location of the thread creation event breakpoint. The code at |
| 165 | this location in the child process will be called by the pthread |
| 166 | library whenever a new thread is created. By setting a special |
| 167 | breakpoint at this location, GDB can detect when a new thread is |
| 168 | created. We obtain this location via the td_ta_event_addr |
| 169 | call. */ |
| 170 | CORE_ADDR td_create_bp_addr; |
| 171 | |
| 172 | /* Location of the thread death event breakpoint. */ |
| 173 | CORE_ADDR td_death_bp_addr; |
| 174 | |
| 175 | /* Pointers to the libthread_db functions. */ |
| 176 | |
| 177 | td_err_e (*td_init_p) (void); |
| 178 | |
| 179 | td_err_e (*td_ta_new_p) (struct ps_prochandle * ps, |
| 180 | td_thragent_t **ta); |
| 181 | td_err_e (*td_ta_map_id2thr_p) (const td_thragent_t *ta, thread_t pt, |
| 182 | td_thrhandle_t *__th); |
| 183 | td_err_e (*td_ta_map_lwp2thr_p) (const td_thragent_t *ta, |
| 184 | lwpid_t lwpid, td_thrhandle_t *th); |
| 185 | td_err_e (*td_ta_thr_iter_p) (const td_thragent_t *ta, |
| 186 | td_thr_iter_f *callback, void *cbdata_p, |
| 187 | td_thr_state_e state, int ti_pri, |
| 188 | sigset_t *ti_sigmask_p, |
| 189 | unsigned int ti_user_flags); |
| 190 | td_err_e (*td_ta_event_addr_p) (const td_thragent_t *ta, |
| 191 | td_event_e event, td_notify_t *ptr); |
| 192 | td_err_e (*td_ta_set_event_p) (const td_thragent_t *ta, |
| 193 | td_thr_events_t *event); |
| 194 | td_err_e (*td_ta_clear_event_p) (const td_thragent_t *ta, |
| 195 | td_thr_events_t *event); |
| 196 | td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta, |
| 197 | td_event_msg_t *msg); |
| 198 | |
| 199 | td_err_e (*td_thr_validate_p) (const td_thrhandle_t *th); |
| 200 | td_err_e (*td_thr_get_info_p) (const td_thrhandle_t *th, |
| 201 | td_thrinfo_t *infop); |
| 202 | td_err_e (*td_thr_event_enable_p) (const td_thrhandle_t *th, |
| 203 | int event); |
| 204 | |
| 205 | td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th, |
| 206 | psaddr_t map_address, |
| 207 | size_t offset, psaddr_t *address); |
| 208 | td_err_e (*td_thr_tlsbase_p) (const td_thrhandle_t *th, |
| 209 | unsigned long int modid, |
| 210 | psaddr_t *base); |
| 211 | }; |
| 212 | |
| 213 | /* List of known processes using thread_db, and the required |
| 214 | bookkeeping. */ |
| 215 | struct thread_db_info *thread_db_list; |
| 216 | |
| 217 | static void thread_db_find_new_threads_1 (ptid_t ptid); |
| 218 | static void thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new); |
| 219 | |
| 220 | static void check_thread_signals (void); |
| 221 | |
| 222 | static void record_thread (struct thread_db_info *info, |
| 223 | struct thread_info *tp, |
| 224 | ptid_t ptid, const td_thrhandle_t *th_p, |
| 225 | const td_thrinfo_t *ti_p); |
| 226 | |
| 227 | /* Add the current inferior to the list of processes using libpthread. |
| 228 | Return a pointer to the newly allocated object that was added to |
| 229 | THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing |
| 230 | LIBTHREAD_DB_SO. */ |
| 231 | |
| 232 | static struct thread_db_info * |
| 233 | add_thread_db_info (void *handle) |
| 234 | { |
| 235 | struct thread_db_info *info; |
| 236 | |
| 237 | info = xcalloc (1, sizeof (*info)); |
| 238 | info->pid = ptid_get_pid (inferior_ptid); |
| 239 | info->handle = handle; |
| 240 | |
| 241 | /* The workaround works by reading from /proc/pid/status, so it is |
| 242 | disabled for core files. */ |
| 243 | if (target_has_execution) |
| 244 | info->need_stale_parent_threads_check = 1; |
| 245 | |
| 246 | info->next = thread_db_list; |
| 247 | thread_db_list = info; |
| 248 | |
| 249 | return info; |
| 250 | } |
| 251 | |
| 252 | /* Return the thread_db_info object representing the bookkeeping |
| 253 | related to process PID, if any; NULL otherwise. */ |
| 254 | |
| 255 | static struct thread_db_info * |
| 256 | get_thread_db_info (int pid) |
| 257 | { |
| 258 | struct thread_db_info *info; |
| 259 | |
| 260 | for (info = thread_db_list; info; info = info->next) |
| 261 | if (pid == info->pid) |
| 262 | return info; |
| 263 | |
| 264 | return NULL; |
| 265 | } |
| 266 | |
| 267 | /* When PID has exited or has been detached, we no longer want to keep |
| 268 | track of it as using libpthread. Call this function to discard |
| 269 | thread_db related info related to PID. Note that this closes |
| 270 | LIBTHREAD_DB_SO's dlopen'ed handle. */ |
| 271 | |
| 272 | static void |
| 273 | delete_thread_db_info (int pid) |
| 274 | { |
| 275 | struct thread_db_info *info, *info_prev; |
| 276 | |
| 277 | info_prev = NULL; |
| 278 | |
| 279 | for (info = thread_db_list; info; info_prev = info, info = info->next) |
| 280 | if (pid == info->pid) |
| 281 | break; |
| 282 | |
| 283 | if (info == NULL) |
| 284 | return; |
| 285 | |
| 286 | if (info->handle != NULL) |
| 287 | dlclose (info->handle); |
| 288 | |
| 289 | xfree (info->filename); |
| 290 | |
| 291 | if (info_prev) |
| 292 | info_prev->next = info->next; |
| 293 | else |
| 294 | thread_db_list = info->next; |
| 295 | |
| 296 | xfree (info); |
| 297 | } |
| 298 | |
| 299 | /* Prototypes for local functions. */ |
| 300 | static int attach_thread (ptid_t ptid, const td_thrhandle_t *th_p, |
| 301 | const td_thrinfo_t *ti_p); |
| 302 | static void detach_thread (ptid_t ptid); |
| 303 | \f |
| 304 | |
| 305 | /* Use "struct private_thread_info" to cache thread state. This is |
| 306 | a substantial optimization. */ |
| 307 | |
| 308 | struct private_thread_info |
| 309 | { |
| 310 | /* Flag set when we see a TD_DEATH event for this thread. */ |
| 311 | unsigned int dying:1; |
| 312 | |
| 313 | /* Cached thread state. */ |
| 314 | td_thrhandle_t th; |
| 315 | thread_t tid; |
| 316 | }; |
| 317 | \f |
| 318 | |
| 319 | static char * |
| 320 | thread_db_err_str (td_err_e err) |
| 321 | { |
| 322 | static char buf[64]; |
| 323 | |
| 324 | switch (err) |
| 325 | { |
| 326 | case TD_OK: |
| 327 | return "generic 'call succeeded'"; |
| 328 | case TD_ERR: |
| 329 | return "generic error"; |
| 330 | case TD_NOTHR: |
| 331 | return "no thread to satisfy query"; |
| 332 | case TD_NOSV: |
| 333 | return "no sync handle to satisfy query"; |
| 334 | case TD_NOLWP: |
| 335 | return "no LWP to satisfy query"; |
| 336 | case TD_BADPH: |
| 337 | return "invalid process handle"; |
| 338 | case TD_BADTH: |
| 339 | return "invalid thread handle"; |
| 340 | case TD_BADSH: |
| 341 | return "invalid synchronization handle"; |
| 342 | case TD_BADTA: |
| 343 | return "invalid thread agent"; |
| 344 | case TD_BADKEY: |
| 345 | return "invalid key"; |
| 346 | case TD_NOMSG: |
| 347 | return "no event message for getmsg"; |
| 348 | case TD_NOFPREGS: |
| 349 | return "FPU register set not available"; |
| 350 | case TD_NOLIBTHREAD: |
| 351 | return "application not linked with libthread"; |
| 352 | case TD_NOEVENT: |
| 353 | return "requested event is not supported"; |
| 354 | case TD_NOCAPAB: |
| 355 | return "capability not available"; |
| 356 | case TD_DBERR: |
| 357 | return "debugger service failed"; |
| 358 | case TD_NOAPLIC: |
| 359 | return "operation not applicable to"; |
| 360 | case TD_NOTSD: |
| 361 | return "no thread-specific data for this thread"; |
| 362 | case TD_MALLOC: |
| 363 | return "malloc failed"; |
| 364 | case TD_PARTIALREG: |
| 365 | return "only part of register set was written/read"; |
| 366 | case TD_NOXREGS: |
| 367 | return "X register set not available for this thread"; |
| 368 | #ifdef THREAD_DB_HAS_TD_NOTALLOC |
| 369 | case TD_NOTALLOC: |
| 370 | return "thread has not yet allocated TLS for given module"; |
| 371 | #endif |
| 372 | #ifdef THREAD_DB_HAS_TD_VERSION |
| 373 | case TD_VERSION: |
| 374 | return "versions of libpthread and libthread_db do not match"; |
| 375 | #endif |
| 376 | #ifdef THREAD_DB_HAS_TD_NOTLS |
| 377 | case TD_NOTLS: |
| 378 | return "there is no TLS segment in the given module"; |
| 379 | #endif |
| 380 | default: |
| 381 | snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err); |
| 382 | return buf; |
| 383 | } |
| 384 | } |
| 385 | \f |
| 386 | /* Return 1 if any threads have been registered. There may be none if |
| 387 | the threading library is not fully initialized yet. */ |
| 388 | |
| 389 | static int |
| 390 | have_threads_callback (struct thread_info *thread, void *args) |
| 391 | { |
| 392 | int pid = * (int *) args; |
| 393 | |
| 394 | if (ptid_get_pid (thread->ptid) != pid) |
| 395 | return 0; |
| 396 | |
| 397 | return thread->priv != NULL; |
| 398 | } |
| 399 | |
| 400 | static int |
| 401 | have_threads (ptid_t ptid) |
| 402 | { |
| 403 | int pid = ptid_get_pid (ptid); |
| 404 | |
| 405 | return iterate_over_threads (have_threads_callback, &pid) != NULL; |
| 406 | } |
| 407 | |
| 408 | \f |
| 409 | /* Fetch the user-level thread id of PTID. */ |
| 410 | |
| 411 | static void |
| 412 | thread_from_lwp (ptid_t ptid) |
| 413 | { |
| 414 | td_thrhandle_t th; |
| 415 | td_thrinfo_t ti; |
| 416 | td_err_e err; |
| 417 | struct thread_db_info *info; |
| 418 | struct thread_info *tp; |
| 419 | |
| 420 | /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */ |
| 421 | th.th_unique = 0; |
| 422 | |
| 423 | /* This ptid comes from linux-nat.c, which should always fill in the |
| 424 | LWP. */ |
| 425 | gdb_assert (ptid_get_lwp (ptid) != 0); |
| 426 | |
| 427 | info = get_thread_db_info (ptid_get_pid (ptid)); |
| 428 | |
| 429 | /* Access an lwp we know is stopped. */ |
| 430 | info->proc_handle.ptid = ptid; |
| 431 | err = info->td_ta_map_lwp2thr_p (info->thread_agent, ptid_get_lwp (ptid), |
| 432 | &th); |
| 433 | if (err != TD_OK) |
| 434 | error (_("Cannot find user-level thread for LWP %ld: %s"), |
| 435 | ptid_get_lwp (ptid), thread_db_err_str (err)); |
| 436 | |
| 437 | err = info->td_thr_get_info_p (&th, &ti); |
| 438 | if (err != TD_OK) |
| 439 | error (_("thread_get_info_callback: cannot get thread info: %s"), |
| 440 | thread_db_err_str (err)); |
| 441 | |
| 442 | /* Fill the cache. */ |
| 443 | tp = find_thread_ptid (ptid); |
| 444 | record_thread (info, tp, ptid, &th, &ti); |
| 445 | } |
| 446 | \f |
| 447 | |
| 448 | /* See linux-nat.h. */ |
| 449 | |
| 450 | int |
| 451 | thread_db_notice_clone (ptid_t parent, ptid_t child) |
| 452 | { |
| 453 | td_thrhandle_t th; |
| 454 | td_thrinfo_t ti; |
| 455 | td_err_e err; |
| 456 | struct thread_db_info *info; |
| 457 | |
| 458 | info = get_thread_db_info (ptid_get_pid (child)); |
| 459 | |
| 460 | if (info == NULL) |
| 461 | return 0; |
| 462 | |
| 463 | thread_from_lwp (child); |
| 464 | |
| 465 | /* If we do not know about the main thread yet, this would be a good |
| 466 | time to find it. */ |
| 467 | thread_from_lwp (parent); |
| 468 | return 1; |
| 469 | } |
| 470 | |
| 471 | static void * |
| 472 | verbose_dlsym (void *handle, const char *name) |
| 473 | { |
| 474 | void *sym = dlsym (handle, name); |
| 475 | if (sym == NULL) |
| 476 | warning (_("Symbol \"%s\" not found in libthread_db: %s"), |
| 477 | name, dlerror ()); |
| 478 | return sym; |
| 479 | } |
| 480 | |
| 481 | static td_err_e |
| 482 | enable_thread_event (int event, CORE_ADDR *bp) |
| 483 | { |
| 484 | td_notify_t notify; |
| 485 | td_err_e err; |
| 486 | struct thread_db_info *info; |
| 487 | |
| 488 | info = get_thread_db_info (ptid_get_pid (inferior_ptid)); |
| 489 | |
| 490 | /* Access an lwp we know is stopped. */ |
| 491 | info->proc_handle.ptid = inferior_ptid; |
| 492 | |
| 493 | /* Get the breakpoint address for thread EVENT. */ |
| 494 | err = info->td_ta_event_addr_p (info->thread_agent, event, ¬ify); |
| 495 | if (err != TD_OK) |
| 496 | return err; |
| 497 | |
| 498 | /* Set up the breakpoint. */ |
| 499 | gdb_assert (exec_bfd); |
| 500 | (*bp) = (gdbarch_convert_from_func_ptr_addr |
| 501 | (target_gdbarch (), |
| 502 | /* Do proper sign extension for the target. */ |
| 503 | (bfd_get_sign_extend_vma (exec_bfd) > 0 |
| 504 | ? (CORE_ADDR) (intptr_t) notify.u.bptaddr |
| 505 | : (CORE_ADDR) (uintptr_t) notify.u.bptaddr), |
| 506 | ¤t_target)); |
| 507 | create_thread_event_breakpoint (target_gdbarch (), *bp); |
| 508 | |
| 509 | return TD_OK; |
| 510 | } |
| 511 | |
| 512 | /* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and |
| 513 | return 1 if this version is lower (and not equal) to |
| 514 | VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */ |
| 515 | |
| 516 | static int |
| 517 | inferior_has_bug (const char *ver_symbol, int ver_major_min, int ver_minor_min) |
| 518 | { |
| 519 | struct bound_minimal_symbol version_msym; |
| 520 | CORE_ADDR version_addr; |
| 521 | char *version; |
| 522 | int err, got, retval = 0; |
| 523 | |
| 524 | version_msym = lookup_minimal_symbol (ver_symbol, NULL, NULL); |
| 525 | if (version_msym.minsym == NULL) |
| 526 | return 0; |
| 527 | |
| 528 | version_addr = BMSYMBOL_VALUE_ADDRESS (version_msym); |
| 529 | got = target_read_string (version_addr, &version, 32, &err); |
| 530 | if (err == 0 && memchr (version, 0, got) == &version[got -1]) |
| 531 | { |
| 532 | int major, minor; |
| 533 | |
| 534 | retval = (sscanf (version, "%d.%d", &major, &minor) == 2 |
| 535 | && (major < ver_major_min |
| 536 | || (major == ver_major_min && minor < ver_minor_min))); |
| 537 | } |
| 538 | xfree (version); |
| 539 | |
| 540 | return retval; |
| 541 | } |
| 542 | |
| 543 | static void |
| 544 | enable_thread_event_reporting (void) |
| 545 | { |
| 546 | td_thr_events_t events; |
| 547 | td_err_e err; |
| 548 | struct thread_db_info *info; |
| 549 | |
| 550 | info = get_thread_db_info (ptid_get_pid (inferior_ptid)); |
| 551 | |
| 552 | /* We cannot use the thread event reporting facility if these |
| 553 | functions aren't available. */ |
| 554 | if (info->td_ta_event_addr_p == NULL |
| 555 | || info->td_ta_set_event_p == NULL |
| 556 | || info->td_ta_event_getmsg_p == NULL |
| 557 | || info->td_thr_event_enable_p == NULL) |
| 558 | return; |
| 559 | |
| 560 | /* Set the process wide mask saying which events we're interested in. */ |
| 561 | td_event_emptyset (&events); |
| 562 | td_event_addset (&events, TD_CREATE); |
| 563 | |
| 564 | /* There is a bug fixed between linuxthreads 2.1.3 and 2.2 by |
| 565 | commit 2e4581e4fba917f1779cd0a010a45698586c190a |
| 566 | * manager.c (pthread_exited): Correctly report event as TD_REAP |
| 567 | instead of TD_DEATH. Fix comments. |
| 568 | where event reporting facility is broken for TD_DEATH events, |
| 569 | so don't enable it if we have glibc but a lower version. */ |
| 570 | if (!inferior_has_bug ("__linuxthreads_version", 2, 2)) |
| 571 | td_event_addset (&events, TD_DEATH); |
| 572 | |
| 573 | err = info->td_ta_set_event_p (info->thread_agent, &events); |
| 574 | if (err != TD_OK) |
| 575 | { |
| 576 | warning (_("Unable to set global thread event mask: %s"), |
| 577 | thread_db_err_str (err)); |
| 578 | return; |
| 579 | } |
| 580 | |
| 581 | /* Delete previous thread event breakpoints, if any. */ |
| 582 | remove_thread_event_breakpoints (); |
| 583 | info->td_create_bp_addr = 0; |
| 584 | info->td_death_bp_addr = 0; |
| 585 | |
| 586 | /* Set up the thread creation event. */ |
| 587 | err = enable_thread_event (TD_CREATE, &info->td_create_bp_addr); |
| 588 | if (err != TD_OK) |
| 589 | { |
| 590 | warning (_("Unable to get location for thread creation breakpoint: %s"), |
| 591 | thread_db_err_str (err)); |
| 592 | return; |
| 593 | } |
| 594 | |
| 595 | /* Set up the thread death event. */ |
| 596 | err = enable_thread_event (TD_DEATH, &info->td_death_bp_addr); |
| 597 | if (err != TD_OK) |
| 598 | { |
| 599 | warning (_("Unable to get location for thread death breakpoint: %s"), |
| 600 | thread_db_err_str (err)); |
| 601 | return; |
| 602 | } |
| 603 | } |
| 604 | |
| 605 | /* Similar as thread_db_find_new_threads_1, but try to silently ignore errors |
| 606 | if appropriate. |
| 607 | |
| 608 | Return 1 if the caller should abort libthread_db initialization. Return 0 |
| 609 | otherwise. */ |
| 610 | |
| 611 | static int |
| 612 | thread_db_find_new_threads_silently (ptid_t ptid) |
| 613 | { |
| 614 | |
| 615 | TRY |
| 616 | { |
| 617 | thread_db_find_new_threads_2 (ptid, 1); |
| 618 | } |
| 619 | |
| 620 | CATCH (except, RETURN_MASK_ERROR) |
| 621 | { |
| 622 | if (libthread_db_debug) |
| 623 | exception_fprintf (gdb_stdlog, except, |
| 624 | "Warning: thread_db_find_new_threads_silently: "); |
| 625 | |
| 626 | /* There is a bug fixed between nptl 2.6.1 and 2.7 by |
| 627 | commit 7d9d8bd18906fdd17364f372b160d7ab896ce909 |
| 628 | where calls to td_thr_get_info fail with TD_ERR for statically linked |
| 629 | executables if td_thr_get_info is called before glibc has initialized |
| 630 | itself. |
| 631 | |
| 632 | If the nptl bug is NOT present in the inferior and still thread_db |
| 633 | reports an error return 1. It means the inferior has corrupted thread |
| 634 | list and GDB should fall back only to LWPs. |
| 635 | |
| 636 | If the nptl bug is present in the inferior return 0 to silently ignore |
| 637 | such errors, and let gdb enumerate threads again later. In such case |
| 638 | GDB cannot properly display LWPs if the inferior thread list is |
| 639 | corrupted. For core files it does not apply, no 'later enumeration' |
| 640 | is possible. */ |
| 641 | |
| 642 | if (!target_has_execution || !inferior_has_bug ("nptl_version", 2, 7)) |
| 643 | { |
| 644 | exception_fprintf (gdb_stderr, except, |
| 645 | _("Warning: couldn't activate thread debugging " |
| 646 | "using libthread_db: ")); |
| 647 | return 1; |
| 648 | } |
| 649 | } |
| 650 | END_CATCH |
| 651 | |
| 652 | return 0; |
| 653 | } |
| 654 | |
| 655 | /* Lookup a library in which given symbol resides. |
| 656 | Note: this is looking in GDB process, not in the inferior. |
| 657 | Returns library name, or NULL. */ |
| 658 | |
| 659 | static const char * |
| 660 | dladdr_to_soname (const void *addr) |
| 661 | { |
| 662 | Dl_info info; |
| 663 | |
| 664 | if (dladdr (addr, &info) != 0) |
| 665 | return info.dli_fname; |
| 666 | return NULL; |
| 667 | } |
| 668 | |
| 669 | /* Attempt to initialize dlopen()ed libthread_db, described by INFO. |
| 670 | Return 1 on success. |
| 671 | Failure could happen if libthread_db does not have symbols we expect, |
| 672 | or when it refuses to work with the current inferior (e.g. due to |
| 673 | version mismatch between libthread_db and libpthread). */ |
| 674 | |
| 675 | static int |
| 676 | try_thread_db_load_1 (struct thread_db_info *info) |
| 677 | { |
| 678 | td_err_e err; |
| 679 | |
| 680 | /* Initialize pointers to the dynamic library functions we will use. |
| 681 | Essential functions first. */ |
| 682 | |
| 683 | info->td_init_p = verbose_dlsym (info->handle, "td_init"); |
| 684 | if (info->td_init_p == NULL) |
| 685 | return 0; |
| 686 | |
| 687 | err = info->td_init_p (); |
| 688 | if (err != TD_OK) |
| 689 | { |
| 690 | warning (_("Cannot initialize libthread_db: %s"), |
| 691 | thread_db_err_str (err)); |
| 692 | return 0; |
| 693 | } |
| 694 | |
| 695 | info->td_ta_new_p = verbose_dlsym (info->handle, "td_ta_new"); |
| 696 | if (info->td_ta_new_p == NULL) |
| 697 | return 0; |
| 698 | |
| 699 | /* Initialize the structure that identifies the child process. */ |
| 700 | info->proc_handle.ptid = inferior_ptid; |
| 701 | |
| 702 | /* Now attempt to open a connection to the thread library. */ |
| 703 | err = info->td_ta_new_p (&info->proc_handle, &info->thread_agent); |
| 704 | if (err != TD_OK) |
| 705 | { |
| 706 | if (libthread_db_debug) |
| 707 | fprintf_unfiltered (gdb_stdlog, _("td_ta_new failed: %s\n"), |
| 708 | thread_db_err_str (err)); |
| 709 | else |
| 710 | switch (err) |
| 711 | { |
| 712 | case TD_NOLIBTHREAD: |
| 713 | #ifdef THREAD_DB_HAS_TD_VERSION |
| 714 | case TD_VERSION: |
| 715 | #endif |
| 716 | /* The errors above are not unexpected and silently ignored: |
| 717 | they just mean we haven't found correct version of |
| 718 | libthread_db yet. */ |
| 719 | break; |
| 720 | default: |
| 721 | warning (_("td_ta_new failed: %s"), thread_db_err_str (err)); |
| 722 | } |
| 723 | return 0; |
| 724 | } |
| 725 | |
| 726 | info->td_ta_map_id2thr_p = verbose_dlsym (info->handle, "td_ta_map_id2thr"); |
| 727 | if (info->td_ta_map_id2thr_p == NULL) |
| 728 | return 0; |
| 729 | |
| 730 | info->td_ta_map_lwp2thr_p = verbose_dlsym (info->handle, |
| 731 | "td_ta_map_lwp2thr"); |
| 732 | if (info->td_ta_map_lwp2thr_p == NULL) |
| 733 | return 0; |
| 734 | |
| 735 | info->td_ta_thr_iter_p = verbose_dlsym (info->handle, "td_ta_thr_iter"); |
| 736 | if (info->td_ta_thr_iter_p == NULL) |
| 737 | return 0; |
| 738 | |
| 739 | info->td_thr_validate_p = verbose_dlsym (info->handle, "td_thr_validate"); |
| 740 | if (info->td_thr_validate_p == NULL) |
| 741 | return 0; |
| 742 | |
| 743 | info->td_thr_get_info_p = verbose_dlsym (info->handle, "td_thr_get_info"); |
| 744 | if (info->td_thr_get_info_p == NULL) |
| 745 | return 0; |
| 746 | |
| 747 | /* These are not essential. */ |
| 748 | info->td_ta_event_addr_p = dlsym (info->handle, "td_ta_event_addr"); |
| 749 | info->td_ta_set_event_p = dlsym (info->handle, "td_ta_set_event"); |
| 750 | info->td_ta_clear_event_p = dlsym (info->handle, "td_ta_clear_event"); |
| 751 | info->td_ta_event_getmsg_p = dlsym (info->handle, "td_ta_event_getmsg"); |
| 752 | info->td_thr_event_enable_p = dlsym (info->handle, "td_thr_event_enable"); |
| 753 | info->td_thr_tls_get_addr_p = dlsym (info->handle, "td_thr_tls_get_addr"); |
| 754 | info->td_thr_tlsbase_p = dlsym (info->handle, "td_thr_tlsbase"); |
| 755 | |
| 756 | /* It's best to avoid td_ta_thr_iter if possible. That walks data |
| 757 | structures in the inferior's address space that may be corrupted, |
| 758 | or, if the target is running, may change while we walk them. If |
| 759 | there's execution (and /proc is mounted), then we're already |
| 760 | attached to all LWPs. Use thread_from_lwp, which uses |
| 761 | td_ta_map_lwp2thr instead, which does not walk the thread list. |
| 762 | |
| 763 | td_ta_map_lwp2thr uses ps_get_thread_area, but we can't use that |
| 764 | currently on core targets, as it uses ptrace directly. */ |
| 765 | if (target_has_execution |
| 766 | && linux_proc_task_list_dir_exists (ptid_get_pid (inferior_ptid))) |
| 767 | { |
| 768 | struct lwp_info *lp; |
| 769 | int pid = ptid_get_pid (inferior_ptid); |
| 770 | |
| 771 | linux_stop_and_wait_all_lwps (); |
| 772 | |
| 773 | ALL_LWPS (lp) |
| 774 | if (ptid_get_pid (lp->ptid) == pid) |
| 775 | thread_from_lwp (lp->ptid); |
| 776 | |
| 777 | linux_unstop_all_lwps (); |
| 778 | } |
| 779 | else if (thread_db_find_new_threads_silently (inferior_ptid) != 0) |
| 780 | { |
| 781 | /* Even if libthread_db initializes, if the thread list is |
| 782 | corrupted, we'd not manage to list any threads. Better reject this |
| 783 | thread_db, and fall back to at least listing LWPs. */ |
| 784 | return 0; |
| 785 | } |
| 786 | |
| 787 | printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n")); |
| 788 | |
| 789 | if (*libthread_db_search_path || libthread_db_debug) |
| 790 | { |
| 791 | struct ui_file *file; |
| 792 | const char *library; |
| 793 | |
| 794 | library = dladdr_to_soname (*info->td_ta_new_p); |
| 795 | if (library == NULL) |
| 796 | library = LIBTHREAD_DB_SO; |
| 797 | |
| 798 | /* If we'd print this to gdb_stdout when debug output is |
| 799 | disabled, still print it to gdb_stdout if debug output is |
| 800 | enabled. User visible output should not depend on debug |
| 801 | settings. */ |
| 802 | file = *libthread_db_search_path != '\0' ? gdb_stdout : gdb_stdlog; |
| 803 | fprintf_unfiltered (file, _("Using host libthread_db library \"%s\".\n"), |
| 804 | library); |
| 805 | } |
| 806 | |
| 807 | /* The thread library was detected. Activate the thread_db target |
| 808 | if this is the first process using it. */ |
| 809 | if (thread_db_list->next == NULL) |
| 810 | push_target (&thread_db_ops); |
| 811 | |
| 812 | /* Enable event reporting, but not when debugging a core file. */ |
| 813 | if (target_has_execution && thread_db_use_events ()) |
| 814 | enable_thread_event_reporting (); |
| 815 | |
| 816 | return 1; |
| 817 | } |
| 818 | |
| 819 | /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute, |
| 820 | relative, or just LIBTHREAD_DB. */ |
| 821 | |
| 822 | static int |
| 823 | try_thread_db_load (const char *library, int check_auto_load_safe) |
| 824 | { |
| 825 | void *handle; |
| 826 | struct thread_db_info *info; |
| 827 | |
| 828 | if (libthread_db_debug) |
| 829 | fprintf_unfiltered (gdb_stdlog, |
| 830 | _("Trying host libthread_db library: %s.\n"), |
| 831 | library); |
| 832 | |
| 833 | if (check_auto_load_safe) |
| 834 | { |
| 835 | if (access (library, R_OK) != 0) |
| 836 | { |
| 837 | /* Do not print warnings by file_is_auto_load_safe if the library does |
| 838 | not exist at this place. */ |
| 839 | if (libthread_db_debug) |
| 840 | fprintf_unfiltered (gdb_stdlog, _("open failed: %s.\n"), |
| 841 | safe_strerror (errno)); |
| 842 | return 0; |
| 843 | } |
| 844 | |
| 845 | if (!file_is_auto_load_safe (library, _("auto-load: Loading libthread-db " |
| 846 | "library \"%s\" from explicit " |
| 847 | "directory.\n"), |
| 848 | library)) |
| 849 | return 0; |
| 850 | } |
| 851 | |
| 852 | handle = dlopen (library, RTLD_NOW); |
| 853 | if (handle == NULL) |
| 854 | { |
| 855 | if (libthread_db_debug) |
| 856 | fprintf_unfiltered (gdb_stdlog, _("dlopen failed: %s.\n"), dlerror ()); |
| 857 | return 0; |
| 858 | } |
| 859 | |
| 860 | if (libthread_db_debug && strchr (library, '/') == NULL) |
| 861 | { |
| 862 | void *td_init; |
| 863 | |
| 864 | td_init = dlsym (handle, "td_init"); |
| 865 | if (td_init != NULL) |
| 866 | { |
| 867 | const char *const libpath = dladdr_to_soname (td_init); |
| 868 | |
| 869 | if (libpath != NULL) |
| 870 | fprintf_unfiltered (gdb_stdlog, _("Host %s resolved to: %s.\n"), |
| 871 | library, libpath); |
| 872 | } |
| 873 | } |
| 874 | |
| 875 | info = add_thread_db_info (handle); |
| 876 | |
| 877 | /* Do not save system library name, that one is always trusted. */ |
| 878 | if (strchr (library, '/') != NULL) |
| 879 | info->filename = gdb_realpath (library); |
| 880 | |
| 881 | if (try_thread_db_load_1 (info)) |
| 882 | return 1; |
| 883 | |
| 884 | /* This library "refused" to work on current inferior. */ |
| 885 | delete_thread_db_info (ptid_get_pid (inferior_ptid)); |
| 886 | return 0; |
| 887 | } |
| 888 | |
| 889 | /* Subroutine of try_thread_db_load_from_pdir to simplify it. |
| 890 | Try loading libthread_db in directory(OBJ)/SUBDIR. |
| 891 | SUBDIR may be NULL. It may also be something like "../lib64". |
| 892 | The result is true for success. */ |
| 893 | |
| 894 | static int |
| 895 | try_thread_db_load_from_pdir_1 (struct objfile *obj, const char *subdir) |
| 896 | { |
| 897 | struct cleanup *cleanup; |
| 898 | char *path, *cp; |
| 899 | int result; |
| 900 | const char *obj_name = objfile_name (obj); |
| 901 | |
| 902 | if (obj_name[0] != '/') |
| 903 | { |
| 904 | warning (_("Expected absolute pathname for libpthread in the" |
| 905 | " inferior, but got %s."), obj_name); |
| 906 | return 0; |
| 907 | } |
| 908 | |
| 909 | path = xmalloc (strlen (obj_name) + (subdir ? strlen (subdir) + 1 : 0) |
| 910 | + 1 + strlen (LIBTHREAD_DB_SO) + 1); |
| 911 | cleanup = make_cleanup (xfree, path); |
| 912 | |
| 913 | strcpy (path, obj_name); |
| 914 | cp = strrchr (path, '/'); |
| 915 | /* This should at minimum hit the first character. */ |
| 916 | gdb_assert (cp != NULL); |
| 917 | cp[1] = '\0'; |
| 918 | if (subdir != NULL) |
| 919 | { |
| 920 | strcat (cp, subdir); |
| 921 | strcat (cp, "/"); |
| 922 | } |
| 923 | strcat (cp, LIBTHREAD_DB_SO); |
| 924 | |
| 925 | result = try_thread_db_load (path, 1); |
| 926 | |
| 927 | do_cleanups (cleanup); |
| 928 | return result; |
| 929 | } |
| 930 | |
| 931 | /* Handle $pdir in libthread-db-search-path. |
| 932 | Look for libthread_db in directory(libpthread)/SUBDIR. |
| 933 | SUBDIR may be NULL. It may also be something like "../lib64". |
| 934 | The result is true for success. */ |
| 935 | |
| 936 | static int |
| 937 | try_thread_db_load_from_pdir (const char *subdir) |
| 938 | { |
| 939 | struct objfile *obj; |
| 940 | |
| 941 | if (!auto_load_thread_db) |
| 942 | return 0; |
| 943 | |
| 944 | ALL_OBJFILES (obj) |
| 945 | if (libpthread_name_p (objfile_name (obj))) |
| 946 | { |
| 947 | if (try_thread_db_load_from_pdir_1 (obj, subdir)) |
| 948 | return 1; |
| 949 | |
| 950 | /* We may have found the separate-debug-info version of |
| 951 | libpthread, and it may live in a directory without a matching |
| 952 | libthread_db. */ |
| 953 | if (obj->separate_debug_objfile_backlink != NULL) |
| 954 | return try_thread_db_load_from_pdir_1 (obj->separate_debug_objfile_backlink, |
| 955 | subdir); |
| 956 | |
| 957 | return 0; |
| 958 | } |
| 959 | |
| 960 | return 0; |
| 961 | } |
| 962 | |
| 963 | /* Handle $sdir in libthread-db-search-path. |
| 964 | Look for libthread_db in the system dirs, or wherever a plain |
| 965 | dlopen(file_without_path) will look. |
| 966 | The result is true for success. */ |
| 967 | |
| 968 | static int |
| 969 | try_thread_db_load_from_sdir (void) |
| 970 | { |
| 971 | return try_thread_db_load (LIBTHREAD_DB_SO, 0); |
| 972 | } |
| 973 | |
| 974 | /* Try to load libthread_db from directory DIR of length DIR_LEN. |
| 975 | The result is true for success. */ |
| 976 | |
| 977 | static int |
| 978 | try_thread_db_load_from_dir (const char *dir, size_t dir_len) |
| 979 | { |
| 980 | struct cleanup *cleanup; |
| 981 | char *path; |
| 982 | int result; |
| 983 | |
| 984 | if (!auto_load_thread_db) |
| 985 | return 0; |
| 986 | |
| 987 | path = xmalloc (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1); |
| 988 | cleanup = make_cleanup (xfree, path); |
| 989 | |
| 990 | memcpy (path, dir, dir_len); |
| 991 | path[dir_len] = '/'; |
| 992 | strcpy (path + dir_len + 1, LIBTHREAD_DB_SO); |
| 993 | |
| 994 | result = try_thread_db_load (path, 1); |
| 995 | |
| 996 | do_cleanups (cleanup); |
| 997 | return result; |
| 998 | } |
| 999 | |
| 1000 | /* Search libthread_db_search_path for libthread_db which "agrees" |
| 1001 | to work on current inferior. |
| 1002 | The result is true for success. */ |
| 1003 | |
| 1004 | static int |
| 1005 | thread_db_load_search (void) |
| 1006 | { |
| 1007 | VEC (char_ptr) *dir_vec; |
| 1008 | struct cleanup *cleanups; |
| 1009 | char *this_dir; |
| 1010 | int i, rc = 0; |
| 1011 | |
| 1012 | dir_vec = dirnames_to_char_ptr_vec (libthread_db_search_path); |
| 1013 | cleanups = make_cleanup_free_char_ptr_vec (dir_vec); |
| 1014 | |
| 1015 | for (i = 0; VEC_iterate (char_ptr, dir_vec, i, this_dir); ++i) |
| 1016 | { |
| 1017 | const int pdir_len = sizeof ("$pdir") - 1; |
| 1018 | size_t this_dir_len; |
| 1019 | |
| 1020 | this_dir_len = strlen (this_dir); |
| 1021 | |
| 1022 | if (strncmp (this_dir, "$pdir", pdir_len) == 0 |
| 1023 | && (this_dir[pdir_len] == '\0' |
| 1024 | || this_dir[pdir_len] == '/')) |
| 1025 | { |
| 1026 | char *subdir = NULL; |
| 1027 | struct cleanup *free_subdir_cleanup |
| 1028 | = make_cleanup (null_cleanup, NULL); |
| 1029 | |
| 1030 | if (this_dir[pdir_len] == '/') |
| 1031 | { |
| 1032 | subdir = xmalloc (strlen (this_dir)); |
| 1033 | make_cleanup (xfree, subdir); |
| 1034 | strcpy (subdir, this_dir + pdir_len + 1); |
| 1035 | } |
| 1036 | rc = try_thread_db_load_from_pdir (subdir); |
| 1037 | do_cleanups (free_subdir_cleanup); |
| 1038 | if (rc) |
| 1039 | break; |
| 1040 | } |
| 1041 | else if (strcmp (this_dir, "$sdir") == 0) |
| 1042 | { |
| 1043 | if (try_thread_db_load_from_sdir ()) |
| 1044 | { |
| 1045 | rc = 1; |
| 1046 | break; |
| 1047 | } |
| 1048 | } |
| 1049 | else |
| 1050 | { |
| 1051 | if (try_thread_db_load_from_dir (this_dir, this_dir_len)) |
| 1052 | { |
| 1053 | rc = 1; |
| 1054 | break; |
| 1055 | } |
| 1056 | } |
| 1057 | } |
| 1058 | |
| 1059 | do_cleanups (cleanups); |
| 1060 | if (libthread_db_debug) |
| 1061 | fprintf_unfiltered (gdb_stdlog, |
| 1062 | _("thread_db_load_search returning %d\n"), rc); |
| 1063 | return rc; |
| 1064 | } |
| 1065 | |
| 1066 | /* Return non-zero if the inferior has a libpthread. */ |
| 1067 | |
| 1068 | static int |
| 1069 | has_libpthread (void) |
| 1070 | { |
| 1071 | struct objfile *obj; |
| 1072 | |
| 1073 | ALL_OBJFILES (obj) |
| 1074 | if (libpthread_name_p (objfile_name (obj))) |
| 1075 | return 1; |
| 1076 | |
| 1077 | return 0; |
| 1078 | } |
| 1079 | |
| 1080 | /* Attempt to load and initialize libthread_db. |
| 1081 | Return 1 on success. */ |
| 1082 | |
| 1083 | static int |
| 1084 | thread_db_load (void) |
| 1085 | { |
| 1086 | struct thread_db_info *info; |
| 1087 | |
| 1088 | info = get_thread_db_info (ptid_get_pid (inferior_ptid)); |
| 1089 | |
| 1090 | if (info != NULL) |
| 1091 | return 1; |
| 1092 | |
| 1093 | /* Don't attempt to use thread_db on executables not running |
| 1094 | yet. */ |
| 1095 | if (!target_has_registers) |
| 1096 | return 0; |
| 1097 | |
| 1098 | /* Don't attempt to use thread_db for remote targets. */ |
| 1099 | if (!(target_can_run (¤t_target) || core_bfd)) |
| 1100 | return 0; |
| 1101 | |
| 1102 | if (thread_db_load_search ()) |
| 1103 | return 1; |
| 1104 | |
| 1105 | /* We couldn't find a libthread_db. |
| 1106 | If the inferior has a libpthread warn the user. */ |
| 1107 | if (has_libpthread ()) |
| 1108 | { |
| 1109 | warning (_("Unable to find libthread_db matching inferior's thread" |
| 1110 | " library, thread debugging will not be available.")); |
| 1111 | return 0; |
| 1112 | } |
| 1113 | |
| 1114 | /* Either this executable isn't using libpthread at all, or it is |
| 1115 | statically linked. Since we can't easily distinguish these two cases, |
| 1116 | no warning is issued. */ |
| 1117 | return 0; |
| 1118 | } |
| 1119 | |
| 1120 | static void |
| 1121 | disable_thread_event_reporting (struct thread_db_info *info) |
| 1122 | { |
| 1123 | if (info->td_ta_clear_event_p != NULL) |
| 1124 | { |
| 1125 | td_thr_events_t events; |
| 1126 | |
| 1127 | /* Set the process wide mask saying we aren't interested in any |
| 1128 | events anymore. */ |
| 1129 | td_event_fillset (&events); |
| 1130 | info->td_ta_clear_event_p (info->thread_agent, &events); |
| 1131 | } |
| 1132 | |
| 1133 | info->td_create_bp_addr = 0; |
| 1134 | info->td_death_bp_addr = 0; |
| 1135 | } |
| 1136 | |
| 1137 | static void |
| 1138 | check_thread_signals (void) |
| 1139 | { |
| 1140 | if (!thread_signals) |
| 1141 | { |
| 1142 | sigset_t mask; |
| 1143 | int i; |
| 1144 | |
| 1145 | lin_thread_get_thread_signals (&mask); |
| 1146 | sigemptyset (&thread_stop_set); |
| 1147 | sigemptyset (&thread_print_set); |
| 1148 | |
| 1149 | for (i = 1; i < NSIG; i++) |
| 1150 | { |
| 1151 | if (sigismember (&mask, i)) |
| 1152 | { |
| 1153 | if (signal_stop_update (gdb_signal_from_host (i), 0)) |
| 1154 | sigaddset (&thread_stop_set, i); |
| 1155 | if (signal_print_update (gdb_signal_from_host (i), 0)) |
| 1156 | sigaddset (&thread_print_set, i); |
| 1157 | thread_signals = 1; |
| 1158 | } |
| 1159 | } |
| 1160 | } |
| 1161 | } |
| 1162 | |
| 1163 | /* Check whether thread_db is usable. This function is called when |
| 1164 | an inferior is created (or otherwise acquired, e.g. attached to) |
| 1165 | and when new shared libraries are loaded into a running process. */ |
| 1166 | |
| 1167 | void |
| 1168 | check_for_thread_db (void) |
| 1169 | { |
| 1170 | /* Do nothing if we couldn't load libthread_db.so.1. */ |
| 1171 | if (!thread_db_load ()) |
| 1172 | return; |
| 1173 | } |
| 1174 | |
| 1175 | /* This function is called via the new_objfile observer. */ |
| 1176 | |
| 1177 | static void |
| 1178 | thread_db_new_objfile (struct objfile *objfile) |
| 1179 | { |
| 1180 | /* This observer must always be called with inferior_ptid set |
| 1181 | correctly. */ |
| 1182 | |
| 1183 | if (objfile != NULL |
| 1184 | /* libpthread with separate debug info has its debug info file already |
| 1185 | loaded (and notified without successful thread_db initialization) |
| 1186 | the time observer_notify_new_objfile is called for the library itself. |
| 1187 | Static executables have their separate debug info loaded already |
| 1188 | before the inferior has started. */ |
| 1189 | && objfile->separate_debug_objfile_backlink == NULL |
| 1190 | /* Only check for thread_db if we loaded libpthread, |
| 1191 | or if this is the main symbol file. |
| 1192 | We need to check OBJF_MAINLINE to handle the case of debugging |
| 1193 | a statically linked executable AND the symbol file is specified AFTER |
| 1194 | the exec file is loaded (e.g., gdb -c core ; file foo). |
| 1195 | For dynamically linked executables, libpthread can be near the end |
| 1196 | of the list of shared libraries to load, and in an app of several |
| 1197 | thousand shared libraries, this can otherwise be painful. */ |
| 1198 | && ((objfile->flags & OBJF_MAINLINE) != 0 |
| 1199 | || libpthread_name_p (objfile_name (objfile)))) |
| 1200 | check_for_thread_db (); |
| 1201 | } |
| 1202 | |
| 1203 | static void |
| 1204 | check_pid_namespace_match (void) |
| 1205 | { |
| 1206 | /* Check is only relevant for local targets targets. */ |
| 1207 | if (target_can_run (¤t_target)) |
| 1208 | { |
| 1209 | /* If the child is in a different PID namespace, its idea of its |
| 1210 | PID will differ from our idea of its PID. When we scan the |
| 1211 | child's thread list, we'll mistakenly think it has no threads |
| 1212 | since the thread PID fields won't match the PID we give to |
| 1213 | libthread_db. */ |
| 1214 | char *our_pid_ns = linux_proc_pid_get_ns (getpid (), "pid"); |
| 1215 | char *inferior_pid_ns = linux_proc_pid_get_ns ( |
| 1216 | ptid_get_pid (inferior_ptid), "pid"); |
| 1217 | |
| 1218 | if (our_pid_ns != NULL && inferior_pid_ns != NULL |
| 1219 | && strcmp (our_pid_ns, inferior_pid_ns) != 0) |
| 1220 | { |
| 1221 | warning (_ ("Target and debugger are in different PID " |
| 1222 | "namespaces; thread lists and other data are " |
| 1223 | "likely unreliable")); |
| 1224 | } |
| 1225 | |
| 1226 | xfree (our_pid_ns); |
| 1227 | xfree (inferior_pid_ns); |
| 1228 | } |
| 1229 | } |
| 1230 | |
| 1231 | /* This function is called via the inferior_created observer. |
| 1232 | This handles the case of debugging statically linked executables. */ |
| 1233 | |
| 1234 | static void |
| 1235 | thread_db_inferior_created (struct target_ops *target, int from_tty) |
| 1236 | { |
| 1237 | check_pid_namespace_match (); |
| 1238 | check_for_thread_db (); |
| 1239 | } |
| 1240 | |
| 1241 | /* Update the thread's state (what's displayed in "info threads"), |
| 1242 | from libthread_db thread state information. */ |
| 1243 | |
| 1244 | static void |
| 1245 | update_thread_state (struct private_thread_info *priv, |
| 1246 | const td_thrinfo_t *ti_p) |
| 1247 | { |
| 1248 | priv->dying = (ti_p->ti_state == TD_THR_UNKNOWN |
| 1249 | || ti_p->ti_state == TD_THR_ZOMBIE); |
| 1250 | } |
| 1251 | |
| 1252 | /* Attach to a new thread. This function is called when we receive a |
| 1253 | TD_CREATE event or when we iterate over all threads and find one |
| 1254 | that wasn't already in our list. Returns true on success. */ |
| 1255 | |
| 1256 | static int |
| 1257 | attach_thread (ptid_t ptid, const td_thrhandle_t *th_p, |
| 1258 | const td_thrinfo_t *ti_p) |
| 1259 | { |
| 1260 | struct thread_info *tp; |
| 1261 | struct thread_db_info *info; |
| 1262 | |
| 1263 | /* If we're being called after a TD_CREATE event, we may already |
| 1264 | know about this thread. There are two ways this can happen. We |
| 1265 | may have iterated over all threads between the thread creation |
| 1266 | and the TD_CREATE event, for instance when the user has issued |
| 1267 | the `info threads' command before the SIGTRAP for hitting the |
| 1268 | thread creation breakpoint was reported. Alternatively, the |
| 1269 | thread may have exited and a new one been created with the same |
| 1270 | thread ID. In the first case we don't need to do anything; in |
| 1271 | the second case we should discard information about the dead |
| 1272 | thread and attach to the new one. */ |
| 1273 | tp = find_thread_ptid (ptid); |
| 1274 | if (tp != NULL) |
| 1275 | { |
| 1276 | /* If tp->priv is NULL, then GDB is already attached to this |
| 1277 | thread, but we do not know anything about it. We can learn |
| 1278 | about it here. This can only happen if we have some other |
| 1279 | way besides libthread_db to notice new threads (i.e. |
| 1280 | PTRACE_EVENT_CLONE); assume the same mechanism notices thread |
| 1281 | exit, so this can not be a stale thread recreated with the |
| 1282 | same ID. */ |
| 1283 | if (tp->priv != NULL) |
| 1284 | { |
| 1285 | if (!tp->priv->dying) |
| 1286 | return 0; |
| 1287 | |
| 1288 | delete_thread (ptid); |
| 1289 | tp = NULL; |
| 1290 | } |
| 1291 | } |
| 1292 | |
| 1293 | /* Under GNU/Linux, we have to attach to each and every thread. */ |
| 1294 | if (target_has_execution |
| 1295 | && tp == NULL) |
| 1296 | { |
| 1297 | int res; |
| 1298 | |
| 1299 | res = lin_lwp_attach_lwp (ptid_build (ptid_get_pid (ptid), |
| 1300 | ti_p->ti_lid, 0)); |
| 1301 | if (res < 0) |
| 1302 | { |
| 1303 | /* Error, stop iterating. */ |
| 1304 | return 0; |
| 1305 | } |
| 1306 | else if (res > 0) |
| 1307 | { |
| 1308 | /* Pretend this thread doesn't exist yet, and keep |
| 1309 | iterating. */ |
| 1310 | return 1; |
| 1311 | } |
| 1312 | |
| 1313 | /* Otherwise, we sucessfully attached to the thread. */ |
| 1314 | } |
| 1315 | |
| 1316 | info = get_thread_db_info (ptid_get_pid (ptid)); |
| 1317 | record_thread (info, tp, ptid, th_p, ti_p); |
| 1318 | return 1; |
| 1319 | } |
| 1320 | |
| 1321 | /* Record a new thread in GDB's thread list. Creates the thread's |
| 1322 | private info. If TP is NULL, creates a new thread. Otherwise, |
| 1323 | uses TP. */ |
| 1324 | |
| 1325 | static void |
| 1326 | record_thread (struct thread_db_info *info, |
| 1327 | struct thread_info *tp, |
| 1328 | ptid_t ptid, const td_thrhandle_t *th_p, |
| 1329 | const td_thrinfo_t *ti_p) |
| 1330 | { |
| 1331 | td_err_e err; |
| 1332 | struct private_thread_info *priv; |
| 1333 | int new_thread = (tp == NULL); |
| 1334 | |
| 1335 | /* A thread ID of zero may mean the thread library has not |
| 1336 | initialized yet. Leave private == NULL until the thread library |
| 1337 | has initialized. */ |
| 1338 | if (ti_p->ti_tid == 0) |
| 1339 | return; |
| 1340 | |
| 1341 | /* Construct the thread's private data. */ |
| 1342 | priv = xmalloc (sizeof (struct private_thread_info)); |
| 1343 | memset (priv, 0, sizeof (struct private_thread_info)); |
| 1344 | |
| 1345 | priv->th = *th_p; |
| 1346 | priv->tid = ti_p->ti_tid; |
| 1347 | update_thread_state (priv, ti_p); |
| 1348 | |
| 1349 | /* Add the thread to GDB's thread list. */ |
| 1350 | if (tp == NULL) |
| 1351 | tp = add_thread_with_info (ptid, priv); |
| 1352 | else |
| 1353 | tp->priv = priv; |
| 1354 | |
| 1355 | /* Enable thread event reporting for this thread, except when |
| 1356 | debugging a core file. */ |
| 1357 | if (target_has_execution && thread_db_use_events () && new_thread) |
| 1358 | { |
| 1359 | err = info->td_thr_event_enable_p (th_p, 1); |
| 1360 | if (err != TD_OK) |
| 1361 | error (_("Cannot enable thread event reporting for %s: %s"), |
| 1362 | target_pid_to_str (ptid), thread_db_err_str (err)); |
| 1363 | } |
| 1364 | |
| 1365 | if (target_has_execution) |
| 1366 | check_thread_signals (); |
| 1367 | } |
| 1368 | |
| 1369 | static void |
| 1370 | detach_thread (ptid_t ptid) |
| 1371 | { |
| 1372 | struct thread_info *thread_info; |
| 1373 | |
| 1374 | /* Don't delete the thread now, because it still reports as active |
| 1375 | until it has executed a few instructions after the event |
| 1376 | breakpoint - if we deleted it now, "info threads" would cause us |
| 1377 | to re-attach to it. Just mark it as having had a TD_DEATH |
| 1378 | event. This means that we won't delete it from our thread list |
| 1379 | until we notice that it's dead (via prune_threads), or until |
| 1380 | something re-uses its thread ID. We'll report the thread exit |
| 1381 | when the underlying LWP dies. */ |
| 1382 | thread_info = find_thread_ptid (ptid); |
| 1383 | gdb_assert (thread_info != NULL && thread_info->priv != NULL); |
| 1384 | thread_info->priv->dying = 1; |
| 1385 | } |
| 1386 | |
| 1387 | static void |
| 1388 | thread_db_detach (struct target_ops *ops, const char *args, int from_tty) |
| 1389 | { |
| 1390 | struct target_ops *target_beneath = find_target_beneath (ops); |
| 1391 | struct thread_db_info *info; |
| 1392 | |
| 1393 | info = get_thread_db_info (ptid_get_pid (inferior_ptid)); |
| 1394 | |
| 1395 | if (info) |
| 1396 | { |
| 1397 | if (target_has_execution && thread_db_use_events ()) |
| 1398 | { |
| 1399 | disable_thread_event_reporting (info); |
| 1400 | |
| 1401 | /* Delete the old thread event breakpoints. Note that |
| 1402 | unlike when mourning, we can remove them here because |
| 1403 | there's still a live inferior to poke at. In any case, |
| 1404 | GDB will not try to insert anything in the inferior when |
| 1405 | removing a breakpoint. */ |
| 1406 | remove_thread_event_breakpoints (); |
| 1407 | } |
| 1408 | |
| 1409 | delete_thread_db_info (ptid_get_pid (inferior_ptid)); |
| 1410 | } |
| 1411 | |
| 1412 | target_beneath->to_detach (target_beneath, args, from_tty); |
| 1413 | |
| 1414 | /* NOTE: From this point on, inferior_ptid is null_ptid. */ |
| 1415 | |
| 1416 | /* If there are no more processes using libpthread, detach the |
| 1417 | thread_db target ops. */ |
| 1418 | if (!thread_db_list) |
| 1419 | unpush_target (&thread_db_ops); |
| 1420 | } |
| 1421 | |
| 1422 | /* Check if PID is currently stopped at the location of a thread event |
| 1423 | breakpoint location. If it is, read the event message and act upon |
| 1424 | the event. */ |
| 1425 | |
| 1426 | static void |
| 1427 | check_event (ptid_t ptid) |
| 1428 | { |
| 1429 | struct regcache *regcache = get_thread_regcache (ptid); |
| 1430 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 1431 | td_event_msg_t msg; |
| 1432 | td_thrinfo_t ti; |
| 1433 | td_err_e err; |
| 1434 | CORE_ADDR stop_pc; |
| 1435 | int loop = 0; |
| 1436 | struct thread_db_info *info; |
| 1437 | |
| 1438 | info = get_thread_db_info (ptid_get_pid (ptid)); |
| 1439 | |
| 1440 | /* Bail out early if we're not at a thread event breakpoint. */ |
| 1441 | stop_pc = regcache_read_pc (regcache); |
| 1442 | if (!target_supports_stopped_by_sw_breakpoint ()) |
| 1443 | stop_pc -= gdbarch_decr_pc_after_break (gdbarch); |
| 1444 | |
| 1445 | if (stop_pc != info->td_create_bp_addr |
| 1446 | && stop_pc != info->td_death_bp_addr) |
| 1447 | return; |
| 1448 | |
| 1449 | /* Access an lwp we know is stopped. */ |
| 1450 | info->proc_handle.ptid = ptid; |
| 1451 | |
| 1452 | /* If we have only looked at the first thread before libpthread was |
| 1453 | initialized, we may not know its thread ID yet. Make sure we do |
| 1454 | before we add another thread to the list. */ |
| 1455 | if (!have_threads (ptid)) |
| 1456 | thread_db_find_new_threads_1 (ptid); |
| 1457 | |
| 1458 | /* If we are at a create breakpoint, we do not know what new lwp |
| 1459 | was created and cannot specifically locate the event message for it. |
| 1460 | We have to call td_ta_event_getmsg() to get |
| 1461 | the latest message. Since we have no way of correlating whether |
| 1462 | the event message we get back corresponds to our breakpoint, we must |
| 1463 | loop and read all event messages, processing them appropriately. |
| 1464 | This guarantees we will process the correct message before continuing |
| 1465 | from the breakpoint. |
| 1466 | |
| 1467 | Currently, death events are not enabled. If they are enabled, |
| 1468 | the death event can use the td_thr_event_getmsg() interface to |
| 1469 | get the message specifically for that lwp and avoid looping |
| 1470 | below. */ |
| 1471 | |
| 1472 | loop = 1; |
| 1473 | |
| 1474 | do |
| 1475 | { |
| 1476 | err = info->td_ta_event_getmsg_p (info->thread_agent, &msg); |
| 1477 | if (err != TD_OK) |
| 1478 | { |
| 1479 | if (err == TD_NOMSG) |
| 1480 | return; |
| 1481 | |
| 1482 | error (_("Cannot get thread event message: %s"), |
| 1483 | thread_db_err_str (err)); |
| 1484 | } |
| 1485 | |
| 1486 | err = info->td_thr_get_info_p (msg.th_p, &ti); |
| 1487 | if (err != TD_OK) |
| 1488 | error (_("Cannot get thread info: %s"), thread_db_err_str (err)); |
| 1489 | |
| 1490 | ptid = ptid_build (ptid_get_pid (ptid), ti.ti_lid, 0); |
| 1491 | |
| 1492 | switch (msg.event) |
| 1493 | { |
| 1494 | case TD_CREATE: |
| 1495 | /* Call attach_thread whether or not we already know about a |
| 1496 | thread with this thread ID. */ |
| 1497 | attach_thread (ptid, msg.th_p, &ti); |
| 1498 | |
| 1499 | break; |
| 1500 | |
| 1501 | case TD_DEATH: |
| 1502 | |
| 1503 | if (!in_thread_list (ptid)) |
| 1504 | error (_("Spurious thread death event.")); |
| 1505 | |
| 1506 | detach_thread (ptid); |
| 1507 | |
| 1508 | break; |
| 1509 | |
| 1510 | default: |
| 1511 | error (_("Spurious thread event.")); |
| 1512 | } |
| 1513 | } |
| 1514 | while (loop); |
| 1515 | } |
| 1516 | |
| 1517 | static ptid_t |
| 1518 | thread_db_wait (struct target_ops *ops, |
| 1519 | ptid_t ptid, struct target_waitstatus *ourstatus, |
| 1520 | int options) |
| 1521 | { |
| 1522 | struct thread_db_info *info; |
| 1523 | struct target_ops *beneath = find_target_beneath (ops); |
| 1524 | |
| 1525 | ptid = beneath->to_wait (beneath, ptid, ourstatus, options); |
| 1526 | |
| 1527 | if (ourstatus->kind == TARGET_WAITKIND_IGNORE) |
| 1528 | return ptid; |
| 1529 | |
| 1530 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
| 1531 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) |
| 1532 | return ptid; |
| 1533 | |
| 1534 | info = get_thread_db_info (ptid_get_pid (ptid)); |
| 1535 | |
| 1536 | /* If this process isn't using thread_db, we're done. */ |
| 1537 | if (info == NULL) |
| 1538 | return ptid; |
| 1539 | |
| 1540 | if (ourstatus->kind == TARGET_WAITKIND_EXECD) |
| 1541 | { |
| 1542 | /* New image, it may or may not end up using thread_db. Assume |
| 1543 | not unless we find otherwise. */ |
| 1544 | delete_thread_db_info (ptid_get_pid (ptid)); |
| 1545 | if (!thread_db_list) |
| 1546 | unpush_target (&thread_db_ops); |
| 1547 | |
| 1548 | /* Thread event breakpoints are deleted by |
| 1549 | update_breakpoints_after_exec. */ |
| 1550 | |
| 1551 | return ptid; |
| 1552 | } |
| 1553 | |
| 1554 | if (ourstatus->kind == TARGET_WAITKIND_STOPPED |
| 1555 | && ourstatus->value.sig == GDB_SIGNAL_TRAP) |
| 1556 | /* Check for a thread event. */ |
| 1557 | check_event (ptid); |
| 1558 | |
| 1559 | /* Fill in the thread's user-level thread id and status. */ |
| 1560 | thread_from_lwp (ptid); |
| 1561 | |
| 1562 | return ptid; |
| 1563 | } |
| 1564 | |
| 1565 | static void |
| 1566 | thread_db_mourn_inferior (struct target_ops *ops) |
| 1567 | { |
| 1568 | struct target_ops *target_beneath = find_target_beneath (ops); |
| 1569 | |
| 1570 | delete_thread_db_info (ptid_get_pid (inferior_ptid)); |
| 1571 | |
| 1572 | target_beneath->to_mourn_inferior (target_beneath); |
| 1573 | |
| 1574 | /* Delete the old thread event breakpoints. Do this after mourning |
| 1575 | the inferior, so that we don't try to uninsert them. */ |
| 1576 | remove_thread_event_breakpoints (); |
| 1577 | |
| 1578 | /* Detach thread_db target ops. */ |
| 1579 | if (!thread_db_list) |
| 1580 | unpush_target (ops); |
| 1581 | } |
| 1582 | |
| 1583 | struct callback_data |
| 1584 | { |
| 1585 | struct thread_db_info *info; |
| 1586 | int new_threads; |
| 1587 | }; |
| 1588 | |
| 1589 | static int |
| 1590 | find_new_threads_callback (const td_thrhandle_t *th_p, void *data) |
| 1591 | { |
| 1592 | td_thrinfo_t ti; |
| 1593 | td_err_e err; |
| 1594 | ptid_t ptid; |
| 1595 | struct thread_info *tp; |
| 1596 | struct callback_data *cb_data = data; |
| 1597 | struct thread_db_info *info = cb_data->info; |
| 1598 | |
| 1599 | err = info->td_thr_get_info_p (th_p, &ti); |
| 1600 | if (err != TD_OK) |
| 1601 | error (_("find_new_threads_callback: cannot get thread info: %s"), |
| 1602 | thread_db_err_str (err)); |
| 1603 | |
| 1604 | if (ti.ti_lid == -1) |
| 1605 | { |
| 1606 | /* A thread with kernel thread ID -1 is either a thread that |
| 1607 | exited and was joined, or a thread that is being created but |
| 1608 | hasn't started yet, and that is reusing the tcb/stack of a |
| 1609 | thread that previously exited and was joined. (glibc marks |
| 1610 | terminated and joined threads with kernel thread ID -1. See |
| 1611 | glibc PR17707. */ |
| 1612 | if (libthread_db_debug) |
| 1613 | fprintf_unfiltered (gdb_stdlog, |
| 1614 | "thread_db: skipping exited and " |
| 1615 | "joined thread (0x%lx)\n", ti.ti_tid); |
| 1616 | return 0; |
| 1617 | } |
| 1618 | |
| 1619 | if (ti.ti_tid == 0) |
| 1620 | { |
| 1621 | /* A thread ID of zero means that this is the main thread, but |
| 1622 | glibc has not yet initialized thread-local storage and the |
| 1623 | pthread library. We do not know what the thread's TID will |
| 1624 | be yet. Just enable event reporting and otherwise ignore |
| 1625 | it. */ |
| 1626 | |
| 1627 | /* In that case, we're not stopped in a fork syscall and don't |
| 1628 | need this glibc bug workaround. */ |
| 1629 | info->need_stale_parent_threads_check = 0; |
| 1630 | |
| 1631 | if (target_has_execution && thread_db_use_events ()) |
| 1632 | { |
| 1633 | err = info->td_thr_event_enable_p (th_p, 1); |
| 1634 | if (err != TD_OK) |
| 1635 | error (_("Cannot enable thread event reporting for LWP %d: %s"), |
| 1636 | (int) ti.ti_lid, thread_db_err_str (err)); |
| 1637 | } |
| 1638 | |
| 1639 | return 0; |
| 1640 | } |
| 1641 | |
| 1642 | /* Ignore stale parent threads, caused by glibc/BZ5983. This is a |
| 1643 | bit expensive, as it needs to open /proc/pid/status, so try to |
| 1644 | avoid doing the work if we know we don't have to. */ |
| 1645 | if (info->need_stale_parent_threads_check) |
| 1646 | { |
| 1647 | int tgid = linux_proc_get_tgid (ti.ti_lid); |
| 1648 | |
| 1649 | if (tgid != -1 && tgid != info->pid) |
| 1650 | return 0; |
| 1651 | } |
| 1652 | |
| 1653 | ptid = ptid_build (info->pid, ti.ti_lid, 0); |
| 1654 | tp = find_thread_ptid (ptid); |
| 1655 | if (tp == NULL || tp->priv == NULL) |
| 1656 | { |
| 1657 | if (attach_thread (ptid, th_p, &ti)) |
| 1658 | cb_data->new_threads += 1; |
| 1659 | else |
| 1660 | /* Problem attaching this thread; perhaps it exited before we |
| 1661 | could attach it? |
| 1662 | This could mean that the thread list inside glibc itself is in |
| 1663 | inconsistent state, and libthread_db could go on looping forever |
| 1664 | (observed with glibc-2.3.6). To prevent that, terminate |
| 1665 | iteration: thread_db_find_new_threads_2 will retry. */ |
| 1666 | return 1; |
| 1667 | } |
| 1668 | else if (target_has_execution && !thread_db_use_events ()) |
| 1669 | { |
| 1670 | /* Need to update this if not using the libthread_db events |
| 1671 | (particularly, the TD_DEATH event). */ |
| 1672 | update_thread_state (tp->priv, &ti); |
| 1673 | } |
| 1674 | |
| 1675 | return 0; |
| 1676 | } |
| 1677 | |
| 1678 | /* Helper for thread_db_find_new_threads_2. |
| 1679 | Returns number of new threads found. */ |
| 1680 | |
| 1681 | static int |
| 1682 | find_new_threads_once (struct thread_db_info *info, int iteration, |
| 1683 | td_err_e *errp) |
| 1684 | { |
| 1685 | struct callback_data data; |
| 1686 | td_err_e err = TD_ERR; |
| 1687 | |
| 1688 | data.info = info; |
| 1689 | data.new_threads = 0; |
| 1690 | |
| 1691 | /* See comment in thread_db_update_thread_list. */ |
| 1692 | gdb_assert (!target_has_execution || thread_db_use_events ()); |
| 1693 | |
| 1694 | TRY |
| 1695 | { |
| 1696 | /* Iterate over all user-space threads to discover new threads. */ |
| 1697 | err = info->td_ta_thr_iter_p (info->thread_agent, |
| 1698 | find_new_threads_callback, |
| 1699 | &data, |
| 1700 | TD_THR_ANY_STATE, |
| 1701 | TD_THR_LOWEST_PRIORITY, |
| 1702 | TD_SIGNO_MASK, |
| 1703 | TD_THR_ANY_USER_FLAGS); |
| 1704 | } |
| 1705 | |
| 1706 | if (libthread_db_debug) |
| 1707 | { |
| 1708 | CATCH (except, RETURN_MASK_ERROR) |
| 1709 | { |
| 1710 | exception_fprintf (gdb_stdlog, except, |
| 1711 | "Warning: find_new_threads_once: "); |
| 1712 | } |
| 1713 | END_CATCH |
| 1714 | |
| 1715 | fprintf_unfiltered (gdb_stdlog, |
| 1716 | _("Found %d new threads in iteration %d.\n"), |
| 1717 | data.new_threads, iteration); |
| 1718 | } |
| 1719 | |
| 1720 | if (errp != NULL) |
| 1721 | *errp = err; |
| 1722 | |
| 1723 | return data.new_threads; |
| 1724 | } |
| 1725 | |
| 1726 | /* Search for new threads, accessing memory through stopped thread |
| 1727 | PTID. If UNTIL_NO_NEW is true, repeat searching until several |
| 1728 | searches in a row do not discover any new threads. */ |
| 1729 | |
| 1730 | static void |
| 1731 | thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new) |
| 1732 | { |
| 1733 | td_err_e err = TD_OK; |
| 1734 | struct thread_db_info *info; |
| 1735 | int i, loop; |
| 1736 | |
| 1737 | info = get_thread_db_info (ptid_get_pid (ptid)); |
| 1738 | |
| 1739 | /* Access an lwp we know is stopped. */ |
| 1740 | info->proc_handle.ptid = ptid; |
| 1741 | |
| 1742 | if (until_no_new) |
| 1743 | { |
| 1744 | /* Require 4 successive iterations which do not find any new threads. |
| 1745 | The 4 is a heuristic: there is an inherent race here, and I have |
| 1746 | seen that 2 iterations in a row are not always sufficient to |
| 1747 | "capture" all threads. */ |
| 1748 | for (i = 0, loop = 0; loop < 4 && err == TD_OK; ++i, ++loop) |
| 1749 | if (find_new_threads_once (info, i, &err) != 0) |
| 1750 | { |
| 1751 | /* Found some new threads. Restart the loop from beginning. */ |
| 1752 | loop = -1; |
| 1753 | } |
| 1754 | } |
| 1755 | else |
| 1756 | find_new_threads_once (info, 0, &err); |
| 1757 | |
| 1758 | if (err != TD_OK) |
| 1759 | error (_("Cannot find new threads: %s"), thread_db_err_str (err)); |
| 1760 | } |
| 1761 | |
| 1762 | static void |
| 1763 | thread_db_find_new_threads_1 (ptid_t ptid) |
| 1764 | { |
| 1765 | thread_db_find_new_threads_2 (ptid, 0); |
| 1766 | } |
| 1767 | |
| 1768 | static int |
| 1769 | update_thread_core (struct lwp_info *info, void *closure) |
| 1770 | { |
| 1771 | info->core = linux_common_core_of_thread (info->ptid); |
| 1772 | return 0; |
| 1773 | } |
| 1774 | |
| 1775 | /* Update the thread list using td_ta_thr_iter. */ |
| 1776 | |
| 1777 | static void |
| 1778 | thread_db_update_thread_list_td_ta_thr_iter (struct target_ops *ops) |
| 1779 | { |
| 1780 | struct thread_db_info *info; |
| 1781 | struct inferior *inf; |
| 1782 | |
| 1783 | prune_threads (); |
| 1784 | |
| 1785 | ALL_INFERIORS (inf) |
| 1786 | { |
| 1787 | struct thread_info *thread; |
| 1788 | |
| 1789 | if (inf->pid == 0) |
| 1790 | continue; |
| 1791 | |
| 1792 | info = get_thread_db_info (inf->pid); |
| 1793 | if (info == NULL) |
| 1794 | continue; |
| 1795 | |
| 1796 | thread = any_live_thread_of_process (inf->pid); |
| 1797 | if (thread == NULL || thread->executing) |
| 1798 | continue; |
| 1799 | |
| 1800 | thread_db_find_new_threads_1 (thread->ptid); |
| 1801 | } |
| 1802 | } |
| 1803 | |
| 1804 | /* Implement the to_update_thread_list target method for this |
| 1805 | target. */ |
| 1806 | |
| 1807 | static void |
| 1808 | thread_db_update_thread_list (struct target_ops *ops) |
| 1809 | { |
| 1810 | /* It's best to avoid td_ta_thr_iter if possible. That walks data |
| 1811 | structures in the inferior's address space that may be corrupted, |
| 1812 | or, if the target is running, the list may change while we walk |
| 1813 | it. In the latter case, it's possible that a thread exits just |
| 1814 | at the exact time that causes GDB to get stuck in an infinite |
| 1815 | loop. To avoid pausing all threads whenever the core wants to |
| 1816 | refresh the thread list, if the kernel supports clone events |
| 1817 | (meaning we're always already attached to all LWPs), we use |
| 1818 | thread_from_lwp immediately when we see an LWP stop. That uses |
| 1819 | thread_db entry points that do not walk libpthread's thread list, |
| 1820 | so should be safe, as well as more efficient. */ |
| 1821 | if (target_has_execution && !thread_db_use_events ()) |
| 1822 | ops->beneath->to_update_thread_list (ops->beneath); |
| 1823 | else |
| 1824 | thread_db_update_thread_list_td_ta_thr_iter (ops); |
| 1825 | |
| 1826 | if (target_has_execution) |
| 1827 | iterate_over_lwps (minus_one_ptid /* iterate over all */, |
| 1828 | update_thread_core, NULL); |
| 1829 | } |
| 1830 | |
| 1831 | static char * |
| 1832 | thread_db_pid_to_str (struct target_ops *ops, ptid_t ptid) |
| 1833 | { |
| 1834 | struct thread_info *thread_info = find_thread_ptid (ptid); |
| 1835 | struct target_ops *beneath; |
| 1836 | |
| 1837 | if (thread_info != NULL && thread_info->priv != NULL) |
| 1838 | { |
| 1839 | static char buf[64]; |
| 1840 | thread_t tid; |
| 1841 | |
| 1842 | tid = thread_info->priv->tid; |
| 1843 | snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld)", |
| 1844 | tid, ptid_get_lwp (ptid)); |
| 1845 | |
| 1846 | return buf; |
| 1847 | } |
| 1848 | |
| 1849 | beneath = find_target_beneath (ops); |
| 1850 | return beneath->to_pid_to_str (beneath, ptid); |
| 1851 | } |
| 1852 | |
| 1853 | /* Return a string describing the state of the thread specified by |
| 1854 | INFO. */ |
| 1855 | |
| 1856 | static char * |
| 1857 | thread_db_extra_thread_info (struct target_ops *self, |
| 1858 | struct thread_info *info) |
| 1859 | { |
| 1860 | if (info->priv == NULL) |
| 1861 | return NULL; |
| 1862 | |
| 1863 | if (info->priv->dying) |
| 1864 | return "Exiting"; |
| 1865 | |
| 1866 | return NULL; |
| 1867 | } |
| 1868 | |
| 1869 | /* Get the address of the thread local variable in load module LM which |
| 1870 | is stored at OFFSET within the thread local storage for thread PTID. */ |
| 1871 | |
| 1872 | static CORE_ADDR |
| 1873 | thread_db_get_thread_local_address (struct target_ops *ops, |
| 1874 | ptid_t ptid, |
| 1875 | CORE_ADDR lm, |
| 1876 | CORE_ADDR offset) |
| 1877 | { |
| 1878 | struct thread_info *thread_info; |
| 1879 | struct target_ops *beneath; |
| 1880 | |
| 1881 | /* If we have not discovered any threads yet, check now. */ |
| 1882 | if (!have_threads (ptid)) |
| 1883 | thread_db_find_new_threads_1 (ptid); |
| 1884 | |
| 1885 | /* Find the matching thread. */ |
| 1886 | thread_info = find_thread_ptid (ptid); |
| 1887 | |
| 1888 | if (thread_info != NULL && thread_info->priv != NULL) |
| 1889 | { |
| 1890 | td_err_e err; |
| 1891 | psaddr_t address; |
| 1892 | struct thread_db_info *info; |
| 1893 | |
| 1894 | info = get_thread_db_info (ptid_get_pid (ptid)); |
| 1895 | |
| 1896 | /* Finally, get the address of the variable. */ |
| 1897 | if (lm != 0) |
| 1898 | { |
| 1899 | /* glibc doesn't provide the needed interface. */ |
| 1900 | if (!info->td_thr_tls_get_addr_p) |
| 1901 | throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR, |
| 1902 | _("No TLS library support")); |
| 1903 | |
| 1904 | /* Note the cast through uintptr_t: this interface only works if |
| 1905 | a target address fits in a psaddr_t, which is a host pointer. |
| 1906 | So a 32-bit debugger can not access 64-bit TLS through this. */ |
| 1907 | err = info->td_thr_tls_get_addr_p (&thread_info->priv->th, |
| 1908 | (psaddr_t)(uintptr_t) lm, |
| 1909 | offset, &address); |
| 1910 | } |
| 1911 | else |
| 1912 | { |
| 1913 | /* If glibc doesn't provide the needed interface throw an error |
| 1914 | that LM is zero - normally cases it should not be. */ |
| 1915 | if (!info->td_thr_tlsbase_p) |
| 1916 | throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR, |
| 1917 | _("TLS load module not found")); |
| 1918 | |
| 1919 | /* This code path handles the case of -static -pthread executables: |
| 1920 | https://sourceware.org/ml/libc-help/2014-03/msg00024.html |
| 1921 | For older GNU libc r_debug.r_map is NULL. For GNU libc after |
| 1922 | PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL. |
| 1923 | The constant number 1 depends on GNU __libc_setup_tls |
| 1924 | initialization of l_tls_modid to 1. */ |
| 1925 | err = info->td_thr_tlsbase_p (&thread_info->priv->th, |
| 1926 | 1, &address); |
| 1927 | address = (char *) address + offset; |
| 1928 | } |
| 1929 | |
| 1930 | #ifdef THREAD_DB_HAS_TD_NOTALLOC |
| 1931 | /* The memory hasn't been allocated, yet. */ |
| 1932 | if (err == TD_NOTALLOC) |
| 1933 | /* Now, if libthread_db provided the initialization image's |
| 1934 | address, we *could* try to build a non-lvalue value from |
| 1935 | the initialization image. */ |
| 1936 | throw_error (TLS_NOT_ALLOCATED_YET_ERROR, |
| 1937 | _("TLS not allocated yet")); |
| 1938 | #endif |
| 1939 | |
| 1940 | /* Something else went wrong. */ |
| 1941 | if (err != TD_OK) |
| 1942 | throw_error (TLS_GENERIC_ERROR, |
| 1943 | (("%s")), thread_db_err_str (err)); |
| 1944 | |
| 1945 | /* Cast assuming host == target. Joy. */ |
| 1946 | /* Do proper sign extension for the target. */ |
| 1947 | gdb_assert (exec_bfd); |
| 1948 | return (bfd_get_sign_extend_vma (exec_bfd) > 0 |
| 1949 | ? (CORE_ADDR) (intptr_t) address |
| 1950 | : (CORE_ADDR) (uintptr_t) address); |
| 1951 | } |
| 1952 | |
| 1953 | beneath = find_target_beneath (ops); |
| 1954 | return beneath->to_get_thread_local_address (beneath, ptid, lm, offset); |
| 1955 | } |
| 1956 | |
| 1957 | /* Implement the to_get_ada_task_ptid target method for this target. */ |
| 1958 | |
| 1959 | static ptid_t |
| 1960 | thread_db_get_ada_task_ptid (struct target_ops *self, long lwp, long thread) |
| 1961 | { |
| 1962 | /* NPTL uses a 1:1 model, so the LWP id suffices. */ |
| 1963 | return ptid_build (ptid_get_pid (inferior_ptid), lwp, 0); |
| 1964 | } |
| 1965 | |
| 1966 | static void |
| 1967 | thread_db_resume (struct target_ops *ops, |
| 1968 | ptid_t ptid, int step, enum gdb_signal signo) |
| 1969 | { |
| 1970 | struct target_ops *beneath = find_target_beneath (ops); |
| 1971 | struct thread_db_info *info; |
| 1972 | |
| 1973 | if (ptid_equal (ptid, minus_one_ptid)) |
| 1974 | info = get_thread_db_info (ptid_get_pid (inferior_ptid)); |
| 1975 | else |
| 1976 | info = get_thread_db_info (ptid_get_pid (ptid)); |
| 1977 | |
| 1978 | /* This workaround is only needed for child fork lwps stopped in a |
| 1979 | PTRACE_O_TRACEFORK event. When the inferior is resumed, the |
| 1980 | workaround can be disabled. */ |
| 1981 | if (info) |
| 1982 | info->need_stale_parent_threads_check = 0; |
| 1983 | |
| 1984 | beneath->to_resume (beneath, ptid, step, signo); |
| 1985 | } |
| 1986 | |
| 1987 | /* qsort helper function for info_auto_load_libthread_db, sort the |
| 1988 | thread_db_info pointers primarily by their FILENAME and secondarily by their |
| 1989 | PID, both in ascending order. */ |
| 1990 | |
| 1991 | static int |
| 1992 | info_auto_load_libthread_db_compare (const void *ap, const void *bp) |
| 1993 | { |
| 1994 | struct thread_db_info *a = *(struct thread_db_info **) ap; |
| 1995 | struct thread_db_info *b = *(struct thread_db_info **) bp; |
| 1996 | int retval; |
| 1997 | |
| 1998 | retval = strcmp (a->filename, b->filename); |
| 1999 | if (retval) |
| 2000 | return retval; |
| 2001 | |
| 2002 | return (a->pid > b->pid) - (a->pid - b->pid); |
| 2003 | } |
| 2004 | |
| 2005 | /* Implement 'info auto-load libthread-db'. */ |
| 2006 | |
| 2007 | static void |
| 2008 | info_auto_load_libthread_db (char *args, int from_tty) |
| 2009 | { |
| 2010 | struct ui_out *uiout = current_uiout; |
| 2011 | const char *cs = args ? args : ""; |
| 2012 | struct thread_db_info *info, **array; |
| 2013 | unsigned info_count, unique_filenames; |
| 2014 | size_t max_filename_len, max_pids_len, pids_len; |
| 2015 | struct cleanup *back_to; |
| 2016 | char *pids; |
| 2017 | int i; |
| 2018 | |
| 2019 | cs = skip_spaces_const (cs); |
| 2020 | if (*cs) |
| 2021 | error (_("'info auto-load libthread-db' does not accept any parameters")); |
| 2022 | |
| 2023 | info_count = 0; |
| 2024 | for (info = thread_db_list; info; info = info->next) |
| 2025 | if (info->filename != NULL) |
| 2026 | info_count++; |
| 2027 | |
| 2028 | array = xmalloc (sizeof (*array) * info_count); |
| 2029 | back_to = make_cleanup (xfree, array); |
| 2030 | |
| 2031 | info_count = 0; |
| 2032 | for (info = thread_db_list; info; info = info->next) |
| 2033 | if (info->filename != NULL) |
| 2034 | array[info_count++] = info; |
| 2035 | |
| 2036 | /* Sort ARRAY by filenames and PIDs. */ |
| 2037 | |
| 2038 | qsort (array, info_count, sizeof (*array), |
| 2039 | info_auto_load_libthread_db_compare); |
| 2040 | |
| 2041 | /* Calculate the number of unique filenames (rows) and the maximum string |
| 2042 | length of PIDs list for the unique filenames (columns). */ |
| 2043 | |
| 2044 | unique_filenames = 0; |
| 2045 | max_filename_len = 0; |
| 2046 | max_pids_len = 0; |
| 2047 | pids_len = 0; |
| 2048 | for (i = 0; i < info_count; i++) |
| 2049 | { |
| 2050 | int pid = array[i]->pid; |
| 2051 | size_t this_pid_len; |
| 2052 | |
| 2053 | for (this_pid_len = 0; pid != 0; pid /= 10) |
| 2054 | this_pid_len++; |
| 2055 | |
| 2056 | if (i == 0 || strcmp (array[i - 1]->filename, array[i]->filename) != 0) |
| 2057 | { |
| 2058 | unique_filenames++; |
| 2059 | max_filename_len = max (max_filename_len, |
| 2060 | strlen (array[i]->filename)); |
| 2061 | |
| 2062 | if (i > 0) |
| 2063 | { |
| 2064 | pids_len -= strlen (", "); |
| 2065 | max_pids_len = max (max_pids_len, pids_len); |
| 2066 | } |
| 2067 | pids_len = 0; |
| 2068 | } |
| 2069 | pids_len += this_pid_len + strlen (", "); |
| 2070 | } |
| 2071 | if (i) |
| 2072 | { |
| 2073 | pids_len -= strlen (", "); |
| 2074 | max_pids_len = max (max_pids_len, pids_len); |
| 2075 | } |
| 2076 | |
| 2077 | /* Table header shifted right by preceding "libthread-db: " would not match |
| 2078 | its columns. */ |
| 2079 | if (info_count > 0 && args == auto_load_info_scripts_pattern_nl) |
| 2080 | ui_out_text (uiout, "\n"); |
| 2081 | |
| 2082 | make_cleanup_ui_out_table_begin_end (uiout, 2, unique_filenames, |
| 2083 | "LinuxThreadDbTable"); |
| 2084 | |
| 2085 | ui_out_table_header (uiout, max_filename_len, ui_left, "filename", |
| 2086 | "Filename"); |
| 2087 | ui_out_table_header (uiout, pids_len, ui_left, "PIDs", "Pids"); |
| 2088 | ui_out_table_body (uiout); |
| 2089 | |
| 2090 | pids = xmalloc (max_pids_len + 1); |
| 2091 | make_cleanup (xfree, pids); |
| 2092 | |
| 2093 | /* Note I is incremented inside the cycle, not at its end. */ |
| 2094 | for (i = 0; i < info_count;) |
| 2095 | { |
| 2096 | struct cleanup *chain = make_cleanup_ui_out_tuple_begin_end (uiout, NULL); |
| 2097 | char *pids_end; |
| 2098 | |
| 2099 | info = array[i]; |
| 2100 | ui_out_field_string (uiout, "filename", info->filename); |
| 2101 | pids_end = pids; |
| 2102 | |
| 2103 | while (i < info_count && strcmp (info->filename, array[i]->filename) == 0) |
| 2104 | { |
| 2105 | if (pids_end != pids) |
| 2106 | { |
| 2107 | *pids_end++ = ','; |
| 2108 | *pids_end++ = ' '; |
| 2109 | } |
| 2110 | pids_end += xsnprintf (pids_end, &pids[max_pids_len + 1] - pids_end, |
| 2111 | "%u", array[i]->pid); |
| 2112 | gdb_assert (pids_end < &pids[max_pids_len + 1]); |
| 2113 | |
| 2114 | i++; |
| 2115 | } |
| 2116 | *pids_end = '\0'; |
| 2117 | |
| 2118 | ui_out_field_string (uiout, "pids", pids); |
| 2119 | |
| 2120 | ui_out_text (uiout, "\n"); |
| 2121 | do_cleanups (chain); |
| 2122 | } |
| 2123 | |
| 2124 | do_cleanups (back_to); |
| 2125 | |
| 2126 | if (info_count == 0) |
| 2127 | ui_out_message (uiout, 0, _("No auto-loaded libthread-db.\n")); |
| 2128 | } |
| 2129 | |
| 2130 | static void |
| 2131 | init_thread_db_ops (void) |
| 2132 | { |
| 2133 | thread_db_ops.to_shortname = "multi-thread"; |
| 2134 | thread_db_ops.to_longname = "multi-threaded child process."; |
| 2135 | thread_db_ops.to_doc = "Threads and pthreads support."; |
| 2136 | thread_db_ops.to_detach = thread_db_detach; |
| 2137 | thread_db_ops.to_wait = thread_db_wait; |
| 2138 | thread_db_ops.to_resume = thread_db_resume; |
| 2139 | thread_db_ops.to_mourn_inferior = thread_db_mourn_inferior; |
| 2140 | thread_db_ops.to_update_thread_list = thread_db_update_thread_list; |
| 2141 | thread_db_ops.to_pid_to_str = thread_db_pid_to_str; |
| 2142 | thread_db_ops.to_stratum = thread_stratum; |
| 2143 | thread_db_ops.to_has_thread_control = tc_schedlock; |
| 2144 | thread_db_ops.to_get_thread_local_address |
| 2145 | = thread_db_get_thread_local_address; |
| 2146 | thread_db_ops.to_extra_thread_info = thread_db_extra_thread_info; |
| 2147 | thread_db_ops.to_get_ada_task_ptid = thread_db_get_ada_task_ptid; |
| 2148 | thread_db_ops.to_magic = OPS_MAGIC; |
| 2149 | |
| 2150 | complete_target_initialization (&thread_db_ops); |
| 2151 | } |
| 2152 | |
| 2153 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 2154 | extern initialize_file_ftype _initialize_thread_db; |
| 2155 | |
| 2156 | void |
| 2157 | _initialize_thread_db (void) |
| 2158 | { |
| 2159 | init_thread_db_ops (); |
| 2160 | |
| 2161 | /* Defer loading of libthread_db.so until inferior is running. |
| 2162 | This allows gdb to load correct libthread_db for a given |
| 2163 | executable -- there could be mutiple versions of glibc, |
| 2164 | compiled with LinuxThreads or NPTL, and until there is |
| 2165 | a running inferior, we can't tell which libthread_db is |
| 2166 | the correct one to load. */ |
| 2167 | |
| 2168 | libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH); |
| 2169 | |
| 2170 | add_setshow_optional_filename_cmd ("libthread-db-search-path", |
| 2171 | class_support, |
| 2172 | &libthread_db_search_path, _("\ |
| 2173 | Set search path for libthread_db."), _("\ |
| 2174 | Show the current search path or libthread_db."), _("\ |
| 2175 | This path is used to search for libthread_db to be loaded into \ |
| 2176 | gdb itself.\n\ |
| 2177 | Its value is a colon (':') separate list of directories to search.\n\ |
| 2178 | Setting the search path to an empty list resets it to its default value."), |
| 2179 | set_libthread_db_search_path, |
| 2180 | NULL, |
| 2181 | &setlist, &showlist); |
| 2182 | |
| 2183 | add_setshow_zuinteger_cmd ("libthread-db", class_maintenance, |
| 2184 | &libthread_db_debug, _("\ |
| 2185 | Set libthread-db debugging."), _("\ |
| 2186 | Show libthread-db debugging."), _("\ |
| 2187 | When non-zero, libthread-db debugging is enabled."), |
| 2188 | NULL, |
| 2189 | show_libthread_db_debug, |
| 2190 | &setdebuglist, &showdebuglist); |
| 2191 | |
| 2192 | add_setshow_boolean_cmd ("libthread-db", class_support, |
| 2193 | &auto_load_thread_db, _("\ |
| 2194 | Enable or disable auto-loading of inferior specific libthread_db."), _("\ |
| 2195 | Show whether auto-loading inferior specific libthread_db is enabled."), _("\ |
| 2196 | If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\ |
| 2197 | locations to load libthread_db compatible with the inferior.\n\ |
| 2198 | Standard system libthread_db still gets loaded even with this option off.\n\ |
| 2199 | This options has security implications for untrusted inferiors."), |
| 2200 | NULL, show_auto_load_thread_db, |
| 2201 | auto_load_set_cmdlist_get (), |
| 2202 | auto_load_show_cmdlist_get ()); |
| 2203 | |
| 2204 | add_cmd ("libthread-db", class_info, info_auto_load_libthread_db, |
| 2205 | _("Print the list of loaded inferior specific libthread_db.\n\ |
| 2206 | Usage: info auto-load libthread-db"), |
| 2207 | auto_load_info_cmdlist_get ()); |
| 2208 | |
| 2209 | /* Add ourselves to objfile event chain. */ |
| 2210 | observer_attach_new_objfile (thread_db_new_objfile); |
| 2211 | |
| 2212 | /* Add ourselves to inferior_created event chain. |
| 2213 | This is needed to handle debugging statically linked programs where |
| 2214 | the new_objfile observer won't get called for libpthread. */ |
| 2215 | observer_attach_inferior_created (thread_db_inferior_created); |
| 2216 | } |