summaryrefslogtreecommitdiff
path: root/gdb/hppah-nat.c
blob: 6b361eb787387c64d1af4e68631ef0ab444dea13 (plain)
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
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
/* Native support code for HPUX PA-RISC.
   Copyright 1986, 1987, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
   1998, 1999, 2000, 2001
   Free Software Foundation, Inc.

   Contributed by the Center for Software Science at the
   University of Utah (pa-gdb-bugs@cs.utah.edu).

   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 "inferior.h"
#include "target.h"
#include <sys/ptrace.h>
#include "gdbcore.h"
#include "gdb_wait.h"
#include "regcache.h"
#include "gdb_string.h"
#include "infttrace.h"
#include <signal.h>

#include "hppa-tdep.h"

static CORE_ADDR text_end;

void
deprecated_hpux_text_end (struct target_ops *exec_ops)
{
  struct section_table *p;

  /* Set text_end to the highest address of the end of any readonly
     code section.  */
  /* FIXME: The comment above does not match the code.  The code
     checks for sections with are either code *or* readonly.  */
  text_end = (CORE_ADDR) 0;
  for (p = exec_ops->to_sections; p < exec_ops->to_sections_end; p++)
    if (bfd_get_section_flags (p->bfd, p->the_bfd_section)
	& (SEC_CODE | SEC_READONLY))
      {
	if (text_end < p->endaddr)
	  text_end = p->endaddr;
      }
}


static void fetch_register (int);

void
fetch_inferior_registers (int regno)
{
  if (regno == -1)
    for (regno = 0; regno < NUM_REGS; regno++)
      fetch_register (regno);
  else
    fetch_register (regno);
}

/* Our own version of the offsetof macro, since we can't assume ANSI C.  */
#define HPPAH_OFFSETOF(type, member) ((int) (&((type *) 0)->member))

/* Store our register values back into the inferior.
   If REGNO is -1, do this for all registers.
   Otherwise, REGNO specifies which register (so we can save time).  */

void
store_inferior_registers (int regno)
{
  unsigned int regaddr;
  char buf[80];
  int i;
  unsigned int offset = U_REGS_OFFSET;
  int scratch;

  if (regno >= 0)
    {
      unsigned int addr, len, offset;

      if (CANNOT_STORE_REGISTER (regno))
	return;

      offset = 0;
      len = DEPRECATED_REGISTER_RAW_SIZE (regno);

      /* Requests for register zero actually want the save_state's
	 ss_flags member.  As RM says: "Oh, what a hack!"  */
      if (regno == 0)
	{
	  save_state_t ss;
	  addr = HPPAH_OFFSETOF (save_state_t, ss_flags);
	  len = sizeof (ss.ss_flags);

	  /* Note that ss_flags is always an int, no matter what
	     DEPRECATED_REGISTER_RAW_SIZE(0) says.  Assuming all HP-UX
	     PA machines are big-endian, put it at the least
	     significant end of the value, and zap the rest of the
	     buffer.  */
	  offset = DEPRECATED_REGISTER_RAW_SIZE (0) - len;
	}

      /* Floating-point registers come from the ss_fpblock area.  */
      else if (regno >= HPPA_FP0_REGNUM)
	addr = (HPPAH_OFFSETOF (save_state_t, ss_fpblock) 
		+ (DEPRECATED_REGISTER_BYTE (regno) - DEPRECATED_REGISTER_BYTE (HPPA_FP0_REGNUM)));

      /* Wide registers come from the ss_wide area.
	 I think it's more PC to test (ss_flags & SS_WIDEREGS) to select
	 between ss_wide and ss_narrow than to use the raw register size.
	 But checking ss_flags would require an extra ptrace call for
	 every register reference.  Bleah.  */
      else if (len == 8)
	addr = (HPPAH_OFFSETOF (save_state_t, ss_wide) 
		+ DEPRECATED_REGISTER_BYTE (regno));

      /* Narrow registers come from the ss_narrow area.  Note that
	 ss_narrow starts with gr1, not gr0.  */
      else if (len == 4)
	addr = (HPPAH_OFFSETOF (save_state_t, ss_narrow)
		+ (DEPRECATED_REGISTER_BYTE (regno) - DEPRECATED_REGISTER_BYTE (1)));
      else
	internal_error (__FILE__, __LINE__,
			"hppah-nat.c (write_register): unexpected register size");

#ifdef GDB_TARGET_IS_HPPA_20W
      /* Unbelieveable.  The PC head and tail must be written in 64bit hunks
	 or we will get an error.  Worse yet, the oddball ptrace/ttrace
	 layering will not allow us to perform a 64bit register store.

	 What a crock.  */
      if (regno == HPPA_PCOQ_HEAD_REGNUM || regno == HPPA_PCOQ_TAIL_REGNUM && len == 8)
	{
	  CORE_ADDR temp;

	  temp = *(CORE_ADDR *)&deprecated_registers[DEPRECATED_REGISTER_BYTE (regno)];

	  /* Set the priv level (stored in the low two bits of the PC.  */
	  temp |= 0x3;

	  ttrace_write_reg_64 (PIDGET (inferior_ptid), (CORE_ADDR)addr,
	                       (CORE_ADDR)&temp);

	  /* If we fail to write the PC, give a true error instead of
	     just a warning.  */
	  if (errno != 0)
	    {
	      char *err = safe_strerror (errno);
	      char *msg = alloca (strlen (err) + 128);
	      sprintf (msg, "writing `%s' register: %s",
		        REGISTER_NAME (regno), err);
	      perror_with_name (msg);
	    }
	  return;
	}

      /* Another crock.  HPUX complains if you write a nonzero value to
	 the high part of IPSW.  What will it take for HP to catch a
	 clue about building sensible interfaces?  */
     if (regno == HPPA_IPSW_REGNUM && len == 8)
	*(int *)&deprecated_registers[DEPRECATED_REGISTER_BYTE (regno)] = 0;
#endif

      for (i = 0; i < len; i += sizeof (int))
	{
	  errno = 0;
	  call_ptrace (PT_WUREGS, PIDGET (inferior_ptid),
	               (PTRACE_ARG3_TYPE) addr + i,
		       *(int *) &deprecated_registers[DEPRECATED_REGISTER_BYTE (regno) + i]);
	  if (errno != 0)
	    {
	      /* Warning, not error, in case we are attached; sometimes
		 the kernel doesn't let us at the registers. */
	      char *err = safe_strerror (errno);
	      char *msg = alloca (strlen (err) + 128);
	      sprintf (msg, "writing `%s' register: %s",
		        REGISTER_NAME (regno), err);
	      /* If we fail to write the PC, give a true error instead of
		 just a warning.  */
	      if (regno == HPPA_PCOQ_HEAD_REGNUM || regno == HPPA_PCOQ_TAIL_REGNUM)
		perror_with_name (msg);
	      else
		warning (msg);
	      return;
	    }
	}
    }
  else
    for (regno = 0; regno < NUM_REGS; regno++)
      store_inferior_registers (regno);
}


/* Fetch a register's value from the process's U area.  */
static void
fetch_register (int regno)
{
  char buf[MAX_REGISTER_SIZE];
  unsigned int addr, len, offset;
  int i;

  offset = 0;
  len = DEPRECATED_REGISTER_RAW_SIZE (regno);

  /* Requests for register zero actually want the save_state's
     ss_flags member.  As RM says: "Oh, what a hack!"  */
  if (regno == 0)
    {
      save_state_t ss;
      addr = HPPAH_OFFSETOF (save_state_t, ss_flags);
      len = sizeof (ss.ss_flags);

      /* Note that ss_flags is always an int, no matter what
	 DEPRECATED_REGISTER_RAW_SIZE(0) says.  Assuming all HP-UX PA
	 machines are big-endian, put it at the least significant end
	 of the value, and zap the rest of the buffer.  */
      offset = DEPRECATED_REGISTER_RAW_SIZE (0) - len;
      memset (buf, 0, sizeof (buf));
    }

  /* Floating-point registers come from the ss_fpblock area.  */
  else if (regno >= HPPA_FP0_REGNUM)
    addr = (HPPAH_OFFSETOF (save_state_t, ss_fpblock) 
	    + (DEPRECATED_REGISTER_BYTE (regno) - DEPRECATED_REGISTER_BYTE (HPPA_FP0_REGNUM)));

  /* Wide registers come from the ss_wide area.
     I think it's more PC to test (ss_flags & SS_WIDEREGS) to select
     between ss_wide and ss_narrow than to use the raw register size.
     But checking ss_flags would require an extra ptrace call for
     every register reference.  Bleah.  */
  else if (len == 8)
    addr = (HPPAH_OFFSETOF (save_state_t, ss_wide) 
	    + DEPRECATED_REGISTER_BYTE (regno));

  /* Narrow registers come from the ss_narrow area.  Note that
     ss_narrow starts with gr1, not gr0.  */
  else if (len == 4)
    addr = (HPPAH_OFFSETOF (save_state_t, ss_narrow)
	    + (DEPRECATED_REGISTER_BYTE (regno) - DEPRECATED_REGISTER_BYTE (1)));

  else
    internal_error (__FILE__, __LINE__,
		    "hppa-nat.c (fetch_register): unexpected register size");

  for (i = 0; i < len; i += sizeof (int))
    {
      errno = 0;
      /* Copy an int from the U area to buf.  Fill the least
         significant end if len != raw_size.  */
      * (int *) &buf[offset + i] =
	  call_ptrace (PT_RUREGS, PIDGET (inferior_ptid),
		       (PTRACE_ARG3_TYPE) addr + i, 0);
      if (errno != 0)
	{
	  /* Warning, not error, in case we are attached; sometimes
	     the kernel doesn't let us at the registers. */
	  char *err = safe_strerror (errno);
	  char *msg = alloca (strlen (err) + 128);
	  sprintf (msg, "reading `%s' register: %s",
		   REGISTER_NAME (regno), err);
	  warning (msg);
	  return;
	}
    }

  /* If we're reading an address from the instruction address queue,
     mask out the bottom two bits --- they contain the privilege
     level.  */
  if (regno == HPPA_PCOQ_HEAD_REGNUM || regno == HPPA_PCOQ_TAIL_REGNUM)
    buf[len - 1] &= ~0x3;

  supply_register (regno, buf);
}


/* Copy LEN bytes to or from inferior's memory starting at MEMADDR
   to debugger memory starting at MYADDR.   Copy to inferior if
   WRITE is nonzero.

   Returns the length copied, which is either the LEN argument or zero.
   This xfer function does not do partial moves, since child_ops
   doesn't allow memory operations to cross below us in the target stack
   anyway.  TARGET is ignored.  */

int
child_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
		   struct mem_attrib *mem,
		   struct target_ops *target)
{
  int i;
  /* Round starting address down to longword boundary.  */
  CORE_ADDR addr = memaddr & - (CORE_ADDR)(sizeof (int));
  /* Round ending address up; get number of longwords that makes.  */
  int count
  = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);

  /* Allocate buffer of that many longwords.
     Note -- do not use alloca to allocate this buffer since there is no
     guarantee of when the buffer will actually be deallocated.

     This routine can be called over and over with the same call chain;
     this (in effect) would pile up all those alloca requests until a call
     to alloca was made from a point higher than this routine in the
     call chain.  */
  int *buffer = (int *) xmalloc (count * sizeof (int));

  if (write)
    {
      /* Fill start and end extra bytes of buffer with existing memory data.  */
      if (addr != memaddr || len < (int) sizeof (int))
	{
	  /* Need part of initial word -- fetch it.  */
	  buffer[0] = call_ptrace (addr < text_end ? PT_RIUSER : PT_RDUSER,
				   PIDGET (inferior_ptid),
				   (PTRACE_ARG3_TYPE) addr, 0);
	}

      if (count > 1)		/* FIXME, avoid if even boundary */
	{
	  buffer[count - 1]
	    = call_ptrace (addr < text_end ? PT_RIUSER : PT_RDUSER,
			   PIDGET (inferior_ptid),
			   (PTRACE_ARG3_TYPE) (addr
					       + (count - 1) * sizeof (int)),
			   0);
	}

      /* Copy data to be written over corresponding part of buffer */
      memcpy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len);

      /* Write the entire buffer.  */
      for (i = 0; i < count; i++, addr += sizeof (int))
	{
	  int pt_status;
	  int pt_request;
	  /* The HP-UX kernel crashes if you use PT_WDUSER to write into the
	     text segment.  FIXME -- does it work to write into the data
	     segment using WIUSER, or do these idiots really expect us to
	     figure out which segment the address is in, so we can use a
	     separate system call for it??!  */
	  errno = 0;
	  pt_request = (addr < text_end) ? PT_WIUSER : PT_WDUSER;
	  pt_status = call_ptrace (pt_request,
				   PIDGET (inferior_ptid),
				   (PTRACE_ARG3_TYPE) addr,
				   buffer[i]);

	  /* Did we fail?  Might we've guessed wrong about which
	     segment this address resides in?  Try the other request,
	     and see if that works...  */
	  if ((pt_status == -1) && errno)
	    {
	      errno = 0;
	      pt_request = (pt_request == PT_WIUSER) ? PT_WDUSER : PT_WIUSER;
	      pt_status = call_ptrace (pt_request,
				       PIDGET (inferior_ptid),
				       (PTRACE_ARG3_TYPE) addr,
				       buffer[i]);

	      /* No, we still fail.  Okay, time to punt. */
	      if ((pt_status == -1) && errno)
		{
		  xfree (buffer);
		  return 0;
		}
	    }
	}
    }
  else
    {
      /* Read all the longwords */
      for (i = 0; i < count; i++, addr += sizeof (int))
	{
	  errno = 0;
	  buffer[i] = call_ptrace (addr < text_end ? PT_RIUSER : PT_RDUSER,
				   PIDGET (inferior_ptid),
				   (PTRACE_ARG3_TYPE) addr, 0);
	  if (errno)
	    {
	      xfree (buffer);
	      return 0;
	    }
	  QUIT;
	}

      /* Copy appropriate bytes out of the buffer.  */
      memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
    }
  xfree (buffer);
  return len;
}

char *saved_child_execd_pathname = NULL;
int saved_vfork_pid;
enum {
  STATE_NONE,
  STATE_GOT_CHILD,
  STATE_GOT_EXEC,
  STATE_GOT_PARENT,
  STATE_FAKE_EXEC
} saved_vfork_state = STATE_NONE;

int
child_follow_fork (int follow_child)
{
  ptid_t last_ptid;
  struct target_waitstatus last_status;
  int has_vforked;
  int parent_pid, child_pid;

  get_last_target_status (&last_ptid, &last_status);
  has_vforked = (last_status.kind == TARGET_WAITKIND_VFORKED);
  parent_pid = ptid_get_pid (last_ptid);
  child_pid = last_status.value.related_pid;

  /* At this point, if we are vforking, breakpoints were already
     detached from the child in child_wait; and the child has already
     called execve().  If we are forking, both the parent and child
     have breakpoints inserted.  */

  if (! follow_child)
    {
      if (! has_vforked)
	{
	  detach_breakpoints (child_pid);
#ifdef SOLIB_REMOVE_INFERIOR_HOOK
	  SOLIB_REMOVE_INFERIOR_HOOK (child_pid);
#endif
	}

      /* Detach from the child. */
      printf_unfiltered ("Detaching after fork from %s\n",
			 target_pid_to_str (pid_to_ptid (child_pid)));
      hppa_require_detach (child_pid, 0);

      /* The parent and child of a vfork share the same address space.
	 Also, on some targets the order in which vfork and exec events
	 are received for parent in child requires some delicate handling
	 of the events.

	 For instance, on ptrace-based HPUX we receive the child's vfork
	 event first, at which time the parent has been suspended by the
	 OS and is essentially untouchable until the child's exit or second
	 exec event arrives.  At that time, the parent's vfork event is
	 delivered to us, and that's when we see and decide how to follow
	 the vfork.  But to get to that point, we must continue the child
	 until it execs or exits.  To do that smoothly, all breakpoints
	 must be removed from the child, in case there are any set between
	 the vfork() and exec() calls.  But removing them from the child
	 also removes them from the parent, due to the shared-address-space
	 nature of a vfork'd parent and child.  On HPUX, therefore, we must
	 take care to restore the bp's to the parent before we continue it.
	 Else, it's likely that we may not stop in the expected place.  (The
	 worst scenario is when the user tries to step over a vfork() call;
	 the step-resume bp must be restored for the step to properly stop
	 in the parent after the call completes!)

	 Sequence of events, as reported to gdb from HPUX:

	 Parent        Child           Action for gdb to take
	 -------------------------------------------------------
	 1                VFORK               Continue child
	 2                EXEC
	 3                EXEC or EXIT
	 4  VFORK

	 Now that the child has safely exec'd or exited, we must restore
	 the parent's breakpoints before we continue it.  Else, we may
	 cause it run past expected stopping points.  */

      if (has_vforked)
	reattach_breakpoints (parent_pid);
    }
  else
    {
      /* Needed to keep the breakpoint lists in sync.  */
      if (! has_vforked)
	detach_breakpoints (child_pid);

      /* Before detaching from the parent, remove all breakpoints from it. */
      remove_breakpoints ();

      /* Also reset the solib inferior hook from the parent. */
#ifdef SOLIB_REMOVE_INFERIOR_HOOK
      SOLIB_REMOVE_INFERIOR_HOOK (PIDGET (inferior_ptid));
#endif

      /* Detach from the parent. */
      target_detach (NULL, 1);

      /* Attach to the child. */
      printf_unfiltered ("Attaching after fork to %s\n",
			 target_pid_to_str (pid_to_ptid (child_pid)));
      hppa_require_attach (child_pid);
      inferior_ptid = pid_to_ptid (child_pid);

      /* If we vforked, then we've also execed by now.  The exec will be
	 reported momentarily.  follow_exec () will handle breakpoints, so
	 we don't have to..  */
      if (!has_vforked)
	follow_inferior_reset_breakpoints ();
    }

  if (has_vforked)
    {
      /* If we followed the parent, don't try to follow the child's exec.  */
      if (saved_vfork_state != STATE_GOT_PARENT
	  && saved_vfork_state != STATE_FAKE_EXEC)
	fprintf_unfiltered (gdb_stdout,
			    "hppa: post follow vfork: confused state\n");

      if (! follow_child || saved_vfork_state == STATE_GOT_PARENT)
	saved_vfork_state = STATE_NONE;
      else
	return 1;
    }
  return 0;
}

/* Format a process id, given PID.  Be sure to terminate
   this with a null--it's going to be printed via a "%s".  */
char *
child_pid_to_str (ptid_t ptid)
{
  /* Static because address returned */
  static char buf[30];
  pid_t pid = PIDGET (ptid);

  /* Extra NUL for paranoia's sake */
  sprintf (buf, "process %d%c", pid, '\0');

  return buf;
}

/* Format a thread id, given TID.  Be sure to terminate
   this with a null--it's going to be printed via a "%s".

   Note: This is a core-gdb tid, not the actual system tid.
   See infttrace.c for details.  */
char *
hppa_tid_to_str (ptid_t ptid)
{
  /* Static because address returned */
  static char buf[30];
  /* This seems strange, but when I did the ptid conversion, it looked
     as though a pid was always being passed.  - Kevin Buettner  */
  pid_t tid = PIDGET (ptid);

  /* Extra NULLs for paranoia's sake */
  sprintf (buf, "system thread %d%c", tid, '\0');

  return buf;
}

/*## */
/* Enable HACK for ttrace work.  In
 * infttrace.c/require_notification_of_events,
 * this is set to 0 so that the loop in child_wait
 * won't loop.
 */
int not_same_real_pid = 1;
/*## */

/* Wait for child to do something.  Return pid of child, or -1 in case
   of error; store status through argument pointer OURSTATUS.  */

ptid_t
child_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
{
  int save_errno;
  int status;
  char *execd_pathname = NULL;
  int exit_status;
  int related_pid;
  int syscall_id;
  enum target_waitkind kind;
  int pid;

  if (saved_vfork_state == STATE_FAKE_EXEC)
    {
      saved_vfork_state = STATE_NONE;
      ourstatus->kind = TARGET_WAITKIND_EXECD;
      ourstatus->value.execd_pathname = saved_child_execd_pathname;
      return inferior_ptid;
    }

  do
    {
      set_sigint_trap ();	/* Causes SIGINT to be passed on to the
				   attached process. */
      set_sigio_trap ();

      pid = ptrace_wait (inferior_ptid, &status);

      save_errno = errno;

      clear_sigio_trap ();

      clear_sigint_trap ();

      if (pid == -1)
	{
	  if (save_errno == EINTR)
	    continue;

	  fprintf_unfiltered (gdb_stderr, "Child process unexpectedly missing: %s.\n",
			      safe_strerror (save_errno));

	  /* Claim it exited with unknown signal.  */
	  ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
	  ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
	  return pid_to_ptid (-1);
	}

      /* Did it exit?
       */
      if (target_has_exited (pid, status, &exit_status))
	{
	  /* ??rehrauer: For now, ignore this. */
	  continue;
	}

      if (!target_thread_alive (pid_to_ptid (pid)))
	{
	  ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
	  return pid_to_ptid (pid);
	}

      if (hpux_has_forked (pid, &related_pid))
	{
	  /* Ignore the parent's fork event.  */
	  if (pid == PIDGET (inferior_ptid))
	    {
	      ourstatus->kind = TARGET_WAITKIND_IGNORE;
	      return inferior_ptid;
	    }

	  /* If this is the child's fork event, report that the
	     process has forked.  */
	  if (related_pid == PIDGET (inferior_ptid))
	    {
	      ourstatus->kind = TARGET_WAITKIND_FORKED;
	      ourstatus->value.related_pid = pid;
	      return inferior_ptid;
	    }
	}

      if (hpux_has_vforked (pid, &related_pid))
	{
	  if (pid == PIDGET (inferior_ptid))
	    {
	      if (saved_vfork_state == STATE_GOT_CHILD)
		saved_vfork_state = STATE_GOT_PARENT;
	      else if (saved_vfork_state == STATE_GOT_EXEC)
		saved_vfork_state = STATE_FAKE_EXEC;
	      else
		fprintf_unfiltered (gdb_stdout,
				    "hppah: parent vfork: confused\n");
	    }
	  else if (related_pid == PIDGET (inferior_ptid))
	    {
	      if (saved_vfork_state == STATE_NONE)
		saved_vfork_state = STATE_GOT_CHILD;
	      else
		fprintf_unfiltered (gdb_stdout,
				    "hppah: child vfork: confused\n");
	    }
	  else
	    fprintf_unfiltered (gdb_stdout,
				"hppah: unknown vfork: confused\n");

	  if (saved_vfork_state == STATE_GOT_CHILD)
	    {
	      child_post_startup_inferior (pid_to_ptid (pid));
	      detach_breakpoints (pid);
#ifdef SOLIB_REMOVE_INFERIOR_HOOK
	      SOLIB_REMOVE_INFERIOR_HOOK (pid);
#endif
	      child_resume (pid_to_ptid (pid), 0, TARGET_SIGNAL_0);
	      ourstatus->kind = TARGET_WAITKIND_IGNORE;
	      return pid_to_ptid (related_pid);
	    }
	  else if (saved_vfork_state == STATE_FAKE_EXEC)
	    {
	      ourstatus->kind = TARGET_WAITKIND_VFORKED;
	      ourstatus->value.related_pid = related_pid;
	      return pid_to_ptid (pid);
	    }
	  else
	    {
	      /* We saw the parent's vfork, but we haven't seen the exec yet.
		 Wait for it, for simplicity's sake.  It should be pending.  */
	      saved_vfork_pid = related_pid;
	      ourstatus->kind = TARGET_WAITKIND_IGNORE;
	      return pid_to_ptid (pid);
	    }
	}

      if (hpux_has_execd (pid, &execd_pathname))
	{
	  /* On HP-UX, events associated with a vforking inferior come in
	     threes: a vfork event for the child (always first), followed
	     a vfork event for the parent and an exec event for the child.
	     The latter two can come in either order.  Make sure we get
	     both.  */
	  if (saved_vfork_state != STATE_NONE)
	    {
	      if (saved_vfork_state == STATE_GOT_CHILD)
		{
		  saved_vfork_state = STATE_GOT_EXEC;
		  /* On HP/UX with ptrace, the child must be resumed before
		     the parent vfork event is delivered.  A single-step
		     suffices.  */
		  if (RESUME_EXECD_VFORKING_CHILD_TO_GET_PARENT_VFORK ())
		    target_resume (pid_to_ptid (pid), 1, TARGET_SIGNAL_0);
		  ourstatus->kind = TARGET_WAITKIND_IGNORE;
		}
	      else if (saved_vfork_state == STATE_GOT_PARENT)
		{
		  saved_vfork_state = STATE_FAKE_EXEC;
		  ourstatus->kind = TARGET_WAITKIND_VFORKED;
		  ourstatus->value.related_pid = saved_vfork_pid;
		}
	      else
		fprintf_unfiltered (gdb_stdout,
				    "hppa: exec: unexpected state\n");

	      saved_child_execd_pathname = execd_pathname;

	      return inferior_ptid;
	    }
	  
	  /* Are we ignoring initial exec events?  (This is likely because
	     we're in the process of starting up the inferior, and another
	     (older) mechanism handles those.)  If so, we'll report this
	     as a regular stop, not an exec.
	   */
	  if (inferior_ignoring_startup_exec_events)
	    {
	      inferior_ignoring_startup_exec_events--;
	    }
	  else
	    {
	      ourstatus->kind = TARGET_WAITKIND_EXECD;
	      ourstatus->value.execd_pathname = execd_pathname;
	      return pid_to_ptid (pid);
	    }
	}

      /* All we must do with these is communicate their occurrence
         to wait_for_inferior...
       */
      if (hpux_has_syscall_event (pid, &kind, &syscall_id))
	{
	  ourstatus->kind = kind;
	  ourstatus->value.syscall_id = syscall_id;
	  return pid_to_ptid (pid);
	}

      /*##  } while (pid != PIDGET (inferior_ptid)); ## *//* Some other child died or stopped */
/* hack for thread testing */
    }
  while ((pid != PIDGET (inferior_ptid)) && not_same_real_pid);
/*## */

  store_waitstatus (ourstatus, status);
  return pid_to_ptid (pid);
}

#if !defined (GDB_NATIVE_HPUX_11)

/* The following code is a substitute for the infttrace.c versions used
   with ttrace() in HPUX 11.  */

/* This value is an arbitrary integer. */
#define PT_VERSION 123456

/* This semaphore is used to coordinate the child and parent processes
   after a fork(), and before an exec() by the child.  See
   parent_attach_all for details.  */

typedef struct
{
  int parent_channel[2];	/* Parent "talks" to [1], child "listens" to [0] */
  int child_channel[2];		/* Child "talks" to [1], parent "listens" to [0] */
}
startup_semaphore_t;

#define SEM_TALK (1)
#define SEM_LISTEN (0)

static startup_semaphore_t startup_semaphore;

#ifdef PT_SETTRC
/* This function causes the caller's process to be traced by its
   parent.  This is intended to be called after GDB forks itself,
   and before the child execs the target.

   Note that HP-UX ptrace is rather funky in how this is done.
   If the parent wants to get the initial exec event of a child,
   it must set the ptrace event mask of the child to include execs.
   (The child cannot do this itself.)  This must be done after the
   child is forked, but before it execs.

   To coordinate the parent and child, we implement a semaphore using
   pipes.  After SETTRC'ing itself, the child tells the parent that
   it is now traceable by the parent, and waits for the parent's
   acknowledgement.  The parent can then set the child's event mask,
   and notify the child that it can now exec.

   (The acknowledgement by parent happens as a result of a call to
   child_acknowledge_created_inferior.)  */

int
parent_attach_all (int pid, PTRACE_ARG3_TYPE addr, int data)
{
  int pt_status = 0;

  /* We need a memory home for a constant.  */
  int tc_magic_child = PT_VERSION;
  int tc_magic_parent = 0;

  /* The remainder of this function is only useful for HPUX 10.0 and
     later, as it depends upon the ability to request notification
     of specific kinds of events by the kernel.  */
#if defined(PT_SET_EVENT_MASK)

  /* Notify the parent that we're potentially ready to exec(). */
  write (startup_semaphore.child_channel[SEM_TALK],
	 &tc_magic_child,
	 sizeof (tc_magic_child));

  /* Wait for acknowledgement from the parent. */
  read (startup_semaphore.parent_channel[SEM_LISTEN],
	&tc_magic_parent,
	sizeof (tc_magic_parent));
  if (tc_magic_child != tc_magic_parent)
    warning ("mismatched semaphore magic");

  /* Discard our copy of the semaphore. */
  (void) close (startup_semaphore.parent_channel[SEM_LISTEN]);
  (void) close (startup_semaphore.parent_channel[SEM_TALK]);
  (void) close (startup_semaphore.child_channel[SEM_LISTEN]);
  (void) close (startup_semaphore.child_channel[SEM_TALK]);
#endif

  return 0;
}
#endif

int
hppa_require_attach (int pid)
{
  int pt_status;
  CORE_ADDR pc;
  CORE_ADDR pc_addr;
  unsigned int regs_offset;

  /* Are we already attached?  There appears to be no explicit way to
     answer this via ptrace, so we try something which should be
     innocuous if we are attached.  If that fails, then we assume
     we're not attached, and so attempt to make it so. */

  errno = 0;
  regs_offset = U_REGS_OFFSET;
  pc_addr = register_addr (PC_REGNUM, regs_offset);
  pc = call_ptrace (PT_READ_U, pid, (PTRACE_ARG3_TYPE) pc_addr, 0);

  if (errno)
    {
      errno = 0;
      pt_status = call_ptrace (PT_ATTACH, pid, (PTRACE_ARG3_TYPE) 0, 0);

      if (errno)
	return -1;

      /* Now we really are attached. */
      errno = 0;
    }
  attach_flag = 1;
  return pid;
}

int
hppa_require_detach (int pid, int signal)
{
  errno = 0;
  call_ptrace (PT_DETACH, pid, (PTRACE_ARG3_TYPE) 1, signal);
  errno = 0;			/* Ignore any errors. */
  return pid;
}

/* Since ptrace doesn't support memory page-protection events, which
   are used to implement "hardware" watchpoints on HP-UX, these are
   dummy versions, which perform no useful work.  */

void
hppa_enable_page_protection_events (int pid)
{
}

void
hppa_disable_page_protection_events (int pid)
{
}

int
hppa_insert_hw_watchpoint (int pid, CORE_ADDR start, LONGEST len, int type)
{
  error ("Hardware watchpoints not implemented on this platform.");
}

int
hppa_remove_hw_watchpoint (int pid, CORE_ADDR start, LONGEST len, int type)
{
  error ("Hardware watchpoints not implemented on this platform.");
}

int
hppa_can_use_hw_watchpoint (int type, int cnt, int ot)
{
  return 0;
}

int
hppa_range_profitable_for_hw_watchpoint (int pid, CORE_ADDR start, LONGEST len)
{
  error ("Hardware watchpoints not implemented on this platform.");
}

char *
hppa_pid_or_tid_to_str (ptid_t id)
{
  /* In the ptrace world, there are only processes. */
  return child_pid_to_str (id);
}

void
hppa_ensure_vforking_parent_remains_stopped (int pid)
{
  /* This assumes that the vforked parent is presently stopped, and
     that the vforked child has just delivered its first exec event.
     Calling kill() this way will cause the SIGTRAP to be delivered as
     soon as the parent is resumed, which happens as soon as the
     vforked child is resumed.  See wait_for_inferior for the use of
     this function.  */
  kill (pid, SIGTRAP);
}

int
hppa_resume_execd_vforking_child_to_get_parent_vfork (void)
{
  return 1;			/* Yes, the child must be resumed. */
}

void
require_notification_of_events (int pid)
{
#if defined(PT_SET_EVENT_MASK)
  int pt_status;
  ptrace_event_t ptrace_events;
  int nsigs;
  int signum;

  /* Instruct the kernel as to the set of events we wish to be
     informed of.  (This support does not exist before HPUX 10.0.
     We'll assume if PT_SET_EVENT_MASK has not been defined by
     <sys/ptrace.h>, then we're being built on pre-10.0.)  */
  memset (&ptrace_events, 0, sizeof (ptrace_events));

  /* Note: By default, all signals are visible to us.  If we wish
     the kernel to keep certain signals hidden from us, we do it
     by calling sigdelset (ptrace_events.pe_signals, signal) for
     each such signal here, before doing PT_SET_EVENT_MASK.  */
  /* RM: The above comment is no longer true. We start with ignoring
     all signals, and then add the ones we are interested in. We could
     do it the other way: start by looking at all signals and then
     deleting the ones that we aren't interested in, except that
     multiple gdb signals may be mapped to the same host signal
     (eg. TARGET_SIGNAL_IO and TARGET_SIGNAL_POLL both get mapped to
     signal 22 on HPUX 10.20) We want to be notified if we are
     interested in either signal.  */
  sigfillset (&ptrace_events.pe_signals);

  /* RM: Let's not bother with signals we don't care about */
  nsigs = (int) TARGET_SIGNAL_LAST;
  for (signum = nsigs; signum > 0; signum--)
    {
      if ((signal_stop_state (signum)) ||
	  (signal_print_state (signum)) ||
	  (!signal_pass_state (signum)))
	{
	  if (target_signal_to_host_p (signum))
	    sigdelset (&ptrace_events.pe_signals,
		       target_signal_to_host (signum));
	}
    }

  ptrace_events.pe_set_event = 0;

  ptrace_events.pe_set_event |= PTRACE_SIGNAL;
  ptrace_events.pe_set_event |= PTRACE_EXEC;
  ptrace_events.pe_set_event |= PTRACE_FORK;
  ptrace_events.pe_set_event |= PTRACE_VFORK;
  /* ??rehrauer: Add this one when we're prepared to catch it...
     ptrace_events.pe_set_event |= PTRACE_EXIT;
   */

  errno = 0;
  pt_status = call_ptrace (PT_SET_EVENT_MASK,
			   pid,
			   (PTRACE_ARG3_TYPE) & ptrace_events,
			   sizeof (ptrace_events));
  if (errno)
    perror_with_name ("ptrace");
  if (pt_status < 0)
    return;
#endif
}

void
require_notification_of_exec_events (int pid)
{
#if defined(PT_SET_EVENT_MASK)
  int pt_status;
  ptrace_event_t ptrace_events;

  /* Instruct the kernel as to the set of events we wish to be
     informed of.  (This support does not exist before HPUX 10.0.
     We'll assume if PT_SET_EVENT_MASK has not been defined by
     <sys/ptrace.h>, then we're being built on pre-10.0.)  */
  memset (&ptrace_events, 0, sizeof (ptrace_events));

  /* Note: By default, all signals are visible to us.  If we wish
     the kernel to keep certain signals hidden from us, we do it
     by calling sigdelset (ptrace_events.pe_signals, signal) for
     each such signal here, before doing PT_SET_EVENT_MASK.  */
  sigemptyset (&ptrace_events.pe_signals);

  ptrace_events.pe_set_event = 0;

  ptrace_events.pe_set_event |= PTRACE_EXEC;
  /* ??rehrauer: Add this one when we're prepared to catch it...
     ptrace_events.pe_set_event |= PTRACE_EXIT;
   */

  errno = 0;
  pt_status = call_ptrace (PT_SET_EVENT_MASK,
			   pid,
			   (PTRACE_ARG3_TYPE) & ptrace_events,
			   sizeof (ptrace_events));
  if (errno)
    perror_with_name ("ptrace");
  if (pt_status < 0)
    return;
#endif
}

/* This function is called by the parent process, with pid being the
   ID of the child process, after the debugger has forked.  */

void
child_acknowledge_created_inferior (int pid)
{
  /* We need a memory home for a constant.  */
  int tc_magic_parent = PT_VERSION;
  int tc_magic_child = 0;

  /* The remainder of this function is only useful for HPUX 10.0 and
     later, as it depends upon the ability to request notification
     of specific kinds of events by the kernel.  */
#if defined(PT_SET_EVENT_MASK)
  /* Wait for the child to tell us that it has forked. */
  read (startup_semaphore.child_channel[SEM_LISTEN],
	&tc_magic_child,
	sizeof (tc_magic_child));

  /* Notify the child that it can exec.

     In the infttrace.c variant of this function, we set the child's
     event mask after the fork but before the exec.  In the ptrace
     world, it seems we can't set the event mask until after the exec.  */
  write (startup_semaphore.parent_channel[SEM_TALK],
	 &tc_magic_parent,
	 sizeof (tc_magic_parent));

  /* We'd better pause a bit before trying to set the event mask,
     though, to ensure that the exec has happened.  We don't want to
     wait() on the child, because that'll screw up the upper layers
     of gdb's execution control that expect to see the exec event.

     After an exec, the child is no longer executing gdb code.  Hence,
     we can't have yet another synchronization via the pipes.  We'll
     just sleep for a second, and hope that's enough delay...  */
  sleep (1);

  /* Instruct the kernel as to the set of events we wish to be
     informed of.  */
  require_notification_of_exec_events (pid);

  /* Discard our copy of the semaphore. */
  (void) close (startup_semaphore.parent_channel[SEM_LISTEN]);
  (void) close (startup_semaphore.parent_channel[SEM_TALK]);
  (void) close (startup_semaphore.child_channel[SEM_LISTEN]);
  (void) close (startup_semaphore.child_channel[SEM_TALK]);
#endif
}

void
child_post_startup_inferior (ptid_t ptid)
{
  require_notification_of_events (PIDGET (ptid));
}

void
child_post_attach (int pid)
{
  require_notification_of_events (pid);
}

int
child_insert_fork_catchpoint (int pid)
{
  /* This request is only available on HPUX 10.0 and later.  */
#if !defined(PT_SET_EVENT_MASK)
  error ("Unable to catch forks prior to HPUX 10.0");
#else
  /* Enable reporting of fork events from the kernel. */
  /* ??rehrauer: For the moment, we're always enabling these events,
     and just ignoring them if there's no catchpoint to catch them.  */
  return 0;
#endif
}

int
child_remove_fork_catchpoint (int pid)
{
  /* This request is only available on HPUX 10.0 and later.  */
#if !defined(PT_SET_EVENT_MASK)
  error ("Unable to catch forks prior to HPUX 10.0");
#else
  /* Disable reporting of fork events from the kernel. */
  /* ??rehrauer: For the moment, we're always enabling these events,
     and just ignoring them if there's no catchpoint to catch them.  */
  return 0;
#endif
}

int
child_insert_vfork_catchpoint (int pid)
{
  /* This request is only available on HPUX 10.0 and later.  */
#if !defined(PT_SET_EVENT_MASK)
  error ("Unable to catch vforks prior to HPUX 10.0");
#else
  /* Enable reporting of vfork events from the kernel. */
  /* ??rehrauer: For the moment, we're always enabling these events,
     and just ignoring them if there's no catchpoint to catch them.  */
  return 0;
#endif
}

int
child_remove_vfork_catchpoint (int pid)
{
  /* This request is only available on HPUX 10.0 and later.  */
#if !defined(PT_SET_EVENT_MASK)
  error ("Unable to catch vforks prior to HPUX 10.0");
#else
  /* Disable reporting of vfork events from the kernel. */
  /* ??rehrauer: For the moment, we're always enabling these events,
     and just ignoring them if there's no catchpoint to catch them.  */
  return 0;
#endif
}

int
hpux_has_forked (int pid, int *childpid)
{
  /* This request is only available on HPUX 10.0 and later.  */
#if !defined(PT_GET_PROCESS_STATE)
  *childpid = 0;
  return 0;
#else
  int pt_status;
  ptrace_state_t ptrace_state;

  errno = 0;
  pt_status = call_ptrace (PT_GET_PROCESS_STATE,
			   pid,
			   (PTRACE_ARG3_TYPE) & ptrace_state,
			   sizeof (ptrace_state));
  if (errno)
    perror_with_name ("ptrace");
  if (pt_status < 0)
    return 0;

  if (ptrace_state.pe_report_event & PTRACE_FORK)
    {
      *childpid = ptrace_state.pe_other_pid;
      return 1;
    }

  return 0;
#endif
}

int
hpux_has_vforked (int pid, int *childpid)
{
  /* This request is only available on HPUX 10.0 and later.  */
#if !defined(PT_GET_PROCESS_STATE)
  *childpid = 0;
  return 0;

#else
  int pt_status;
  ptrace_state_t ptrace_state;

  errno = 0;
  pt_status = call_ptrace (PT_GET_PROCESS_STATE,
			   pid,
			   (PTRACE_ARG3_TYPE) & ptrace_state,
			   sizeof (ptrace_state));
  if (errno)
    perror_with_name ("ptrace");
  if (pt_status < 0)
    return 0;

  if (ptrace_state.pe_report_event & PTRACE_VFORK)
    {
      *childpid = ptrace_state.pe_other_pid;
      return 1;
    }

  return 0;
#endif
}

int
child_insert_exec_catchpoint (int pid)
{
  /* This request is only available on HPUX 10.0 and later.   */
#if !defined(PT_SET_EVENT_MASK)
  error ("Unable to catch execs prior to HPUX 10.0");

#else
  /* Enable reporting of exec events from the kernel.  */
  /* ??rehrauer: For the moment, we're always enabling these events,
     and just ignoring them if there's no catchpoint to catch them.  */
  return 0;
#endif
}

int
child_remove_exec_catchpoint (int pid)
{
  /* This request is only available on HPUX 10.0 and later.  */
#if !defined(PT_SET_EVENT_MASK)
  error ("Unable to catch execs prior to HPUX 10.0");

#else
  /* Disable reporting of exec events from the kernel. */
  /* ??rehrauer: For the moment, we're always enabling these events,
     and just ignoring them if there's no catchpoint to catch them.  */
  return 0;
#endif
}

int
hpux_has_execd (int pid, char **execd_pathname)
{
  /* This request is only available on HPUX 10.0 and later.  */
#if !defined(PT_GET_PROCESS_STATE)
  *execd_pathname = NULL;
  return 0;

#else
  int pt_status;
  ptrace_state_t ptrace_state;

  errno = 0;
  pt_status = call_ptrace (PT_GET_PROCESS_STATE,
			   pid,
			   (PTRACE_ARG3_TYPE) & ptrace_state,
			   sizeof (ptrace_state));
  if (errno)
    perror_with_name ("ptrace");
  if (pt_status < 0)
    return 0;

  if (ptrace_state.pe_report_event & PTRACE_EXEC)
    {
      char *exec_file = target_pid_to_exec_file (pid);
      *execd_pathname = savestring (exec_file, strlen (exec_file));
      return 1;
    }

  return 0;
#endif
}

int
child_reported_exec_events_per_exec_call (void)
{
  return 2;			/* ptrace reports the event twice per call. */
}

int
hpux_has_syscall_event (int pid, enum target_waitkind *kind, int *syscall_id)
{
  /* This request is only available on HPUX 10.30 and later, via
     the ttrace interface.  */

  *kind = TARGET_WAITKIND_SPURIOUS;
  *syscall_id = -1;
  return 0;
}

char *
child_pid_to_exec_file (int pid)
{
  static char exec_file_buffer[1024];
  int pt_status;
  CORE_ADDR top_of_stack;
  char four_chars[4];
  int name_index;
  int i;
  ptid_t saved_inferior_ptid;
  int done;

#ifdef PT_GET_PROCESS_PATHNAME
  /* As of 10.x HP-UX, there's an explicit request to get the pathname. */
  pt_status = call_ptrace (PT_GET_PROCESS_PATHNAME,
			   pid,
			   (PTRACE_ARG3_TYPE) exec_file_buffer,
			   sizeof (exec_file_buffer) - 1);
  if (pt_status == 0)
    return exec_file_buffer;
#endif

  /* It appears that this request is broken prior to 10.30.
     If it fails, try a really, truly amazingly gross hack
     that DDE uses, of pawing through the process' data
     segment to find the pathname.  */

  top_of_stack = 0x7b03a000;
  name_index = 0;
  done = 0;

  /* On the chance that pid != inferior_ptid, set inferior_ptid
     to pid, so that (grrrr!) implicit uses of inferior_ptid get
     the right id.  */

  saved_inferior_ptid = inferior_ptid;
  inferior_ptid = pid_to_ptid (pid);

  /* Try to grab a null-terminated string. */
  while (!done)
    {
      if (target_read_memory (top_of_stack, four_chars, 4) != 0)
	{
	  inferior_ptid = saved_inferior_ptid;
	  return NULL;
	}
      for (i = 0; i < 4; i++)
	{
	  exec_file_buffer[name_index++] = four_chars[i];
	  done = (four_chars[i] == '\0');
	  if (done)
	    break;
	}
      top_of_stack += 4;
    }

  if (exec_file_buffer[0] == '\0')
    {
      inferior_ptid = saved_inferior_ptid;
      return NULL;
    }

  inferior_ptid = saved_inferior_ptid;
  return exec_file_buffer;
}

void
pre_fork_inferior (void)
{
  int status;

  status = pipe (startup_semaphore.parent_channel);
  if (status < 0)
    {
      warning ("error getting parent pipe for startup semaphore");
      return;
    }

  status = pipe (startup_semaphore.child_channel);
  if (status < 0)
    {
      warning ("error getting child pipe for startup semaphore");
      return;
    }
}


/* Check to see if the given thread is alive.

   This is a no-op, as ptrace doesn't support threads, so we just
   return "TRUE".  */

int
child_thread_alive (ptid_t ptid)
{
  return 1;
}

#endif /* ! GDB_NATIVE_HPUX_11 */