File: dtrace.c

package info (click to toggle)
dtrace 2.0.5-1
  • links: PTS
  • area: main
  • in suites: sid
  • size: 24,408 kB
  • sloc: ansic: 61,247; sh: 17,997; asm: 1,717; lex: 947; awk: 754; yacc: 695; perl: 37; sed: 17; makefile: 15
file content (1606 lines) | stat: -rw-r--r-- 39,065 bytes parent folder | download
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
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
/*
 * Oracle Linux DTrace.
 * Copyright (c) 2006, 2026, Oracle and/or its affiliates. All rights reserved.
 * Licensed under the Universal Permissive License v 1.0 as shown at
 * http://oss.oracle.com/licenses/upl.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/compiler.h>
#include <locale.h>

#include <dtrace.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <fcntl.h>
#include <errno.h>
#include <signal.h>
#include <alloca.h>
#include <port.h>

#include <dt_git_version.h>

typedef struct dtrace_cmd {
	void (*dc_func)(struct dtrace_cmd *);	/* function to compile arg */
	dtrace_probespec_t dc_spec;		/* probe specifier context */
	char *dc_arg;				/* argument from main argv */
	const char *dc_name;			/* name for error messages */
	const char *dc_desc;			/* desc for error messages */
	dtrace_prog_t *dc_prog;			/* program compiled from arg */
	char dc_ofile[PATH_MAX];		/* derived output file name */
} dtrace_cmd_t;

#define	DMODE_VERS	0	/* display version information and exit (-V) */
#define	DMODE_EXEC	1	/* compile program for enabling (e/E) */
#define	DMODE_LINK	2	/* compile program for linking with ELF (-G) */
#define	DMODE_LIST	3	/* compile program and list probes (-l) */
#define	DMODE_HEADER	4	/* compile program for headergen (-h) */

#define DONE_SAW_END	1	/* If END is not enabled, we pretend */
#define DONE_SAW_EXIT	2	/* exit() action processed */

#define	E_SUCCESS	0
#define	E_ERROR		1
#define	E_USAGE		2

static const char DTRACE_OPTSTR[] =
	"3:6:aAb:Bc:CD:ef:FGhHi:I:lL:m:n:o:p:P:qs:SU:vVwx:X:Z";

static char **g_argv;
static int g_argc;
static char **g_objv;
static int g_objc;
static dtrace_cmd_t *g_cmdv;
static int g_cmdc;
static struct dtrace_proc **g_psv;
static int g_psc;
static int g_pslive;
static char *g_pname;
static int g_quiet;
static int g_testing;
static int g_flowindent;
static int g_intr;
static int g_impatient;
static int g_newline;
static int g_total;
static int g_cflags;
static int g_oflags = 0;
static int g_verbose;
static int g_exec = 1;
static int g_mode = DMODE_EXEC;
static int g_status = E_SUCCESS;
static const char *g_ofile = NULL;
static FILE *g_ofp = NULL;
static dtrace_hdl_t *g_dtp;

static int
usage(FILE *fp)
{
	static const char predact[] = "[[ predicate ] action ]";

	fprintf(fp, "Usage: %s [-32|-64] [-CeFGhHlqSvVwZ] "
	    "[-b bufsz] [-c cmd] [-D name[=def]]\n\t[-I path] [-L path] "
	    "[-o output] [-p pid] [-s script] [-U name]\n\t"
	    "[-x opt[=val]] [-X a|c|s|t]\n\n"
	    "\t[-P provider %s]\n"
	    "\t[-m [ provider: ] module %s]\n"
	    "\t[-f [[ provider: ] module: ] func %s]\n"
	    "\t[-n [[[ provider: ] module: ] func: ] name %s]\n"
	    "\t[-i probe-id %s] [ args ... ]\n\n", g_pname,
	    predact, predact, predact, predact, predact);

	fprintf(fp, "\tpredicate -> '/' D-expression '/'\n");
	fprintf(fp, "\t   action -> '{' D-statements '}'\n");

	fprintf(fp, "\n"
	    "\t-32 generate 32-bit D programs and ELF files\n"
	    "\t-64 generate 64-bit D programs and ELF files\n\n"
	    "\t-b  set trace buffer size\n"
	    "\t-c  run specified command and exit upon its completion\n"
	    "\t-C  run cpp(1) preprocessor on script files\n"
	    "\t-D  define symbol when invoking preprocessor\n"
	    "\t-e  exit after compiling request but prior to enabling probes\n"
	    "\t-f  enable or list probes matching the specified function name\n"
	    "\t-F  coalesce trace output by function\n"
	    "\t-G  generate an ELF file containing embedded dtrace program\n"
	    "\t-h  generate a header file with definitions for static probes\n"
	    "\t-H  print included files when invoking preprocessor\n"
	    "\t-i  enable or list probes matching the specified probe id\n"
	    "\t-I  add include directory to preprocessor search path\n"
	    "\t-l  list probes matching specified criteria\n"
	    "\t-L  add library directory to library search path\n"
	    "\t-m  enable or list probes matching the specified module name\n"
	    "\t-n  enable or list probes matching the specified probe name\n"
	    "\t-o  set output file\n"
	    "\t-p  grab specified process-ID and cache its symbol tables\n"
	    "\t-P  enable or list probes matching the specified provider name\n"
	    "\t-q  set quiet mode (only output explicitly traced data)\n"
	    "\t-s  enable or list probes according to the specified D script\n"
	    "\t-S  print D compiler intermediate code\n"
	    "\t-U  undefine symbol when invoking preprocessor\n"
	    "\t-v  set verbose mode (report stability attributes, arguments)\n"
	    "\t-V  report DTrace API version\n"
	    "\t-w  permit destructive actions\n"
	    "\t-x  enable or modify compiler and tracing options\n"
	    "\t-X  specify ISO C conformance settings for preprocessor\n"
	    "\t-Z  permit probe descriptions that match zero probes\n");

	return E_USAGE;
}

static void
verror(const char *fmt, va_list ap)
{
	int error = errno;

	fprintf(stderr, "%s: ", g_pname);
	vfprintf(stderr, fmt, ap);

	if (fmt[strlen(fmt) - 1] != '\n')
		fprintf(stderr, ": %s\n", strerror(error));
}

/*PRINTFLIKE1*/
_dt_printflike_(1,2)
static void
fatal(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	verror(fmt, ap);
	va_end(ap);

	/*
	 * Close the DTrace handle to ensure that any controlled processes are
	 * correctly restored and continued.
	 */
	dtrace_close(g_dtp);

	exit(E_ERROR);
}

/*PRINTFLIKE1*/
_dt_printflike_(1,2)
static void
dfatal(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);

	fprintf(stderr, "%s: ", g_pname);
	if (fmt != NULL)
		vfprintf(stderr, fmt, ap);

	va_end(ap);

	if (fmt != NULL && fmt[strlen(fmt) - 1] != '\n')
		fprintf(stderr, ": %s\n",
		    dtrace_errmsg(g_dtp, dtrace_errno(g_dtp)));
	else if (fmt == NULL)
		fprintf(stderr, "%s\n",
		    dtrace_errmsg(g_dtp, dtrace_errno(g_dtp)));

	/*
	 * Close the DTrace handle to ensure that any controlled processes are
	 * correctly restored and continued.
	 */
	dtrace_close(g_dtp);

	exit(E_ERROR);
}

/*PRINTFLIKE1*/
_dt_printflike_(1,2)
static void
error(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	verror(fmt, ap);
	va_end(ap);
}

/*PRINTFLIKE1*/
_dt_printflike_(1,2)
static void
notice(const char *fmt, ...)
{
	va_list ap;

	if (g_quiet)
		return; /* -q or quiet pragma suppresses notice()s */

	va_start(ap, fmt);
	verror(fmt, ap);
	va_end(ap);
}

/*PRINTFLIKE1*/
_dt_printflike_(1,2)
static void
oprintf(const char *fmt, ...)
{
	va_list ap;
	int n;

	if (g_ofp == NULL)
		return;

	va_start(ap, fmt);
	n = vfprintf(g_ofp, fmt, ap);
	va_end(ap);

	if (n < 0) {
		if (errno != EINTR) {
			fatal("failed to write to %s",
			    g_ofile ? g_ofile : "<stdout>");
		}
		clearerr(g_ofp);
	}
}

static char **
make_argv(char *s)
{
	const char *ws = "\f\n\r\t\v ";
	char **argv = malloc(sizeof(char *) * (strlen(s) / 2 + 1));
	int argc = 0;
	char *p = s;

	if (argv == NULL)
		return NULL;

	for (p = strtok(s, ws); p != NULL; p = strtok(NULL, ws))
		argv[argc++] = p;

	if (argc == 0)
		argv[argc++] = s;

	argv[argc] = NULL;
	return argv;
}

static void
print_probe_info(const dtrace_probeinfo_t *p)
{
	char buf[BUFSIZ];
	int i;

	oprintf("\n\tProbe Description Attributes\n");

	oprintf("\t\tIdentifier Names: %s\n",
	    dtrace_stability_name(p->dtp_attr.dtat_name));
	oprintf("\t\tData Semantics:   %s\n",
	    dtrace_stability_name(p->dtp_attr.dtat_data));
	oprintf("\t\tDependency Class: %s\n",
	    dtrace_class_name(p->dtp_attr.dtat_class));

	oprintf("\n\tArgument Attributes\n");

	oprintf("\t\tIdentifier Names: %s\n",
	    dtrace_stability_name(p->dtp_arga.dtat_name));
	oprintf("\t\tData Semantics:   %s\n",
	    dtrace_stability_name(p->dtp_arga.dtat_data));
	oprintf("\t\tDependency Class: %s\n",
	    dtrace_class_name(p->dtp_arga.dtat_class));

	oprintf("\n\tArgument Types\n");

	for (i = 0; i < p->dtp_argc; i++) {
		if (ctf_type_name(p->dtp_argv[i].dtt_ctfp,
		    p->dtp_argv[i].dtt_type, buf, sizeof(buf)) == NULL)
			strlcpy(buf, "(unknown)", sizeof(buf));
		oprintf("\t\targs[%d]: %s\n", i, buf);
	}

	if (p->dtp_argc == 0)
		oprintf("\t\tNone\n");

	oprintf("\n");
}

/*ARGSUSED*/
static int
info_stmt(dtrace_hdl_t *dtp, dtrace_prog_t *pgp,
    dtrace_stmtdesc_t *stp, dtrace_ecbdesc_t **last)
{
	dtrace_ecbdesc_t *edp = stp->dtsd_ecbdesc;
	dtrace_probedesc_t *pdp = &edp->dted_probe;
	dtrace_probeinfo_t p;

	if (edp == *last)
		return 0;

	oprintf("\n%s:%s:%s:%s\n", pdp->prv, pdp->mod, pdp->fun, pdp->prb);

	if (dtrace_probe_info(dtp, pdp, &p) == 0)
		print_probe_info(&p);
	else
		return -1;

	*last = edp;
	return 0;
}

/*
 * Execute the specified program by enabling the corresponding instrumentation.
 * If -e has been specified, we get the program info but do not enable it.  If
 * -v has been specified, we print a stability report for the program.
 */
static void
exec_prog(const dtrace_cmd_t *dcp)
{
	dtrace_ecbdesc_t *last = NULL;
	dtrace_proginfo_t dpi;

	if (!g_exec) {
		dtrace_program_info(g_dtp, dcp->dc_prog, &dpi);
	} else if (dtrace_program_exec(g_dtp, dcp->dc_prog, &dpi) == -1) {
		dfatal("failed to enable '%s'", dcp->dc_name);
	} else {
		notice("%s '%s' matched %u probe%s\n",
		    dcp->dc_desc, dcp->dc_name,
		    dpi.dpi_matches, dpi.dpi_matches == 1 ? "" : "s");
	}

	if (g_verbose) {
		oprintf("\nStability attributes for %s %s:\n",
		    dcp->dc_desc, dcp->dc_name);

		oprintf("\n\tMinimum Probe Description Attributes\n");
		oprintf("\t\tIdentifier Names: %s\n",
		    dtrace_stability_name(dpi.dpi_descattr.dtat_name));
		oprintf("\t\tData Semantics:   %s\n",
		    dtrace_stability_name(dpi.dpi_descattr.dtat_data));
		oprintf("\t\tDependency Class: %s\n",
		    dtrace_class_name(dpi.dpi_descattr.dtat_class));

		oprintf("\n\tMinimum Statement Attributes\n");

		oprintf("\t\tIdentifier Names: %s\n",
		    dtrace_stability_name(dpi.dpi_stmtattr.dtat_name));
		oprintf("\t\tData Semantics:   %s\n",
		    dtrace_stability_name(dpi.dpi_stmtattr.dtat_data));
		oprintf("\t\tDependency Class: %s\n",
		    dtrace_class_name(dpi.dpi_stmtattr.dtat_class));

		if (!g_exec)
			dtrace_stmt_iter(g_dtp, dcp->dc_prog,
			    (dtrace_stmt_f *)info_stmt, &last);
		else
			oprintf("\n");
	}

	g_total += dpi.dpi_matches;
}

/*
 * Link the specified D program in DOF form into an ELF file for use in either
 * helpers, userland provider definitions, or both.  If -o was specified, that
 * path is used as the output file name.  If -o wasn't specified and the input
 * program is from a script whose name is %.d, use basename(%.o) as the output
 * file name.  Otherwise we use "d.out" as the default output file name.
 */
static void
link_prog(dtrace_cmd_t *dcp)
{
	char *p;

	if (g_cmdc == 1 && g_ofile != NULL) {
		strlcpy(dcp->dc_ofile, g_ofile, sizeof(dcp->dc_ofile));
	} else if ((p = strrchr(dcp->dc_arg, '.')) != NULL &&
	    strcmp(p, ".d") == 0) {
		p[0] = '\0'; /* strip .d suffix */
		snprintf(dcp->dc_ofile, sizeof(dcp->dc_ofile),
		    "%s.o", basename(dcp->dc_arg));
	} else
		snprintf(dcp->dc_ofile, sizeof(dcp->dc_ofile),
		    g_cmdc > 1 ?  "%s.%d" : "%s", "d.out", (int)(dcp - g_cmdv));

	if (dtrace_program_link(g_dtp, dcp->dc_prog, DTRACE_D_PROBES,
	    dcp->dc_ofile, g_objc, g_objv) != 0)
		dfatal("failed to link %s %s", dcp->dc_desc, dcp->dc_name);
}

/*ARGSUSED*/
static int
list_probe(dtrace_hdl_t *dtp, const dtrace_probedesc_t *pdp, void *arg)
{
	dtrace_probeinfo_t p;

	oprintf("%5d %10s %17s %33s %s\n",
		pdp->id, pdp->prv, pdp->mod, pdp->fun, pdp->prb);

	if (g_verbose) {
		if (dtrace_probe_info(dtp, pdp, &p) == 0)
			print_probe_info(&p);
		else
			return -1;
	}

	return 0;
}

/*ARGSUSED*/
static int
list_stmt(dtrace_hdl_t *dtp, dtrace_prog_t *pgp,
    dtrace_stmtdesc_t *stp, dtrace_ecbdesc_t **last)
{
	dtrace_ecbdesc_t *edp = stp->dtsd_ecbdesc;

	if (edp == *last)
		return 0;

	if (dtrace_probe_iter(g_dtp, &edp->dted_probe, list_probe, NULL) < 0) {
		error("failed to match %s:%s:%s:%s: %s\n",
		    edp->dted_probe.prv, edp->dted_probe.mod,
		    edp->dted_probe.fun, edp->dted_probe.prb,
		    dtrace_errmsg(dtp, dtrace_errno(dtp)));
	}

	*last = edp;
	return 0;
}

/*
 * List the probes corresponding to the specified program by iterating over
 * each statement and then matching probes to the statement probe descriptions.
 */
static void
list_prog(const dtrace_cmd_t *dcp)
{
	dtrace_ecbdesc_t *last = NULL;

	dtrace_stmt_iter(g_dtp, dcp->dc_prog,
	    (dtrace_stmt_f *)list_stmt, &last);
}

static void
compile_file(dtrace_cmd_t *dcp)
{
	char *arg0;
	FILE *fp;

	if ((fp = fopen(dcp->dc_arg, "r")) == NULL)
		fatal("failed to open %s", dcp->dc_arg);

	arg0 = g_argv[0];
	g_argv[0] = dcp->dc_arg;

	if ((dcp->dc_prog = dtrace_program_fcompile(g_dtp, fp,
	    g_cflags, g_argc, g_argv)) == NULL)
		dfatal("failed to compile script %s", dcp->dc_arg);

	g_argv[0] = arg0;
	fclose(fp);

	dcp->dc_desc = "script";
	dcp->dc_name = dcp->dc_arg;
}

static void
compile_str(dtrace_cmd_t *dcp)
{
	char *p;

	if ((dcp->dc_prog = dtrace_program_strcompile(g_dtp, dcp->dc_arg,
	    dcp->dc_spec, g_cflags | DTRACE_C_PSPEC, g_argc, g_argv)) == NULL)
		dfatal("invalid probe specifier %s", dcp->dc_arg);

	if ((p = strpbrk(dcp->dc_arg, "{/;")) != NULL)
		*p = '\0'; /* crop name for reporting */

	dcp->dc_desc = "description";
	dcp->dc_name = dcp->dc_arg;
}

static void
prochandler(pid_t pid, const char *msg, void *arg)
{
	/*
	 * These days, this is only called on process death.  We can easily
	 * prove this by checking P's nullity state.
	 */

	if (pid < 0) {
		g_pslive--;
		return;
	}

	/*
	 * We don't know what's happened here, but at least we can print a
	 * message out, if there is one.
	 */
	if (msg != NULL)
		notice("%s\n", msg);
}

/*ARGSUSED*/
static int
errhandler(const dtrace_errdata_t *data, void *arg)
{
	error("%s\n", data->dteda_msg);
	return DTRACE_HANDLE_OK;
}

/*ARGSUSED*/
static int
drophandler(const dtrace_dropdata_t *data, void *arg)
{
	error("%s\n", data->dtdda_msg);
	return DTRACE_HANDLE_OK;
}

/*ARGSUSED*/
static int
setopthandler(const dtrace_setoptdata_t *data, void *arg)
{
	if (strcmp(data->dtsda_option, "quiet") == 0)
		g_quiet = data->dtsda_newval != DTRACEOPT_UNSET;

	if (strcmp(data->dtsda_option, "flowindent") == 0)
		g_flowindent = data->dtsda_newval != DTRACEOPT_UNSET;

	return DTRACE_HANDLE_OK;
}

#define	BUFDUMPHDR(hdr) \
	printf("%s: %s%s\n", g_pname, hdr, strlen(hdr) > 0 ? ":" : "");

#define	BUFDUMPSTR(ptr, field) \
	printf("%s: %20s => ", g_pname, #field);	\
	if ((ptr)->field != NULL) {			\
		const char *c = (ptr)->field;		\
		printf("\"");				\
		do {					\
			if (*c == '\n') {		\
				printf("\\n");		\
				continue;		\
			}				\
							\
			printf("%c", *c);		\
		} while (*c++ != '\0');			\
		printf("\"\n");				\
	} else						\
		printf("<NULL>\n");

#define	BUFDUMPASSTR(ptr, field, str) \
	printf("%s: %20s => %s\n", g_pname, #field, str);

#define	BUFDUMP(ptr, field) \
	printf("%s: %20s => %lld\n", g_pname, #field, \
	    (long long)(ptr)->field);

#define	BUFDUMPPTR(ptr, field) \
	printf("%s: %20s => %s\n", g_pname, #field, \
	    (ptr)->field != NULL ? "<non-NULL>" : "<NULL>");

/*ARGSUSED*/
static int
bufhandler(const dtrace_bufdata_t *bufdata, void *arg)
{
	const dtrace_aggdata_t *agg = bufdata->dtbda_aggdata;
	const dtrace_recdesc_t *rec = bufdata->dtbda_recdesc;
	const dtrace_probedesc_t *pd;
	uint32_t flags = bufdata->dtbda_flags;
	char buf[512], *c = buf, *end = c + sizeof(buf);
	int i, printed;

	struct {
		const char *name;
		uint32_t value;
	} flagnames[] = {
	    { "AGGVAL",		DTRACE_BUFDATA_AGGVAL },
	    { "AGGKEY",		DTRACE_BUFDATA_AGGKEY },
	    { "AGGFORMAT",	DTRACE_BUFDATA_AGGFORMAT },
	    { "AGGLAST",	DTRACE_BUFDATA_AGGLAST },
	    { "???",		UINT32_MAX },
	    { NULL }
	};

	if (bufdata->dtbda_probe != NULL)
		pd = bufdata->dtbda_probe->dtpda_pdesc;
	else
		pd = NULL;

	BUFDUMPHDR(">>> Called buffer handler");
	BUFDUMPHDR("");

	BUFDUMPHDR("  dtrace_bufdata");
	BUFDUMPSTR(bufdata, dtbda_buffered);
	BUFDUMPPTR(bufdata, dtbda_probe);
	BUFDUMPPTR(bufdata, dtbda_aggdata);
	BUFDUMPPTR(bufdata, dtbda_recdesc);

	snprintf(c, end - c, "0x%x ", bufdata->dtbda_flags);
	c += strlen(c);

	for (i = 0, printed = 0; flagnames[i].name != NULL; i++) {
		if (!(flags & flagnames[i].value))
			continue;

		snprintf(c, end - c,
		    "%s%s", printed++ ? " | " : "(", flagnames[i].name);
		c += strlen(c);
		flags &= ~flagnames[i].value;
	}

	if (printed)
		snprintf(c, end - c, ")");

	BUFDUMPASSTR(bufdata, dtbda_flags, buf);
	BUFDUMPHDR("");

	if (pd != NULL) {
		BUFDUMPHDR("  dtrace_probedesc");
		BUFDUMPSTR(pd, prv);
		BUFDUMPSTR(pd, mod);
		BUFDUMPSTR(pd, fun);
		BUFDUMPSTR(pd, prb);
		BUFDUMPHDR("");
	}

	if (rec != NULL) {
		BUFDUMPHDR("  dtrace_recdesc");
		BUFDUMP(rec, dtrd_action);
		BUFDUMP(rec, dtrd_size);

		if (agg != NULL) {
			uint8_t *data;
			int lim = rec->dtrd_size;

			sprintf(buf, "%d (data: ", rec->dtrd_offset);
			c = buf + strlen(buf);

			if (lim > sizeof(uint64_t))
				lim = sizeof(uint64_t);

			data = (uint8_t *)agg->dtada_data + rec->dtrd_offset;

			for (i = 0; i < lim; i++) {
				snprintf(c, end - c, "%s%02x",
				    i == 0 ? "" : " ", *data++);
				c += strlen(c);
			}

			snprintf(c, end - c,
			    "%s)", lim < rec->dtrd_size ? " ..." : "");
			BUFDUMPASSTR(rec, dtrd_offset, buf);
		} else {
			BUFDUMP(rec, dtrd_offset);
		}

		BUFDUMPHDR("");
	}

	if (agg != NULL) {
		dtrace_aggdesc_t *desc = agg->dtada_desc;

		BUFDUMPHDR("  dtrace_aggdesc");
		BUFDUMPSTR(desc, dtagd_name);
		BUFDUMP(desc, dtagd_varid);
		BUFDUMP(desc, dtagd_nkrecs);	/* FIXME: +1 for varid */
		BUFDUMPHDR("");
	}

	return DTRACE_HANDLE_OK;
}

/*ARGSUSED*/
static int
chewrec(const dtrace_probedata_t *data, const dtrace_recdesc_t *rec, void *arg)
{
	dtrace_actkind_t act;
	uintptr_t addr;

	if (rec == NULL) {
		/*
		 * We have processed the final record; output the newline if
		 * we're not in quiet mode.
		 */
		if (!g_quiet)
			oprintf("\n");

		return DTRACE_CONSUME_NEXT;
	}

	act = rec->dtrd_action;
	addr = (uintptr_t)data->dtpda_data;

	if (act == DTRACEACT_EXIT) {
		g_status = *((uint32_t *)addr);
		return DTRACE_CONSUME_NEXT;
	}

	return DTRACE_CONSUME_THIS;
}

/*ARGSUSED*/
static int
chew(const dtrace_probedata_t *data, void *arg)
{
	dtrace_probedesc_t *pd = data->dtpda_pdesc;
	processorid_t cpu = data->dtpda_cpu;
	static int heading;

	if (g_impatient) {
		g_newline = 0;
		return DTRACE_CONSUME_ABORT;
	}

	if (heading == 0) {
		if (!g_flowindent) {
			if (!g_quiet) {
				if (!g_testing) {
					oprintf("%3s %6s %32s\n",
					    "CPU", "ID", "FUNCTION:NAME");
				} else {
					oprintf("%32s\n", "FUNCTION:NAME");
				}
			}
		} else {
			if (!g_testing) {
				oprintf("%3s %-41s\n", "CPU", "FUNCTION");
			} else {
				oprintf("%-41s\n", "FUNCTION");
			}
		}
		heading = 1;
	}

	if (!g_flowindent) {
		if (!g_quiet) {
			size_t len = strlen(pd->fun) + strlen(pd->prb) + 2;
			char *name = alloca(len);

			if (name == NULL)
				fatal("failed to allocate memory for name");

			snprintf(name, len, "%s:%s", pd->fun, pd->prb);

			if (!g_testing)
				oprintf("%3d %6d %32s ", cpu, pd->id, name);
			else
				oprintf("%32s ", name);
		}
	} else {
		int indent = data->dtpda_indent;
		char *name;
		size_t len;

		if (data->dtpda_flow == DTRACEFLOW_NONE) {
			len = indent + strlen(pd->fun) + strlen(pd->prb) + 5;
			name = alloca(len);
			snprintf(name, len, "%*s%s%s:%s", indent, "",
				 data->dtpda_prefix, pd->fun, pd->prb);
		} else {
			len = indent + strlen(pd->fun) + 5;
			name = alloca(len);
			snprintf(name, len, "%*s%s%s", indent, "",
				 data->dtpda_prefix, pd->fun);
		}

		if (!g_testing) {
			oprintf("%3d %-41s ", cpu, name);
		} else {
			oprintf("%-41s ", name);
		}
	}

	return DTRACE_CONSUME_THIS;
}

static void
go(void)
{
	int i;
	dtrace_optval_t quiet;

	struct {
		char *name;
		char *optname;
		dtrace_optval_t val;
	} bufs[] = {
		{ "buffer size", "bufsize" },
		{ "aggregation size", "aggsize" },
		{ "speculation size", "specsize" },
		{ "dynamic variable size", "dynvarsize" },
		{ NULL }
	}, rates[] = {
		{ "cleaning rate", "cleanrate" },
		{ "status rate", "statusrate" },
		{ NULL }
	};

	for (i = 0; bufs[i].name != NULL; i++) {
		if (dtrace_getopt(g_dtp, bufs[i].optname, &bufs[i].val) == -1)
			fatal("couldn't get option %s", bufs[i].optname);
	}

	for (i = 0; rates[i].name != NULL; i++) {
		if (dtrace_getopt(g_dtp, rates[i].optname, &rates[i].val) == -1)
			fatal("couldn't get option %s", rates[i].optname);
	}

	if (dtrace_go(g_dtp, g_cflags) == -1)
		dfatal("could not enable tracing");

	dtrace_getopt(g_dtp, "quietresize", &quiet);

	if (quiet != DTRACEOPT_UNSET)
		return;

	for (i = 0; bufs[i].name != NULL; i++) {
		dtrace_optval_t j = 0, mul = 10;
		dtrace_optval_t nsize;

		if (bufs[i].val == DTRACEOPT_UNSET)
			continue;

		dtrace_getopt(g_dtp, bufs[i].optname, &nsize);

		if (nsize == DTRACEOPT_UNSET || nsize == 0)
			continue;

		if (nsize >= bufs[i].val - sizeof(uint64_t))
			continue;

		for (; (INT64_C(1) << mul) <= nsize; j++, mul += 10)
			continue;

		if (!(nsize & ((INT64_C(1) << (mul - 10)) - 1))) {
			error("%s lowered to %lld%c\n", bufs[i].name,
			    (long long)nsize >> (mul - 10), " kmgtpe"[j]);
		} else {
			error("%s lowered to %lld bytes\n", bufs[i].name,
			    (long long)nsize);
		}
	}

	for (i = 0; rates[i].name != NULL; i++) {
		dtrace_optval_t nval;
		char *dir;

		if (rates[i].val == DTRACEOPT_UNSET)
			continue;

		dtrace_getopt(g_dtp, rates[i].optname, &nval);

		if (nval == DTRACEOPT_UNSET || nval == 0)
			continue;

		if (rates[i].val == nval)
			continue;

		dir = nval > rates[i].val ? "reduced" : "increased";

		if (nval <= NANOSEC && (NANOSEC % nval) == 0) {
			error("%s %s to %lld hz\n", rates[i].name, dir,
			    (long long)NANOSEC / (long long)nval);
			continue;
		}

		if ((nval % NANOSEC) == 0) {
			error("%s %s to once every %lld seconds\n",
			    rates[i].name, dir,
			    (long long)nval / (long long)NANOSEC);
			continue;
		}

		error("%s %s to once every %lld nanoseconds\n",
		    rates[i].name, dir, (long long)nval);
	}
}

/*ARGSUSED*/
static void
intr(int signo)
{
	if (!g_intr)
		g_newline = 1;

	if (g_intr++)
		g_impatient = 1;
}

int
main(int argc, char *argv[])
{
	struct sigaction act, oact;
	dtrace_optval_t opt;
	dtrace_cmd_t *dcp;

	int done = 0, mode = 0;
	int err, i, c;
	char *p, **v;
	pid_t pid;
	struct dtrace_proc *proc;

	setlocale(LC_NUMERIC, "");

	g_ofp = stdout;

	g_pname = basename(argv[0]);

	if (argc == 1)
		return usage(stderr);

	if ((g_argv = malloc(sizeof(char *) * argc)) == NULL ||
	    (g_cmdv = malloc(sizeof(dtrace_cmd_t) * argc)) == NULL ||
	    (g_psv = malloc(sizeof(struct dtrace_proc *) * argc)) == NULL)
		fatal("failed to allocate memory for arguments");

	g_argv[g_argc++] = argv[0];	/* propagate argv[0] to D as $0/$$0 */
	argv[0] = g_pname;		/* rewrite argv[0] for getopt errors */

	/*
	 * Make an initial pass through argv[] processing any arguments that
	 * affect our behavior mode (g_mode) and flags used for dtrace_open().
	 * We also accumulate arguments that are not affiliated with getopt
	 * options into g_argv[], and abort if any invalid options are found.
	 */
	optind = 1;

	while ((c = getopt(argc, argv, DTRACE_OPTSTR)) != EOF) {
		switch (c) {
		case '3':
			if (strcmp(optarg, "2") != 0) {
				fprintf(stderr,
				    "%s: illegal option -- 3%s\n",
				    argv[0], optarg);
				return usage(stderr);
			}
			g_oflags &= ~DTRACE_O_LP64;
			g_oflags |= DTRACE_O_ILP32;
			break;

		case '6':
			if (strcmp(optarg, "4") != 0) {
				fprintf(stderr,
				    "%s: illegal option -- 6%s\n",
				    argv[0], optarg);
				return usage(stderr);
			}
			g_oflags &= ~DTRACE_O_ILP32;
			g_oflags |= DTRACE_O_LP64;
			break;

		case 'e':
			g_exec = 0;
			done = 1;
			break;

		case 'h':
			g_mode = DMODE_HEADER;
			g_cflags |= DTRACE_C_ZDEFS; /* -h implies -Z */
			g_exec = 0;
			mode++;
			break;

		case 'G':
			g_mode = DMODE_LINK;
			g_cflags |= DTRACE_C_ZDEFS; /* -G implies -Z */
			g_exec = 0;
			mode++;
			break;

		case 'l':
			g_mode = DMODE_LIST;
			g_cflags |= DTRACE_C_ZDEFS; /* -l implies -Z */
			mode++;
			break;

		case 'v':
			g_verbose++;
			break;

		case 'V':
			g_mode = DMODE_VERS;
			mode++;
			break;

		default:
			if (strchr(DTRACE_OPTSTR, c) == NULL)
				return usage(stderr);
		}
	}

	for (; optind < argc; optind++)
		g_argv[g_argc++] = argv[optind];

	if (mode > 1) {
		fprintf(stderr, "%s: only one of the [-GhlV] options "
		    "can be specified at a time\n", g_pname);
		return E_USAGE;
	}

	if (g_mode == DMODE_VERS) {
		if (!g_verbose)
			return printf("%s: %s\n", g_pname, _dtrace_version) <= 0;
		else {
			printf("%s: %s\n", g_pname, _dtrace_version);
			printf("This is DTrace %s\n", _DT_VERSION);
			printf("dtrace(1) version-control ID: %s\n", DT_GIT_VERSION);
			return printf("libdtrace version-control ID: %s\n", _libdtrace_vcs_version) <= 0;
		}
	}

	/*
	 * Generate a helpful error message if the user forgets to run as root.
	 *
	 * Note that DMODE_VERS has already been handled, and DMODE_HEADER and
	 * DMODE_LINK are okay without root.
	 *
	 * Insist on root for tracing, but also for DMODE_LIST and even for
	 * DMODE_EXEC with g_exec==0, since otherwise too many probes will
	 * simply not be recognized, likely causing puzzling behavior.
	 */
	if (getuid() != 0 && (g_mode == DMODE_LIST || g_mode == DMODE_EXEC)) {
		fprintf(stderr, "%s: run as root for tracing and listing probes\n", g_pname);
		return E_USAGE;
	}

	/*
	 * If we're in linker mode and the data model hasn't been specified,
	 * we try to guess the appropriate setting by examining the object
	 * files. We ignore certain errors since we'll catch them later when
	 * we actually process the object files.
	 */
	if (g_mode == DMODE_LINK &&
	    (g_oflags & (DTRACE_O_ILP32 | DTRACE_O_LP64)) == 0 &&
	    elf_version(EV_CURRENT) != EV_NONE) {
		int fd;
		Elf *elf;
		GElf_Ehdr ehdr;

		for (i = 1; i < g_argc; i++) {
			if ((fd = open(g_argv[i], O_RDONLY)) == -1)
				break;

			if ((elf = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
				close(fd);
				break;
			}

			if (elf_kind(elf) != ELF_K_ELF ||
			    gelf_getehdr(elf, &ehdr) == NULL) {
				close(fd);
				elf_end(elf);
				break;
			}

			close(fd);
			elf_end(elf);

			if (ehdr.e_ident[EI_CLASS] == ELFCLASS64) {
				if (g_oflags & DTRACE_O_ILP32) {
					fatal("can't mix 32-bit and 64-bit "
					    "object files\n");
				}
				g_oflags |= DTRACE_O_LP64;
			} else if (ehdr.e_ident[EI_CLASS] == ELFCLASS32) {
				if (g_oflags & DTRACE_O_LP64) {
					fatal("can't mix 32-bit and 64-bit "
					    "object files\n");
				}
				g_oflags |= DTRACE_O_ILP32;
			} else {
				break;
			}
		}
	}

	/*
	 * Open libdtrace.
	 */
	g_dtp = dtrace_open(DTRACE_VERSION, g_oflags, &err);
	if (g_dtp == NULL)
		fatal("failed to initialize dtrace: %s\n",
		      dtrace_errmsg(NULL, err));

	/*
	 * Set default options.
	 */
	dtrace_setopt(g_dtp, "bufsize", "4m");
	dtrace_setopt(g_dtp, "aggsize", "4m");

	/*
	 * The very first thing we do after buffer-size sanitization is run
	 * through the environment and set DTrace options based on environment
	 * variables.
	 */
	dtrace_setoptenv(g_dtp, "DTRACE_OPT_");

	/*
	 * If -G is specified, enable -xlink=dynamic and -xunodefs to permit
	 * references to undefined symbols to remain as unresolved relocations.
	 */
	if (g_mode == DMODE_LINK) {
		dtrace_setopt(g_dtp, "linkmode", "dynamic");
		dtrace_setopt(g_dtp, "unodefs", NULL);

		/*
		 * Use the remaining arguments as the list of object files
		 * when in linker mode.
		 */
		g_objc = g_argc - 1;
		g_objv = g_argv + 1;

		/*
		 * We still use g_argv[0], the name of the executable.
		 */
		g_argc = 1;
	}

	/*
	 * Now that we have libdtrace open, make a second pass through argv[]
	 * to perform any dtrace_setopt() calls and change any compiler flags.
	 * We also accumulate any program specifications into our g_cmdv[] at
	 * this time; these will compiled as part of the fourth processing pass.
	 */
	optind = 1;
	while ((c = getopt(argc, argv, DTRACE_OPTSTR)) != EOF) {
		switch (c) {
		case 'b':
			if (dtrace_setopt(g_dtp,
				"bufsize", optarg) != 0)
				dfatal("failed to set -b %s", optarg);
			break;

		case 'B':
			g_ofp = NULL;
			break;

		case 'C':
			g_cflags |= DTRACE_C_CPP;
			break;

		case 'D':
			if (dtrace_setopt(g_dtp, "define", optarg) != 0)
				dfatal("failed to set -D %s", optarg);
			break;

		case 'f':
			dcp = &g_cmdv[g_cmdc++];
			dcp->dc_func = compile_str;
			dcp->dc_spec = DTRACE_PROBESPEC_FUNC;
			dcp->dc_arg = optarg;
			break;

		case 'F':
			if (dtrace_setopt(g_dtp, "flowindent", 0) != 0)
				dfatal("failed to set -F");
			break;

		case 'H':
			if (dtrace_setopt(g_dtp, "cpphdrs", 0) != 0)
				dfatal("failed to set -H");
			break;

		case 'i':
			dcp = &g_cmdv[g_cmdc++];
			dcp->dc_func = compile_str;
			dcp->dc_spec = DTRACE_PROBESPEC_NAME;
			dcp->dc_arg = optarg;
			break;

		case 'I':
			if (dtrace_setopt(g_dtp, "incdir", optarg) != 0)
				dfatal("failed to set -I %s", optarg);
			break;

		case 'L':
			if (dtrace_setopt(g_dtp, "libdir", optarg) != 0)
				dfatal("failed to set -L %s", optarg);
			break;

		case 'm':
			dcp = &g_cmdv[g_cmdc++];
			dcp->dc_func = compile_str;
			dcp->dc_spec = DTRACE_PROBESPEC_MOD;
			dcp->dc_arg = optarg;
			break;

		case 'n':
			dcp = &g_cmdv[g_cmdc++];
			dcp->dc_func = compile_str;
			dcp->dc_spec = DTRACE_PROBESPEC_NAME;
			dcp->dc_arg = optarg;
			break;

		case 'P':
			dcp = &g_cmdv[g_cmdc++];
			dcp->dc_func = compile_str;
			dcp->dc_spec = DTRACE_PROBESPEC_PROVIDER;
			dcp->dc_arg = optarg;
			break;

		case 'q':
			if (dtrace_setopt(g_dtp, "quiet", 0) != 0)
				dfatal("failed to set -q");
			break;

		case 'o':
			g_ofile = optarg;
			break;

		case 's':
			dcp = &g_cmdv[g_cmdc++];
			dcp->dc_func = compile_file;
			dcp->dc_spec = DTRACE_PROBESPEC_NONE;
			dcp->dc_arg = optarg;
			break;

		case 'S':
			g_cflags |= DTRACE_C_DIFV;
			break;

		case 'U':
			if (dtrace_setopt(g_dtp, "undef", optarg) != 0)
				dfatal("failed to set -U %s", optarg);
			break;

		case 'w':
			if (dtrace_setopt(g_dtp, "destructive", 0) != 0)
				dfatal("failed to set -w");
			break;

		case 'x':
			if ((p = strchr(optarg, '=')) != NULL)
				*p++ = '\0';

			if (dtrace_setopt(g_dtp, optarg, p) != 0)
				dfatal("failed to set -x %s", optarg);
			break;

		case 'X':
			if (dtrace_setopt(g_dtp, "stdc", optarg) != 0)
				dfatal("failed to set -X %s", optarg);
			break;

		case 'Z':
			g_cflags |= DTRACE_C_ZDEFS;
			break;

		default:
			if (strchr(DTRACE_OPTSTR, c) == NULL)
				return usage(stderr);
		}
	}

	if (g_ofp == NULL && g_mode != DMODE_EXEC) {
		fprintf(stderr, "%s: -B not valid in combination"
		    " with [-Gl] options\n", g_pname);
		return E_USAGE;
	}

	if (g_ofp == NULL && g_ofile != NULL) {
		fprintf(stderr, "%s: -B not valid in combination"
		    " with -o option\n", g_pname);
		return E_USAGE;
	}

	/*
	 * Turn on testing mode if requested.  This only affects dtrace.c, so is
	 * not controlled by a dtrace option.  This quiesces a variety of
	 * nondetermistic output, for better expected-results comparison.
	 */
	if (getenv("_DTRACE_TESTING") != NULL) {
		g_testing = 1;
		if (dtrace_setopt(g_dtp, "quietresize", 0) != 0)
			fprintf(stderr, "%s: cannot set quietresize for "
			    "testing", g_pname);
	}

	/*
	 * In our third pass we handle any command-line options related to
	 * grabbing or creating victim processes.  The behavior of these calls
	 * may been affected by any library options set by the second pass.
	 */
	optind = 1;
	while ((c = getopt(argc, argv, DTRACE_OPTSTR)) != EOF) {
		switch (c) {
		case 'c':
			if ((v = make_argv(optarg)) == NULL)
				fatal("failed to allocate memory");

			proc = dtrace_proc_create(g_dtp, v[0], v, 0);
			if (proc == NULL) {
				free(v);
				dfatal(NULL); /* dtrace_errmsg() only */
			}

			g_psv[g_psc++] = proc;
			free(v);
			break;

		case 'p':
			errno = 0;
			pid = strtol(optarg, &p, 10);

			if (errno != 0 || p == optarg || p[0] != '\0')
				fatal("invalid pid: %s\n", optarg);

			proc = dtrace_proc_grab_pid(g_dtp, pid, 0);
			if (proc == NULL)
				dfatal(NULL); /* dtrace_errmsg() only */

			g_psv[g_psc++] = proc;
			break;
		}
	}

	/*
	 * Now we are ready to initialize libdtrace based on the chosen
	 * options.
	 */
	if (dtrace_init(g_dtp) < 0)
		dfatal("failed to initialize libdtrace");

	/*
	 * In our fourth pass we finish g_cmdv[] by calling dc_func to convert
	 * each string or file specification into a compiled program structure.
	 */
	for (i = 0; i < g_cmdc; i++)
		g_cmdv[i].dc_func(&g_cmdv[i]);

	/*
	 * We only need to register handler if we are going to execute probe
	 * clauses.
	 */
	if (g_mode == DMODE_EXEC) {
		if (dtrace_handle_err(g_dtp, &errhandler, NULL) == -1)
			dfatal("failed to establish error handler");

		if (dtrace_handle_drop(g_dtp, &drophandler, NULL) == -1)
			dfatal("failed to establish drop handler");

		if (dtrace_handle_proc(g_dtp, &prochandler, NULL) == -1)
			dfatal("failed to establish proc handler");

		if (dtrace_handle_setopt(g_dtp, &setopthandler, NULL) == -1)
			dfatal("failed to establish setopt handler");

		if (g_ofp == NULL &&
		    dtrace_handle_buffered(g_dtp, &bufhandler, NULL) == -1)
			dfatal("failed to establish buffered handler");
	}

	dtrace_getopt(g_dtp, "flowindent", &opt);
	g_flowindent = opt != DTRACEOPT_UNSET;

	dtrace_getopt(g_dtp, "quiet", &opt);
	g_quiet = opt != DTRACEOPT_UNSET;

	/*
	 * Now make a fifth and final pass over the options that have been
	 * turned into programs and saved in g_cmdv[], performing any mode-
	 * specific processing.  If g_mode is DMODE_EXEC, we will break out
	 * of the switch() and continue on to the data processing loop.  For
	 * other modes, we will exit dtrace once mode-specific work is done.
	 */
	switch (g_mode) {
	case DMODE_EXEC:
		if (g_ofile != NULL && (g_ofp = fopen(g_ofile, "a")) == NULL)
			fatal("failed to open output file '%s'", g_ofile);

		sigemptyset(&act.sa_mask);
		act.sa_flags = 0;
		act.sa_handler = intr;
		if (sigaction(SIGINT, NULL, &oact) == 0 && oact.sa_handler != SIG_IGN)
			sigaction(SIGINT, &act, NULL);
		if (sigaction(SIGTERM, NULL, &oact) == 0 && oact.sa_handler != SIG_IGN)
			sigaction(SIGTERM, &act, NULL);

		for (i = 0; i < g_cmdc; i++)
			exec_prog(&g_cmdv[i]);

		if (done || g_intr) {
			dtrace_close(g_dtp);
			return g_status;
		}
		break;

	case DMODE_LINK:
		if (g_cmdc == 0) {
			fprintf(stderr, "%s: -G requires one or more "
			    "scripts or enabling options\n", g_pname);
			dtrace_close(g_dtp);
			return E_USAGE;
		}

		for (i = 0; i < g_cmdc; i++)
			link_prog(&g_cmdv[i]);

		if (g_cmdc > 1 && g_ofile != NULL) {
			char **objv = alloca(g_cmdc * sizeof(char *));

			for (i = 0; i < g_cmdc; i++)
				objv[i] = g_cmdv[i].dc_ofile;

			if (dtrace_program_link(g_dtp, NULL, DTRACE_D_PROBES,
			    g_ofile, g_cmdc, objv) != 0)
				dfatal(NULL); /* dtrace_errmsg() only */
		}

		dtrace_close(g_dtp);
		return g_status;

	case DMODE_LIST:
		if (g_ofile != NULL && (g_ofp = fopen(g_ofile, "a")) == NULL)
			fatal("failed to open output file '%s'", g_ofile);

		oprintf("%5s %10s %17s %33s %s\n",
		    "ID", "PROVIDER", "MODULE", "FUNCTION", "NAME");

		for (i = 0; i < g_cmdc; i++)
			list_prog(&g_cmdv[i]);

		if (g_cmdc == 0) {
			dtrace_cmd_t pseudo_cmd;

			/*
			 * If we are listing the default case "dtrace -l",
			 * compile the string ":::" to give providers an
			 * attempt to provide probes.
			 */
			pseudo_cmd.dc_spec = DTRACE_PROBESPEC_NAME;
			pseudo_cmd.dc_arg = ":::";
			compile_str(&pseudo_cmd);

			if (dtrace_probe_iter(g_dtp, NULL, list_probe, NULL) < 0)
				dfatal(NULL); /* dtrace_errmsg() only */
		}

		dtrace_close(g_dtp);
		return g_status;

	case DMODE_HEADER:
		if (g_cmdc == 0) {
			fprintf(stderr, "%s: -h requires one or more "
			    "scripts or enabling options\n", g_pname);
			dtrace_close(g_dtp);
			return E_USAGE;
		}

		if (g_ofile == NULL) {
			char *p;

			if (g_cmdc > 1) {
				fprintf(stderr, "%s: -h requires an "
				    "output file if multiple scripts are "
				    "specified\n", g_pname);
				dtrace_close(g_dtp);
				return E_USAGE;
			}

			if ((p = strrchr(g_cmdv[0].dc_arg, '.')) == NULL ||
			    strcmp(p, ".d") != 0) {
				fprintf(stderr, "%s: -h requires an "
				    "output file if no scripts are "
				    "specified\n", g_pname);
				dtrace_close(g_dtp);
				return E_USAGE;
			}

			p[0] = '\0'; /* strip .d suffix */
			g_ofile = p = g_cmdv[0].dc_ofile;
			snprintf(p, sizeof(g_cmdv[0].dc_ofile),
			    "%s.h", basename(g_cmdv[0].dc_arg));
		}

		if ((g_ofp = fopen(g_ofile, "w")) == NULL)
			fatal("failed to open header file '%s'", g_ofile);

		oprintf("/*\n * Generated by dtrace(1M).\n */\n\n");

		if (dtrace_program_header(g_dtp, g_ofp, g_ofile) != 0 ||
		    fclose(g_ofp) == EOF)
			dfatal("failed to create header file %s", g_ofile);

		dtrace_close(g_dtp);
		return g_status;
	}

	/*
	 * If -Z was not specified and no probes have been matched, no probe
	 * criteria was specified on the command line and we abort.
	 */
	if (g_total == 0 && !(g_cflags & DTRACE_C_ZDEFS))
		dfatal("no probes %s\n", g_cmdc ? "matched" : "specified");

	/*
	 * Start tracing.
	 */
	if (g_intr)
		goto out;
	go();

	dtrace_getopt(g_dtp, "flowindent", &opt);
	g_flowindent = opt != DTRACEOPT_UNSET;

	dtrace_getopt(g_dtp, "quiet", &opt);
	g_quiet = opt != DTRACEOPT_UNSET;

	dtrace_getopt(g_dtp, "destructive", &opt);
	if (opt != DTRACEOPT_UNSET)
		notice("allowing destructive actions\n");

	/*
	 * Now that tracing is active and we are ready to consume trace data,
	 * continue any grabbed or created processes, setting them running
	 * using the /proc control mechanism inside of libdtrace.
	 */
	for (i = 0; i < g_psc; i++)
		dtrace_proc_continue(g_dtp, g_psv[i]);
	if (g_intr)
		goto release_procs;

	g_pslive = g_psc; /* count for prochandler() */

	do {
		if ((g_newline) && (!g_testing)) {
			/*
			 * Output a newline just to make the output look
			 * slightly cleaner.  Note that we do this even in
			 * "quiet" mode...  We don't do it when testing, as the
			 * newline appears at an essentially random position in
			 * the output.
			 */
			oprintf("\n");
			g_newline = 0;
		}

		if (done == DONE_SAW_EXIT || g_intr ||
		    (g_psc != 0 && g_pslive <= 0)) {
			done = DONE_SAW_END;
			if (dtrace_stop(g_dtp) == -1)
				dfatal("couldn't stop tracing");
		}

		switch (dtrace_work(g_dtp, g_ofp, chew, chewrec, NULL)) {
		case DTRACE_WORKSTATUS_DONE:
			if (done != DONE_SAW_END)
				done = DONE_SAW_EXIT;
			break;
		case DTRACE_WORKSTATUS_OKAY:
			break;
		default:
			if (!g_impatient && dtrace_errno(g_dtp) != EINTR)
				dfatal("processing aborted");
		}

		if (g_ofp != NULL && fflush(g_ofp) == EOF)
			clearerr(g_ofp);
	} while (done != DONE_SAW_END);

	oprintf("\n");

	if (!g_impatient) {
		if (dtrace_aggregate_print(g_dtp, g_ofp, NULL) == -1 &&
		    dtrace_errno(g_dtp) != EINTR)
			dfatal("failed to print aggregations");
	}

release_procs:
	for (i = 0; i < g_psc; i++)
		dtrace_proc_release(g_dtp, g_psv[i]);

out:
	dtrace_close(g_dtp);

	free(g_argv);
	free(g_cmdv);
	free(g_psv);

	return g_status;
}