| 1 | /* libthread_db assisted debugging support, generic parts. |
| 2 | |
| 3 | Copyright (C) 1999-2019 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include <dlfcn.h> |
| 22 | #include "gdb_proc_service.h" |
| 23 | #include "nat/gdb_thread_db.h" |
| 24 | #include "common/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 "observable.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 | #include <signal.h> |
| 46 | #include <ctype.h> |
| 47 | #include "nat/linux-namespaces.h" |
| 48 | #include <algorithm> |
| 49 | #include "common/pathstuff.h" |
| 50 | #include "valprint.h" |
| 51 | |
| 52 | /* GNU/Linux libthread_db support. |
| 53 | |
| 54 | libthread_db is a library, provided along with libpthread.so, which |
| 55 | exposes the internals of the thread library to a debugger. It |
| 56 | allows GDB to find existing threads, new threads as they are |
| 57 | created, thread IDs (usually, the result of pthread_self), and |
| 58 | thread-local variables. |
| 59 | |
| 60 | The libthread_db interface originates on Solaris, where it is both |
| 61 | more powerful and more complicated. This implementation only works |
| 62 | for NPTL, the glibc threading library. It assumes that each thread |
| 63 | is permanently assigned to a single light-weight process (LWP). At |
| 64 | some point it also supported the older LinuxThreads library, but it |
| 65 | no longer does. |
| 66 | |
| 67 | libthread_db-specific information is stored in the "private" field |
| 68 | of struct thread_info. When the field is NULL we do not yet have |
| 69 | information about the new thread; this could be temporary (created, |
| 70 | but the thread library's data structures do not reflect it yet) |
| 71 | or permanent (created using clone instead of pthread_create). |
| 72 | |
| 73 | Process IDs managed by linux-thread-db.c match those used by |
| 74 | linux-nat.c: a common PID for all processes, an LWP ID for each |
| 75 | thread, and no TID. We save the TID in private. Keeping it out |
| 76 | of the ptid_t prevents thread IDs changing when libpthread is |
| 77 | loaded or unloaded. */ |
| 78 | |
| 79 | static const target_info thread_db_target_info = { |
| 80 | "multi-thread", |
| 81 | N_("multi-threaded child process."), |
| 82 | N_("Threads and pthreads support.") |
| 83 | }; |
| 84 | |
| 85 | class thread_db_target final : public target_ops |
| 86 | { |
| 87 | public: |
| 88 | const target_info &info () const override |
| 89 | { return thread_db_target_info; } |
| 90 | |
| 91 | strata stratum () const override { return thread_stratum; } |
| 92 | |
| 93 | void detach (inferior *, int) override; |
| 94 | ptid_t wait (ptid_t, struct target_waitstatus *, int) override; |
| 95 | void resume (ptid_t, int, enum gdb_signal) override; |
| 96 | void mourn_inferior () override; |
| 97 | void update_thread_list () override; |
| 98 | std::string pid_to_str (ptid_t) override; |
| 99 | CORE_ADDR get_thread_local_address (ptid_t ptid, |
| 100 | CORE_ADDR load_module_addr, |
| 101 | CORE_ADDR offset) override; |
| 102 | const char *extra_thread_info (struct thread_info *) override; |
| 103 | ptid_t get_ada_task_ptid (long lwp, long thread) override; |
| 104 | |
| 105 | thread_info *thread_handle_to_thread_info (const gdb_byte *thread_handle, |
| 106 | int handle_len, |
| 107 | inferior *inf) override; |
| 108 | gdb::byte_vector thread_info_to_thread_handle (struct thread_info *) override; |
| 109 | }; |
| 110 | |
| 111 | static char *libthread_db_search_path; |
| 112 | |
| 113 | /* Set to non-zero if thread_db auto-loading is enabled |
| 114 | by the "set auto-load libthread-db" command. */ |
| 115 | static int auto_load_thread_db = 1; |
| 116 | |
| 117 | /* Set to non-zero if load-time libthread_db tests have been enabled |
| 118 | by the "maintenence set check-libthread-db" command. */ |
| 119 | static int check_thread_db_on_load = 0; |
| 120 | |
| 121 | /* "show" command for the auto_load_thread_db configuration variable. */ |
| 122 | |
| 123 | static void |
| 124 | show_auto_load_thread_db (struct ui_file *file, int from_tty, |
| 125 | struct cmd_list_element *c, const char *value) |
| 126 | { |
| 127 | fprintf_filtered (file, _("Auto-loading of inferior specific libthread_db " |
| 128 | "is %s.\n"), |
| 129 | value); |
| 130 | } |
| 131 | |
| 132 | static void |
| 133 | set_libthread_db_search_path (const char *ignored, int from_tty, |
| 134 | struct cmd_list_element *c) |
| 135 | { |
| 136 | if (*libthread_db_search_path == '\0') |
| 137 | { |
| 138 | xfree (libthread_db_search_path); |
| 139 | libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH); |
| 140 | } |
| 141 | } |
| 142 | |
| 143 | /* If non-zero, print details of libthread_db processing. */ |
| 144 | |
| 145 | static unsigned int libthread_db_debug; |
| 146 | |
| 147 | static void |
| 148 | show_libthread_db_debug (struct ui_file *file, int from_tty, |
| 149 | struct cmd_list_element *c, const char *value) |
| 150 | { |
| 151 | fprintf_filtered (file, _("libthread-db debugging is %s.\n"), value); |
| 152 | } |
| 153 | |
| 154 | /* If we're running on GNU/Linux, we must explicitly attach to any new |
| 155 | threads. */ |
| 156 | |
| 157 | /* This module's target vector. */ |
| 158 | static thread_db_target the_thread_db_target; |
| 159 | |
| 160 | /* Non-zero if we have determined the signals used by the threads |
| 161 | library. */ |
| 162 | static int thread_signals; |
| 163 | static sigset_t thread_stop_set; |
| 164 | static sigset_t thread_print_set; |
| 165 | |
| 166 | struct thread_db_info |
| 167 | { |
| 168 | struct thread_db_info *next; |
| 169 | |
| 170 | /* Process id this object refers to. */ |
| 171 | int pid; |
| 172 | |
| 173 | /* Handle from dlopen for libthread_db.so. */ |
| 174 | void *handle; |
| 175 | |
| 176 | /* Absolute pathname from gdb_realpath to disk file used for dlopen-ing |
| 177 | HANDLE. It may be NULL for system library. */ |
| 178 | char *filename; |
| 179 | |
| 180 | /* Structure that identifies the child process for the |
| 181 | <proc_service.h> interface. */ |
| 182 | struct ps_prochandle proc_handle; |
| 183 | |
| 184 | /* Connection to the libthread_db library. */ |
| 185 | td_thragent_t *thread_agent; |
| 186 | |
| 187 | /* True if we need to apply the workaround for glibc/BZ5983. When |
| 188 | we catch a PTRACE_O_TRACEFORK, and go query the child's thread |
| 189 | list, nptl_db returns the parent's threads in addition to the new |
| 190 | (single) child thread. If this flag is set, we do extra work to |
| 191 | be able to ignore such stale entries. */ |
| 192 | int need_stale_parent_threads_check; |
| 193 | |
| 194 | /* Pointers to the libthread_db functions. */ |
| 195 | |
| 196 | td_init_ftype *td_init_p; |
| 197 | td_ta_new_ftype *td_ta_new_p; |
| 198 | td_ta_delete_ftype *td_ta_delete_p; |
| 199 | td_ta_map_lwp2thr_ftype *td_ta_map_lwp2thr_p; |
| 200 | td_ta_thr_iter_ftype *td_ta_thr_iter_p; |
| 201 | td_thr_get_info_ftype *td_thr_get_info_p; |
| 202 | td_thr_tls_get_addr_ftype *td_thr_tls_get_addr_p; |
| 203 | td_thr_tlsbase_ftype *td_thr_tlsbase_p; |
| 204 | }; |
| 205 | |
| 206 | /* List of known processes using thread_db, and the required |
| 207 | bookkeeping. */ |
| 208 | struct thread_db_info *thread_db_list; |
| 209 | |
| 210 | static void thread_db_find_new_threads_1 (thread_info *stopped); |
| 211 | static void thread_db_find_new_threads_2 (thread_info *stopped, |
| 212 | bool until_no_new); |
| 213 | |
| 214 | static void check_thread_signals (void); |
| 215 | |
| 216 | static struct thread_info *record_thread |
| 217 | (struct thread_db_info *info, struct thread_info *tp, |
| 218 | ptid_t ptid, const td_thrhandle_t *th_p, const td_thrinfo_t *ti_p); |
| 219 | |
| 220 | /* Add the current inferior to the list of processes using libpthread. |
| 221 | Return a pointer to the newly allocated object that was added to |
| 222 | THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing |
| 223 | LIBTHREAD_DB_SO. */ |
| 224 | |
| 225 | static struct thread_db_info * |
| 226 | add_thread_db_info (void *handle) |
| 227 | { |
| 228 | struct thread_db_info *info = XCNEW (struct thread_db_info); |
| 229 | |
| 230 | info->pid = inferior_ptid.pid (); |
| 231 | info->handle = handle; |
| 232 | |
| 233 | /* The workaround works by reading from /proc/pid/status, so it is |
| 234 | disabled for core files. */ |
| 235 | if (target_has_execution) |
| 236 | info->need_stale_parent_threads_check = 1; |
| 237 | |
| 238 | info->next = thread_db_list; |
| 239 | thread_db_list = info; |
| 240 | |
| 241 | return info; |
| 242 | } |
| 243 | |
| 244 | /* Return the thread_db_info object representing the bookkeeping |
| 245 | related to process PID, if any; NULL otherwise. */ |
| 246 | |
| 247 | static struct thread_db_info * |
| 248 | get_thread_db_info (int pid) |
| 249 | { |
| 250 | struct thread_db_info *info; |
| 251 | |
| 252 | for (info = thread_db_list; info; info = info->next) |
| 253 | if (pid == info->pid) |
| 254 | return info; |
| 255 | |
| 256 | return NULL; |
| 257 | } |
| 258 | |
| 259 | static const char *thread_db_err_str (td_err_e err); |
| 260 | |
| 261 | /* When PID has exited or has been detached, we no longer want to keep |
| 262 | track of it as using libpthread. Call this function to discard |
| 263 | thread_db related info related to PID. Note that this closes |
| 264 | LIBTHREAD_DB_SO's dlopen'ed handle. */ |
| 265 | |
| 266 | static void |
| 267 | delete_thread_db_info (int pid) |
| 268 | { |
| 269 | struct thread_db_info *info, *info_prev; |
| 270 | |
| 271 | info_prev = NULL; |
| 272 | |
| 273 | for (info = thread_db_list; info; info_prev = info, info = info->next) |
| 274 | if (pid == info->pid) |
| 275 | break; |
| 276 | |
| 277 | if (info == NULL) |
| 278 | return; |
| 279 | |
| 280 | if (info->thread_agent != NULL && info->td_ta_delete_p != NULL) |
| 281 | { |
| 282 | td_err_e err = info->td_ta_delete_p (info->thread_agent); |
| 283 | |
| 284 | if (err != TD_OK) |
| 285 | warning (_("Cannot deregister process %d from libthread_db: %s"), |
| 286 | pid, thread_db_err_str (err)); |
| 287 | info->thread_agent = NULL; |
| 288 | } |
| 289 | |
| 290 | if (info->handle != NULL) |
| 291 | dlclose (info->handle); |
| 292 | |
| 293 | xfree (info->filename); |
| 294 | |
| 295 | if (info_prev) |
| 296 | info_prev->next = info->next; |
| 297 | else |
| 298 | thread_db_list = info->next; |
| 299 | |
| 300 | xfree (info); |
| 301 | } |
| 302 | |
| 303 | /* Use "struct private_thread_info" to cache thread state. This is |
| 304 | a substantial optimization. */ |
| 305 | |
| 306 | struct thread_db_thread_info : public private_thread_info |
| 307 | { |
| 308 | /* Flag set when we see a TD_DEATH event for this thread. */ |
| 309 | bool dying = false; |
| 310 | |
| 311 | /* Cached thread state. */ |
| 312 | td_thrhandle_t th {}; |
| 313 | thread_t tid {}; |
| 314 | }; |
| 315 | |
| 316 | static thread_db_thread_info * |
| 317 | get_thread_db_thread_info (thread_info *thread) |
| 318 | { |
| 319 | return static_cast<thread_db_thread_info *> (thread->priv.get ()); |
| 320 | } |
| 321 | |
| 322 | static const char * |
| 323 | thread_db_err_str (td_err_e err) |
| 324 | { |
| 325 | static char buf[64]; |
| 326 | |
| 327 | switch (err) |
| 328 | { |
| 329 | case TD_OK: |
| 330 | return "generic 'call succeeded'"; |
| 331 | case TD_ERR: |
| 332 | return "generic error"; |
| 333 | case TD_NOTHR: |
| 334 | return "no thread to satisfy query"; |
| 335 | case TD_NOSV: |
| 336 | return "no sync handle to satisfy query"; |
| 337 | case TD_NOLWP: |
| 338 | return "no LWP to satisfy query"; |
| 339 | case TD_BADPH: |
| 340 | return "invalid process handle"; |
| 341 | case TD_BADTH: |
| 342 | return "invalid thread handle"; |
| 343 | case TD_BADSH: |
| 344 | return "invalid synchronization handle"; |
| 345 | case TD_BADTA: |
| 346 | return "invalid thread agent"; |
| 347 | case TD_BADKEY: |
| 348 | return "invalid key"; |
| 349 | case TD_NOMSG: |
| 350 | return "no event message for getmsg"; |
| 351 | case TD_NOFPREGS: |
| 352 | return "FPU register set not available"; |
| 353 | case TD_NOLIBTHREAD: |
| 354 | return "application not linked with libthread"; |
| 355 | case TD_NOEVENT: |
| 356 | return "requested event is not supported"; |
| 357 | case TD_NOCAPAB: |
| 358 | return "capability not available"; |
| 359 | case TD_DBERR: |
| 360 | return "debugger service failed"; |
| 361 | case TD_NOAPLIC: |
| 362 | return "operation not applicable to"; |
| 363 | case TD_NOTSD: |
| 364 | return "no thread-specific data for this thread"; |
| 365 | case TD_MALLOC: |
| 366 | return "malloc failed"; |
| 367 | case TD_PARTIALREG: |
| 368 | return "only part of register set was written/read"; |
| 369 | case TD_NOXREGS: |
| 370 | return "X register set not available for this thread"; |
| 371 | #ifdef THREAD_DB_HAS_TD_NOTALLOC |
| 372 | case TD_NOTALLOC: |
| 373 | return "thread has not yet allocated TLS for given module"; |
| 374 | #endif |
| 375 | #ifdef THREAD_DB_HAS_TD_VERSION |
| 376 | case TD_VERSION: |
| 377 | return "versions of libpthread and libthread_db do not match"; |
| 378 | #endif |
| 379 | #ifdef THREAD_DB_HAS_TD_NOTLS |
| 380 | case TD_NOTLS: |
| 381 | return "there is no TLS segment in the given module"; |
| 382 | #endif |
| 383 | default: |
| 384 | snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err); |
| 385 | return buf; |
| 386 | } |
| 387 | } |
| 388 | |
| 389 | /* Fetch the user-level thread id of PTID. STOPPED is a stopped |
| 390 | thread that we can use to access memory. */ |
| 391 | |
| 392 | static struct thread_info * |
| 393 | thread_from_lwp (thread_info *stopped, ptid_t ptid) |
| 394 | { |
| 395 | td_thrhandle_t th; |
| 396 | td_thrinfo_t ti; |
| 397 | td_err_e err; |
| 398 | struct thread_db_info *info; |
| 399 | struct thread_info *tp; |
| 400 | |
| 401 | /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */ |
| 402 | th.th_unique = 0; |
| 403 | |
| 404 | /* This ptid comes from linux-nat.c, which should always fill in the |
| 405 | LWP. */ |
| 406 | gdb_assert (ptid.lwp () != 0); |
| 407 | |
| 408 | info = get_thread_db_info (ptid.pid ()); |
| 409 | |
| 410 | /* Access an lwp we know is stopped. */ |
| 411 | info->proc_handle.thread = stopped; |
| 412 | err = info->td_ta_map_lwp2thr_p (info->thread_agent, ptid.lwp (), |
| 413 | &th); |
| 414 | if (err != TD_OK) |
| 415 | error (_("Cannot find user-level thread for LWP %ld: %s"), |
| 416 | ptid.lwp (), thread_db_err_str (err)); |
| 417 | |
| 418 | err = info->td_thr_get_info_p (&th, &ti); |
| 419 | if (err != TD_OK) |
| 420 | error (_("thread_get_info_callback: cannot get thread info: %s"), |
| 421 | thread_db_err_str (err)); |
| 422 | |
| 423 | /* Fill the cache. */ |
| 424 | tp = find_thread_ptid (ptid); |
| 425 | return record_thread (info, tp, ptid, &th, &ti); |
| 426 | } |
| 427 | \f |
| 428 | |
| 429 | /* See linux-nat.h. */ |
| 430 | |
| 431 | int |
| 432 | thread_db_notice_clone (ptid_t parent, ptid_t child) |
| 433 | { |
| 434 | struct thread_db_info *info; |
| 435 | |
| 436 | info = get_thread_db_info (child.pid ()); |
| 437 | |
| 438 | if (info == NULL) |
| 439 | return 0; |
| 440 | |
| 441 | thread_info *stopped = find_thread_ptid (parent); |
| 442 | |
| 443 | thread_from_lwp (stopped, child); |
| 444 | |
| 445 | /* If we do not know about the main thread's pthread info yet, this |
| 446 | would be a good time to find it. */ |
| 447 | thread_from_lwp (stopped, parent); |
| 448 | return 1; |
| 449 | } |
| 450 | |
| 451 | static void * |
| 452 | verbose_dlsym (void *handle, const char *name) |
| 453 | { |
| 454 | void *sym = dlsym (handle, name); |
| 455 | if (sym == NULL) |
| 456 | warning (_("Symbol \"%s\" not found in libthread_db: %s"), |
| 457 | name, dlerror ()); |
| 458 | return sym; |
| 459 | } |
| 460 | |
| 461 | /* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and |
| 462 | return 1 if this version is lower (and not equal) to |
| 463 | VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */ |
| 464 | |
| 465 | static int |
| 466 | inferior_has_bug (const char *ver_symbol, int ver_major_min, int ver_minor_min) |
| 467 | { |
| 468 | struct bound_minimal_symbol version_msym; |
| 469 | CORE_ADDR version_addr; |
| 470 | gdb::unique_xmalloc_ptr<char> version; |
| 471 | int err, got, retval = 0; |
| 472 | |
| 473 | version_msym = lookup_minimal_symbol (ver_symbol, NULL, NULL); |
| 474 | if (version_msym.minsym == NULL) |
| 475 | return 0; |
| 476 | |
| 477 | version_addr = BMSYMBOL_VALUE_ADDRESS (version_msym); |
| 478 | got = target_read_string (version_addr, &version, 32, &err); |
| 479 | if (err == 0 && memchr (version.get (), 0, got) == version.get () + got - 1) |
| 480 | { |
| 481 | int major, minor; |
| 482 | |
| 483 | retval = (sscanf (version.get (), "%d.%d", &major, &minor) == 2 |
| 484 | && (major < ver_major_min |
| 485 | || (major == ver_major_min && minor < ver_minor_min))); |
| 486 | } |
| 487 | |
| 488 | return retval; |
| 489 | } |
| 490 | |
| 491 | /* Similar as thread_db_find_new_threads_1, but try to silently ignore errors |
| 492 | if appropriate. |
| 493 | |
| 494 | Return 1 if the caller should abort libthread_db initialization. Return 0 |
| 495 | otherwise. */ |
| 496 | |
| 497 | static int |
| 498 | thread_db_find_new_threads_silently (thread_info *stopped) |
| 499 | { |
| 500 | |
| 501 | try |
| 502 | { |
| 503 | thread_db_find_new_threads_2 (stopped, true); |
| 504 | } |
| 505 | |
| 506 | catch (const gdb_exception_error &except) |
| 507 | { |
| 508 | if (libthread_db_debug) |
| 509 | exception_fprintf (gdb_stdlog, except, |
| 510 | "Warning: thread_db_find_new_threads_silently: "); |
| 511 | |
| 512 | /* There is a bug fixed between nptl 2.6.1 and 2.7 by |
| 513 | commit 7d9d8bd18906fdd17364f372b160d7ab896ce909 |
| 514 | where calls to td_thr_get_info fail with TD_ERR for statically linked |
| 515 | executables if td_thr_get_info is called before glibc has initialized |
| 516 | itself. |
| 517 | |
| 518 | If the nptl bug is NOT present in the inferior and still thread_db |
| 519 | reports an error return 1. It means the inferior has corrupted thread |
| 520 | list and GDB should fall back only to LWPs. |
| 521 | |
| 522 | If the nptl bug is present in the inferior return 0 to silently ignore |
| 523 | such errors, and let gdb enumerate threads again later. In such case |
| 524 | GDB cannot properly display LWPs if the inferior thread list is |
| 525 | corrupted. For core files it does not apply, no 'later enumeration' |
| 526 | is possible. */ |
| 527 | |
| 528 | if (!target_has_execution || !inferior_has_bug ("nptl_version", 2, 7)) |
| 529 | { |
| 530 | exception_fprintf (gdb_stderr, except, |
| 531 | _("Warning: couldn't activate thread debugging " |
| 532 | "using libthread_db: ")); |
| 533 | return 1; |
| 534 | } |
| 535 | } |
| 536 | |
| 537 | return 0; |
| 538 | } |
| 539 | |
| 540 | /* Lookup a library in which given symbol resides. |
| 541 | Note: this is looking in GDB process, not in the inferior. |
| 542 | Returns library name, or NULL. */ |
| 543 | |
| 544 | static const char * |
| 545 | dladdr_to_soname (const void *addr) |
| 546 | { |
| 547 | Dl_info info; |
| 548 | |
| 549 | if (dladdr (addr, &info) != 0) |
| 550 | return info.dli_fname; |
| 551 | return NULL; |
| 552 | } |
| 553 | |
| 554 | /* State for check_thread_db_callback. */ |
| 555 | |
| 556 | struct check_thread_db_info |
| 557 | { |
| 558 | /* The libthread_db under test. */ |
| 559 | struct thread_db_info *info; |
| 560 | |
| 561 | /* True if progress should be logged. */ |
| 562 | bool log_progress; |
| 563 | |
| 564 | /* True if the callback was called. */ |
| 565 | bool threads_seen; |
| 566 | |
| 567 | /* Name of last libthread_db function called. */ |
| 568 | const char *last_call; |
| 569 | |
| 570 | /* Value returned by last libthread_db call. */ |
| 571 | td_err_e last_result; |
| 572 | }; |
| 573 | |
| 574 | static struct check_thread_db_info *tdb_testinfo; |
| 575 | |
| 576 | /* Callback for check_thread_db. */ |
| 577 | |
| 578 | static int |
| 579 | check_thread_db_callback (const td_thrhandle_t *th, void *arg) |
| 580 | { |
| 581 | gdb_assert (tdb_testinfo != NULL); |
| 582 | tdb_testinfo->threads_seen = true; |
| 583 | |
| 584 | #define LOG(fmt, args...) \ |
| 585 | do \ |
| 586 | { \ |
| 587 | if (tdb_testinfo->log_progress) \ |
| 588 | { \ |
| 589 | debug_printf (fmt, ## args); \ |
| 590 | gdb_flush (gdb_stdlog); \ |
| 591 | } \ |
| 592 | } \ |
| 593 | while (0) |
| 594 | |
| 595 | #define CHECK_1(expr, args...) \ |
| 596 | do \ |
| 597 | { \ |
| 598 | if (!(expr)) \ |
| 599 | { \ |
| 600 | LOG (" ... FAIL!\n"); \ |
| 601 | error (args); \ |
| 602 | } \ |
| 603 | } \ |
| 604 | while (0) |
| 605 | |
| 606 | #define CHECK(expr) \ |
| 607 | CHECK_1 (expr, "(%s) == false", #expr) |
| 608 | |
| 609 | #define CALL_UNCHECKED(func, args...) \ |
| 610 | do \ |
| 611 | { \ |
| 612 | tdb_testinfo->last_call = #func; \ |
| 613 | tdb_testinfo->last_result \ |
| 614 | = tdb_testinfo->info->func ## _p (args); \ |
| 615 | } \ |
| 616 | while (0) |
| 617 | |
| 618 | #define CHECK_CALL() \ |
| 619 | CHECK_1 (tdb_testinfo->last_result == TD_OK, \ |
| 620 | _("%s failed: %s"), \ |
| 621 | tdb_testinfo->last_call, \ |
| 622 | thread_db_err_str (tdb_testinfo->last_result)) \ |
| 623 | |
| 624 | #define CALL(func, args...) \ |
| 625 | do \ |
| 626 | { \ |
| 627 | CALL_UNCHECKED (func, args); \ |
| 628 | CHECK_CALL (); \ |
| 629 | } \ |
| 630 | while (0) |
| 631 | |
| 632 | LOG (" Got thread"); |
| 633 | |
| 634 | /* Check td_ta_thr_iter passed consistent arguments. */ |
| 635 | CHECK (th != NULL); |
| 636 | CHECK (arg == (void *) tdb_testinfo); |
| 637 | CHECK (th->th_ta_p == tdb_testinfo->info->thread_agent); |
| 638 | |
| 639 | LOG (" %s", core_addr_to_string_nz ((CORE_ADDR) th->th_unique)); |
| 640 | |
| 641 | /* Check td_thr_get_info. */ |
| 642 | td_thrinfo_t ti; |
| 643 | CALL (td_thr_get_info, th, &ti); |
| 644 | |
| 645 | LOG (" => %d", ti.ti_lid); |
| 646 | |
| 647 | CHECK (ti.ti_ta_p == th->th_ta_p); |
| 648 | CHECK (ti.ti_tid == (thread_t) th->th_unique); |
| 649 | |
| 650 | /* Check td_ta_map_lwp2thr. */ |
| 651 | td_thrhandle_t th2; |
| 652 | memset (&th2, 23, sizeof (td_thrhandle_t)); |
| 653 | CALL_UNCHECKED (td_ta_map_lwp2thr, th->th_ta_p, ti.ti_lid, &th2); |
| 654 | |
| 655 | if (tdb_testinfo->last_result == TD_ERR && !target_has_execution) |
| 656 | { |
| 657 | /* Some platforms require execution for td_ta_map_lwp2thr. */ |
| 658 | LOG (_("; can't map_lwp2thr")); |
| 659 | } |
| 660 | else |
| 661 | { |
| 662 | CHECK_CALL (); |
| 663 | |
| 664 | LOG (" => %s", core_addr_to_string_nz ((CORE_ADDR) th2.th_unique)); |
| 665 | |
| 666 | CHECK (memcmp (th, &th2, sizeof (td_thrhandle_t)) == 0); |
| 667 | } |
| 668 | |
| 669 | /* Attempt TLS access. Assuming errno is TLS, this calls |
| 670 | thread_db_get_thread_local_address, which in turn calls |
| 671 | td_thr_tls_get_addr for live inferiors or td_thr_tlsbase |
| 672 | for core files. This test is skipped if the thread has |
| 673 | not been recorded; proceeding in that case would result |
| 674 | in the test having the side-effect of noticing threads |
| 675 | which seems wrong. |
| 676 | |
| 677 | Note that in glibc's libthread_db td_thr_tls_get_addr is |
| 678 | a thin wrapper around td_thr_tlsbase; this check always |
| 679 | hits the bulk of the code. |
| 680 | |
| 681 | Note also that we don't actually check any libthread_db |
| 682 | calls are made, we just assume they were; future changes |
| 683 | to how GDB accesses TLS could result in this passing |
| 684 | without exercising the calls it's supposed to. */ |
| 685 | ptid_t ptid = ptid_t (tdb_testinfo->info->pid, ti.ti_lid, 0); |
| 686 | struct thread_info *thread_info = find_thread_ptid (ptid); |
| 687 | if (thread_info != NULL && thread_info->priv != NULL) |
| 688 | { |
| 689 | LOG ("; errno"); |
| 690 | |
| 691 | scoped_restore_current_thread restore_current_thread; |
| 692 | switch_to_thread (ptid); |
| 693 | |
| 694 | expression_up expr = parse_expression ("(int) errno"); |
| 695 | struct value *val = evaluate_expression (expr.get ()); |
| 696 | |
| 697 | if (tdb_testinfo->log_progress) |
| 698 | { |
| 699 | struct value_print_options opts; |
| 700 | |
| 701 | get_user_print_options (&opts); |
| 702 | LOG (" = "); |
| 703 | value_print (val, gdb_stdlog, &opts); |
| 704 | } |
| 705 | } |
| 706 | |
| 707 | LOG (" ... OK\n"); |
| 708 | |
| 709 | #undef LOG |
| 710 | #undef CHECK_1 |
| 711 | #undef CHECK |
| 712 | #undef CALL_UNCHECKED |
| 713 | #undef CHECK_CALL |
| 714 | #undef CALL |
| 715 | |
| 716 | return 0; |
| 717 | } |
| 718 | |
| 719 | /* Run integrity checks on the dlopen()ed libthread_db described by |
| 720 | INFO. Returns true on success, displays a warning and returns |
| 721 | false on failure. Logs progress messages to gdb_stdlog during |
| 722 | the test if LOG_PROGRESS is true. */ |
| 723 | |
| 724 | static bool |
| 725 | check_thread_db (struct thread_db_info *info, bool log_progress) |
| 726 | { |
| 727 | bool test_passed = true; |
| 728 | |
| 729 | if (log_progress) |
| 730 | debug_printf (_("Running libthread_db integrity checks:\n")); |
| 731 | |
| 732 | /* GDB avoids using td_ta_thr_iter wherever possible (see comment |
| 733 | in try_thread_db_load_1 below) so in order to test it we may |
| 734 | have to locate it ourselves. */ |
| 735 | td_ta_thr_iter_ftype *td_ta_thr_iter_p = info->td_ta_thr_iter_p; |
| 736 | if (td_ta_thr_iter_p == NULL) |
| 737 | { |
| 738 | void *thr_iter = verbose_dlsym (info->handle, "td_ta_thr_iter"); |
| 739 | if (thr_iter == NULL) |
| 740 | return 0; |
| 741 | |
| 742 | td_ta_thr_iter_p = (td_ta_thr_iter_ftype *) thr_iter; |
| 743 | } |
| 744 | |
| 745 | /* Set up the test state we share with the callback. */ |
| 746 | gdb_assert (tdb_testinfo == NULL); |
| 747 | struct check_thread_db_info tdb_testinfo_buf; |
| 748 | tdb_testinfo = &tdb_testinfo_buf; |
| 749 | |
| 750 | memset (tdb_testinfo, 0, sizeof (struct check_thread_db_info)); |
| 751 | tdb_testinfo->info = info; |
| 752 | tdb_testinfo->log_progress = log_progress; |
| 753 | |
| 754 | /* td_ta_thr_iter shouldn't be used on running processes. Note that |
| 755 | it's possible the inferior will stop midway through modifying one |
| 756 | of its thread lists, in which case the check will spuriously |
| 757 | fail. */ |
| 758 | linux_stop_and_wait_all_lwps (); |
| 759 | |
| 760 | try |
| 761 | { |
| 762 | td_err_e err = td_ta_thr_iter_p (info->thread_agent, |
| 763 | check_thread_db_callback, |
| 764 | tdb_testinfo, |
| 765 | TD_THR_ANY_STATE, |
| 766 | TD_THR_LOWEST_PRIORITY, |
| 767 | TD_SIGNO_MASK, |
| 768 | TD_THR_ANY_USER_FLAGS); |
| 769 | |
| 770 | if (err != TD_OK) |
| 771 | error (_("td_ta_thr_iter failed: %s"), thread_db_err_str (err)); |
| 772 | |
| 773 | if (!tdb_testinfo->threads_seen) |
| 774 | error (_("no threads seen")); |
| 775 | } |
| 776 | catch (const gdb_exception_error &except) |
| 777 | { |
| 778 | if (warning_pre_print) |
| 779 | fputs_unfiltered (warning_pre_print, gdb_stderr); |
| 780 | |
| 781 | exception_fprintf (gdb_stderr, except, |
| 782 | _("libthread_db integrity checks failed: ")); |
| 783 | |
| 784 | test_passed = false; |
| 785 | } |
| 786 | |
| 787 | if (test_passed && log_progress) |
| 788 | debug_printf (_("libthread_db integrity checks passed.\n")); |
| 789 | |
| 790 | tdb_testinfo = NULL; |
| 791 | |
| 792 | linux_unstop_all_lwps (); |
| 793 | |
| 794 | return test_passed; |
| 795 | } |
| 796 | |
| 797 | /* Attempt to initialize dlopen()ed libthread_db, described by INFO. |
| 798 | Return true on success. |
| 799 | Failure could happen if libthread_db does not have symbols we expect, |
| 800 | or when it refuses to work with the current inferior (e.g. due to |
| 801 | version mismatch between libthread_db and libpthread). */ |
| 802 | |
| 803 | static bool |
| 804 | try_thread_db_load_1 (struct thread_db_info *info) |
| 805 | { |
| 806 | td_err_e err; |
| 807 | |
| 808 | /* Initialize pointers to the dynamic library functions we will use. |
| 809 | Essential functions first. */ |
| 810 | |
| 811 | #define TDB_VERBOSE_DLSYM(info, func) \ |
| 812 | info->func ## _p = (func ## _ftype *) verbose_dlsym (info->handle, #func) |
| 813 | |
| 814 | #define TDB_DLSYM(info, func) \ |
| 815 | info->func ## _p = (func ## _ftype *) dlsym (info->handle, #func) |
| 816 | |
| 817 | #define CHK(a) \ |
| 818 | do \ |
| 819 | { \ |
| 820 | if ((a) == NULL) \ |
| 821 | return false; \ |
| 822 | } while (0) |
| 823 | |
| 824 | CHK (TDB_VERBOSE_DLSYM (info, td_init)); |
| 825 | |
| 826 | err = info->td_init_p (); |
| 827 | if (err != TD_OK) |
| 828 | { |
| 829 | warning (_("Cannot initialize libthread_db: %s"), |
| 830 | thread_db_err_str (err)); |
| 831 | return false; |
| 832 | } |
| 833 | |
| 834 | CHK (TDB_VERBOSE_DLSYM (info, td_ta_new)); |
| 835 | |
| 836 | /* Initialize the structure that identifies the child process. */ |
| 837 | info->proc_handle.thread = inferior_thread (); |
| 838 | |
| 839 | /* Now attempt to open a connection to the thread library. */ |
| 840 | err = info->td_ta_new_p (&info->proc_handle, &info->thread_agent); |
| 841 | if (err != TD_OK) |
| 842 | { |
| 843 | if (libthread_db_debug) |
| 844 | fprintf_unfiltered (gdb_stdlog, _("td_ta_new failed: %s\n"), |
| 845 | thread_db_err_str (err)); |
| 846 | else |
| 847 | switch (err) |
| 848 | { |
| 849 | case TD_NOLIBTHREAD: |
| 850 | #ifdef THREAD_DB_HAS_TD_VERSION |
| 851 | case TD_VERSION: |
| 852 | #endif |
| 853 | /* The errors above are not unexpected and silently ignored: |
| 854 | they just mean we haven't found correct version of |
| 855 | libthread_db yet. */ |
| 856 | break; |
| 857 | default: |
| 858 | warning (_("td_ta_new failed: %s"), thread_db_err_str (err)); |
| 859 | } |
| 860 | return false; |
| 861 | } |
| 862 | |
| 863 | /* These are essential. */ |
| 864 | CHK (TDB_VERBOSE_DLSYM (info, td_ta_map_lwp2thr)); |
| 865 | CHK (TDB_VERBOSE_DLSYM (info, td_thr_get_info)); |
| 866 | |
| 867 | /* These are not essential. */ |
| 868 | TDB_DLSYM (info, td_thr_tls_get_addr); |
| 869 | TDB_DLSYM (info, td_thr_tlsbase); |
| 870 | TDB_DLSYM (info, td_ta_delete); |
| 871 | |
| 872 | /* It's best to avoid td_ta_thr_iter if possible. That walks data |
| 873 | structures in the inferior's address space that may be corrupted, |
| 874 | or, if the target is running, may change while we walk them. If |
| 875 | there's execution (and /proc is mounted), then we're already |
| 876 | attached to all LWPs. Use thread_from_lwp, which uses |
| 877 | td_ta_map_lwp2thr instead, which does not walk the thread list. |
| 878 | |
| 879 | td_ta_map_lwp2thr uses ps_get_thread_area, but we can't use that |
| 880 | currently on core targets, as it uses ptrace directly. */ |
| 881 | if (target_has_execution |
| 882 | && linux_proc_task_list_dir_exists (inferior_ptid.pid ())) |
| 883 | info->td_ta_thr_iter_p = NULL; |
| 884 | else |
| 885 | CHK (TDB_VERBOSE_DLSYM (info, td_ta_thr_iter)); |
| 886 | |
| 887 | #undef TDB_VERBOSE_DLSYM |
| 888 | #undef TDB_DLSYM |
| 889 | #undef CHK |
| 890 | |
| 891 | /* Run integrity checks if requested. */ |
| 892 | if (check_thread_db_on_load) |
| 893 | { |
| 894 | if (!check_thread_db (info, libthread_db_debug)) |
| 895 | return false; |
| 896 | } |
| 897 | |
| 898 | if (info->td_ta_thr_iter_p == NULL) |
| 899 | { |
| 900 | struct lwp_info *lp; |
| 901 | int pid = inferior_ptid.pid (); |
| 902 | thread_info *curr_thread = inferior_thread (); |
| 903 | |
| 904 | linux_stop_and_wait_all_lwps (); |
| 905 | |
| 906 | ALL_LWPS (lp) |
| 907 | if (lp->ptid.pid () == pid) |
| 908 | thread_from_lwp (curr_thread, lp->ptid); |
| 909 | |
| 910 | linux_unstop_all_lwps (); |
| 911 | } |
| 912 | else if (thread_db_find_new_threads_silently (inferior_thread ()) != 0) |
| 913 | { |
| 914 | /* Even if libthread_db initializes, if the thread list is |
| 915 | corrupted, we'd not manage to list any threads. Better reject this |
| 916 | thread_db, and fall back to at least listing LWPs. */ |
| 917 | return false; |
| 918 | } |
| 919 | |
| 920 | printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n")); |
| 921 | |
| 922 | if (*libthread_db_search_path || libthread_db_debug) |
| 923 | { |
| 924 | struct ui_file *file; |
| 925 | const char *library; |
| 926 | |
| 927 | library = dladdr_to_soname ((const void *) *info->td_ta_new_p); |
| 928 | if (library == NULL) |
| 929 | library = LIBTHREAD_DB_SO; |
| 930 | |
| 931 | /* If we'd print this to gdb_stdout when debug output is |
| 932 | disabled, still print it to gdb_stdout if debug output is |
| 933 | enabled. User visible output should not depend on debug |
| 934 | settings. */ |
| 935 | file = *libthread_db_search_path != '\0' ? gdb_stdout : gdb_stdlog; |
| 936 | fprintf_unfiltered (file, _("Using host libthread_db library \"%s\".\n"), |
| 937 | library); |
| 938 | } |
| 939 | |
| 940 | /* The thread library was detected. Activate the thread_db target |
| 941 | if this is the first process using it. */ |
| 942 | if (thread_db_list->next == NULL) |
| 943 | push_target (&the_thread_db_target); |
| 944 | |
| 945 | return true; |
| 946 | } |
| 947 | |
| 948 | /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute, |
| 949 | relative, or just LIBTHREAD_DB. */ |
| 950 | |
| 951 | static bool |
| 952 | try_thread_db_load (const char *library, bool check_auto_load_safe) |
| 953 | { |
| 954 | void *handle; |
| 955 | struct thread_db_info *info; |
| 956 | |
| 957 | if (libthread_db_debug) |
| 958 | fprintf_unfiltered (gdb_stdlog, |
| 959 | _("Trying host libthread_db library: %s.\n"), |
| 960 | library); |
| 961 | |
| 962 | if (check_auto_load_safe) |
| 963 | { |
| 964 | if (access (library, R_OK) != 0) |
| 965 | { |
| 966 | /* Do not print warnings by file_is_auto_load_safe if the library does |
| 967 | not exist at this place. */ |
| 968 | if (libthread_db_debug) |
| 969 | fprintf_unfiltered (gdb_stdlog, _("open failed: %s.\n"), |
| 970 | safe_strerror (errno)); |
| 971 | return false; |
| 972 | } |
| 973 | |
| 974 | if (!file_is_auto_load_safe (library, _("auto-load: Loading libthread-db " |
| 975 | "library \"%s\" from explicit " |
| 976 | "directory.\n"), |
| 977 | library)) |
| 978 | return false; |
| 979 | } |
| 980 | |
| 981 | handle = dlopen (library, RTLD_NOW); |
| 982 | if (handle == NULL) |
| 983 | { |
| 984 | if (libthread_db_debug) |
| 985 | fprintf_unfiltered (gdb_stdlog, _("dlopen failed: %s.\n"), dlerror ()); |
| 986 | return false; |
| 987 | } |
| 988 | |
| 989 | if (libthread_db_debug && strchr (library, '/') == NULL) |
| 990 | { |
| 991 | void *td_init; |
| 992 | |
| 993 | td_init = dlsym (handle, "td_init"); |
| 994 | if (td_init != NULL) |
| 995 | { |
| 996 | const char *const libpath = dladdr_to_soname (td_init); |
| 997 | |
| 998 | if (libpath != NULL) |
| 999 | fprintf_unfiltered (gdb_stdlog, _("Host %s resolved to: %s.\n"), |
| 1000 | library, libpath); |
| 1001 | } |
| 1002 | } |
| 1003 | |
| 1004 | info = add_thread_db_info (handle); |
| 1005 | |
| 1006 | /* Do not save system library name, that one is always trusted. */ |
| 1007 | if (strchr (library, '/') != NULL) |
| 1008 | info->filename = gdb_realpath (library).release (); |
| 1009 | |
| 1010 | if (try_thread_db_load_1 (info)) |
| 1011 | return true; |
| 1012 | |
| 1013 | /* This library "refused" to work on current inferior. */ |
| 1014 | delete_thread_db_info (inferior_ptid.pid ()); |
| 1015 | return false; |
| 1016 | } |
| 1017 | |
| 1018 | /* Subroutine of try_thread_db_load_from_pdir to simplify it. |
| 1019 | Try loading libthread_db in directory(OBJ)/SUBDIR. |
| 1020 | SUBDIR may be NULL. It may also be something like "../lib64". |
| 1021 | The result is true for success. */ |
| 1022 | |
| 1023 | static bool |
| 1024 | try_thread_db_load_from_pdir_1 (struct objfile *obj, const char *subdir) |
| 1025 | { |
| 1026 | const char *obj_name = objfile_name (obj); |
| 1027 | |
| 1028 | if (obj_name[0] != '/') |
| 1029 | { |
| 1030 | warning (_("Expected absolute pathname for libpthread in the" |
| 1031 | " inferior, but got %s."), obj_name); |
| 1032 | return false; |
| 1033 | } |
| 1034 | |
| 1035 | std::string path = obj_name; |
| 1036 | size_t cp = path.rfind ('/'); |
| 1037 | /* This should at minimum hit the first character. */ |
| 1038 | gdb_assert (cp != std::string::npos); |
| 1039 | path.resize (cp + 1); |
| 1040 | if (subdir != NULL) |
| 1041 | path = path + subdir + "/"; |
| 1042 | path += LIBTHREAD_DB_SO; |
| 1043 | |
| 1044 | return try_thread_db_load (path.c_str (), true); |
| 1045 | } |
| 1046 | |
| 1047 | /* Handle $pdir in libthread-db-search-path. |
| 1048 | Look for libthread_db in directory(libpthread)/SUBDIR. |
| 1049 | SUBDIR may be NULL. It may also be something like "../lib64". |
| 1050 | The result is true for success. */ |
| 1051 | |
| 1052 | static bool |
| 1053 | try_thread_db_load_from_pdir (const char *subdir) |
| 1054 | { |
| 1055 | if (!auto_load_thread_db) |
| 1056 | return false; |
| 1057 | |
| 1058 | for (objfile *obj : current_program_space->objfiles ()) |
| 1059 | if (libpthread_name_p (objfile_name (obj))) |
| 1060 | { |
| 1061 | if (try_thread_db_load_from_pdir_1 (obj, subdir)) |
| 1062 | return true; |
| 1063 | |
| 1064 | /* We may have found the separate-debug-info version of |
| 1065 | libpthread, and it may live in a directory without a matching |
| 1066 | libthread_db. */ |
| 1067 | if (obj->separate_debug_objfile_backlink != NULL) |
| 1068 | return try_thread_db_load_from_pdir_1 (obj->separate_debug_objfile_backlink, |
| 1069 | subdir); |
| 1070 | |
| 1071 | return false; |
| 1072 | } |
| 1073 | |
| 1074 | return false; |
| 1075 | } |
| 1076 | |
| 1077 | /* Handle $sdir in libthread-db-search-path. |
| 1078 | Look for libthread_db in the system dirs, or wherever a plain |
| 1079 | dlopen(file_without_path) will look. |
| 1080 | The result is true for success. */ |
| 1081 | |
| 1082 | static bool |
| 1083 | try_thread_db_load_from_sdir (void) |
| 1084 | { |
| 1085 | return try_thread_db_load (LIBTHREAD_DB_SO, false); |
| 1086 | } |
| 1087 | |
| 1088 | /* Try to load libthread_db from directory DIR of length DIR_LEN. |
| 1089 | The result is true for success. */ |
| 1090 | |
| 1091 | static bool |
| 1092 | try_thread_db_load_from_dir (const char *dir, size_t dir_len) |
| 1093 | { |
| 1094 | if (!auto_load_thread_db) |
| 1095 | return false; |
| 1096 | |
| 1097 | std::string path = std::string (dir, dir_len) + "/" + LIBTHREAD_DB_SO; |
| 1098 | |
| 1099 | return try_thread_db_load (path.c_str (), true); |
| 1100 | } |
| 1101 | |
| 1102 | /* Search libthread_db_search_path for libthread_db which "agrees" |
| 1103 | to work on current inferior. |
| 1104 | The result is true for success. */ |
| 1105 | |
| 1106 | static bool |
| 1107 | thread_db_load_search (void) |
| 1108 | { |
| 1109 | bool rc = false; |
| 1110 | |
| 1111 | std::vector<gdb::unique_xmalloc_ptr<char>> dir_vec |
| 1112 | = dirnames_to_char_ptr_vec (libthread_db_search_path); |
| 1113 | |
| 1114 | for (const gdb::unique_xmalloc_ptr<char> &this_dir_up : dir_vec) |
| 1115 | { |
| 1116 | const char *this_dir = this_dir_up.get (); |
| 1117 | const int pdir_len = sizeof ("$pdir") - 1; |
| 1118 | size_t this_dir_len; |
| 1119 | |
| 1120 | this_dir_len = strlen (this_dir); |
| 1121 | |
| 1122 | if (strncmp (this_dir, "$pdir", pdir_len) == 0 |
| 1123 | && (this_dir[pdir_len] == '\0' |
| 1124 | || this_dir[pdir_len] == '/')) |
| 1125 | { |
| 1126 | const char *subdir = NULL; |
| 1127 | |
| 1128 | std::string subdir_holder; |
| 1129 | if (this_dir[pdir_len] == '/') |
| 1130 | { |
| 1131 | subdir_holder = std::string (this_dir + pdir_len + 1); |
| 1132 | subdir = subdir_holder.c_str (); |
| 1133 | } |
| 1134 | rc = try_thread_db_load_from_pdir (subdir); |
| 1135 | if (rc) |
| 1136 | break; |
| 1137 | } |
| 1138 | else if (strcmp (this_dir, "$sdir") == 0) |
| 1139 | { |
| 1140 | if (try_thread_db_load_from_sdir ()) |
| 1141 | { |
| 1142 | rc = 1; |
| 1143 | break; |
| 1144 | } |
| 1145 | } |
| 1146 | else |
| 1147 | { |
| 1148 | if (try_thread_db_load_from_dir (this_dir, this_dir_len)) |
| 1149 | { |
| 1150 | rc = 1; |
| 1151 | break; |
| 1152 | } |
| 1153 | } |
| 1154 | } |
| 1155 | |
| 1156 | if (libthread_db_debug) |
| 1157 | fprintf_unfiltered (gdb_stdlog, |
| 1158 | _("thread_db_load_search returning %d\n"), rc); |
| 1159 | return rc; |
| 1160 | } |
| 1161 | |
| 1162 | /* Return true if the inferior has a libpthread. */ |
| 1163 | |
| 1164 | static bool |
| 1165 | has_libpthread (void) |
| 1166 | { |
| 1167 | for (objfile *obj : current_program_space->objfiles ()) |
| 1168 | if (libpthread_name_p (objfile_name (obj))) |
| 1169 | return true; |
| 1170 | |
| 1171 | return false; |
| 1172 | } |
| 1173 | |
| 1174 | /* Attempt to load and initialize libthread_db. |
| 1175 | Return 1 on success. */ |
| 1176 | |
| 1177 | static bool |
| 1178 | thread_db_load (void) |
| 1179 | { |
| 1180 | struct thread_db_info *info; |
| 1181 | |
| 1182 | info = get_thread_db_info (inferior_ptid.pid ()); |
| 1183 | |
| 1184 | if (info != NULL) |
| 1185 | return true; |
| 1186 | |
| 1187 | /* Don't attempt to use thread_db on executables not running |
| 1188 | yet. */ |
| 1189 | if (!target_has_registers) |
| 1190 | return false; |
| 1191 | |
| 1192 | /* Don't attempt to use thread_db for remote targets. */ |
| 1193 | if (!(target_can_run () || core_bfd)) |
| 1194 | return false; |
| 1195 | |
| 1196 | if (thread_db_load_search ()) |
| 1197 | return true; |
| 1198 | |
| 1199 | /* We couldn't find a libthread_db. |
| 1200 | If the inferior has a libpthread warn the user. */ |
| 1201 | if (has_libpthread ()) |
| 1202 | { |
| 1203 | warning (_("Unable to find libthread_db matching inferior's thread" |
| 1204 | " library, thread debugging will not be available.")); |
| 1205 | return false; |
| 1206 | } |
| 1207 | |
| 1208 | /* Either this executable isn't using libpthread at all, or it is |
| 1209 | statically linked. Since we can't easily distinguish these two cases, |
| 1210 | no warning is issued. */ |
| 1211 | return false; |
| 1212 | } |
| 1213 | |
| 1214 | static void |
| 1215 | check_thread_signals (void) |
| 1216 | { |
| 1217 | if (!thread_signals) |
| 1218 | { |
| 1219 | sigset_t mask; |
| 1220 | int i; |
| 1221 | |
| 1222 | lin_thread_get_thread_signals (&mask); |
| 1223 | sigemptyset (&thread_stop_set); |
| 1224 | sigemptyset (&thread_print_set); |
| 1225 | |
| 1226 | for (i = 1; i < NSIG; i++) |
| 1227 | { |
| 1228 | if (sigismember (&mask, i)) |
| 1229 | { |
| 1230 | if (signal_stop_update (gdb_signal_from_host (i), 0)) |
| 1231 | sigaddset (&thread_stop_set, i); |
| 1232 | if (signal_print_update (gdb_signal_from_host (i), 0)) |
| 1233 | sigaddset (&thread_print_set, i); |
| 1234 | thread_signals = 1; |
| 1235 | } |
| 1236 | } |
| 1237 | } |
| 1238 | } |
| 1239 | |
| 1240 | /* Check whether thread_db is usable. This function is called when |
| 1241 | an inferior is created (or otherwise acquired, e.g. attached to) |
| 1242 | and when new shared libraries are loaded into a running process. */ |
| 1243 | |
| 1244 | void |
| 1245 | check_for_thread_db (void) |
| 1246 | { |
| 1247 | /* Do nothing if we couldn't load libthread_db.so.1. */ |
| 1248 | if (!thread_db_load ()) |
| 1249 | return; |
| 1250 | } |
| 1251 | |
| 1252 | /* This function is called via the new_objfile observer. */ |
| 1253 | |
| 1254 | static void |
| 1255 | thread_db_new_objfile (struct objfile *objfile) |
| 1256 | { |
| 1257 | /* This observer must always be called with inferior_ptid set |
| 1258 | correctly. */ |
| 1259 | |
| 1260 | if (objfile != NULL |
| 1261 | /* libpthread with separate debug info has its debug info file already |
| 1262 | loaded (and notified without successful thread_db initialization) |
| 1263 | the time gdb::observers::new_objfile.notify is called for the library itself. |
| 1264 | Static executables have their separate debug info loaded already |
| 1265 | before the inferior has started. */ |
| 1266 | && objfile->separate_debug_objfile_backlink == NULL |
| 1267 | /* Only check for thread_db if we loaded libpthread, |
| 1268 | or if this is the main symbol file. |
| 1269 | We need to check OBJF_MAINLINE to handle the case of debugging |
| 1270 | a statically linked executable AND the symbol file is specified AFTER |
| 1271 | the exec file is loaded (e.g., gdb -c core ; file foo). |
| 1272 | For dynamically linked executables, libpthread can be near the end |
| 1273 | of the list of shared libraries to load, and in an app of several |
| 1274 | thousand shared libraries, this can otherwise be painful. */ |
| 1275 | && ((objfile->flags & OBJF_MAINLINE) != 0 |
| 1276 | || libpthread_name_p (objfile_name (objfile)))) |
| 1277 | check_for_thread_db (); |
| 1278 | } |
| 1279 | |
| 1280 | static void |
| 1281 | check_pid_namespace_match (void) |
| 1282 | { |
| 1283 | /* Check is only relevant for local targets targets. */ |
| 1284 | if (target_can_run ()) |
| 1285 | { |
| 1286 | /* If the child is in a different PID namespace, its idea of its |
| 1287 | PID will differ from our idea of its PID. When we scan the |
| 1288 | child's thread list, we'll mistakenly think it has no threads |
| 1289 | since the thread PID fields won't match the PID we give to |
| 1290 | libthread_db. */ |
| 1291 | if (!linux_ns_same (inferior_ptid.pid (), LINUX_NS_PID)) |
| 1292 | { |
| 1293 | warning (_ ("Target and debugger are in different PID " |
| 1294 | "namespaces; thread lists and other data are " |
| 1295 | "likely unreliable. " |
| 1296 | "Connect to gdbserver inside the container.")); |
| 1297 | } |
| 1298 | } |
| 1299 | } |
| 1300 | |
| 1301 | /* This function is called via the inferior_created observer. |
| 1302 | This handles the case of debugging statically linked executables. */ |
| 1303 | |
| 1304 | static void |
| 1305 | thread_db_inferior_created (struct target_ops *target, int from_tty) |
| 1306 | { |
| 1307 | check_pid_namespace_match (); |
| 1308 | check_for_thread_db (); |
| 1309 | } |
| 1310 | |
| 1311 | /* Update the thread's state (what's displayed in "info threads"), |
| 1312 | from libthread_db thread state information. */ |
| 1313 | |
| 1314 | static void |
| 1315 | update_thread_state (thread_db_thread_info *priv, |
| 1316 | const td_thrinfo_t *ti_p) |
| 1317 | { |
| 1318 | priv->dying = (ti_p->ti_state == TD_THR_UNKNOWN |
| 1319 | || ti_p->ti_state == TD_THR_ZOMBIE); |
| 1320 | } |
| 1321 | |
| 1322 | /* Record a new thread in GDB's thread list. Creates the thread's |
| 1323 | private info. If TP is NULL or TP is marked as having exited, |
| 1324 | creates a new thread. Otherwise, uses TP. */ |
| 1325 | |
| 1326 | static struct thread_info * |
| 1327 | record_thread (struct thread_db_info *info, |
| 1328 | struct thread_info *tp, |
| 1329 | ptid_t ptid, const td_thrhandle_t *th_p, |
| 1330 | const td_thrinfo_t *ti_p) |
| 1331 | { |
| 1332 | /* A thread ID of zero may mean the thread library has not |
| 1333 | initialized yet. Leave private == NULL until the thread library |
| 1334 | has initialized. */ |
| 1335 | if (ti_p->ti_tid == 0) |
| 1336 | return tp; |
| 1337 | |
| 1338 | /* Construct the thread's private data. */ |
| 1339 | thread_db_thread_info *priv = new thread_db_thread_info; |
| 1340 | |
| 1341 | priv->th = *th_p; |
| 1342 | priv->tid = ti_p->ti_tid; |
| 1343 | update_thread_state (priv, ti_p); |
| 1344 | |
| 1345 | /* Add the thread to GDB's thread list. If we already know about a |
| 1346 | thread with this PTID, but it's marked exited, then the kernel |
| 1347 | reused the tid of an old thread. */ |
| 1348 | if (tp == NULL || tp->state == THREAD_EXITED) |
| 1349 | tp = add_thread_with_info (ptid, priv); |
| 1350 | else |
| 1351 | tp->priv.reset (priv); |
| 1352 | |
| 1353 | if (target_has_execution) |
| 1354 | check_thread_signals (); |
| 1355 | |
| 1356 | return tp; |
| 1357 | } |
| 1358 | |
| 1359 | void |
| 1360 | thread_db_target::detach (inferior *inf, int from_tty) |
| 1361 | { |
| 1362 | delete_thread_db_info (inf->pid); |
| 1363 | |
| 1364 | beneath ()->detach (inf, from_tty); |
| 1365 | |
| 1366 | /* NOTE: From this point on, inferior_ptid is null_ptid. */ |
| 1367 | |
| 1368 | /* If there are no more processes using libpthread, detach the |
| 1369 | thread_db target ops. */ |
| 1370 | if (!thread_db_list) |
| 1371 | unpush_target (this); |
| 1372 | } |
| 1373 | |
| 1374 | ptid_t |
| 1375 | thread_db_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, |
| 1376 | int options) |
| 1377 | { |
| 1378 | struct thread_db_info *info; |
| 1379 | |
| 1380 | ptid = beneath ()->wait (ptid, ourstatus, options); |
| 1381 | |
| 1382 | switch (ourstatus->kind) |
| 1383 | { |
| 1384 | case TARGET_WAITKIND_IGNORE: |
| 1385 | case TARGET_WAITKIND_EXITED: |
| 1386 | case TARGET_WAITKIND_THREAD_EXITED: |
| 1387 | case TARGET_WAITKIND_SIGNALLED: |
| 1388 | return ptid; |
| 1389 | } |
| 1390 | |
| 1391 | info = get_thread_db_info (ptid.pid ()); |
| 1392 | |
| 1393 | /* If this process isn't using thread_db, we're done. */ |
| 1394 | if (info == NULL) |
| 1395 | return ptid; |
| 1396 | |
| 1397 | if (ourstatus->kind == TARGET_WAITKIND_EXECD) |
| 1398 | { |
| 1399 | /* New image, it may or may not end up using thread_db. Assume |
| 1400 | not unless we find otherwise. */ |
| 1401 | delete_thread_db_info (ptid.pid ()); |
| 1402 | if (!thread_db_list) |
| 1403 | unpush_target (&the_thread_db_target); |
| 1404 | |
| 1405 | return ptid; |
| 1406 | } |
| 1407 | |
| 1408 | /* Fill in the thread's user-level thread id and status. */ |
| 1409 | thread_from_lwp (find_thread_ptid (ptid), ptid); |
| 1410 | |
| 1411 | return ptid; |
| 1412 | } |
| 1413 | |
| 1414 | void |
| 1415 | thread_db_target::mourn_inferior () |
| 1416 | { |
| 1417 | delete_thread_db_info (inferior_ptid.pid ()); |
| 1418 | |
| 1419 | beneath ()->mourn_inferior (); |
| 1420 | |
| 1421 | /* Detach thread_db target ops. */ |
| 1422 | if (!thread_db_list) |
| 1423 | unpush_target (&the_thread_db_target); |
| 1424 | } |
| 1425 | |
| 1426 | struct callback_data |
| 1427 | { |
| 1428 | struct thread_db_info *info; |
| 1429 | int new_threads; |
| 1430 | }; |
| 1431 | |
| 1432 | static int |
| 1433 | find_new_threads_callback (const td_thrhandle_t *th_p, void *data) |
| 1434 | { |
| 1435 | td_thrinfo_t ti; |
| 1436 | td_err_e err; |
| 1437 | struct thread_info *tp; |
| 1438 | struct callback_data *cb_data = (struct callback_data *) data; |
| 1439 | struct thread_db_info *info = cb_data->info; |
| 1440 | |
| 1441 | err = info->td_thr_get_info_p (th_p, &ti); |
| 1442 | if (err != TD_OK) |
| 1443 | error (_("find_new_threads_callback: cannot get thread info: %s"), |
| 1444 | thread_db_err_str (err)); |
| 1445 | |
| 1446 | if (ti.ti_lid == -1) |
| 1447 | { |
| 1448 | /* A thread with kernel thread ID -1 is either a thread that |
| 1449 | exited and was joined, or a thread that is being created but |
| 1450 | hasn't started yet, and that is reusing the tcb/stack of a |
| 1451 | thread that previously exited and was joined. (glibc marks |
| 1452 | terminated and joined threads with kernel thread ID -1. See |
| 1453 | glibc PR17707. */ |
| 1454 | if (libthread_db_debug) |
| 1455 | fprintf_unfiltered (gdb_stdlog, |
| 1456 | "thread_db: skipping exited and " |
| 1457 | "joined thread (0x%lx)\n", |
| 1458 | (unsigned long) ti.ti_tid); |
| 1459 | return 0; |
| 1460 | } |
| 1461 | |
| 1462 | if (ti.ti_tid == 0) |
| 1463 | { |
| 1464 | /* A thread ID of zero means that this is the main thread, but |
| 1465 | glibc has not yet initialized thread-local storage and the |
| 1466 | pthread library. We do not know what the thread's TID will |
| 1467 | be yet. */ |
| 1468 | |
| 1469 | /* In that case, we're not stopped in a fork syscall and don't |
| 1470 | need this glibc bug workaround. */ |
| 1471 | info->need_stale_parent_threads_check = 0; |
| 1472 | |
| 1473 | return 0; |
| 1474 | } |
| 1475 | |
| 1476 | /* Ignore stale parent threads, caused by glibc/BZ5983. This is a |
| 1477 | bit expensive, as it needs to open /proc/pid/status, so try to |
| 1478 | avoid doing the work if we know we don't have to. */ |
| 1479 | if (info->need_stale_parent_threads_check) |
| 1480 | { |
| 1481 | int tgid = linux_proc_get_tgid (ti.ti_lid); |
| 1482 | |
| 1483 | if (tgid != -1 && tgid != info->pid) |
| 1484 | return 0; |
| 1485 | } |
| 1486 | |
| 1487 | ptid_t ptid (info->pid, ti.ti_lid); |
| 1488 | tp = find_thread_ptid (ptid); |
| 1489 | if (tp == NULL || tp->priv == NULL) |
| 1490 | record_thread (info, tp, ptid, th_p, &ti); |
| 1491 | |
| 1492 | return 0; |
| 1493 | } |
| 1494 | |
| 1495 | /* Helper for thread_db_find_new_threads_2. |
| 1496 | Returns number of new threads found. */ |
| 1497 | |
| 1498 | static int |
| 1499 | find_new_threads_once (struct thread_db_info *info, int iteration, |
| 1500 | td_err_e *errp) |
| 1501 | { |
| 1502 | struct callback_data data; |
| 1503 | td_err_e err = TD_ERR; |
| 1504 | |
| 1505 | data.info = info; |
| 1506 | data.new_threads = 0; |
| 1507 | |
| 1508 | /* See comment in thread_db_update_thread_list. */ |
| 1509 | gdb_assert (info->td_ta_thr_iter_p != NULL); |
| 1510 | |
| 1511 | try |
| 1512 | { |
| 1513 | /* Iterate over all user-space threads to discover new threads. */ |
| 1514 | err = info->td_ta_thr_iter_p (info->thread_agent, |
| 1515 | find_new_threads_callback, |
| 1516 | &data, |
| 1517 | TD_THR_ANY_STATE, |
| 1518 | TD_THR_LOWEST_PRIORITY, |
| 1519 | TD_SIGNO_MASK, |
| 1520 | TD_THR_ANY_USER_FLAGS); |
| 1521 | } |
| 1522 | catch (const gdb_exception_error &except) |
| 1523 | { |
| 1524 | if (libthread_db_debug) |
| 1525 | { |
| 1526 | exception_fprintf (gdb_stdlog, except, |
| 1527 | "Warning: find_new_threads_once: "); |
| 1528 | } |
| 1529 | } |
| 1530 | |
| 1531 | if (libthread_db_debug) |
| 1532 | { |
| 1533 | fprintf_unfiltered (gdb_stdlog, |
| 1534 | _("Found %d new threads in iteration %d.\n"), |
| 1535 | data.new_threads, iteration); |
| 1536 | } |
| 1537 | |
| 1538 | if (errp != NULL) |
| 1539 | *errp = err; |
| 1540 | |
| 1541 | return data.new_threads; |
| 1542 | } |
| 1543 | |
| 1544 | /* Search for new threads, accessing memory through stopped thread |
| 1545 | PTID. If UNTIL_NO_NEW is true, repeat searching until several |
| 1546 | searches in a row do not discover any new threads. */ |
| 1547 | |
| 1548 | static void |
| 1549 | thread_db_find_new_threads_2 (thread_info *stopped, bool until_no_new) |
| 1550 | { |
| 1551 | td_err_e err = TD_OK; |
| 1552 | struct thread_db_info *info; |
| 1553 | int i, loop; |
| 1554 | |
| 1555 | info = get_thread_db_info (stopped->ptid.pid ()); |
| 1556 | |
| 1557 | /* Access an lwp we know is stopped. */ |
| 1558 | info->proc_handle.thread = stopped; |
| 1559 | |
| 1560 | if (until_no_new) |
| 1561 | { |
| 1562 | /* Require 4 successive iterations which do not find any new threads. |
| 1563 | The 4 is a heuristic: there is an inherent race here, and I have |
| 1564 | seen that 2 iterations in a row are not always sufficient to |
| 1565 | "capture" all threads. */ |
| 1566 | for (i = 0, loop = 0; loop < 4 && err == TD_OK; ++i, ++loop) |
| 1567 | if (find_new_threads_once (info, i, &err) != 0) |
| 1568 | { |
| 1569 | /* Found some new threads. Restart the loop from beginning. */ |
| 1570 | loop = -1; |
| 1571 | } |
| 1572 | } |
| 1573 | else |
| 1574 | find_new_threads_once (info, 0, &err); |
| 1575 | |
| 1576 | if (err != TD_OK) |
| 1577 | error (_("Cannot find new threads: %s"), thread_db_err_str (err)); |
| 1578 | } |
| 1579 | |
| 1580 | static void |
| 1581 | thread_db_find_new_threads_1 (thread_info *stopped) |
| 1582 | { |
| 1583 | thread_db_find_new_threads_2 (stopped, 0); |
| 1584 | } |
| 1585 | |
| 1586 | /* Implement the to_update_thread_list target method for this |
| 1587 | target. */ |
| 1588 | |
| 1589 | void |
| 1590 | thread_db_target::update_thread_list () |
| 1591 | { |
| 1592 | struct thread_db_info *info; |
| 1593 | |
| 1594 | prune_threads (); |
| 1595 | |
| 1596 | for (inferior *inf : all_inferiors ()) |
| 1597 | { |
| 1598 | struct thread_info *thread; |
| 1599 | |
| 1600 | if (inf->pid == 0) |
| 1601 | continue; |
| 1602 | |
| 1603 | info = get_thread_db_info (inf->pid); |
| 1604 | if (info == NULL) |
| 1605 | continue; |
| 1606 | |
| 1607 | thread = any_live_thread_of_inferior (inf); |
| 1608 | if (thread == NULL || thread->executing) |
| 1609 | continue; |
| 1610 | |
| 1611 | /* It's best to avoid td_ta_thr_iter if possible. That walks |
| 1612 | data structures in the inferior's address space that may be |
| 1613 | corrupted, or, if the target is running, the list may change |
| 1614 | while we walk it. In the latter case, it's possible that a |
| 1615 | thread exits just at the exact time that causes GDB to get |
| 1616 | stuck in an infinite loop. To avoid pausing all threads |
| 1617 | whenever the core wants to refresh the thread list, we |
| 1618 | instead use thread_from_lwp immediately when we see an LWP |
| 1619 | stop. That uses thread_db entry points that do not walk |
| 1620 | libpthread's thread list, so should be safe, as well as more |
| 1621 | efficient. */ |
| 1622 | if (target_has_execution_1 (thread->ptid)) |
| 1623 | continue; |
| 1624 | |
| 1625 | thread_db_find_new_threads_1 (thread); |
| 1626 | } |
| 1627 | |
| 1628 | /* Give the beneath target a chance to do extra processing. */ |
| 1629 | this->beneath ()->update_thread_list (); |
| 1630 | } |
| 1631 | |
| 1632 | std::string |
| 1633 | thread_db_target::pid_to_str (ptid_t ptid) |
| 1634 | { |
| 1635 | struct thread_info *thread_info = find_thread_ptid (ptid); |
| 1636 | |
| 1637 | if (thread_info != NULL && thread_info->priv != NULL) |
| 1638 | { |
| 1639 | thread_db_thread_info *priv = get_thread_db_thread_info (thread_info); |
| 1640 | |
| 1641 | return string_printf ("Thread 0x%lx (LWP %ld)", |
| 1642 | (unsigned long) priv->tid, ptid.lwp ()); |
| 1643 | } |
| 1644 | |
| 1645 | return beneath ()->pid_to_str (ptid); |
| 1646 | } |
| 1647 | |
| 1648 | /* Return a string describing the state of the thread specified by |
| 1649 | INFO. */ |
| 1650 | |
| 1651 | const char * |
| 1652 | thread_db_target::extra_thread_info (thread_info *info) |
| 1653 | { |
| 1654 | if (info->priv == NULL) |
| 1655 | return NULL; |
| 1656 | |
| 1657 | thread_db_thread_info *priv = get_thread_db_thread_info (info); |
| 1658 | |
| 1659 | if (priv->dying) |
| 1660 | return "Exiting"; |
| 1661 | |
| 1662 | return NULL; |
| 1663 | } |
| 1664 | |
| 1665 | /* Return pointer to the thread_info struct which corresponds to |
| 1666 | THREAD_HANDLE (having length HANDLE_LEN). */ |
| 1667 | |
| 1668 | thread_info * |
| 1669 | thread_db_target::thread_handle_to_thread_info (const gdb_byte *thread_handle, |
| 1670 | int handle_len, |
| 1671 | inferior *inf) |
| 1672 | { |
| 1673 | thread_t handle_tid; |
| 1674 | |
| 1675 | /* Thread handle sizes must match in order to proceed. We don't use an |
| 1676 | assert here because the resulting internal error will cause GDB to |
| 1677 | exit. This isn't necessarily an internal error due to the possibility |
| 1678 | of garbage being passed as the thread handle via the python interface. */ |
| 1679 | if (handle_len != sizeof (handle_tid)) |
| 1680 | error (_("Thread handle size mismatch: %d vs %zu (from libthread_db)"), |
| 1681 | handle_len, sizeof (handle_tid)); |
| 1682 | |
| 1683 | handle_tid = * (const thread_t *) thread_handle; |
| 1684 | |
| 1685 | for (thread_info *tp : inf->non_exited_threads ()) |
| 1686 | { |
| 1687 | thread_db_thread_info *priv = get_thread_db_thread_info (tp); |
| 1688 | |
| 1689 | if (priv != NULL && handle_tid == priv->tid) |
| 1690 | return tp; |
| 1691 | } |
| 1692 | |
| 1693 | return NULL; |
| 1694 | } |
| 1695 | |
| 1696 | /* Return the thread handle associated the thread_info pointer TP. */ |
| 1697 | |
| 1698 | gdb::byte_vector |
| 1699 | thread_db_target::thread_info_to_thread_handle (struct thread_info *tp) |
| 1700 | { |
| 1701 | thread_db_thread_info *priv = get_thread_db_thread_info (tp); |
| 1702 | |
| 1703 | if (priv == NULL) |
| 1704 | return gdb::byte_vector (); |
| 1705 | |
| 1706 | int handle_size = sizeof (priv->tid); |
| 1707 | gdb::byte_vector rv (handle_size); |
| 1708 | |
| 1709 | memcpy (rv.data (), &priv->tid, handle_size); |
| 1710 | |
| 1711 | return rv; |
| 1712 | } |
| 1713 | |
| 1714 | /* Get the address of the thread local variable in load module LM which |
| 1715 | is stored at OFFSET within the thread local storage for thread PTID. */ |
| 1716 | |
| 1717 | CORE_ADDR |
| 1718 | thread_db_target::get_thread_local_address (ptid_t ptid, |
| 1719 | CORE_ADDR lm, |
| 1720 | CORE_ADDR offset) |
| 1721 | { |
| 1722 | struct thread_info *thread_info; |
| 1723 | |
| 1724 | /* Find the matching thread. */ |
| 1725 | thread_info = find_thread_ptid (ptid); |
| 1726 | |
| 1727 | /* We may not have discovered the thread yet. */ |
| 1728 | if (thread_info != NULL && thread_info->priv == NULL) |
| 1729 | thread_info = thread_from_lwp (thread_info, ptid); |
| 1730 | |
| 1731 | if (thread_info != NULL && thread_info->priv != NULL) |
| 1732 | { |
| 1733 | td_err_e err; |
| 1734 | psaddr_t address; |
| 1735 | thread_db_info *info = get_thread_db_info (ptid.pid ()); |
| 1736 | thread_db_thread_info *priv = get_thread_db_thread_info (thread_info); |
| 1737 | |
| 1738 | /* Finally, get the address of the variable. */ |
| 1739 | if (lm != 0) |
| 1740 | { |
| 1741 | /* glibc doesn't provide the needed interface. */ |
| 1742 | if (!info->td_thr_tls_get_addr_p) |
| 1743 | throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR, |
| 1744 | _("No TLS library support")); |
| 1745 | |
| 1746 | /* Note the cast through uintptr_t: this interface only works if |
| 1747 | a target address fits in a psaddr_t, which is a host pointer. |
| 1748 | So a 32-bit debugger can not access 64-bit TLS through this. */ |
| 1749 | err = info->td_thr_tls_get_addr_p (&priv->th, |
| 1750 | (psaddr_t)(uintptr_t) lm, |
| 1751 | offset, &address); |
| 1752 | } |
| 1753 | else |
| 1754 | { |
| 1755 | /* If glibc doesn't provide the needed interface throw an error |
| 1756 | that LM is zero - normally cases it should not be. */ |
| 1757 | if (!info->td_thr_tlsbase_p) |
| 1758 | throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR, |
| 1759 | _("TLS load module not found")); |
| 1760 | |
| 1761 | /* This code path handles the case of -static -pthread executables: |
| 1762 | https://sourceware.org/ml/libc-help/2014-03/msg00024.html |
| 1763 | For older GNU libc r_debug.r_map is NULL. For GNU libc after |
| 1764 | PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL. |
| 1765 | The constant number 1 depends on GNU __libc_setup_tls |
| 1766 | initialization of l_tls_modid to 1. */ |
| 1767 | err = info->td_thr_tlsbase_p (&priv->th, 1, &address); |
| 1768 | address = (char *) address + offset; |
| 1769 | } |
| 1770 | |
| 1771 | #ifdef THREAD_DB_HAS_TD_NOTALLOC |
| 1772 | /* The memory hasn't been allocated, yet. */ |
| 1773 | if (err == TD_NOTALLOC) |
| 1774 | /* Now, if libthread_db provided the initialization image's |
| 1775 | address, we *could* try to build a non-lvalue value from |
| 1776 | the initialization image. */ |
| 1777 | throw_error (TLS_NOT_ALLOCATED_YET_ERROR, |
| 1778 | _("TLS not allocated yet")); |
| 1779 | #endif |
| 1780 | |
| 1781 | /* Something else went wrong. */ |
| 1782 | if (err != TD_OK) |
| 1783 | throw_error (TLS_GENERIC_ERROR, |
| 1784 | (("%s")), thread_db_err_str (err)); |
| 1785 | |
| 1786 | /* Cast assuming host == target. Joy. */ |
| 1787 | /* Do proper sign extension for the target. */ |
| 1788 | gdb_assert (exec_bfd); |
| 1789 | return (bfd_get_sign_extend_vma (exec_bfd) > 0 |
| 1790 | ? (CORE_ADDR) (intptr_t) address |
| 1791 | : (CORE_ADDR) (uintptr_t) address); |
| 1792 | } |
| 1793 | |
| 1794 | return beneath ()->get_thread_local_address (ptid, lm, offset); |
| 1795 | } |
| 1796 | |
| 1797 | /* Implement the to_get_ada_task_ptid target method for this target. */ |
| 1798 | |
| 1799 | ptid_t |
| 1800 | thread_db_target::get_ada_task_ptid (long lwp, long thread) |
| 1801 | { |
| 1802 | /* NPTL uses a 1:1 model, so the LWP id suffices. */ |
| 1803 | return ptid_t (inferior_ptid.pid (), lwp, 0); |
| 1804 | } |
| 1805 | |
| 1806 | void |
| 1807 | thread_db_target::resume (ptid_t ptid, int step, enum gdb_signal signo) |
| 1808 | { |
| 1809 | struct thread_db_info *info; |
| 1810 | |
| 1811 | if (ptid == minus_one_ptid) |
| 1812 | info = get_thread_db_info (inferior_ptid.pid ()); |
| 1813 | else |
| 1814 | info = get_thread_db_info (ptid.pid ()); |
| 1815 | |
| 1816 | /* This workaround is only needed for child fork lwps stopped in a |
| 1817 | PTRACE_O_TRACEFORK event. When the inferior is resumed, the |
| 1818 | workaround can be disabled. */ |
| 1819 | if (info) |
| 1820 | info->need_stale_parent_threads_check = 0; |
| 1821 | |
| 1822 | beneath ()->resume (ptid, step, signo); |
| 1823 | } |
| 1824 | |
| 1825 | /* std::sort helper function for info_auto_load_libthread_db, sort the |
| 1826 | thread_db_info pointers primarily by their FILENAME and secondarily by their |
| 1827 | PID, both in ascending order. */ |
| 1828 | |
| 1829 | static bool |
| 1830 | info_auto_load_libthread_db_compare (const struct thread_db_info *a, |
| 1831 | const struct thread_db_info *b) |
| 1832 | { |
| 1833 | int retval; |
| 1834 | |
| 1835 | retval = strcmp (a->filename, b->filename); |
| 1836 | if (retval) |
| 1837 | return retval < 0; |
| 1838 | |
| 1839 | return a->pid < b->pid; |
| 1840 | } |
| 1841 | |
| 1842 | /* Implement 'info auto-load libthread-db'. */ |
| 1843 | |
| 1844 | static void |
| 1845 | info_auto_load_libthread_db (const char *args, int from_tty) |
| 1846 | { |
| 1847 | struct ui_out *uiout = current_uiout; |
| 1848 | const char *cs = args ? args : ""; |
| 1849 | struct thread_db_info *info; |
| 1850 | unsigned unique_filenames; |
| 1851 | size_t max_filename_len, pids_len; |
| 1852 | int i; |
| 1853 | |
| 1854 | cs = skip_spaces (cs); |
| 1855 | if (*cs) |
| 1856 | error (_("'info auto-load libthread-db' does not accept any parameters")); |
| 1857 | |
| 1858 | std::vector<struct thread_db_info *> array; |
| 1859 | for (info = thread_db_list; info; info = info->next) |
| 1860 | if (info->filename != NULL) |
| 1861 | array.push_back (info); |
| 1862 | |
| 1863 | /* Sort ARRAY by filenames and PIDs. */ |
| 1864 | std::sort (array.begin (), array.end (), |
| 1865 | info_auto_load_libthread_db_compare); |
| 1866 | |
| 1867 | /* Calculate the number of unique filenames (rows) and the maximum string |
| 1868 | length of PIDs list for the unique filenames (columns). */ |
| 1869 | |
| 1870 | unique_filenames = 0; |
| 1871 | max_filename_len = 0; |
| 1872 | pids_len = 0; |
| 1873 | for (i = 0; i < array.size (); i++) |
| 1874 | { |
| 1875 | int pid = array[i]->pid; |
| 1876 | size_t this_pid_len; |
| 1877 | |
| 1878 | for (this_pid_len = 0; pid != 0; pid /= 10) |
| 1879 | this_pid_len++; |
| 1880 | |
| 1881 | if (i == 0 || strcmp (array[i - 1]->filename, array[i]->filename) != 0) |
| 1882 | { |
| 1883 | unique_filenames++; |
| 1884 | max_filename_len = std::max (max_filename_len, |
| 1885 | strlen (array[i]->filename)); |
| 1886 | |
| 1887 | if (i > 0) |
| 1888 | pids_len -= strlen (", "); |
| 1889 | pids_len = 0; |
| 1890 | } |
| 1891 | pids_len += this_pid_len + strlen (", "); |
| 1892 | } |
| 1893 | if (i) |
| 1894 | pids_len -= strlen (", "); |
| 1895 | |
| 1896 | /* Table header shifted right by preceding "libthread-db: " would not match |
| 1897 | its columns. */ |
| 1898 | if (array.size () > 0 && args == auto_load_info_scripts_pattern_nl) |
| 1899 | uiout->text ("\n"); |
| 1900 | |
| 1901 | { |
| 1902 | ui_out_emit_table table_emitter (uiout, 2, unique_filenames, |
| 1903 | "LinuxThreadDbTable"); |
| 1904 | |
| 1905 | uiout->table_header (max_filename_len, ui_left, "filename", "Filename"); |
| 1906 | uiout->table_header (pids_len, ui_left, "PIDs", "Pids"); |
| 1907 | uiout->table_body (); |
| 1908 | |
| 1909 | /* Note I is incremented inside the cycle, not at its end. */ |
| 1910 | for (i = 0; i < array.size ();) |
| 1911 | { |
| 1912 | ui_out_emit_tuple tuple_emitter (uiout, NULL); |
| 1913 | |
| 1914 | info = array[i]; |
| 1915 | uiout->field_string ("filename", info->filename); |
| 1916 | |
| 1917 | std::string pids; |
| 1918 | while (i < array.size () && strcmp (info->filename, |
| 1919 | array[i]->filename) == 0) |
| 1920 | { |
| 1921 | if (!pids.empty ()) |
| 1922 | pids += ", "; |
| 1923 | string_appendf (pids, "%u", array[i]->pid); |
| 1924 | i++; |
| 1925 | } |
| 1926 | |
| 1927 | uiout->field_string ("pids", pids.c_str ()); |
| 1928 | |
| 1929 | uiout->text ("\n"); |
| 1930 | } |
| 1931 | } |
| 1932 | |
| 1933 | if (array.empty ()) |
| 1934 | uiout->message (_("No auto-loaded libthread-db.\n")); |
| 1935 | } |
| 1936 | |
| 1937 | /* Implement 'maintenance check libthread-db'. */ |
| 1938 | |
| 1939 | static void |
| 1940 | maintenance_check_libthread_db (const char *args, int from_tty) |
| 1941 | { |
| 1942 | int inferior_pid = inferior_ptid.pid (); |
| 1943 | struct thread_db_info *info; |
| 1944 | |
| 1945 | if (inferior_pid == 0) |
| 1946 | error (_("No inferior running")); |
| 1947 | |
| 1948 | info = get_thread_db_info (inferior_pid); |
| 1949 | if (info == NULL) |
| 1950 | error (_("No libthread_db loaded")); |
| 1951 | |
| 1952 | check_thread_db (info, true); |
| 1953 | } |
| 1954 | |
| 1955 | void |
| 1956 | _initialize_thread_db (void) |
| 1957 | { |
| 1958 | /* Defer loading of libthread_db.so until inferior is running. |
| 1959 | This allows gdb to load correct libthread_db for a given |
| 1960 | executable -- there could be multiple versions of glibc, |
| 1961 | and until there is a running inferior, we can't tell which |
| 1962 | libthread_db is the correct one to load. */ |
| 1963 | |
| 1964 | libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH); |
| 1965 | |
| 1966 | add_setshow_optional_filename_cmd ("libthread-db-search-path", |
| 1967 | class_support, |
| 1968 | &libthread_db_search_path, _("\ |
| 1969 | Set search path for libthread_db."), _("\ |
| 1970 | Show the current search path or libthread_db."), _("\ |
| 1971 | This path is used to search for libthread_db to be loaded into \ |
| 1972 | gdb itself.\n\ |
| 1973 | Its value is a colon (':') separate list of directories to search.\n\ |
| 1974 | Setting the search path to an empty list resets it to its default value."), |
| 1975 | set_libthread_db_search_path, |
| 1976 | NULL, |
| 1977 | &setlist, &showlist); |
| 1978 | |
| 1979 | add_setshow_zuinteger_cmd ("libthread-db", class_maintenance, |
| 1980 | &libthread_db_debug, _("\ |
| 1981 | Set libthread-db debugging."), _("\ |
| 1982 | Show libthread-db debugging."), _("\ |
| 1983 | When non-zero, libthread-db debugging is enabled."), |
| 1984 | NULL, |
| 1985 | show_libthread_db_debug, |
| 1986 | &setdebuglist, &showdebuglist); |
| 1987 | |
| 1988 | add_setshow_boolean_cmd ("libthread-db", class_support, |
| 1989 | &auto_load_thread_db, _("\ |
| 1990 | Enable or disable auto-loading of inferior specific libthread_db."), _("\ |
| 1991 | Show whether auto-loading inferior specific libthread_db is enabled."), _("\ |
| 1992 | If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\ |
| 1993 | locations to load libthread_db compatible with the inferior.\n\ |
| 1994 | Standard system libthread_db still gets loaded even with this option off.\n\ |
| 1995 | This option has security implications for untrusted inferiors."), |
| 1996 | NULL, show_auto_load_thread_db, |
| 1997 | auto_load_set_cmdlist_get (), |
| 1998 | auto_load_show_cmdlist_get ()); |
| 1999 | |
| 2000 | add_cmd ("libthread-db", class_info, info_auto_load_libthread_db, |
| 2001 | _("Print the list of loaded inferior specific libthread_db.\n\ |
| 2002 | Usage: info auto-load libthread-db"), |
| 2003 | auto_load_info_cmdlist_get ()); |
| 2004 | |
| 2005 | add_cmd ("libthread-db", class_maintenance, |
| 2006 | maintenance_check_libthread_db, _("\ |
| 2007 | Run integrity checks on the current inferior's libthread_db."), |
| 2008 | &maintenancechecklist); |
| 2009 | |
| 2010 | add_setshow_boolean_cmd ("check-libthread-db", |
| 2011 | class_maintenance, |
| 2012 | &check_thread_db_on_load, _("\ |
| 2013 | Set whether to check libthread_db at load time."), _("\ |
| 2014 | Show whether to check libthread_db at load time."), _("\ |
| 2015 | If enabled GDB will run integrity checks on inferior specific libthread_db\n\ |
| 2016 | as they are loaded."), |
| 2017 | NULL, |
| 2018 | NULL, |
| 2019 | &maintenance_set_cmdlist, |
| 2020 | &maintenance_show_cmdlist); |
| 2021 | |
| 2022 | /* Add ourselves to objfile event chain. */ |
| 2023 | gdb::observers::new_objfile.attach (thread_db_new_objfile); |
| 2024 | |
| 2025 | /* Add ourselves to inferior_created event chain. |
| 2026 | This is needed to handle debugging statically linked programs where |
| 2027 | the new_objfile observer won't get called for libpthread. */ |
| 2028 | gdb::observers::inferior_created.attach (thread_db_inferior_created); |
| 2029 | } |