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0d62e5e8 | 1 | /* Thread management interface, for the remote server for GDB. |
1d506c26 | 2 | Copyright (C) 2002-2024 Free Software Foundation, Inc. |
0d62e5e8 DJ |
3 | |
4 | Contributed by MontaVista Software. | |
5 | ||
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 10 | the Free Software Foundation; either version 3 of the License, or |
0d62e5e8 DJ |
11 | (at your option) any later version. |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
0d62e5e8 DJ |
20 | |
21 | #include "server.h" | |
22 | ||
23 | #include "linux-low.h" | |
24 | ||
f9d949fb | 25 | #include "debug.h" |
0050a760 | 26 | #include "gdb_proc_service.h" |
125f8a3d | 27 | #include "nat/gdb_thread_db.h" |
268a13a5 | 28 | #include "gdbsupport/gdb_vecs.h" |
2db9a427 | 29 | #include "nat/linux-procfs.h" |
268a13a5 | 30 | #include "gdbsupport/scoped_restore.h" |
0d62e5e8 | 31 | |
96f15937 | 32 | #ifndef USE_LIBTHREAD_DB_DIRECTLY |
cdbfd419 | 33 | #include <dlfcn.h> |
96f15937 | 34 | #endif |
cdbfd419 PP |
35 | #include <limits.h> |
36 | #include <ctype.h> | |
37 | ||
38 | struct thread_db | |
39 | { | |
40 | /* Structure that identifies the child process for the | |
41 | <proc_service.h> interface. */ | |
42 | struct ps_prochandle proc_handle; | |
43 | ||
44 | /* Connection to the libthread_db library. */ | |
45 | td_thragent_t *thread_agent; | |
46 | ||
9836d6ea PA |
47 | /* If this flag has been set, we've already asked GDB for all |
48 | symbols we might need; assume symbol cache misses are | |
49 | failures. */ | |
50 | int all_symbols_looked_up; | |
51 | ||
96f15937 | 52 | #ifndef USE_LIBTHREAD_DB_DIRECTLY |
cdbfd419 PP |
53 | /* Handle of the libthread_db from dlopen. */ |
54 | void *handle; | |
96f15937 | 55 | #endif |
cdbfd419 PP |
56 | |
57 | /* Addresses of libthread_db functions. */ | |
96e9210f | 58 | td_ta_new_ftype *td_ta_new_p; |
96e9210f PA |
59 | td_ta_map_lwp2thr_ftype *td_ta_map_lwp2thr_p; |
60 | td_thr_get_info_ftype *td_thr_get_info_p; | |
96e9210f PA |
61 | td_ta_thr_iter_ftype *td_ta_thr_iter_p; |
62 | td_thr_tls_get_addr_ftype *td_thr_tls_get_addr_p; | |
63 | td_thr_tlsbase_ftype *td_thr_tlsbase_p; | |
64 | td_symbol_list_ftype *td_symbol_list_p; | |
cdbfd419 PP |
65 | }; |
66 | ||
67 | static char *libthread_db_search_path; | |
186947f7 | 68 | |
95954743 | 69 | static int find_one_thread (ptid_t); |
0d62e5e8 DJ |
70 | static int find_new_threads_callback (const td_thrhandle_t *th_p, void *data); |
71 | ||
54363045 | 72 | static const char * |
0d62e5e8 DJ |
73 | thread_db_err_str (td_err_e err) |
74 | { | |
75 | static char buf[64]; | |
76 | ||
77 | switch (err) | |
78 | { | |
79 | case TD_OK: | |
80 | return "generic 'call succeeded'"; | |
81 | case TD_ERR: | |
82 | return "generic error"; | |
83 | case TD_NOTHR: | |
84 | return "no thread to satisfy query"; | |
85 | case TD_NOSV: | |
86 | return "no sync handle to satisfy query"; | |
87 | case TD_NOLWP: | |
88 | return "no LWP to satisfy query"; | |
89 | case TD_BADPH: | |
90 | return "invalid process handle"; | |
91 | case TD_BADTH: | |
92 | return "invalid thread handle"; | |
93 | case TD_BADSH: | |
94 | return "invalid synchronization handle"; | |
95 | case TD_BADTA: | |
96 | return "invalid thread agent"; | |
97 | case TD_BADKEY: | |
98 | return "invalid key"; | |
99 | case TD_NOMSG: | |
100 | return "no event message for getmsg"; | |
101 | case TD_NOFPREGS: | |
102 | return "FPU register set not available"; | |
103 | case TD_NOLIBTHREAD: | |
104 | return "application not linked with libthread"; | |
105 | case TD_NOEVENT: | |
106 | return "requested event is not supported"; | |
107 | case TD_NOCAPAB: | |
108 | return "capability not available"; | |
109 | case TD_DBERR: | |
110 | return "debugger service failed"; | |
111 | case TD_NOAPLIC: | |
112 | return "operation not applicable to"; | |
113 | case TD_NOTSD: | |
114 | return "no thread-specific data for this thread"; | |
115 | case TD_MALLOC: | |
116 | return "malloc failed"; | |
117 | case TD_PARTIALREG: | |
118 | return "only part of register set was written/read"; | |
119 | case TD_NOXREGS: | |
120 | return "X register set not available for this thread"; | |
3db0444b DJ |
121 | #ifdef HAVE_TD_VERSION |
122 | case TD_VERSION: | |
123 | return "version mismatch between libthread_db and libpthread"; | |
124 | #endif | |
0d62e5e8 | 125 | default: |
6cebaf6e | 126 | xsnprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err); |
0d62e5e8 DJ |
127 | return buf; |
128 | } | |
129 | } | |
130 | ||
131 | #if 0 | |
132 | static char * | |
133 | thread_db_state_str (td_thr_state_e state) | |
134 | { | |
135 | static char buf[64]; | |
136 | ||
137 | switch (state) | |
138 | { | |
139 | case TD_THR_STOPPED: | |
140 | return "stopped by debugger"; | |
141 | case TD_THR_RUN: | |
142 | return "runnable"; | |
143 | case TD_THR_ACTIVE: | |
144 | return "active"; | |
145 | case TD_THR_ZOMBIE: | |
146 | return "zombie"; | |
147 | case TD_THR_SLEEP: | |
148 | return "sleeping"; | |
149 | case TD_THR_STOPPED_ASLEEP: | |
150 | return "stopped by debugger AND blocked"; | |
151 | default: | |
6cebaf6e | 152 | xsnprintf (buf, sizeof (buf), "unknown thread_db state %d", state); |
0d62e5e8 DJ |
153 | return buf; |
154 | } | |
155 | } | |
156 | #endif | |
157 | ||
3295ff3b | 158 | /* Get thread info about PTID. */ |
94c207e0 | 159 | |
ae13219e | 160 | static int |
95954743 | 161 | find_one_thread (ptid_t ptid) |
0d62e5e8 | 162 | { |
8dc7b443 | 163 | thread_info *thread = find_thread_ptid (ptid); |
3295ff3b | 164 | lwp_info *lwp = get_thread_lwp (thread); |
54a0b537 | 165 | if (lwp->thread_known) |
ae13219e DJ |
166 | return 1; |
167 | ||
3295ff3b SM |
168 | /* Get information about this thread. libthread_db will need to read some |
169 | memory, which will be done on the current process, so make PTID's process | |
170 | the current one. */ | |
171 | process_info *proc = find_process_pid (ptid.pid ()); | |
172 | gdb_assert (proc != nullptr); | |
173 | ||
174 | scoped_restore_current_thread restore_thread; | |
175 | switch_to_process (proc); | |
176 | ||
177 | thread_db *thread_db = proc->priv->thread_db; | |
178 | td_thrhandle_t th; | |
179 | int lwpid = ptid.lwp (); | |
180 | td_err_e err = thread_db->td_ta_map_lwp2thr_p (thread_db->thread_agent, lwpid, | |
181 | &th); | |
ae13219e | 182 | if (err != TD_OK) |
24a09b5f DJ |
183 | error ("Cannot get thread handle for LWP %d: %s", |
184 | lwpid, thread_db_err_str (err)); | |
ae13219e | 185 | |
3295ff3b | 186 | td_thrinfo_t ti; |
cdbfd419 | 187 | err = thread_db->td_thr_get_info_p (&th, &ti); |
ae13219e | 188 | if (err != TD_OK) |
24a09b5f DJ |
189 | error ("Cannot get thread info for LWP %d: %s", |
190 | lwpid, thread_db_err_str (err)); | |
ae13219e | 191 | |
c058728c SM |
192 | threads_debug_printf ("Found thread %ld (LWP %d)", |
193 | (unsigned long) ti.ti_tid, ti.ti_lid); | |
ae13219e | 194 | |
95954743 | 195 | if (lwpid != ti.ti_lid) |
24a09b5f DJ |
196 | { |
197 | warning ("PID mismatch! Expected %ld, got %ld", | |
95954743 | 198 | (long) lwpid, (long) ti.ti_lid); |
24a09b5f DJ |
199 | return 0; |
200 | } | |
ae13219e | 201 | |
24a09b5f DJ |
202 | /* If the new thread ID is zero, a final thread ID will be available |
203 | later. Do not enable thread debugging yet. */ | |
204 | if (ti.ti_tid == 0) | |
205 | return 0; | |
ae13219e | 206 | |
54a0b537 PA |
207 | lwp->thread_known = 1; |
208 | lwp->th = th; | |
f6327dcb | 209 | lwp->thread_handle = ti.ti_tid; |
ae13219e | 210 | |
ae13219e DJ |
211 | return 1; |
212 | } | |
213 | ||
5f7d1694 PP |
214 | /* Attach a thread. Return true on success. */ |
215 | ||
216 | static int | |
217 | attach_thread (const td_thrhandle_t *th_p, td_thrinfo_t *ti_p) | |
ae13219e | 218 | { |
7ae1a6a6 PA |
219 | struct process_info *proc = current_process (); |
220 | int pid = pid_of (proc); | |
184ea2f7 | 221 | ptid_t ptid = ptid_t (pid, ti_p->ti_lid); |
54a0b537 | 222 | struct lwp_info *lwp; |
7ae1a6a6 | 223 | int err; |
ae13219e | 224 | |
c058728c SM |
225 | threads_debug_printf ("Attaching to thread %ld (LWP %d)", |
226 | (unsigned long) ti_p->ti_tid, ti_p->ti_lid); | |
fd000fb3 | 227 | err = the_linux_target->attach_lwp (ptid); |
7ae1a6a6 | 228 | if (err != 0) |
0d62e5e8 | 229 | { |
50fa3001 | 230 | std::string reason = linux_ptrace_attach_fail_reason_string (ptid, err); |
4d9b86e1 | 231 | |
422186a9 | 232 | warning ("Could not attach to thread %ld (LWP %d): %s", |
4d9b86e1 SM |
233 | (unsigned long) ti_p->ti_tid, ti_p->ti_lid, reason.c_str ()); |
234 | ||
5f7d1694 | 235 | return 0; |
0d62e5e8 DJ |
236 | } |
237 | ||
7ae1a6a6 PA |
238 | lwp = find_lwp_pid (ptid); |
239 | gdb_assert (lwp != NULL); | |
54a0b537 PA |
240 | lwp->thread_known = 1; |
241 | lwp->th = *th_p; | |
f6327dcb | 242 | lwp->thread_handle = ti_p->ti_tid; |
24a09b5f | 243 | |
5f7d1694 PP |
244 | return 1; |
245 | } | |
246 | ||
247 | /* Attach thread if we haven't seen it yet. | |
248 | Increment *COUNTER if we have attached a new thread. | |
249 | Return false on failure. */ | |
250 | ||
251 | static int | |
252 | maybe_attach_thread (const td_thrhandle_t *th_p, td_thrinfo_t *ti_p, | |
253 | int *counter) | |
254 | { | |
255 | struct lwp_info *lwp; | |
256 | ||
f2907e49 | 257 | lwp = find_lwp_pid (ptid_t (ti_p->ti_lid)); |
5f7d1694 PP |
258 | if (lwp != NULL) |
259 | return 1; | |
260 | ||
261 | if (!attach_thread (th_p, ti_p)) | |
262 | return 0; | |
263 | ||
264 | if (counter != NULL) | |
265 | *counter += 1; | |
266 | ||
267 | return 1; | |
0d62e5e8 DJ |
268 | } |
269 | ||
270 | static int | |
271 | find_new_threads_callback (const td_thrhandle_t *th_p, void *data) | |
272 | { | |
273 | td_thrinfo_t ti; | |
274 | td_err_e err; | |
fe978cb0 | 275 | struct thread_db *thread_db = current_process ()->priv->thread_db; |
0d62e5e8 | 276 | |
cdbfd419 | 277 | err = thread_db->td_thr_get_info_p (th_p, &ti); |
0d62e5e8 DJ |
278 | if (err != TD_OK) |
279 | error ("Cannot get thread info: %s", thread_db_err_str (err)); | |
280 | ||
a33e3959 PA |
281 | if (ti.ti_lid == -1) |
282 | { | |
283 | /* A thread with kernel thread ID -1 is either a thread that | |
284 | exited and was joined, or a thread that is being created but | |
285 | hasn't started yet, and that is reusing the tcb/stack of a | |
286 | thread that previously exited and was joined. (glibc marks | |
287 | terminated and joined threads with kernel thread ID -1. See | |
288 | glibc PR17707. */ | |
c058728c SM |
289 | threads_debug_printf ("thread_db: skipping exited and " |
290 | "joined thread (0x%lx)", | |
291 | (unsigned long) ti.ti_tid); | |
a33e3959 PA |
292 | return 0; |
293 | } | |
294 | ||
0d62e5e8 DJ |
295 | /* Check for zombies. */ |
296 | if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE) | |
297 | return 0; | |
298 | ||
5f7d1694 PP |
299 | if (!maybe_attach_thread (th_p, &ti, (int *) data)) |
300 | { | |
301 | /* Terminate iteration early: we might be looking at stale data in | |
302 | the inferior. The thread_db_find_new_threads will retry. */ | |
303 | return 1; | |
304 | } | |
0d62e5e8 DJ |
305 | |
306 | return 0; | |
307 | } | |
308 | ||
309 | static void | |
310 | thread_db_find_new_threads (void) | |
311 | { | |
312 | td_err_e err; | |
fbd5db48 | 313 | ptid_t ptid = current_ptid; |
fe978cb0 | 314 | struct thread_db *thread_db = current_process ()->priv->thread_db; |
5f7d1694 | 315 | int loop, iteration; |
0d62e5e8 | 316 | |
ae13219e DJ |
317 | /* This function is only called when we first initialize thread_db. |
318 | First locate the initial thread. If it is not ready for | |
319 | debugging yet, then stop. */ | |
95954743 | 320 | if (find_one_thread (ptid) == 0) |
ae13219e DJ |
321 | return; |
322 | ||
5f7d1694 PP |
323 | /* Require 4 successive iterations which do not find any new threads. |
324 | The 4 is a heuristic: there is an inherent race here, and I have | |
325 | seen that 2 iterations in a row are not always sufficient to | |
326 | "capture" all threads. */ | |
327 | for (loop = 0, iteration = 0; loop < 4; ++loop, ++iteration) | |
328 | { | |
329 | int new_thread_count = 0; | |
330 | ||
331 | /* Iterate over all user-space threads to discover new threads. */ | |
332 | err = thread_db->td_ta_thr_iter_p (thread_db->thread_agent, | |
333 | find_new_threads_callback, | |
334 | &new_thread_count, | |
493e2a69 MS |
335 | TD_THR_ANY_STATE, |
336 | TD_THR_LOWEST_PRIORITY, | |
5f7d1694 | 337 | TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS); |
c058728c SM |
338 | threads_debug_printf ("Found %d threads in iteration %d.", |
339 | new_thread_count, iteration); | |
5f7d1694 PP |
340 | |
341 | if (new_thread_count != 0) | |
342 | { | |
343 | /* Found new threads. Restart iteration from beginning. */ | |
344 | loop = -1; | |
345 | } | |
346 | } | |
0d62e5e8 DJ |
347 | if (err != TD_OK) |
348 | error ("Cannot find new threads: %s", thread_db_err_str (err)); | |
349 | } | |
350 | ||
fd500816 DJ |
351 | /* Cache all future symbols that thread_db might request. We can not |
352 | request symbols at arbitrary states in the remote protocol, only | |
353 | when the client tells us that new symbols are available. So when | |
354 | we load the thread library, make sure to check the entire list. */ | |
355 | ||
356 | static void | |
357 | thread_db_look_up_symbols (void) | |
358 | { | |
fe978cb0 | 359 | struct thread_db *thread_db = current_process ()->priv->thread_db; |
cdbfd419 | 360 | const char **sym_list; |
fd500816 DJ |
361 | CORE_ADDR unused; |
362 | ||
cdbfd419 | 363 | for (sym_list = thread_db->td_symbol_list_p (); *sym_list; sym_list++) |
9836d6ea PA |
364 | look_up_one_symbol (*sym_list, &unused, 1); |
365 | ||
366 | /* We're not interested in any other libraries loaded after this | |
367 | point, only in symbols in libpthread.so. */ | |
368 | thread_db->all_symbols_looked_up = 1; | |
369 | } | |
370 | ||
371 | int | |
372 | thread_db_look_up_one_symbol (const char *name, CORE_ADDR *addrp) | |
373 | { | |
fe978cb0 | 374 | struct thread_db *thread_db = current_process ()->priv->thread_db; |
9836d6ea PA |
375 | int may_ask_gdb = !thread_db->all_symbols_looked_up; |
376 | ||
377 | /* If we've passed the call to thread_db_look_up_symbols, then | |
378 | anything not in the cache must not exist; we're not interested | |
379 | in any libraries loaded after that point, only in symbols in | |
380 | libpthread.so. It might not be an appropriate time to look | |
381 | up a symbol, e.g. while we're trying to fetch registers. */ | |
382 | return look_up_one_symbol (name, addrp, may_ask_gdb); | |
fd500816 DJ |
383 | } |
384 | ||
dae5f5cf DJ |
385 | int |
386 | thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset, | |
387 | CORE_ADDR load_module, CORE_ADDR *address) | |
388 | { | |
dae5f5cf DJ |
389 | psaddr_t addr; |
390 | td_err_e err; | |
54a0b537 | 391 | struct lwp_info *lwp; |
cdbfd419 PP |
392 | struct process_info *proc; |
393 | struct thread_db *thread_db; | |
394 | ||
395 | proc = get_thread_process (thread); | |
fe978cb0 | 396 | thread_db = proc->priv->thread_db; |
dae5f5cf | 397 | |
7fe519cb | 398 | /* If the thread layer is not (yet) initialized, fail. */ |
8a4ac37e | 399 | if (thread_db == NULL || !thread_db->all_symbols_looked_up) |
7fe519cb UW |
400 | return TD_ERR; |
401 | ||
5876f503 JK |
402 | /* If td_thr_tls_get_addr is missing rather do not expect td_thr_tlsbase |
403 | could work. */ | |
404 | if (thread_db->td_thr_tls_get_addr_p == NULL | |
405 | || (load_module == 0 && thread_db->td_thr_tlsbase_p == NULL)) | |
cdbfd419 PP |
406 | return -1; |
407 | ||
54a0b537 PA |
408 | lwp = get_thread_lwp (thread); |
409 | if (!lwp->thread_known) | |
9c80ecd6 | 410 | find_one_thread (thread->id); |
54a0b537 | 411 | if (!lwp->thread_known) |
dae5f5cf DJ |
412 | return TD_NOTHR; |
413 | ||
24583e45 TBA |
414 | scoped_restore_current_thread restore_thread; |
415 | switch_to_thread (thread); | |
5876f503 JK |
416 | |
417 | if (load_module != 0) | |
418 | { | |
419 | /* Note the cast through uintptr_t: this interface only works if | |
420 | a target address fits in a psaddr_t, which is a host pointer. | |
421 | So a 32-bit debugger can not access 64-bit TLS through this. */ | |
422 | err = thread_db->td_thr_tls_get_addr_p (&lwp->th, | |
423 | (psaddr_t) (uintptr_t) load_module, | |
424 | offset, &addr); | |
425 | } | |
426 | else | |
427 | { | |
428 | /* This code path handles the case of -static -pthread executables: | |
429 | https://sourceware.org/ml/libc-help/2014-03/msg00024.html | |
430 | For older GNU libc r_debug.r_map is NULL. For GNU libc after | |
431 | PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL. | |
432 | The constant number 1 depends on GNU __libc_setup_tls | |
433 | initialization of l_tls_modid to 1. */ | |
434 | err = thread_db->td_thr_tlsbase_p (&lwp->th, 1, &addr); | |
435 | addr = (char *) addr + offset; | |
436 | } | |
437 | ||
dae5f5cf DJ |
438 | if (err == TD_OK) |
439 | { | |
186947f7 | 440 | *address = (CORE_ADDR) (uintptr_t) addr; |
dae5f5cf DJ |
441 | return 0; |
442 | } | |
443 | else | |
444 | return err; | |
cdbfd419 PP |
445 | } |
446 | ||
f6327dcb KB |
447 | /* See linux-low.h. */ |
448 | ||
449 | bool | |
450 | thread_db_thread_handle (ptid_t ptid, gdb_byte **handle, int *handle_len) | |
451 | { | |
452 | struct thread_db *thread_db; | |
453 | struct lwp_info *lwp; | |
8dc7b443 | 454 | thread_info *thread = find_thread_ptid (ptid); |
f6327dcb KB |
455 | |
456 | if (thread == NULL) | |
457 | return false; | |
458 | ||
459 | thread_db = get_thread_process (thread)->priv->thread_db; | |
460 | ||
461 | if (thread_db == NULL) | |
462 | return false; | |
463 | ||
464 | lwp = get_thread_lwp (thread); | |
465 | ||
9c80ecd6 | 466 | if (!lwp->thread_known && !find_one_thread (thread->id)) |
f6327dcb KB |
467 | return false; |
468 | ||
469 | gdb_assert (lwp->thread_known); | |
470 | ||
471 | *handle = (gdb_byte *) &lwp->thread_handle; | |
472 | *handle_len = sizeof (lwp->thread_handle); | |
473 | return true; | |
474 | } | |
475 | ||
96f15937 PP |
476 | #ifdef USE_LIBTHREAD_DB_DIRECTLY |
477 | ||
478 | static int | |
479 | thread_db_load_search (void) | |
480 | { | |
481 | td_err_e err; | |
9836d6ea | 482 | struct thread_db *tdb; |
96f15937 PP |
483 | struct process_info *proc = current_process (); |
484 | ||
fe978cb0 | 485 | gdb_assert (proc->priv->thread_db == NULL); |
96f15937 | 486 | |
8d749320 | 487 | tdb = XCNEW (struct thread_db); |
fe978cb0 | 488 | proc->priv->thread_db = tdb; |
f9e39928 | 489 | |
9836d6ea | 490 | tdb->td_ta_new_p = &td_ta_new; |
96f15937 PP |
491 | |
492 | /* Attempt to open a connection to the thread library. */ | |
9836d6ea | 493 | err = tdb->td_ta_new_p (&tdb->proc_handle, &tdb->thread_agent); |
96f15937 PP |
494 | if (err != TD_OK) |
495 | { | |
c058728c | 496 | threads_debug_printf ("td_ta_new(): %s", thread_db_err_str (err)); |
9836d6ea | 497 | free (tdb); |
fe978cb0 | 498 | proc->priv->thread_db = NULL; |
96f15937 PP |
499 | return 0; |
500 | } | |
501 | ||
9836d6ea PA |
502 | tdb->td_ta_map_lwp2thr_p = &td_ta_map_lwp2thr; |
503 | tdb->td_thr_get_info_p = &td_thr_get_info; | |
504 | tdb->td_ta_thr_iter_p = &td_ta_thr_iter; | |
505 | tdb->td_symbol_list_p = &td_symbol_list; | |
96f15937 | 506 | |
96f15937 | 507 | /* These are not essential. */ |
9836d6ea | 508 | tdb->td_thr_tls_get_addr_p = &td_thr_tls_get_addr; |
5876f503 | 509 | tdb->td_thr_tlsbase_p = &td_thr_tlsbase; |
96f15937 PP |
510 | |
511 | return 1; | |
512 | } | |
513 | ||
514 | #else | |
515 | ||
cdbfd419 PP |
516 | static int |
517 | try_thread_db_load_1 (void *handle) | |
518 | { | |
519 | td_err_e err; | |
9836d6ea | 520 | struct thread_db *tdb; |
cdbfd419 PP |
521 | struct process_info *proc = current_process (); |
522 | ||
fe978cb0 | 523 | gdb_assert (proc->priv->thread_db == NULL); |
cdbfd419 | 524 | |
8d749320 | 525 | tdb = XCNEW (struct thread_db); |
fe978cb0 | 526 | proc->priv->thread_db = tdb; |
f9e39928 | 527 | |
9836d6ea | 528 | tdb->handle = handle; |
cdbfd419 PP |
529 | |
530 | /* Initialize pointers to the dynamic library functions we will use. | |
531 | Essential functions first. */ | |
532 | ||
533 | #define CHK(required, a) \ | |
534 | do \ | |
535 | { \ | |
536 | if ((a) == NULL) \ | |
537 | { \ | |
c058728c | 538 | threads_debug_printf ("dlsym: %s", dlerror ()); \ |
cdbfd419 | 539 | if (required) \ |
9836d6ea PA |
540 | { \ |
541 | free (tdb); \ | |
fe978cb0 | 542 | proc->priv->thread_db = NULL; \ |
9836d6ea PA |
543 | return 0; \ |
544 | } \ | |
cdbfd419 PP |
545 | } \ |
546 | } \ | |
547 | while (0) | |
548 | ||
96e9210f PA |
549 | #define TDB_DLSYM(tdb, func) \ |
550 | tdb->func ## _p = (func ## _ftype *) dlsym (tdb->handle, #func) | |
551 | ||
552 | CHK (1, TDB_DLSYM (tdb, td_ta_new)); | |
cdbfd419 PP |
553 | |
554 | /* Attempt to open a connection to the thread library. */ | |
9836d6ea | 555 | err = tdb->td_ta_new_p (&tdb->proc_handle, &tdb->thread_agent); |
cdbfd419 PP |
556 | if (err != TD_OK) |
557 | { | |
c058728c | 558 | threads_debug_printf ("td_ta_new(): %s", thread_db_err_str (err)); |
9836d6ea | 559 | free (tdb); |
fe978cb0 | 560 | proc->priv->thread_db = NULL; |
cdbfd419 PP |
561 | return 0; |
562 | } | |
563 | ||
96e9210f PA |
564 | CHK (1, TDB_DLSYM (tdb, td_ta_map_lwp2thr)); |
565 | CHK (1, TDB_DLSYM (tdb, td_thr_get_info)); | |
566 | CHK (1, TDB_DLSYM (tdb, td_ta_thr_iter)); | |
567 | CHK (1, TDB_DLSYM (tdb, td_symbol_list)); | |
cdbfd419 | 568 | |
cdbfd419 | 569 | /* These are not essential. */ |
96e9210f PA |
570 | CHK (0, TDB_DLSYM (tdb, td_thr_tls_get_addr)); |
571 | CHK (0, TDB_DLSYM (tdb, td_thr_tlsbase)); | |
cdbfd419 PP |
572 | |
573 | #undef CHK | |
96e9210f | 574 | #undef TDB_DLSYM |
cdbfd419 | 575 | |
cdbfd419 PP |
576 | return 1; |
577 | } | |
578 | ||
10e86dd7 DE |
579 | #ifdef HAVE_DLADDR |
580 | ||
cdbfd419 PP |
581 | /* Lookup a library in which given symbol resides. |
582 | Note: this is looking in the GDBSERVER process, not in the inferior. | |
583 | Returns library name, or NULL. */ | |
584 | ||
585 | static const char * | |
586 | dladdr_to_soname (const void *addr) | |
587 | { | |
588 | Dl_info info; | |
589 | ||
590 | if (dladdr (addr, &info) != 0) | |
591 | return info.dli_fname; | |
592 | return NULL; | |
593 | } | |
594 | ||
10e86dd7 DE |
595 | #endif |
596 | ||
cdbfd419 PP |
597 | static int |
598 | try_thread_db_load (const char *library) | |
599 | { | |
600 | void *handle; | |
601 | ||
c058728c SM |
602 | threads_debug_printf ("Trying host libthread_db library: %s.", |
603 | library); | |
cdbfd419 PP |
604 | handle = dlopen (library, RTLD_NOW); |
605 | if (handle == NULL) | |
606 | { | |
c058728c | 607 | threads_debug_printf ("dlopen failed: %s.", dlerror ()); |
cdbfd419 PP |
608 | return 0; |
609 | } | |
610 | ||
10e86dd7 | 611 | #ifdef HAVE_DLADDR |
cdbfd419 PP |
612 | if (debug_threads && strchr (library, '/') == NULL) |
613 | { | |
614 | void *td_init; | |
615 | ||
616 | td_init = dlsym (handle, "td_init"); | |
617 | if (td_init != NULL) | |
618 | { | |
619 | const char *const libpath = dladdr_to_soname (td_init); | |
620 | ||
621 | if (libpath != NULL) | |
c058728c | 622 | threads_debug_printf ("Host %s resolved to: %s.", library, libpath); |
cdbfd419 PP |
623 | } |
624 | } | |
10e86dd7 | 625 | #endif |
cdbfd419 PP |
626 | |
627 | if (try_thread_db_load_1 (handle)) | |
628 | return 1; | |
629 | ||
630 | /* This library "refused" to work on current inferior. */ | |
631 | dlclose (handle); | |
632 | return 0; | |
633 | } | |
634 | ||
98a5dd13 DE |
635 | /* Handle $sdir in libthread-db-search-path. |
636 | Look for libthread_db in the system dirs, or wherever a plain | |
637 | dlopen(file_without_path) will look. | |
638 | The result is true for success. */ | |
639 | ||
cdbfd419 | 640 | static int |
98a5dd13 DE |
641 | try_thread_db_load_from_sdir (void) |
642 | { | |
643 | return try_thread_db_load (LIBTHREAD_DB_SO); | |
644 | } | |
645 | ||
646 | /* Try to load libthread_db from directory DIR of length DIR_LEN. | |
647 | The result is true for success. */ | |
648 | ||
649 | static int | |
650 | try_thread_db_load_from_dir (const char *dir, size_t dir_len) | |
cdbfd419 PP |
651 | { |
652 | char path[PATH_MAX]; | |
98a5dd13 DE |
653 | |
654 | if (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1 > sizeof (path)) | |
655 | { | |
224c3ddb | 656 | char *cp = (char *) xmalloc (dir_len + 1); |
98a5dd13 DE |
657 | |
658 | memcpy (cp, dir, dir_len); | |
659 | cp[dir_len] = '\0'; | |
660 | warning (_("libthread-db-search-path component too long," | |
661 | " ignored: %s."), cp); | |
662 | free (cp); | |
663 | return 0; | |
664 | } | |
665 | ||
666 | memcpy (path, dir, dir_len); | |
667 | path[dir_len] = '/'; | |
668 | strcpy (path + dir_len + 1, LIBTHREAD_DB_SO); | |
669 | return try_thread_db_load (path); | |
670 | } | |
671 | ||
672 | /* Search libthread_db_search_path for libthread_db which "agrees" | |
673 | to work on current inferior. | |
674 | The result is true for success. */ | |
675 | ||
676 | static int | |
677 | thread_db_load_search (void) | |
678 | { | |
e80aaf61 | 679 | int rc = 0; |
cdbfd419 PP |
680 | |
681 | if (libthread_db_search_path == NULL) | |
682 | libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH); | |
683 | ||
e80aaf61 SM |
684 | std::vector<gdb::unique_xmalloc_ptr<char>> dir_vec |
685 | = dirnames_to_char_ptr_vec (libthread_db_search_path); | |
e6712ff1 | 686 | |
e80aaf61 | 687 | for (const gdb::unique_xmalloc_ptr<char> &this_dir_up : dir_vec) |
cdbfd419 | 688 | { |
e80aaf61 | 689 | char *this_dir = this_dir_up.get (); |
e6712ff1 | 690 | const int pdir_len = sizeof ("$pdir") - 1; |
98a5dd13 DE |
691 | size_t this_dir_len; |
692 | ||
e6712ff1 | 693 | this_dir_len = strlen (this_dir); |
cdbfd419 | 694 | |
e6712ff1 DE |
695 | if (strncmp (this_dir, "$pdir", pdir_len) == 0 |
696 | && (this_dir[pdir_len] == '\0' | |
697 | || this_dir[pdir_len] == '/')) | |
98a5dd13 DE |
698 | { |
699 | /* We don't maintain a list of loaded libraries so we don't know | |
700 | where libpthread lives. We *could* fetch the info, but we don't | |
701 | do that yet. Ignore it. */ | |
702 | } | |
e6712ff1 | 703 | else if (strcmp (this_dir, "$sdir") == 0) |
98a5dd13 DE |
704 | { |
705 | if (try_thread_db_load_from_sdir ()) | |
cdbfd419 | 706 | { |
98a5dd13 | 707 | rc = 1; |
cdbfd419 PP |
708 | break; |
709 | } | |
cdbfd419 | 710 | } |
98a5dd13 | 711 | else |
cdbfd419 | 712 | { |
98a5dd13 DE |
713 | if (try_thread_db_load_from_dir (this_dir, this_dir_len)) |
714 | { | |
715 | rc = 1; | |
716 | break; | |
717 | } | |
cdbfd419 PP |
718 | } |
719 | } | |
cdbfd419 | 720 | |
c058728c | 721 | threads_debug_printf ("thread_db_load_search returning %d", rc); |
cdbfd419 | 722 | return rc; |
dae5f5cf DJ |
723 | } |
724 | ||
96f15937 PP |
725 | #endif /* USE_LIBTHREAD_DB_DIRECTLY */ |
726 | ||
0d62e5e8 | 727 | int |
9b4c5f87 | 728 | thread_db_init (void) |
0d62e5e8 | 729 | { |
95954743 | 730 | struct process_info *proc = current_process (); |
0d62e5e8 | 731 | |
fd500816 DJ |
732 | /* FIXME drow/2004-10-16: This is the "overall process ID", which |
733 | GNU/Linux calls tgid, "thread group ID". When we support | |
734 | attaching to threads, the original thread may not be the correct | |
735 | thread. We would have to get the process ID from /proc for NPTL. | |
fd500816 DJ |
736 | |
737 | This isn't the only place in gdbserver that assumes that the first | |
738 | process in the list is the thread group leader. */ | |
ea025f5f | 739 | |
cdbfd419 | 740 | if (thread_db_load_search ()) |
0d62e5e8 | 741 | { |
2db9a427 PA |
742 | /* It's best to avoid td_ta_thr_iter if possible. That walks |
743 | data structures in the inferior's address space that may be | |
744 | corrupted, or, if the target is running, the list may change | |
745 | while we walk it. In the latter case, it's possible that a | |
746 | thread exits just at the exact time that causes GDBserver to | |
9b4c5f87 AT |
747 | get stuck in an infinite loop. As the kernel supports clone |
748 | events and /proc/PID/task/ exists, then we already know about | |
2db9a427 PA |
749 | all threads in the process. When we need info out of |
750 | thread_db on a given thread (e.g., for TLS), we'll use | |
751 | find_one_thread then. That uses thread_db entry points that | |
752 | do not walk libpthread's thread list, so should be safe, as | |
753 | well as more efficient. */ | |
9b4c5f87 | 754 | if (!linux_proc_task_list_dir_exists (pid_of (proc))) |
2db9a427 | 755 | thread_db_find_new_threads (); |
fd500816 | 756 | thread_db_look_up_symbols (); |
0d62e5e8 | 757 | return 1; |
cdbfd419 | 758 | } |
0d62e5e8 | 759 | |
cdbfd419 PP |
760 | return 0; |
761 | } | |
762 | ||
763 | /* Disconnect from libthread_db and free resources. */ | |
764 | ||
8336d594 PA |
765 | static void |
766 | disable_thread_event_reporting (struct process_info *proc) | |
cdbfd419 | 767 | { |
fe978cb0 | 768 | struct thread_db *thread_db = proc->priv->thread_db; |
cdbfd419 PP |
769 | if (thread_db) |
770 | { | |
21e1bee4 PP |
771 | td_err_e (*td_ta_clear_event_p) (const td_thragent_t *ta, |
772 | td_thr_events_t *event); | |
773 | ||
fd7dd3e6 | 774 | #ifndef USE_LIBTHREAD_DB_DIRECTLY |
96e9210f PA |
775 | td_ta_clear_event_p |
776 | = (td_ta_clear_event_ftype *) dlsym (thread_db->handle, | |
777 | "td_ta_clear_event"); | |
fd7dd3e6 | 778 | #else |
fd7dd3e6 PA |
779 | td_ta_clear_event_p = &td_ta_clear_event; |
780 | #endif | |
781 | ||
8336d594 | 782 | if (td_ta_clear_event_p != NULL) |
21e1bee4 | 783 | { |
24583e45 | 784 | scoped_restore_current_thread restore_thread; |
21e1bee4 | 785 | td_thr_events_t events; |
8336d594 | 786 | |
f9e39928 | 787 | switch_to_process (proc); |
21e1bee4 | 788 | |
fd7dd3e6 PA |
789 | /* Set the process wide mask saying we aren't interested |
790 | in any events anymore. */ | |
21e1bee4 PP |
791 | td_event_fillset (&events); |
792 | (*td_ta_clear_event_p) (thread_db->thread_agent, &events); | |
793 | } | |
8336d594 PA |
794 | } |
795 | } | |
796 | ||
797 | void | |
798 | thread_db_detach (struct process_info *proc) | |
799 | { | |
fe978cb0 | 800 | struct thread_db *thread_db = proc->priv->thread_db; |
f9e39928 PA |
801 | |
802 | if (thread_db) | |
803 | { | |
804 | disable_thread_event_reporting (proc); | |
f9e39928 | 805 | } |
8336d594 PA |
806 | } |
807 | ||
808 | /* Disconnect from libthread_db and free resources. */ | |
809 | ||
810 | void | |
811 | thread_db_mourn (struct process_info *proc) | |
812 | { | |
fe978cb0 | 813 | struct thread_db *thread_db = proc->priv->thread_db; |
8336d594 PA |
814 | if (thread_db) |
815 | { | |
96e9210f | 816 | td_ta_delete_ftype *td_ta_delete_p; |
8336d594 PA |
817 | |
818 | #ifndef USE_LIBTHREAD_DB_DIRECTLY | |
96e9210f | 819 | td_ta_delete_p = (td_ta_delete_ftype *) dlsym (thread_db->handle, "td_ta_delete"); |
8336d594 PA |
820 | #else |
821 | td_ta_delete_p = &td_ta_delete; | |
822 | #endif | |
cdbfd419 | 823 | |
cdbfd419 PP |
824 | if (td_ta_delete_p != NULL) |
825 | (*td_ta_delete_p) (thread_db->thread_agent); | |
826 | ||
fd7dd3e6 | 827 | #ifndef USE_LIBTHREAD_DB_DIRECTLY |
cdbfd419 | 828 | dlclose (thread_db->handle); |
96f15937 PP |
829 | #endif /* USE_LIBTHREAD_DB_DIRECTLY */ |
830 | ||
cdbfd419 | 831 | free (thread_db); |
fe978cb0 | 832 | proc->priv->thread_db = NULL; |
cdbfd419 PP |
833 | } |
834 | } | |
835 | ||
836 | /* Handle "set libthread-db-search-path" monitor command and return 1. | |
837 | For any other command, return 0. */ | |
838 | ||
839 | int | |
840 | thread_db_handle_monitor_command (char *mon) | |
841 | { | |
84e578fb DE |
842 | const char *cmd = "set libthread-db-search-path"; |
843 | size_t cmd_len = strlen (cmd); | |
844 | ||
845 | if (strncmp (mon, cmd, cmd_len) == 0 | |
846 | && (mon[cmd_len] == '\0' | |
847 | || mon[cmd_len] == ' ')) | |
cdbfd419 | 848 | { |
84e578fb | 849 | const char *cp = mon + cmd_len; |
cdbfd419 PP |
850 | |
851 | if (libthread_db_search_path != NULL) | |
852 | free (libthread_db_search_path); | |
853 | ||
854 | /* Skip leading space (if any). */ | |
855 | while (isspace (*cp)) | |
856 | ++cp; | |
857 | ||
84e578fb DE |
858 | if (*cp == '\0') |
859 | cp = LIBTHREAD_DB_SEARCH_PATH; | |
cdbfd419 PP |
860 | libthread_db_search_path = xstrdup (cp); |
861 | ||
862 | monitor_output ("libthread-db-search-path set to `"); | |
863 | monitor_output (libthread_db_search_path); | |
864 | monitor_output ("'\n"); | |
865 | return 1; | |
0d62e5e8 DJ |
866 | } |
867 | ||
cdbfd419 | 868 | /* Tell server.c to perform default processing. */ |
0d62e5e8 DJ |
869 | return 0; |
870 | } | |
86299109 KB |
871 | |
872 | /* See linux-low.h. */ | |
873 | ||
874 | void | |
94c207e0 | 875 | thread_db_notice_clone (struct thread_info *parent_thr, ptid_t child_ptid) |
86299109 | 876 | { |
94c207e0 PA |
877 | process_info *parent_proc = get_thread_process (parent_thr); |
878 | struct thread_db *thread_db = parent_proc->priv->thread_db; | |
86299109 KB |
879 | |
880 | /* If the thread layer isn't initialized, return. It may just | |
881 | be that the program uses clone, but does not use libthread_db. */ | |
882 | if (thread_db == NULL || !thread_db->all_symbols_looked_up) | |
883 | return; | |
884 | ||
94c207e0 PA |
885 | /* find_one_thread calls into libthread_db which accesses memory via |
886 | the current thread. Temporarily switch to a thread we know is | |
887 | stopped. */ | |
24583e45 TBA |
888 | scoped_restore_current_thread restore_thread; |
889 | switch_to_thread (parent_thr); | |
94c207e0 PA |
890 | |
891 | if (!find_one_thread (child_ptid)) | |
422186a9 | 892 | warning ("Cannot find thread after clone."); |
86299109 | 893 | } |