1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
|
/* libthread_db assisted debugging support, generic parts.
Copyright 1999, 2000, 2001, 2003, 2004 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "gdb_assert.h"
#include <dlfcn.h>
#include "gdb_proc_service.h"
#include "gdb_thread_db.h"
#include "bfd.h"
#include "gdbthread.h"
#include "inferior.h"
#include "symfile.h"
#include "objfiles.h"
#include "target.h"
#include "regcache.h"
#include "solib-svr4.h"
#ifdef HAVE_GNU_LIBC_VERSION_H
#include <gnu/libc-version.h>
#endif
#ifndef LIBTHREAD_DB_SO
#define LIBTHREAD_DB_SO "libthread_db.so.1"
#endif
/* If we're running on GNU/Linux, we must explicitly attach to any new
threads. */
/* FIXME: There is certainly some room for improvements:
- Cache LWP ids.
- Bypass libthread_db when fetching or storing registers for
threads bound to a LWP. */
/* This module's target vector. */
static struct target_ops thread_db_ops;
/* The target vector that we call for things this module can't handle. */
static struct target_ops *target_beneath;
/* Pointer to the next function on the objfile event chain. */
static void (*target_new_objfile_chain) (struct objfile * objfile);
/* Non-zero if we're using this module's target vector. */
static int using_thread_db;
/* Non-zero if we have determined the signals used by the threads
library. */
static int thread_signals;
static sigset_t thread_stop_set;
static sigset_t thread_print_set;
/* Structure that identifies the child process for the
<proc_service.h> interface. */
static struct ps_prochandle proc_handle;
/* Connection to the libthread_db library. */
static td_thragent_t *thread_agent;
/* Pointers to the libthread_db functions. */
static td_err_e (*td_init_p) (void);
static td_err_e (*td_ta_new_p) (struct ps_prochandle * ps,
td_thragent_t **ta);
static td_err_e (*td_ta_map_id2thr_p) (const td_thragent_t *ta, thread_t pt,
td_thrhandle_t *__th);
static td_err_e (*td_ta_map_lwp2thr_p) (const td_thragent_t *ta,
lwpid_t lwpid, td_thrhandle_t *th);
static td_err_e (*td_ta_thr_iter_p) (const td_thragent_t *ta,
td_thr_iter_f *callback, void *cbdata_p,
td_thr_state_e state, int ti_pri,
sigset_t *ti_sigmask_p,
unsigned int ti_user_flags);
static td_err_e (*td_ta_event_addr_p) (const td_thragent_t *ta,
td_event_e event, td_notify_t *ptr);
static td_err_e (*td_ta_set_event_p) (const td_thragent_t *ta,
td_thr_events_t *event);
static td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
td_event_msg_t *msg);
static td_err_e (*td_thr_validate_p) (const td_thrhandle_t *th);
static td_err_e (*td_thr_get_info_p) (const td_thrhandle_t *th,
td_thrinfo_t *infop);
static td_err_e (*td_thr_getfpregs_p) (const td_thrhandle_t *th,
gdb_prfpregset_t *regset);
static td_err_e (*td_thr_getgregs_p) (const td_thrhandle_t *th,
prgregset_t gregs);
static td_err_e (*td_thr_setfpregs_p) (const td_thrhandle_t *th,
const gdb_prfpregset_t *fpregs);
static td_err_e (*td_thr_setgregs_p) (const td_thrhandle_t *th,
prgregset_t gregs);
static td_err_e (*td_thr_event_enable_p) (const td_thrhandle_t *th,
int event);
static td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th,
void *map_address,
size_t offset, void **address);
/* Location of the thread creation event breakpoint. The code at this
location in the child process will be called by the pthread library
whenever a new thread is created. By setting a special breakpoint
at this location, GDB can detect when a new thread is created. We
obtain this location via the td_ta_event_addr call. */
static CORE_ADDR td_create_bp_addr;
/* Location of the thread death event breakpoint. */
static CORE_ADDR td_death_bp_addr;
/* Prototypes for local functions. */
static void thread_db_find_new_threads (void);
static void attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
const td_thrinfo_t *ti_p, int verbose);
static void detach_thread (ptid_t ptid, int verbose);
/* Building process ids. */
#define GET_PID(ptid) ptid_get_pid (ptid)
#define GET_LWP(ptid) ptid_get_lwp (ptid)
#define GET_THREAD(ptid) ptid_get_tid (ptid)
#define is_lwp(ptid) (GET_LWP (ptid) != 0)
#define is_thread(ptid) (GET_THREAD (ptid) != 0)
#define BUILD_LWP(lwp, pid) ptid_build (pid, lwp, 0)
#define BUILD_THREAD(tid, pid) ptid_build (pid, 0, tid)
/* Use "struct private_thread_info" to cache thread state. This is
a substantial optimization. */
struct private_thread_info
{
/* Flag set when we see a TD_DEATH event for this thread. */
unsigned int dying:1;
/* Cached thread state. */
unsigned int th_valid:1;
unsigned int ti_valid:1;
td_thrhandle_t th;
td_thrinfo_t ti;
};
static char *
thread_db_err_str (td_err_e err)
{
static char buf[64];
switch (err)
{
case TD_OK:
return "generic 'call succeeded'";
case TD_ERR:
return "generic error";
case TD_NOTHR:
return "no thread to satisfy query";
case TD_NOSV:
return "no sync handle to satisfy query";
case TD_NOLWP:
return "no LWP to satisfy query";
case TD_BADPH:
return "invalid process handle";
case TD_BADTH:
return "invalid thread handle";
case TD_BADSH:
return "invalid synchronization handle";
case TD_BADTA:
return "invalid thread agent";
case TD_BADKEY:
return "invalid key";
case TD_NOMSG:
return "no event message for getmsg";
case TD_NOFPREGS:
return "FPU register set not available";
case TD_NOLIBTHREAD:
return "application not linked with libthread";
case TD_NOEVENT:
return "requested event is not supported";
case TD_NOCAPAB:
return "capability not available";
case TD_DBERR:
return "debugger service failed";
case TD_NOAPLIC:
return "operation not applicable to";
case TD_NOTSD:
return "no thread-specific data for this thread";
case TD_MALLOC:
return "malloc failed";
case TD_PARTIALREG:
return "only part of register set was written/read";
case TD_NOXREGS:
return "X register set not available for this thread";
default:
snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
return buf;
}
}
static char *
thread_db_state_str (td_thr_state_e state)
{
static char buf[64];
switch (state)
{
case TD_THR_STOPPED:
return "stopped by debugger";
case TD_THR_RUN:
return "runnable";
case TD_THR_ACTIVE:
return "active";
case TD_THR_ZOMBIE:
return "zombie";
case TD_THR_SLEEP:
return "sleeping";
case TD_THR_STOPPED_ASLEEP:
return "stopped by debugger AND blocked";
default:
snprintf (buf, sizeof (buf), "unknown thread_db state %d", state);
return buf;
}
}
/* A callback function for td_ta_thr_iter, which we use to map all
threads to LWPs.
THP is a handle to the current thread; if INFOP is not NULL, the
struct thread_info associated with this thread is returned in
*INFOP.
If the thread is a zombie, TD_THR_ZOMBIE is returned. Otherwise,
zero is returned to indicate success. */
static int
thread_get_info_callback (const td_thrhandle_t *thp, void *infop)
{
td_thrinfo_t ti;
td_err_e err;
struct thread_info *thread_info;
ptid_t thread_ptid;
err = td_thr_get_info_p (thp, &ti);
if (err != TD_OK)
error ("thread_get_info_callback: cannot get thread info: %s",
thread_db_err_str (err));
/* Fill the cache. */
thread_ptid = BUILD_THREAD (ti.ti_tid, GET_PID (inferior_ptid));
thread_info = find_thread_pid (thread_ptid);
/* In the case of a zombie thread, don't continue. We don't want to
attach to it thinking it is a new thread. */
if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
{
if (infop != NULL)
*(struct thread_info **) infop = thread_info;
if (thread_info != NULL)
{
memcpy (&thread_info->private->th, thp, sizeof (*thp));
thread_info->private->th_valid = 1;
memcpy (&thread_info->private->ti, &ti, sizeof (ti));
thread_info->private->ti_valid = 1;
}
return TD_THR_ZOMBIE;
}
if (thread_info == NULL)
{
/* New thread. Attach to it now (why wait?). */
attach_thread (thread_ptid, thp, &ti, 1);
thread_info = find_thread_pid (thread_ptid);
gdb_assert (thread_info != NULL);
}
memcpy (&thread_info->private->th, thp, sizeof (*thp));
thread_info->private->th_valid = 1;
memcpy (&thread_info->private->ti, &ti, sizeof (ti));
thread_info->private->ti_valid = 1;
if (infop != NULL)
*(struct thread_info **) infop = thread_info;
return 0;
}
/* Accessor functions for the thread_db information, with caching. */
static void
thread_db_map_id2thr (struct thread_info *thread_info, int fatal)
{
td_err_e err;
if (thread_info->private->th_valid)
return;
err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (thread_info->ptid),
&thread_info->private->th);
if (err != TD_OK)
{
if (fatal)
error ("Cannot find thread %ld: %s",
(long) GET_THREAD (thread_info->ptid),
thread_db_err_str (err));
}
else
thread_info->private->th_valid = 1;
}
static td_thrinfo_t *
thread_db_get_info (struct thread_info *thread_info)
{
td_err_e err;
if (thread_info->private->ti_valid)
return &thread_info->private->ti;
if (!thread_info->private->th_valid)
thread_db_map_id2thr (thread_info, 1);
err =
td_thr_get_info_p (&thread_info->private->th, &thread_info->private->ti);
if (err != TD_OK)
error ("thread_db_get_info: cannot get thread info: %s",
thread_db_err_str (err));
thread_info->private->ti_valid = 1;
return &thread_info->private->ti;
}
/* Convert between user-level thread ids and LWP ids. */
static ptid_t
thread_from_lwp (ptid_t ptid)
{
td_thrhandle_t th;
td_err_e err;
struct thread_info *thread_info;
ptid_t thread_ptid;
if (GET_LWP (ptid) == 0)
ptid = BUILD_LWP (GET_PID (ptid), GET_PID (ptid));
gdb_assert (is_lwp (ptid));
err = td_ta_map_lwp2thr_p (thread_agent, GET_LWP (ptid), &th);
if (err != TD_OK)
error ("Cannot find user-level thread for LWP %ld: %s",
GET_LWP (ptid), thread_db_err_str (err));
thread_info = NULL;
/* Fetch the thread info. If we get back TD_THR_ZOMBIE, then the
event thread has already died. If another gdb interface has called
thread_alive() previously, the thread won't be found on the thread list
anymore. In that case, we don't want to process this ptid anymore
to avoid the possibility of later treating it as a newly
discovered thread id that we should add to the list. Thus,
we return a -1 ptid which is also how the thread list marks a
dead thread. */
if (thread_get_info_callback (&th, &thread_info) == TD_THR_ZOMBIE
&& thread_info == NULL)
return pid_to_ptid (-1);
gdb_assert (thread_info && thread_info->private->ti_valid);
return BUILD_THREAD (thread_info->private->ti.ti_tid, GET_PID (ptid));
}
static ptid_t
lwp_from_thread (ptid_t ptid)
{
struct thread_info *thread_info;
ptid_t thread_ptid;
if (!is_thread (ptid))
return ptid;
thread_info = find_thread_pid (ptid);
thread_db_get_info (thread_info);
return BUILD_LWP (thread_info->private->ti.ti_lid, GET_PID (ptid));
}
void
thread_db_init (struct target_ops *target)
{
target_beneath = target;
}
static void *
verbose_dlsym (void *handle, const char *name)
{
void *sym = dlsym (handle, name);
if (sym == NULL)
warning ("Symbol \"%s\" not found in libthread_db: %s", name, dlerror ());
return sym;
}
static int
thread_db_load (void)
{
void *handle;
td_err_e err;
handle = dlopen (LIBTHREAD_DB_SO, RTLD_NOW);
if (handle == NULL)
{
fprintf_filtered (gdb_stderr, "\n\ndlopen failed on '%s' - %s\n",
LIBTHREAD_DB_SO, dlerror ());
fprintf_filtered (gdb_stderr,
"GDB will not be able to debug pthreads.\n\n");
return 0;
}
/* Initialize pointers to the dynamic library functions we will use.
Essential functions first. */
td_init_p = verbose_dlsym (handle, "td_init");
if (td_init_p == NULL)
return 0;
td_ta_new_p = verbose_dlsym (handle, "td_ta_new");
if (td_ta_new_p == NULL)
return 0;
td_ta_map_id2thr_p = verbose_dlsym (handle, "td_ta_map_id2thr");
if (td_ta_map_id2thr_p == NULL)
return 0;
td_ta_map_lwp2thr_p = verbose_dlsym (handle, "td_ta_map_lwp2thr");
if (td_ta_map_lwp2thr_p == NULL)
return 0;
td_ta_thr_iter_p = verbose_dlsym (handle, "td_ta_thr_iter");
if (td_ta_thr_iter_p == NULL)
return 0;
td_thr_validate_p = verbose_dlsym (handle, "td_thr_validate");
if (td_thr_validate_p == NULL)
return 0;
td_thr_get_info_p = verbose_dlsym (handle, "td_thr_get_info");
if (td_thr_get_info_p == NULL)
return 0;
td_thr_getfpregs_p = verbose_dlsym (handle, "td_thr_getfpregs");
if (td_thr_getfpregs_p == NULL)
return 0;
td_thr_getgregs_p = verbose_dlsym (handle, "td_thr_getgregs");
if (td_thr_getgregs_p == NULL)
return 0;
td_thr_setfpregs_p = verbose_dlsym (handle, "td_thr_setfpregs");
if (td_thr_setfpregs_p == NULL)
return 0;
td_thr_setgregs_p = verbose_dlsym (handle, "td_thr_setgregs");
if (td_thr_setgregs_p == NULL)
return 0;
/* Initialize the library. */
err = td_init_p ();
if (err != TD_OK)
{
warning ("Cannot initialize libthread_db: %s", thread_db_err_str (err));
return 0;
}
/* These are not essential. */
td_ta_event_addr_p = dlsym (handle, "td_ta_event_addr");
td_ta_set_event_p = dlsym (handle, "td_ta_set_event");
td_ta_event_getmsg_p = dlsym (handle, "td_ta_event_getmsg");
td_thr_event_enable_p = dlsym (handle, "td_thr_event_enable");
td_thr_tls_get_addr_p = dlsym (handle, "td_thr_tls_get_addr");
return 1;
}
static td_err_e
enable_thread_event (td_thragent_t *thread_agent, int event, CORE_ADDR *bp)
{
td_notify_t notify;
td_err_e err;
/* Get the breakpoint address for thread EVENT. */
err = td_ta_event_addr_p (thread_agent, event, ¬ify);
if (err != TD_OK)
return err;
/* Set up the breakpoint. */
(*bp) = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
(CORE_ADDR) notify.u.bptaddr,
¤t_target);
create_thread_event_breakpoint ((*bp));
return TD_OK;
}
static void
enable_thread_event_reporting (void)
{
td_thr_events_t events;
td_notify_t notify;
td_err_e err;
#ifdef HAVE_GNU_LIBC_VERSION_H
const char *libc_version;
int libc_major, libc_minor;
#endif
/* We cannot use the thread event reporting facility if these
functions aren't available. */
if (td_ta_event_addr_p == NULL || td_ta_set_event_p == NULL
|| td_ta_event_getmsg_p == NULL || td_thr_event_enable_p == NULL)
return;
/* Set the process wide mask saying which events we're interested in. */
td_event_emptyset (&events);
td_event_addset (&events, TD_CREATE);
#ifdef HAVE_GNU_LIBC_VERSION_H
/* FIXME: kettenis/2000-04-23: The event reporting facility is
broken for TD_DEATH events in glibc 2.1.3, so don't enable it for
now. */
libc_version = gnu_get_libc_version ();
if (sscanf (libc_version, "%d.%d", &libc_major, &libc_minor) == 2
&& (libc_major > 2 || (libc_major == 2 && libc_minor > 1)))
#endif
td_event_addset (&events, TD_DEATH);
err = td_ta_set_event_p (thread_agent, &events);
if (err != TD_OK)
{
warning ("Unable to set global thread event mask: %s",
thread_db_err_str (err));
return;
}
/* Delete previous thread event breakpoints, if any. */
remove_thread_event_breakpoints ();
td_create_bp_addr = 0;
td_death_bp_addr = 0;
/* Set up the thread creation event. */
err = enable_thread_event (thread_agent, TD_CREATE, &td_create_bp_addr);
if (err != TD_OK)
{
warning ("Unable to get location for thread creation breakpoint: %s",
thread_db_err_str (err));
return;
}
/* Set up the thread death event. */
err = enable_thread_event (thread_agent, TD_DEATH, &td_death_bp_addr);
if (err != TD_OK)
{
warning ("Unable to get location for thread death breakpoint: %s",
thread_db_err_str (err));
return;
}
}
static void
disable_thread_event_reporting (void)
{
td_thr_events_t events;
/* Set the process wide mask saying we aren't interested in any
events anymore. */
td_event_emptyset (&events);
td_ta_set_event_p (thread_agent, &events);
/* Delete thread event breakpoints, if any. */
remove_thread_event_breakpoints ();
td_create_bp_addr = 0;
td_death_bp_addr = 0;
}
static void
check_thread_signals (void)
{
#ifdef GET_THREAD_SIGNALS
if (!thread_signals)
{
sigset_t mask;
int i;
GET_THREAD_SIGNALS (&mask);
sigemptyset (&thread_stop_set);
sigemptyset (&thread_print_set);
for (i = 1; i < NSIG; i++)
{
if (sigismember (&mask, i))
{
if (signal_stop_update (target_signal_from_host (i), 0))
sigaddset (&thread_stop_set, i);
if (signal_print_update (target_signal_from_host (i), 0))
sigaddset (&thread_print_set, i);
thread_signals = 1;
}
}
}
#endif
}
static void
thread_db_new_objfile (struct objfile *objfile)
{
td_err_e err;
/* First time through, report that libthread_db was successfuly
loaded. Can't print this in in thread_db_load as, at that stage,
the interpreter and it's console haven't started. The real
problem here is that libthread_db is loaded too early - it should
only be loaded when there is a program to debug. */
{
static int dejavu;
if (!dejavu)
{
Dl_info info;
const char *library = NULL;
/* Try dladdr. */
if (dladdr ((*td_ta_new_p), &info) != 0)
library = info.dli_fname;
/* Try dlinfo? */
if (library == NULL)
/* Paranoid - don't let a NULL path slip through. */
library = LIBTHREAD_DB_SO;
printf_unfiltered ("Using host libthread_db library \"%s\".\n",
library);
dejavu = 1;
}
}
/* Don't attempt to use thread_db on targets which can not run
(core files). */
if (objfile == NULL || !target_has_execution)
{
/* All symbols have been discarded. If the thread_db target is
active, deactivate it now. */
if (using_thread_db)
{
gdb_assert (proc_handle.pid == 0);
unpush_target (&thread_db_ops);
using_thread_db = 0;
}
goto quit;
}
if (using_thread_db)
/* Nothing to do. The thread library was already detected and the
target vector was already activated. */
goto quit;
/* Initialize the structure that identifies the child process. Note
that at this point there is no guarantee that we actually have a
child process. */
proc_handle.pid = GET_PID (inferior_ptid);
/* Now attempt to open a connection to the thread library. */
err = td_ta_new_p (&proc_handle, &thread_agent);
switch (err)
{
case TD_NOLIBTHREAD:
/* No thread library was detected. */
break;
case TD_OK:
printf_unfiltered ("[Thread debugging using libthread_db enabled]\n");
/* The thread library was detected. Activate the thread_db target. */
push_target (&thread_db_ops);
using_thread_db = 1;
/* We can only poke around if there actually is a child process.
If there is no child process alive, postpone the steps below
until one has been created. */
if (proc_handle.pid != 0)
{
enable_thread_event_reporting ();
thread_db_find_new_threads ();
}
break;
default:
warning ("Cannot initialize thread debugging library: %s",
thread_db_err_str (err));
break;
}
quit:
if (target_new_objfile_chain)
target_new_objfile_chain (objfile);
}
/* Attach to a new thread. This function is called when we receive a
TD_CREATE event or when we iterate over all threads and find one
that wasn't already in our list. */
static void
attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
const td_thrinfo_t *ti_p, int verbose)
{
struct thread_info *tp;
td_err_e err;
/* If we're being called after a TD_CREATE event, we may already
know about this thread. There are two ways this can happen. We
may have iterated over all threads between the thread creation
and the TD_CREATE event, for instance when the user has issued
the `info threads' command before the SIGTRAP for hitting the
thread creation breakpoint was reported. Alternatively, the
thread may have exited and a new one been created with the same
thread ID. In the first case we don't need to do anything; in
the second case we should discard information about the dead
thread and attach to the new one. */
if (in_thread_list (ptid))
{
tp = find_thread_pid (ptid);
gdb_assert (tp != NULL);
if (!tp->private->dying)
return;
delete_thread (ptid);
}
check_thread_signals ();
/* Add the thread to GDB's thread list. */
tp = add_thread (ptid);
tp->private = xmalloc (sizeof (struct private_thread_info));
memset (tp->private, 0, sizeof (struct private_thread_info));
if (verbose)
printf_unfiltered ("[New %s]\n", target_pid_to_str (ptid));
if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
return; /* A zombie thread -- do not attach. */
/* Under GNU/Linux, we have to attach to each and every thread. */
#ifdef ATTACH_LWP
ATTACH_LWP (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid)), 0);
#endif
/* Enable thread event reporting for this thread. */
err = td_thr_event_enable_p (th_p, 1);
if (err != TD_OK)
error ("Cannot enable thread event reporting for %s: %s",
target_pid_to_str (ptid), thread_db_err_str (err));
}
static void
thread_db_attach (char *args, int from_tty)
{
target_beneath->to_attach (args, from_tty);
/* Destroy thread info; it's no longer valid. */
init_thread_list ();
/* The child process is now the actual multi-threaded
program. Snatch its process ID... */
proc_handle.pid = GET_PID (inferior_ptid);
/* ...and perform the remaining initialization steps. */
enable_thread_event_reporting ();
thread_db_find_new_threads ();
}
static void
detach_thread (ptid_t ptid, int verbose)
{
struct thread_info *thread_info;
if (verbose)
printf_unfiltered ("[%s exited]\n", target_pid_to_str (ptid));
/* Don't delete the thread now, because it still reports as active
until it has executed a few instructions after the event
breakpoint - if we deleted it now, "info threads" would cause us
to re-attach to it. Just mark it as having had a TD_DEATH
event. This means that we won't delete it from our thread list
until we notice that it's dead (via prune_threads), or until
something re-uses its thread ID. */
thread_info = find_thread_pid (ptid);
gdb_assert (thread_info != NULL);
thread_info->private->dying = 1;
}
static void
thread_db_detach (char *args, int from_tty)
{
disable_thread_event_reporting ();
/* There's no need to save & restore inferior_ptid here, since the
inferior is supposed to be survive this function call. */
inferior_ptid = lwp_from_thread (inferior_ptid);
/* Forget about the child's process ID. We shouldn't need it
anymore. */
proc_handle.pid = 0;
target_beneath->to_detach (args, from_tty);
}
static int
clear_lwpid_callback (struct thread_info *thread, void *dummy)
{
/* If we know that our thread implementation is 1-to-1, we could save
a certain amount of information; it's not clear how much, so we
are always conservative. */
thread->private->th_valid = 0;
thread->private->ti_valid = 0;
return 0;
}
static void
thread_db_resume (ptid_t ptid, int step, enum target_signal signo)
{
struct cleanup *old_chain = save_inferior_ptid ();
if (GET_PID (ptid) == -1)
inferior_ptid = lwp_from_thread (inferior_ptid);
else if (is_thread (ptid))
ptid = lwp_from_thread (ptid);
/* Clear cached data which may not be valid after the resume. */
iterate_over_threads (clear_lwpid_callback, NULL);
target_beneath->to_resume (ptid, step, signo);
do_cleanups (old_chain);
}
/* Check if PID is currently stopped at the location of a thread event
breakpoint location. If it is, read the event message and act upon
the event. */
static void
check_event (ptid_t ptid)
{
td_event_msg_t msg;
td_thrinfo_t ti;
td_err_e err;
CORE_ADDR stop_pc;
int loop = 0;
/* Bail out early if we're not at a thread event breakpoint. */
stop_pc = read_pc_pid (ptid) - DECR_PC_AFTER_BREAK;
if (stop_pc != td_create_bp_addr && stop_pc != td_death_bp_addr)
return;
/* If we are at a create breakpoint, we do not know what new lwp
was created and cannot specifically locate the event message for it.
We have to call td_ta_event_getmsg() to get
the latest message. Since we have no way of correlating whether
the event message we get back corresponds to our breakpoint, we must
loop and read all event messages, processing them appropriately.
This guarantees we will process the correct message before continuing
from the breakpoint.
Currently, death events are not enabled. If they are enabled,
the death event can use the td_thr_event_getmsg() interface to
get the message specifically for that lwp and avoid looping
below. */
loop = 1;
do
{
err = td_ta_event_getmsg_p (thread_agent, &msg);
if (err != TD_OK)
{
if (err == TD_NOMSG)
return;
error ("Cannot get thread event message: %s",
thread_db_err_str (err));
}
err = td_thr_get_info_p (msg.th_p, &ti);
if (err != TD_OK)
error ("Cannot get thread info: %s", thread_db_err_str (err));
ptid = BUILD_THREAD (ti.ti_tid, GET_PID (ptid));
switch (msg.event)
{
case TD_CREATE:
/* Call attach_thread whether or not we already know about a
thread with this thread ID. */
attach_thread (ptid, msg.th_p, &ti, 1);
break;
case TD_DEATH:
if (!in_thread_list (ptid))
error ("Spurious thread death event.");
detach_thread (ptid, 1);
break;
default:
error ("Spurious thread event.");
}
}
while (loop);
}
static ptid_t
thread_db_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
{
extern ptid_t trap_ptid;
if (GET_PID (ptid) != -1 && is_thread (ptid))
ptid = lwp_from_thread (ptid);
ptid = target_beneath->to_wait (ptid, ourstatus);
if (proc_handle.pid == 0)
/* The current child process isn't the actual multi-threaded
program yet, so don't try to do any special thread-specific
post-processing and bail out early. */
return ptid;
if (ourstatus->kind == TARGET_WAITKIND_EXITED)
return pid_to_ptid (-1);
if (ourstatus->kind == TARGET_WAITKIND_STOPPED
&& ourstatus->value.sig == TARGET_SIGNAL_TRAP)
/* Check for a thread event. */
check_event (ptid);
if (!ptid_equal (trap_ptid, null_ptid))
trap_ptid = thread_from_lwp (trap_ptid);
/* Change the ptid back into the higher level PID + TID format.
If the thread is dead and no longer on the thread list, we will
get back a dead ptid. This can occur if the thread death event
gets postponed by other simultaneous events. In such a case,
we want to just ignore the event and continue on. */
ptid = thread_from_lwp (ptid);
if (GET_PID (ptid) == -1)
ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
return ptid;
}
static int
thread_db_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
struct mem_attrib *attrib, struct target_ops *target)
{
struct cleanup *old_chain = save_inferior_ptid ();
int xfer;
if (is_thread (inferior_ptid))
{
/* FIXME: This seems to be necessary to make sure breakpoints
are removed. */
if (!target_thread_alive (inferior_ptid))
inferior_ptid = pid_to_ptid (GET_PID (inferior_ptid));
else
inferior_ptid = lwp_from_thread (inferior_ptid);
}
xfer =
target_beneath->to_xfer_memory (memaddr, myaddr, len, write, attrib,
target);
do_cleanups (old_chain);
return xfer;
}
static void
thread_db_fetch_registers (int regno)
{
struct thread_info *thread_info;
prgregset_t gregset;
gdb_prfpregset_t fpregset;
td_err_e err;
if (!is_thread (inferior_ptid))
{
/* Pass the request to the target beneath us. */
target_beneath->to_fetch_registers (regno);
return;
}
thread_info = find_thread_pid (inferior_ptid);
thread_db_map_id2thr (thread_info, 1);
err = td_thr_getgregs_p (&thread_info->private->th, gregset);
if (err != TD_OK)
error ("Cannot fetch general-purpose registers for thread %ld: %s",
(long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
err = td_thr_getfpregs_p (&thread_info->private->th, &fpregset);
if (err != TD_OK)
error ("Cannot get floating-point registers for thread %ld: %s",
(long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
/* Note that we must call supply_gregset after calling the thread_db
routines because the thread_db routines call ps_lgetgregs and
friends which clobber GDB's register cache. */
supply_gregset ((gdb_gregset_t *) gregset);
supply_fpregset (&fpregset);
}
static void
thread_db_store_registers (int regno)
{
prgregset_t gregset;
gdb_prfpregset_t fpregset;
td_err_e err;
struct thread_info *thread_info;
if (!is_thread (inferior_ptid))
{
/* Pass the request to the target beneath us. */
target_beneath->to_store_registers (regno);
return;
}
thread_info = find_thread_pid (inferior_ptid);
thread_db_map_id2thr (thread_info, 1);
if (regno != -1)
{
char raw[MAX_REGISTER_SIZE];
deprecated_read_register_gen (regno, raw);
thread_db_fetch_registers (-1);
regcache_raw_supply (current_regcache, regno, raw);
}
fill_gregset ((gdb_gregset_t *) gregset, -1);
fill_fpregset (&fpregset, -1);
err = td_thr_setgregs_p (&thread_info->private->th, gregset);
if (err != TD_OK)
error ("Cannot store general-purpose registers for thread %ld: %s",
(long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
err = td_thr_setfpregs_p (&thread_info->private->th, &fpregset);
if (err != TD_OK)
error ("Cannot store floating-point registers for thread %ld: %s",
(long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
}
static void
thread_db_kill (void)
{
/* There's no need to save & restore inferior_ptid here, since the
inferior isn't supposed to survive this function call. */
inferior_ptid = lwp_from_thread (inferior_ptid);
target_beneath->to_kill ();
}
static void
thread_db_create_inferior (char *exec_file, char *allargs, char **env,
int from_tty)
{
unpush_target (&thread_db_ops);
using_thread_db = 0;
target_beneath->to_create_inferior (exec_file, allargs, env, from_tty);
}
static void
thread_db_post_startup_inferior (ptid_t ptid)
{
if (proc_handle.pid == 0)
{
/* The child process is now the actual multi-threaded
program. Snatch its process ID... */
proc_handle.pid = GET_PID (ptid);
/* ...and perform the remaining initialization steps. */
enable_thread_event_reporting ();
thread_db_find_new_threads ();
}
}
static void
thread_db_mourn_inferior (void)
{
remove_thread_event_breakpoints ();
/* Forget about the child's process ID. We shouldn't need it
anymore. */
proc_handle.pid = 0;
target_beneath->to_mourn_inferior ();
/* Detach thread_db target ops. */
unpush_target (&thread_db_ops);
using_thread_db = 0;
}
static int
thread_db_thread_alive (ptid_t ptid)
{
td_thrhandle_t th;
td_err_e err;
if (is_thread (ptid))
{
struct thread_info *thread_info;
thread_info = find_thread_pid (ptid);
thread_db_map_id2thr (thread_info, 0);
if (!thread_info->private->th_valid)
return 0;
err = td_thr_validate_p (&thread_info->private->th);
if (err != TD_OK)
return 0;
if (!thread_info->private->ti_valid)
{
err =
td_thr_get_info_p (&thread_info->private->th,
&thread_info->private->ti);
if (err != TD_OK)
return 0;
thread_info->private->ti_valid = 1;
}
if (thread_info->private->ti.ti_state == TD_THR_UNKNOWN
|| thread_info->private->ti.ti_state == TD_THR_ZOMBIE)
return 0; /* A zombie thread. */
return 1;
}
if (target_beneath->to_thread_alive)
return target_beneath->to_thread_alive (ptid);
return 0;
}
static int
find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
{
td_thrinfo_t ti;
td_err_e err;
ptid_t ptid;
err = td_thr_get_info_p (th_p, &ti);
if (err != TD_OK)
error ("find_new_threads_callback: cannot get thread info: %s",
thread_db_err_str (err));
if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
return 0; /* A zombie -- ignore. */
ptid = BUILD_THREAD (ti.ti_tid, GET_PID (inferior_ptid));
if (!in_thread_list (ptid))
attach_thread (ptid, th_p, &ti, 1);
return 0;
}
static void
thread_db_find_new_threads (void)
{
td_err_e err;
/* Iterate over all user-space threads to discover new threads. */
err = td_ta_thr_iter_p (thread_agent, find_new_threads_callback, NULL,
TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS);
if (err != TD_OK)
error ("Cannot find new threads: %s", thread_db_err_str (err));
}
static char *
thread_db_pid_to_str (ptid_t ptid)
{
if (is_thread (ptid))
{
static char buf[64];
td_thrinfo_t *ti_p;
td_err_e err;
struct thread_info *thread_info;
thread_info = find_thread_pid (ptid);
thread_db_map_id2thr (thread_info, 0);
if (!thread_info->private->th_valid)
{
snprintf (buf, sizeof (buf), "Thread %ld (Missing)",
GET_THREAD (ptid));
return buf;
}
ti_p = thread_db_get_info (thread_info);
if (ti_p->ti_state == TD_THR_ACTIVE && ti_p->ti_lid != 0)
{
snprintf (buf, sizeof (buf), "Thread %ld (LWP %d)",
(long) ti_p->ti_tid, ti_p->ti_lid);
}
else
{
snprintf (buf, sizeof (buf), "Thread %ld (%s)",
(long) ti_p->ti_tid,
thread_db_state_str (ti_p->ti_state));
}
return buf;
}
if (target_beneath->to_pid_to_str (ptid))
return target_beneath->to_pid_to_str (ptid);
return normal_pid_to_str (ptid);
}
/* Get the address of the thread local variable in OBJFILE which is
stored at OFFSET within the thread local storage for thread PTID. */
static CORE_ADDR
thread_db_get_thread_local_address (ptid_t ptid, struct objfile *objfile,
CORE_ADDR offset)
{
if (is_thread (ptid))
{
int objfile_is_library = (objfile->flags & OBJF_SHARED);
td_err_e err;
void *address;
CORE_ADDR lm;
struct thread_info *thread_info;
/* glibc doesn't provide the needed interface. */
if (!td_thr_tls_get_addr_p)
error ("Cannot find thread-local variables in this thread library.");
/* Get the address of the link map for this objfile. */
lm = svr4_fetch_objfile_link_map (objfile);
/* Whoops, we couldn't find one. Bail out. */
if (!lm)
{
if (objfile_is_library)
error ("Cannot find shared library `%s' link_map in dynamic"
" linker's module list", objfile->name);
else
error ("Cannot find executable file `%s' link_map in dynamic"
" linker's module list", objfile->name);
}
/* Get info about the thread. */
thread_info = find_thread_pid (ptid);
thread_db_map_id2thr (thread_info, 1);
/* Finally, get the address of the variable. */
err = td_thr_tls_get_addr_p (&thread_info->private->th, (void *) lm,
offset, &address);
#ifdef THREAD_DB_HAS_TD_NOTALLOC
/* The memory hasn't been allocated, yet. */
if (err == TD_NOTALLOC)
{
/* Now, if libthread_db provided the initialization image's
address, we *could* try to build a non-lvalue value from
the initialization image. */
if (objfile_is_library)
error ("The inferior has not yet allocated storage for"
" thread-local variables in\n"
"the shared library `%s'\n"
"for the thread %ld",
objfile->name, (long) GET_THREAD (ptid));
else
error ("The inferior has not yet allocated storage for"
" thread-local variables in\n"
"the executable `%s'\n"
"for the thread %ld",
objfile->name, (long) GET_THREAD (ptid));
}
#endif
/* Something else went wrong. */
if (err != TD_OK)
{
if (objfile_is_library)
error ("Cannot find thread-local storage for thread %ld, "
"shared library %s:\n%s",
(long) GET_THREAD (ptid),
objfile->name, thread_db_err_str (err));
else
error ("Cannot find thread-local storage for thread %ld, "
"executable file %s:\n%s",
(long) GET_THREAD (ptid),
objfile->name, thread_db_err_str (err));
}
/* Cast assuming host == target. Joy. */
return (CORE_ADDR) address;
}
if (target_beneath->to_get_thread_local_address)
return target_beneath->to_get_thread_local_address (ptid, objfile,
offset);
error ("Cannot find thread-local values on this target.");
}
static void
init_thread_db_ops (void)
{
thread_db_ops.to_shortname = "multi-thread";
thread_db_ops.to_longname = "multi-threaded child process.";
thread_db_ops.to_doc = "Threads and pthreads support.";
thread_db_ops.to_attach = thread_db_attach;
thread_db_ops.to_detach = thread_db_detach;
thread_db_ops.to_resume = thread_db_resume;
thread_db_ops.to_wait = thread_db_wait;
thread_db_ops.to_fetch_registers = thread_db_fetch_registers;
thread_db_ops.to_store_registers = thread_db_store_registers;
thread_db_ops.to_xfer_memory = thread_db_xfer_memory;
thread_db_ops.to_kill = thread_db_kill;
thread_db_ops.to_create_inferior = thread_db_create_inferior;
thread_db_ops.to_post_startup_inferior = thread_db_post_startup_inferior;
thread_db_ops.to_mourn_inferior = thread_db_mourn_inferior;
thread_db_ops.to_thread_alive = thread_db_thread_alive;
thread_db_ops.to_find_new_threads = thread_db_find_new_threads;
thread_db_ops.to_pid_to_str = thread_db_pid_to_str;
thread_db_ops.to_stratum = thread_stratum;
thread_db_ops.to_has_thread_control = tc_schedlock;
thread_db_ops.to_get_thread_local_address
= thread_db_get_thread_local_address;
thread_db_ops.to_magic = OPS_MAGIC;
}
void
_initialize_thread_db (void)
{
/* Only initialize the module if we can load libthread_db. */
if (thread_db_load ())
{
init_thread_db_ops ();
add_target (&thread_db_ops);
/* Add ourselves to objfile event chain. */
target_new_objfile_chain = deprecated_target_new_objfile_hook;
deprecated_target_new_objfile_hook = thread_db_new_objfile;
}
}
|