xref: /dragonfly/usr.bin/ktrdump/ktrdump.c (revision 52f9f0d9)
1 /*-
2  * Copyright (c) 2002 Jake Burkholder
3  * Copyright (c) 2004 Robert Watson
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $FreeBSD: src/usr.bin/ktrdump/ktrdump.c,v 1.10 2005/05/21 09:55:06 ru Exp $
28  * $DragonFly: src/usr.bin/ktrdump/ktrdump.c,v 1.13 2008/11/10 02:05:31 swildner Exp $
29  */
30 
31 #include <sys/cdefs.h>
32 
33 #include <sys/types.h>
34 #include <sys/ktr.h>
35 #include <sys/mman.h>
36 #include <sys/stat.h>
37 #include <sys/queue.h>
38 
39 #include <ctype.h>
40 #include <devinfo.h>
41 #include <err.h>
42 #include <fcntl.h>
43 #include <kvm.h>
44 #include <limits.h>
45 #include <nlist.h>
46 #include <stdint.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 #include <evtr.h>
52 #include <stdarg.h>
53 
54 struct ktr_buffer {
55 	struct ktr_entry *ents;
56 	int modified;
57 	int reset;
58 	int beg_idx;		/* Beginning index */
59 	int end_idx;		/* Ending index */
60 };
61 
62 static struct nlist nl1[] = {
63 	{ .n_name = "_ktr_version" },
64 	{ .n_name = "_ktr_entries" },
65 	{ .n_name = "_ncpus" },
66 	{ .n_name = NULL }
67 };
68 
69 static struct nlist nl2[] = {
70 	{ .n_name = "_tsc_frequency" },
71 	{ .n_name = NULL }
72 };
73 
74 static struct nlist nl_version_ktr_idx[] = {
75 	{ .n_name = "_ktr_idx" },
76 	{ .n_name = "_ktr_buf" },
77 	{ .n_name = NULL }
78 };
79 
80 static struct nlist nl_version_ktr_cpu[] = {
81 	{ .n_name = "_ktr_cpu" },
82 	{ .n_name = NULL }
83 };
84 
85 struct save_ctx {
86 	char save_buf[512];
87 	const void *save_kptr;
88 };
89 
90 typedef void (*ktr_iter_cb_t)(void *, int, int, struct ktr_entry *, uint64_t *);
91 
92 #ifdef __x86_64__
93 /* defined according to the x86_64 ABI spec */
94 struct my_va_list {
95 	uint32_t gp_offset;	/* offset to next available gpr in reg_save_area */
96 	uint32_t fp_offset;	/* offset to next available fpr in reg_save_area */
97 	void *overflow_arg_area;	/* args that are passed on the stack */
98 	struct reg_save_area *reg_save_area;		/* register args */
99 	/*
100 	 * NOT part of the ABI. ->overflow_arg_area gets advanced when code
101 	 * iterates over the arguments with va_arg(). That means we need to
102 	 * keep a copy in order to free the allocated memory (if any)
103 	 */
104 	void *overflow_arg_area_save;
105 } __attribute__((packed));
106 
107 typedef struct my_va_list *machine_va_list;
108 
109 struct reg_save_area {
110 	uint64_t rdi, rsi, rdx, rcx, r8, r9;
111 	/* XMM registers follow, but we don't use them */
112 };
113 #elif __i386__
114 typedef void *machine_va_list;
115 #endif
116 
117 static int cflag;
118 static int dflag;
119 static int fflag;
120 static int iflag;
121 static int lflag;
122 static int nflag;
123 static int qflag;
124 static int rflag;
125 static int sflag;
126 static int tflag;
127 static int xflag;
128 static int pflag;
129 static int Mflag;
130 static int Nflag;
131 static double tsc_frequency;
132 static double correction_factor = 0.0;
133 
134 static char corefile[PATH_MAX];
135 static char execfile[PATH_MAX];
136 
137 static char errbuf[_POSIX2_LINE_MAX];
138 static int ncpus;
139 static kvm_t *kd;
140 static int entries_per_buf;
141 static int fifo_mask;
142 static int ktr_version;
143 
144 static void usage(void);
145 static int earliest_ts(struct ktr_buffer *);
146 static void dump_machine_info(evtr_t);
147 static void dump_device_info(evtr_t);
148 static void print_header(FILE *, int);
149 static void print_entry(FILE *, int, int, struct ktr_entry *, u_int64_t *);
150 static void print_callback(void *, int, int, struct ktr_entry *, uint64_t *);
151 static void dump_callback(void *, int, int, struct ktr_entry *, uint64_t *);
152 static struct ktr_info *kvm_ktrinfo(void *, struct save_ctx *);
153 static const char *kvm_string(const char *, struct save_ctx *);
154 static const char *trunc_path(const char *, int);
155 static void read_symbols(const char *);
156 static const char *address_to_symbol(void *, struct save_ctx *);
157 static struct ktr_buffer *ktr_bufs_init(void);
158 static void get_indices(struct ktr_entry **, int *);
159 static void load_bufs(struct ktr_buffer *, struct ktr_entry **, int *);
160 static void iterate_buf(FILE *, struct ktr_buffer *, int, u_int64_t *, ktr_iter_cb_t);
161 static void iterate_bufs_timesorted(FILE *, struct ktr_buffer *, u_int64_t *, ktr_iter_cb_t);
162 static void kvmfprintf(FILE *fp, const char *ctl, va_list va);
163 static int va_list_from_blob(machine_va_list *valist, const char *fmt, char *blob, size_t blobsize);
164 static void va_list_cleanup(machine_va_list *valist);
165 /*
166  * Reads the ktr trace buffer from kernel memory and prints the trace entries.
167  */
168 int
169 main(int ac, char **av)
170 {
171 	struct ktr_buffer *ktr_bufs;
172 	struct ktr_entry **ktr_kbuf;
173 	ktr_iter_cb_t callback = &print_callback;
174 	int *ktr_idx;
175 	FILE *fo;
176 	void *ctx;
177 	int64_t tts;
178 	int *ktr_start_index;
179 	int c;
180 	int n;
181 
182 	/*
183 	 * Parse commandline arguments.
184 	 */
185 	fo = stdout;
186 	while ((c = getopt(ac, av, "acfinqrtxpslA:N:M:o:d")) != -1) {
187 		switch (c) {
188 		case 'a':
189 			cflag = 1;
190 			iflag = 1;
191 			rflag = 1;
192 			xflag = 1;
193 			pflag = 1;
194 			sflag = 1;
195 			break;
196 		case 'c':
197 			cflag = 1;
198 			break;
199 		case 'd':
200 			dflag = 1;
201 			sflag = 1;
202 			callback = &dump_callback;
203 			break;
204 		case 'N':
205 			if (strlcpy(execfile, optarg, sizeof(execfile))
206 			    >= sizeof(execfile))
207 				errx(1, "%s: File name too long", optarg);
208 			Nflag = 1;
209 			break;
210 		case 'f':
211 			fflag = 1;
212 			break;
213 		case 'l':
214 			lflag = 1;
215 			break;
216 		case 'i':
217 			iflag = 1;
218 			break;
219 		case 'A':
220 			correction_factor = strtod(optarg, NULL);
221 			break;
222 		case 'M':
223 			if (strlcpy(corefile, optarg, sizeof(corefile))
224 			    >= sizeof(corefile))
225 				errx(1, "%s: File name too long", optarg);
226 			Mflag = 1;
227 			break;
228 		case 'n':
229 			nflag = 1;
230 			break;
231 		case 'o':
232 			if ((fo = fopen(optarg, "w")) == NULL)
233 				err(1, "%s", optarg);
234 			break;
235 		case 'p':
236 			pflag++;
237 			break;
238 		case 'q':
239 			qflag++;
240 			break;
241 		case 'r':
242 			rflag = 1;
243 			break;
244 		case 's':
245 			sflag = 1;	/* sort across the cpus */
246 			break;
247 		case 't':
248 			tflag = 1;
249 			break;
250 		case 'x':
251 			xflag = 1;
252 			break;
253 		case '?':
254 		default:
255 			usage();
256 		}
257 	}
258 	ctx = fo;
259 	if (dflag) {
260 		ctx = evtr_open_write(fo);
261 		if (!ctx) {
262 			err(1, "Can't create event stream");
263 		}
264 	}
265 	if (cflag + iflag + tflag + xflag + fflag + pflag == 0) {
266 		cflag = 1;
267 		iflag = 1;
268 		tflag = 1;
269 		pflag = 1;
270 	}
271 	if (correction_factor != 0.0 && (rflag == 0 || nflag)) {
272 		fprintf(stderr, "Correction factor can only be applied with -r and without -n\n");
273 		exit(1);
274 	}
275 	ac -= optind;
276 	av += optind;
277 	if (ac != 0)
278 		usage();
279 
280 	/*
281 	 * Open our execfile and corefile, resolve needed symbols and read in
282 	 * the trace buffer.
283 	 */
284 	if ((kd = kvm_openfiles(Nflag ? execfile : NULL,
285 	    Mflag ? corefile : NULL, NULL, O_RDONLY, errbuf)) == NULL)
286 		errx(1, "%s", errbuf);
287 	if (kvm_nlist(kd, nl1) != 0)
288 		errx(1, "%s", kvm_geterr(kd));
289 	if (kvm_read(kd, nl1[0].n_value, &ktr_version, sizeof(ktr_version)) == -1)
290 		errx(1, "%s", kvm_geterr(kd));
291 	if (kvm_read(kd, nl1[2].n_value, &ncpus, sizeof(ncpus)) == -1)
292 		errx(1, "%s", kvm_geterr(kd));
293 	ktr_start_index = malloc(sizeof(*ktr_start_index) * ncpus);
294 	if (ktr_version >= KTR_VERSION_WITH_FREQ && kvm_nlist(kd, nl2) == 0) {
295 		if (kvm_read(kd, nl2[0].n_value, &tts, sizeof(tts)) == -1)
296 			errx(1, "%s", kvm_geterr(kd));
297 		tsc_frequency = (double)tts;
298 	}
299 	if (ktr_version > KTR_VERSION)
300 		errx(1, "ktr version too high for us to handle");
301 	if (kvm_read(kd, nl1[1].n_value, &entries_per_buf,
302 				sizeof(entries_per_buf)) == -1)
303 		errx(1, "%s", kvm_geterr(kd));
304 	fifo_mask = entries_per_buf - 1;
305 
306 	printf("TSC frequency is %6.3f MHz\n", tsc_frequency / 1000000.0);
307 
308 	if (dflag) {
309 		dump_machine_info((evtr_t)ctx);
310 		dump_device_info((evtr_t)ctx);
311 	}
312 	ktr_kbuf = calloc(ncpus, sizeof(*ktr_kbuf));
313 	ktr_idx = calloc(ncpus, sizeof(*ktr_idx));
314 
315 	if (nflag == 0)
316 		read_symbols(Nflag ? execfile : NULL);
317 
318 	if (ktr_version < KTR_VERSION_KTR_CPU) {
319 		if (kvm_nlist(kd, nl_version_ktr_idx))
320 			errx(1, "%s", kvm_geterr(kd));
321 	} else {
322 		if (kvm_nlist(kd, nl_version_ktr_cpu))
323 			errx(1, "%s", kvm_geterr(kd));
324 	}
325 
326 	get_indices(ktr_kbuf, ktr_idx);
327 
328 	ktr_bufs = ktr_bufs_init();
329 
330 	if (sflag) {
331 		u_int64_t last_timestamp = 0;
332 		do {
333 			load_bufs(ktr_bufs, ktr_kbuf, ktr_idx);
334 			iterate_bufs_timesorted(ctx, ktr_bufs, &last_timestamp,
335 						callback);
336 			if (lflag)
337 				usleep(1000000 / 10);
338 		} while (lflag);
339 	} else {
340 		u_int64_t *last_timestamp = calloc(sizeof(u_int64_t), ncpus);
341 		do {
342 			load_bufs(ktr_bufs, ktr_kbuf, ktr_idx);
343 			for (n = 0; n < ncpus; ++n)
344 				iterate_buf(ctx, ktr_bufs, n, &last_timestamp[n],
345 					callback);
346 			if (lflag)
347 				usleep(1000000 / 10);
348 		} while (lflag);
349 	}
350 	if (dflag)
351 		evtr_close(ctx);
352 	return (0);
353 }
354 
355 static
356 int
357 dump_devinfo(struct devinfo_dev *dev, void *arg)
358 {
359 	struct evtr_event ev;
360 	evtr_t evtr = (evtr_t)arg;
361 	const char *fmt = "#devicenames[\"%s\"] = %#lx";
362 	char fmtdatabuf[sizeof(char *) + sizeof(devinfo_handle_t)];
363 	char *fmtdata = fmtdatabuf;
364 
365 	if (!dev->dd_name[0])
366 		return 0;
367 	ev.type = EVTR_TYPE_PROBE;
368 	ev.ts = 0;
369 	ev.line = 0;
370 	ev.file = NULL;
371 	ev.cpu = -1;
372 	ev.func = NULL;
373 	ev.fmt = fmt;
374 	((char **)fmtdata)[0] = &dev->dd_name[0];
375 	fmtdata += sizeof(char *);
376 	((devinfo_handle_t *)fmtdata)[0] = dev->dd_handle;
377 	ev.fmtdata = fmtdatabuf;
378 	ev.fmtdatalen = sizeof(fmtdatabuf);
379 
380 	if (evtr_dump_event(evtr, &ev)) {
381 		err(1, evtr_errmsg(evtr));
382 	}
383 
384 	return devinfo_foreach_device_child(dev, dump_devinfo, evtr);
385 }
386 
387 static
388 void
389 dump_device_info(evtr_t evtr)
390 {
391 	struct devinfo_dev *root;
392 	if (devinfo_init())
393 		return;
394 	if (!(root = devinfo_handle_to_device(DEVINFO_ROOT_DEVICE))) {
395 		warn("can't find root device");
396 		return;
397 	}
398 	devinfo_foreach_device_child(root, dump_devinfo, evtr);
399 }
400 
401 static
402 void
403 dump_machine_info(evtr_t evtr)
404 {
405 	struct evtr_event ev;
406 	int i;
407 
408 	bzero(&ev, sizeof(ev));
409 	ev.type = EVTR_TYPE_SYSINFO;
410 	ev.ncpus = ncpus;
411 	evtr_dump_event(evtr, &ev);
412 	if (evtr_error(evtr)) {
413 		err(1, evtr_errmsg(evtr));
414 	}
415 
416 	for (i = 0; i < ncpus; ++i) {
417 		bzero(&ev, sizeof(ev));
418 		ev.type = EVTR_TYPE_CPUINFO;
419 		ev.cpu = i;
420 		ev.cpuinfo.freq = tsc_frequency;
421 		evtr_dump_event(evtr, &ev);
422 		if (evtr_error(evtr)) {
423 			err(1, evtr_errmsg(evtr));
424 		}
425 	}
426 }
427 
428 static void
429 print_header(FILE *fo, int row)
430 {
431 	if (qflag == 0 && (u_int32_t)row % 20 == 0) {
432 		fprintf(fo, "%-6s ", "index");
433 		if (cflag)
434 			fprintf(fo, "%-3s ", "cpu");
435 		if (tflag || rflag)
436 			fprintf(fo, "%-16s ", "timestamp");
437 		if (xflag) {
438 			if (nflag)
439 			    fprintf(fo, "%-10s %-10s", "caller2", "caller1");
440 			else
441 			    fprintf(fo, "%-20s %-20s", "caller2", "caller1");
442 		}
443 		if (iflag)
444 			fprintf(fo, "%-20s ", "ID");
445 		if (fflag)
446 			fprintf(fo, "%10s%-30s ", "", "file and line");
447 		if (pflag)
448 			fprintf(fo, "%s", "trace");
449 		fprintf(fo, "\n");
450 	}
451 }
452 
453 static void
454 print_entry(FILE *fo, int n, int row, struct ktr_entry *entry,
455 	    u_int64_t *last_timestamp)
456 {
457 	struct ktr_info *info = NULL;
458 	static struct save_ctx nctx, pctx, fmtctx, symctx, infoctx;
459 
460 	fprintf(fo, " %06x ", row & 0x00FFFFFF);
461 	if (cflag)
462 		fprintf(fo, "%-3d ", n);
463 	if (tflag || rflag) {
464 		if (rflag && !nflag && tsc_frequency != 0.0) {
465 			fprintf(fo, "%13.3f uS ",
466 				(double)(entry->ktr_timestamp - *last_timestamp) * 1000000.0 / tsc_frequency - correction_factor);
467 		} else if (rflag) {
468 			fprintf(fo, "%-16ju ",
469 			    (uintmax_t)(entry->ktr_timestamp - *last_timestamp));
470 		} else {
471 			fprintf(fo, "%-16ju ",
472 			    (uintmax_t)entry->ktr_timestamp);
473 		}
474 	}
475 	if (xflag) {
476 		if (nflag) {
477 		    fprintf(fo, "%p %p ",
478 			    entry->ktr_caller2, entry->ktr_caller1);
479 		} else {
480 		    fprintf(fo, "%-25s ",
481 			    address_to_symbol(entry->ktr_caller2, &symctx));
482 		    fprintf(fo, "%-25s ",
483 			    address_to_symbol(entry->ktr_caller1, &symctx));
484 		}
485 	}
486 	if (iflag) {
487 		info = kvm_ktrinfo(entry->ktr_info, &infoctx);
488 		if (info)
489 			fprintf(fo, "%-20s ", kvm_string(info->kf_name, &nctx));
490 		else
491 			fprintf(fo, "%-20s ", "<empty>");
492 	}
493 	if (fflag)
494 		fprintf(fo, "%34s:%-4d ",
495 			trunc_path(kvm_string(entry->ktr_file, &pctx), 34),
496 			entry->ktr_line);
497 	if (pflag) {
498 		if (info == NULL)
499 			info = kvm_ktrinfo(entry->ktr_info, &infoctx);
500 		if (info) {
501 			machine_va_list ap;
502 			const char *fmt;
503 			fmt = kvm_string(info->kf_format, &fmtctx);
504 			if (va_list_from_blob(&ap, fmt,
505 					      (char *)&entry->ktr_data,
506 					      info->kf_data_size))
507 				err(2, "Can't generate va_list from %s\n", fmt);
508 			kvmfprintf(fo, kvm_string(info->kf_format, &fmtctx),
509 				   (void *)ap);
510 			va_list_cleanup(&ap);
511 		}
512 	}
513 	fprintf(fo, "\n");
514 	*last_timestamp = entry->ktr_timestamp;
515 }
516 
517 static
518 void
519 print_callback(void *ctx, int n, int row, struct ktr_entry *entry, uint64_t *last_ts)
520 {
521 	FILE *fo = (FILE *)ctx;
522 	print_header(fo, row);
523 	print_entry(fo, n, row, entry, last_ts);
524 }
525 
526 /*
527  * If free == 0, replace all (kvm) string pointers in fmtdata with pointers
528  * to user-allocated copies of the strings.
529  * If free != 0, free those pointers.
530  */
531 static
532 int
533 mangle_string_ptrs(const char *fmt, uint8_t *fmtdata, int dofree)
534 {
535 	const char *f, *p;
536 	size_t skipsize, intsz;
537 	static struct save_ctx strctx;
538 	int ret = 0;
539 
540 	for (f = fmt; f[0] != '\0'; ++f) {
541 		if (f[0] != '%')
542 			continue;
543 		++f;
544 		skipsize = 0;
545 		for (p = f; p[0]; ++p) {
546 			int again = 0;
547 			/*
548 			 * Eat flags. Notice this will accept duplicate
549 			 * flags.
550 			 */
551 			switch (p[0]) {
552 			case '#':
553 			case '0':
554 			case '-':
555 			case ' ':
556 			case '+':
557 			case '\'':
558 				again = !0;
559 				break;
560 			}
561 			if (!again)
562 				break;
563 		}
564 		/* Eat minimum field width, if any */
565 		for (; isdigit(p[0]); ++p)
566 			;
567 		if (p[0] == '.')
568 			++p;
569 		/* Eat precision, if any */
570 		for (; isdigit(p[0]); ++p)
571 			;
572 		intsz = 0;
573 		switch (p[0]) {
574 		case 'l':
575 			if (p[1] == 'l') {
576 				++p;
577 				intsz = sizeof(long long);
578 			} else {
579 				intsz = sizeof(long);
580 			}
581 			break;
582 		case 'j':
583 			intsz = sizeof(intmax_t);
584 			break;
585 		case 't':
586 			intsz = sizeof(ptrdiff_t);
587 			break;
588 		case 'z':
589 			intsz = sizeof(size_t);
590 			break;
591 		default:
592 			break;
593 		}
594 		if (intsz != 0)
595 			++p;
596 		else
597 			intsz = sizeof(int);
598 
599 		switch (p[0]) {
600 		case 'd':
601 		case 'i':
602 		case 'o':
603 		case 'u':
604 		case 'x':
605 		case 'X':
606 		case 'c':
607 			skipsize = intsz;
608 			break;
609 		case 'p':
610 			skipsize = sizeof(void *);
611 			break;
612 		case 'f':
613 			if (p[-1] == 'l')
614 				skipsize = sizeof(double);
615 			else
616 				skipsize = sizeof(float);
617 			break;
618 		case 's':
619 			if (dofree) {
620 			  char *t = ((char **)fmtdata)[0];
621 			  free(t);
622 			  skipsize = sizeof(char *);
623 			} else {
624 			  char *t = strdup(kvm_string(((char **)fmtdata)[0],
625 							  &strctx));
626 			  ((const char **)fmtdata)[0] = t;
627 
628 				skipsize = sizeof(char *);
629 			}
630 			++ret;
631 			break;
632 		default:
633 			fprintf(stderr, "Unknown conversion specifier %c "
634 				"in fmt starting with %s", p[0], f - 1);
635 			return -1;
636 		}
637 		fmtdata += skipsize;
638 	}
639 	return ret;
640 }
641 
642 static
643 void
644 dump_callback(void *ctx, int n, int row __unused, struct ktr_entry *entry,
645 	      uint64_t *last_ts __unused)
646 {
647 	evtr_t evtr = (evtr_t)ctx;
648 	struct evtr_event ev;
649 	static struct save_ctx pctx, fmtctx, infoctx;
650 	struct ktr_info *ki;
651 	int conv = 0;	/* pointless */
652 
653 	ev.ts = entry->ktr_timestamp;
654 	ev.type = EVTR_TYPE_PROBE;
655 	ev.line = entry->ktr_line;
656 	ev.file = kvm_string(entry->ktr_file, &pctx);
657 	ev.func = NULL;
658 	ev.cpu = n;
659 	if ((ki = kvm_ktrinfo(entry->ktr_info, &infoctx))) {
660 		ev.fmt = kvm_string(ki->kf_format, &fmtctx);
661 		ev.fmtdata = entry->ktr_data;
662 		if ((conv = mangle_string_ptrs(ev.fmt,
663 					       __DECONST(uint8_t *, ev.fmtdata),
664 					       0)) < 0)
665 			errx(1, "Can't parse format string\n");
666 		ev.fmtdatalen = ki->kf_data_size;
667 	} else {
668 		ev.fmt = ev.fmtdata = NULL;
669 		ev.fmtdatalen = 0;
670 	}
671 	if (evtr_dump_event(evtr, &ev)) {
672 		err(1, evtr_errmsg(evtr));
673 	}
674 	if (ev.fmtdata && conv) {
675 		mangle_string_ptrs(ev.fmt, __DECONST(uint8_t *, ev.fmtdata),
676 				   !0);
677 	}
678 }
679 
680 static
681 struct ktr_info *
682 kvm_ktrinfo(void *kptr, struct save_ctx *ctx)
683 {
684 	struct ktr_info *ki = (void *)ctx->save_buf;
685 
686 	if (kptr == NULL)
687 		return(NULL);
688 	if (ctx->save_kptr != kptr) {
689 		if (kvm_read(kd, (uintptr_t)kptr, ki, sizeof(*ki)) == -1) {
690 			bzero(&ki, sizeof(*ki));
691 		} else {
692 			ctx->save_kptr = kptr;
693 		}
694 	}
695 	return(ki);
696 }
697 
698 static
699 const char *
700 kvm_string(const char *kptr, struct save_ctx *ctx)
701 {
702 	u_int l;
703 	u_int n;
704 
705 	if (kptr == NULL)
706 		return("?");
707 	if (ctx->save_kptr != (const void *)kptr) {
708 		ctx->save_kptr = (const void *)kptr;
709 		l = 0;
710 		while (l < sizeof(ctx->save_buf) - 1) {
711 			n = 256 - ((intptr_t)(kptr + l) & 255);
712 			if (n > sizeof(ctx->save_buf) - l - 1)
713 				n = sizeof(ctx->save_buf) - l - 1;
714 			if (kvm_read(kd, (uintptr_t)(kptr + l), ctx->save_buf + l, n) < 0)
715 				break;
716 			while (l < sizeof(ctx->save_buf) && n) {
717 			    if (ctx->save_buf[l] == 0)
718 				    break;
719 			    --n;
720 			    ++l;
721 			}
722 			if (n)
723 			    break;
724 		}
725 		ctx->save_buf[l] = 0;
726 	}
727 	return(ctx->save_buf);
728 }
729 
730 static
731 const char *
732 trunc_path(const char *str, int maxlen)
733 {
734 	int len = strlen(str);
735 
736 	if (len > maxlen)
737 		return(str + len - maxlen);
738 	else
739 		return(str);
740 }
741 
742 struct symdata {
743 	TAILQ_ENTRY(symdata) link;
744 	const char *symname;
745 	char *symaddr;
746 	char symtype;
747 };
748 
749 static TAILQ_HEAD(symlist, symdata) symlist;
750 static struct symdata *symcache;
751 static char *symbegin;
752 static char *symend;
753 
754 static
755 void
756 read_symbols(const char *file)
757 {
758 	char buf[256];
759 	char cmd[256];
760 	size_t buflen = sizeof(buf);
761 	FILE *fp;
762 	struct symdata *sym;
763 	char *s1;
764 	char *s2;
765 	char *s3;
766 
767 	TAILQ_INIT(&symlist);
768 
769 	if (file == NULL) {
770 		if (sysctlbyname("kern.bootfile", buf, &buflen, NULL, 0) < 0)
771 			file = "/boot/kernel";
772 		else
773 			file = buf;
774 	}
775 	snprintf(cmd, sizeof(cmd), "nm -n %s", file);
776 	if ((fp = popen(cmd, "r")) != NULL) {
777 		while (fgets(buf, sizeof(buf), fp) != NULL) {
778 		    s1 = strtok(buf, " \t\n");
779 		    s2 = strtok(NULL, " \t\n");
780 		    s3 = strtok(NULL, " \t\n");
781 		    if (s1 && s2 && s3) {
782 			sym = malloc(sizeof(struct symdata));
783 			sym->symaddr = (char *)strtoul(s1, NULL, 16);
784 			sym->symtype = s2[0];
785 			sym->symname = strdup(s3);
786 			if (strcmp(s3, "kernbase") == 0)
787 				symbegin = sym->symaddr;
788 			if (strcmp(s3, "end") == 0)
789 				symend = sym->symaddr;
790 			TAILQ_INSERT_TAIL(&symlist, sym, link);
791 		    }
792 		}
793 		pclose(fp);
794 	}
795 	symcache = TAILQ_FIRST(&symlist);
796 }
797 
798 static
799 const char *
800 address_to_symbol(void *kptr, struct save_ctx *ctx)
801 {
802 	char *buf = ctx->save_buf;
803 	int size = sizeof(ctx->save_buf);
804 
805 	if (symcache == NULL ||
806 	   (char *)kptr < symbegin || (char *)kptr >= symend
807 	) {
808 		snprintf(buf, size, "%p", kptr);
809 		return(buf);
810 	}
811 	while ((char *)symcache->symaddr < (char *)kptr) {
812 		if (TAILQ_NEXT(symcache, link) == NULL)
813 			break;
814 		symcache = TAILQ_NEXT(symcache, link);
815 	}
816 	while ((char *)symcache->symaddr > (char *)kptr) {
817 		if (symcache != TAILQ_FIRST(&symlist))
818 			symcache = TAILQ_PREV(symcache, symlist, link);
819 	}
820 	snprintf(buf, size, "%s+%d", symcache->symname,
821 		(int)((char *)kptr - symcache->symaddr));
822 	return(buf);
823 }
824 
825 static
826 struct ktr_buffer *
827 ktr_bufs_init(void)
828 {
829 	struct ktr_buffer *ktr_bufs, *it;
830 	int i;
831 
832 	ktr_bufs = malloc(sizeof(*ktr_bufs) * ncpus);
833 	if (!ktr_bufs)
834 		err(1, "can't allocate data structures\n");
835 	for (i = 0; i < ncpus; ++i) {
836 		it = ktr_bufs + i;
837 		it->ents = malloc(sizeof(struct ktr_entry) * entries_per_buf);
838 		if (it->ents == NULL)
839 			err(1, "can't allocate data structures\n");
840 		it->reset = 1;
841 		it->beg_idx = -1;
842 		it->end_idx = -1;
843 	}
844 	return ktr_bufs;
845 }
846 
847 static
848 void
849 get_indices(struct ktr_entry **ktr_kbuf, int *ktr_idx)
850 {
851 	static struct ktr_cpu *ktr_cpus;
852 	int i;
853 
854 	if (ktr_cpus == NULL)
855 		ktr_cpus = malloc(sizeof(*ktr_cpus) * ncpus);
856 
857 	if (ktr_version < KTR_VERSION_KTR_CPU) {
858 		if (kvm_read(kd, nl_version_ktr_idx[0].n_value, ktr_idx,
859 		    sizeof(*ktr_idx) * ncpus) == -1) {
860 			errx(1, "%s", kvm_geterr(kd));
861 		}
862 		if (ktr_kbuf[0] == NULL) {
863 			if (kvm_read(kd, nl_version_ktr_idx[1].n_value,
864 			    ktr_kbuf, sizeof(*ktr_kbuf) * ncpus) == -1) {
865 				errx(1, "%s", kvm_geterr(kd));
866 			}
867 		}
868 	} else {
869 		if (kvm_read(kd, nl_version_ktr_cpu[0].n_value,
870 			     ktr_cpus, sizeof(*ktr_cpus) * ncpus) == -1) {
871 				errx(1, "%s", kvm_geterr(kd));
872 		}
873 		for (i = 0; i < ncpus; ++i) {
874 			ktr_idx[i] = ktr_cpus[i].core.ktr_idx;
875 			ktr_kbuf[i] = ktr_cpus[i].core.ktr_buf;
876 		}
877 	}
878 }
879 
880 /*
881  * Get the trace buffer data from the kernel
882  */
883 static
884 void
885 load_bufs(struct ktr_buffer *ktr_bufs, struct ktr_entry **kbufs, int *ktr_idx)
886 {
887 	struct ktr_buffer *kbuf;
888 	int i;
889 
890 	get_indices(kbufs, ktr_idx);
891 	for (i = 0; i < ncpus; ++i) {
892 		kbuf = &ktr_bufs[i];
893 		if (ktr_idx[i] == kbuf->end_idx)
894 			continue;
895 		kbuf->end_idx = ktr_idx[i];
896 
897 		/*
898 		 * If we do not have a notion of the beginning index, assume
899 		 * it is entries_per_buf before the ending index.  Don't
900 		 * worry about underflows/negative numbers, the indices will
901 		 * be masked.
902 		 */
903 		if (kbuf->reset) {
904 			kbuf->beg_idx = kbuf->end_idx - entries_per_buf + 1;
905 			kbuf->reset = 0;
906 		}
907 		if (kvm_read(kd, (uintptr_t)kbufs[i], ktr_bufs[i].ents,
908 				sizeof(struct ktr_entry) * entries_per_buf)
909 									== -1)
910 			errx(1, "%s", kvm_geterr(kd));
911 		kbuf->modified = 1;
912 		kbuf->beg_idx = earliest_ts(kbuf);
913 	}
914 
915 }
916 
917 /*
918  * Locate the earliest timestamp iterating backwards from end_idx, but
919  * not going further back then beg_idx.  We have to do this because
920  * the kernel uses a circulating buffer.
921  */
922 static
923 int
924 earliest_ts(struct ktr_buffer *buf)
925 {
926 	struct ktr_entry *save;
927 	int count, scan, i, earliest;
928 
929 	count = 0;
930 	earliest = buf->end_idx - 1;
931 	save = &buf->ents[earliest & fifo_mask];
932 	for (scan = buf->end_idx - 1; scan != buf->beg_idx -1; --scan) {
933 		i = scan & fifo_mask;
934 		if (buf->ents[i].ktr_timestamp <= save->ktr_timestamp &&
935 		    buf->ents[i].ktr_timestamp > 0)
936 			earliest = scan;
937 		/*
938 		 * We may have gotten so far behind that beg_idx wrapped
939 		 * more then once around the buffer.  Just stop
940 		 */
941 		if (++count == entries_per_buf)
942 			break;
943 	}
944 	return earliest;
945 }
946 
947 static
948 void
949 iterate_buf(FILE *fo, struct ktr_buffer *ktr_bufs, int cpu,
950 	    u_int64_t *last_timestamp, ktr_iter_cb_t cb)
951 {
952 	struct ktr_buffer *buf = ktr_bufs + cpu;
953 
954 	if (buf->modified == 0)
955 		return;
956 	if (*last_timestamp == 0) {
957 		*last_timestamp =
958 			buf->ents[buf->beg_idx & fifo_mask].ktr_timestamp;
959 	}
960 	while (buf->beg_idx != buf->end_idx) {
961 		cb(fo, cpu, buf->beg_idx,
962 		   &buf->ents[buf->beg_idx & fifo_mask],
963 		   last_timestamp);
964 		++buf->beg_idx;
965 	}
966 	buf->modified = 0;
967 }
968 
969 static
970 void
971 iterate_bufs_timesorted(FILE *fo, struct ktr_buffer *ktr_bufs,
972 			u_int64_t *last_timestamp, ktr_iter_cb_t cb)
973 {
974 	struct ktr_entry *ent;
975 	struct ktr_buffer *buf;
976 	int n, bestn;
977 	u_int64_t ts;
978 	static int row = 0;
979 
980 	for (;;) {
981 		ts = 0;
982 		bestn = -1;
983 		for (n = 0; n < ncpus; ++n) {
984 			buf = ktr_bufs + n;
985 			if (buf->beg_idx == buf->end_idx)
986 				continue;
987 			ent = &buf->ents[buf->beg_idx & fifo_mask];
988 			if (ts == 0 || (ts >= ent->ktr_timestamp)) {
989 				ts = ent->ktr_timestamp;
990 				bestn = n;
991 			}
992 		}
993 		if ((bestn < 0) || (ts < *last_timestamp))
994 			break;
995 		buf = ktr_bufs + bestn;
996 		cb(fo, bestn, row,
997 		   &buf->ents[buf->beg_idx & fifo_mask],
998 		   last_timestamp);
999 		++buf->beg_idx;
1000 		*last_timestamp = ts;
1001 		++row;
1002 	}
1003 }
1004 
1005 static
1006 void
1007 kvmfprintf(FILE *fp, const char *ctl, va_list va)
1008 {
1009 	int n;
1010 	int is_long;
1011 	int is_done;
1012 	char fmt[256];
1013 	static struct save_ctx strctx;
1014 	const char *s;
1015 
1016 	while (*ctl) {
1017 		for (n = 0; ctl[n]; ++n) {
1018 			fmt[n] = ctl[n];
1019 			if (ctl[n] == '%')
1020 				break;
1021 		}
1022 		if (n == 0) {
1023 			is_long = 0;
1024 			is_done = 0;
1025 			n = 1;
1026 			while (n < (int)sizeof(fmt)) {
1027 				fmt[n] = ctl[n];
1028 				fmt[n+1] = 0;
1029 
1030 				switch(ctl[n]) {
1031 				case 'p':
1032 					is_long = 1;
1033 					/* fall through */
1034 				case 'd':
1035 				case 'u':
1036 				case 'x':
1037 				case 'o':
1038 				case 'X':
1039 					/*
1040 					 * Integral
1041 					 */
1042 					switch(is_long) {
1043 					case 0:
1044 						fprintf(fp, fmt,
1045 							va_arg(va, int));
1046 						break;
1047 					case 1:
1048 						fprintf(fp, fmt,
1049 							va_arg(va, long));
1050 						break;
1051 					case 2:
1052 						fprintf(fp, fmt,
1053 						    va_arg(va, long long));
1054 						break;
1055 					case 3:
1056 						fprintf(fp, fmt,
1057 						    va_arg(va, size_t));
1058 						break;
1059 					}
1060 					++n;
1061 					is_done = 1;
1062 					break;
1063 				case 'c':
1064 				        fprintf(fp, "%c", va_arg(va, int));
1065 					++n;
1066 					is_done = 1;
1067 					break;
1068 				case 's':
1069 					/*
1070 					 * String
1071 					 */
1072 					s = kvm_string(va_arg(va, char *), &strctx);
1073 					fwrite(s, 1, strlen(s), fp);
1074 					++n;
1075 					is_done = 1;
1076 					break;
1077 				case 'f':
1078 					/*
1079 					 * Floating
1080 					 */
1081 					fprintf(fp, fmt,
1082 						va_arg(va, double));
1083 					++n;
1084 					break;
1085 				case 'j':
1086 					is_long = 2;
1087 					break;
1088 				case 'z':
1089 					is_long = 3;
1090 					break;
1091 				case 'l':
1092 					if (is_long)
1093 						is_long = 2;
1094 					else
1095 						is_long = 1;
1096 					break;
1097 				case '.':
1098 				case '-':
1099 				case '+':
1100 				case '0':
1101 				case '1':
1102 				case '2':
1103 				case '3':
1104 				case '4':
1105 				case '5':
1106 				case '6':
1107 				case '7':
1108 				case '8':
1109 				case '9':
1110 					break;
1111 				default:
1112 					is_done = 1;
1113 					break;
1114 				}
1115 				if (is_done)
1116 					break;
1117 				++n;
1118 			}
1119 		} else {
1120 			fmt[n] = 0;
1121 			fprintf(fp, fmt, NULL);
1122 		}
1123 		ctl += n;
1124 	}
1125 }
1126 
1127 static void
1128 usage(void)
1129 {
1130 	fprintf(stderr, "usage: ktrdump [-acfilnpqrstx] [-A factor] "
1131 			"[-N execfile] [-M corefile] [-o outfile]\n");
1132 	exit(1);
1133 }
1134 
1135 enum argument_class {
1136 	ARGCLASS_NONE,
1137 	ARGCLASS_INTEGER,
1138 	ARGCLASS_FP,
1139 	ARGCLASS_MEMORY,
1140 	ARGCLASS_ERR,
1141 };
1142 static size_t
1143 conversion_size(const char *fmt, enum argument_class *argclass)
1144 {
1145 	const char *p;
1146 	size_t convsize, intsz;
1147 
1148 	*argclass = ARGCLASS_ERR;
1149 	if (fmt[0] != '%')
1150 		return -1;
1151 
1152 	convsize = -1;
1153 	for (p = fmt + 1; p[0]; ++p) {
1154 		int again = 0;
1155 		/*
1156 		 * Eat flags. Notice this will accept duplicate
1157 		 * flags.
1158 		 */
1159 		switch (p[0]) {
1160 		case '#':
1161 		case '0':
1162 		case '-':
1163 		case ' ':
1164 		case '+':
1165 		case '\'':
1166 			again = !0;
1167 			break;
1168 		}
1169 		if (!again)
1170 			break;
1171 	}
1172 	/* Eat minimum field width, if any */
1173 	for (; isdigit(p[0]); ++p)
1174 			;
1175 	if (p[0] == '.')
1176 		++p;
1177 	/* Eat precision, if any */
1178 	for (; isdigit(p[0]); ++p)
1179 		;
1180 	intsz = 0;
1181 	switch (p[0]) {
1182 	case 'h':
1183 		if (p[1] == 'h') {
1184 			++p;
1185 			intsz = sizeof(char);
1186 		} else {
1187 			intsz = sizeof(short);
1188 		}
1189 		break;
1190 	case 'l':
1191 		if (p[1] == 'l') {
1192 			++p;
1193 			intsz = sizeof(long long);
1194 		} else {
1195 			intsz = sizeof(long);
1196 		}
1197 		break;
1198 	case 'j':
1199 		intsz = sizeof(intmax_t);
1200 		break;
1201 	case 't':
1202 		intsz = sizeof(ptrdiff_t);
1203 		break;
1204 	case 'z':
1205 		intsz = sizeof(size_t);
1206 		break;
1207 	default:
1208 		p--;	/* Anticipate the ++p that follows. Yes, I know. Eeek. */
1209 		break;
1210 	}
1211 	if (intsz == 0)
1212 		intsz = sizeof(int);
1213 	++p;
1214 
1215 	switch (p[0]) {
1216 	case 'c':
1217 		/* for %c, we only store 1 byte in the ktr entry */
1218 		convsize = sizeof(char);
1219 		*argclass = ARGCLASS_INTEGER;
1220 		break;
1221 	case 'd':
1222 	case 'i':
1223 	case 'o':
1224 	case 'u':
1225 	case 'x':
1226 	case 'X':
1227 		convsize = intsz;
1228 		*argclass = ARGCLASS_INTEGER;
1229 		break;
1230 	case 'p':
1231 		convsize = sizeof(void *);
1232 		*argclass = ARGCLASS_INTEGER;
1233 		break;
1234 	case 'f':
1235 		if (p[-1] == 'l')
1236 			convsize = sizeof(double);
1237 		else
1238 			convsize = sizeof(float);
1239 		break;
1240 		*argclass = ARGCLASS_FP;
1241 	case 's':
1242 		convsize = sizeof(char *);
1243 		*argclass = ARGCLASS_INTEGER;
1244 		break;
1245 	case '%':
1246 		convsize = 0;
1247 		*argclass = ARGCLASS_NONE;
1248 		break;
1249 	default:
1250 		fprintf(stderr, "Unknown conversion specifier %c "
1251 			"in fmt starting with %s", p[0], fmt - 1);
1252 		return -2;
1253 	}
1254 	return convsize;
1255 }
1256 
1257 #ifdef __x86_64__
1258 static int
1259 va_list_push_integral(struct my_va_list *valist, void *val, size_t valsize,
1260 		     size_t *stacksize)
1261 {
1262 	uint64_t r;
1263 
1264 	switch (valsize) {
1265 	case 1:
1266 		r = *(uint8_t *)val; break;
1267 	case 2:
1268 		r = *(uint32_t *)val; break;
1269 	case 4:
1270 		r = (*(uint32_t *)val); break;
1271 	case 8:
1272 		r = *(uint64_t *)val; break;
1273 	default:
1274 		err(1, "WTF\n");
1275 	}
1276 	/* we always need to push the full 8 bytes */
1277 	if ((valist->gp_offset + valsize) <= 48) {	/* got a free reg */
1278 
1279 		memcpy(((char *)valist->reg_save_area + valist->gp_offset),
1280 		       &r, sizeof(r));
1281 		valist->gp_offset += sizeof(r);
1282 		return 0;
1283 	}
1284 	/* push to "stack" */
1285 	if (!(valist->overflow_arg_area = realloc(valist->overflow_arg_area,
1286 						  *stacksize + sizeof(r))))
1287 		return -1;
1288 	/*
1289 	 * Keep a pointer to the start of the allocated memory block so
1290 	 * we can free it later. We need to update it after every realloc().
1291 	 */
1292 	valist->overflow_arg_area_save = valist->overflow_arg_area;
1293 	memcpy((char *)valist->overflow_arg_area + *stacksize, &r, sizeof(r));
1294 	*stacksize += sizeof(r);
1295 	return 0;
1296 }
1297 
1298 static void
1299 va_list_rewind(struct my_va_list *valist)
1300 {
1301 	valist->gp_offset = 0;
1302 }
1303 
1304 static void
1305 va_list_cleanup(machine_va_list *_valist)
1306 {
1307 	machine_va_list valist;
1308 	if (!_valist || !*_valist)
1309 		return;
1310 	valist = *_valist;
1311 	if (valist->reg_save_area)
1312 		free(valist->reg_save_area);
1313 	if (valist->overflow_arg_area_save)
1314 		free(valist->overflow_arg_area_save);
1315 	free(valist);
1316 }
1317 
1318 static int
1319 va_list_from_blob(machine_va_list *_valist, const char *fmt, char *blob, size_t blobsize)
1320 {
1321 	machine_va_list valist;
1322 	struct reg_save_area *regs;
1323 	const char *f;
1324 	size_t sz;
1325 
1326 	if (!(valist = malloc(sizeof(*valist))))
1327 		return -1;
1328 	if (!(regs = malloc(sizeof(*regs))))
1329 		goto free_valist;
1330 	*valist = (struct my_va_list) {
1331 		.gp_offset = 0,
1332 		.fp_offset = 0,
1333 		.overflow_arg_area = NULL,
1334 		.reg_save_area = regs,
1335 		.overflow_arg_area_save = NULL,
1336 	};
1337 	enum argument_class argclass;
1338 	size_t stacksize = 0;
1339 
1340 	for (f = fmt; *f != '\0'; ++f) {
1341 		if (*f != '%')
1342 			continue;
1343 		sz = conversion_size(f, &argclass);
1344 		if (argclass == ARGCLASS_INTEGER) {
1345 			if (blobsize < sz) {
1346 				fprintf(stderr, "not enough data available "
1347 					"for format: %s", fmt);
1348 				goto free_areas;
1349 			}
1350 			if (va_list_push_integral(valist, blob, sz, &stacksize))
1351 				goto free_areas;
1352 			blob += sz;
1353 			blobsize -= sz;
1354 		} else if (argclass != ARGCLASS_NONE)
1355 			goto free_areas;
1356 		/* walk past the '%' */
1357 		++f;
1358 	}
1359 	if (blobsize) {
1360 		fprintf(stderr, "Couldn't consume all data for format %s "
1361 			"(%zd bytes left over)\n", fmt, blobsize);
1362 		goto free_areas;
1363 	}
1364 	va_list_rewind(valist);
1365 	*_valist = valist;
1366 	return 0;
1367 free_areas:
1368 	if (valist->reg_save_area)
1369 		free(valist->reg_save_area);
1370 	if (valist->overflow_arg_area_save)
1371 		free(valist->overflow_arg_area_save);
1372 free_valist:
1373 	free(valist);
1374 	*_valist = NULL;
1375 	return -1;
1376 }
1377 #elif __i386__
1378 
1379 static void
1380 va_list_cleanup(machine_va_list *valist)
1381 {
1382 	if (*valist)
1383 		free(*valist);
1384 }
1385 
1386 static int
1387 va_list_from_blob(machine_va_list *valist, const char *fmt, char *blob, size_t blobsize)
1388 {
1389 	const char *f;
1390 	char *n;
1391 	size_t bytes, sz;
1392 	enum argument_class argclass;
1393 
1394 	n = NULL;
1395 	bytes = 0;
1396 	for (f = fmt; *f != '\0'; ++f) {
1397 		if (*f != '%')
1398 			continue;
1399 		sz = conversion_size(f, &argclass);
1400 		if (blobsize < sz) {
1401 			fprintf(stderr, "not enough data available "
1402 				"for format: %s", fmt);
1403 			goto free_va;
1404 		}
1405 		if ((argclass == ARGCLASS_INTEGER) && (sz < 4)) {
1406 			int i = -1;	/* do C integer promotion */
1407 			if (sz == 1)
1408 				i = *(char *)blob;
1409 			else
1410 				i = *(short *)blob;
1411 			if (!(n = realloc(n, bytes + 4)))
1412 				goto free_va;
1413 			memcpy(n + bytes, &i, sizeof(i));
1414 			bytes += 4;
1415 		} else {
1416 			if (!(n = realloc(n, bytes + sz)))
1417 				goto free_va;
1418 			memcpy(n + bytes, blob, sz);
1419 			bytes += sz;
1420 		}
1421 		blob += sz;
1422 		blobsize -= sz;
1423 
1424 	}
1425 	if (blobsize) {
1426 		fprintf(stderr, "Couldn't consume all data for format %s "
1427 			"(%zd bytes left over)\n", fmt, blobsize);
1428 		goto free_va;
1429 	}
1430 	*valist = n;
1431 	return 0;
1432 free_va:
1433 	if (n)
1434 		free(n);
1435 	*valist = NULL;
1436 	return -1;
1437 }
1438 
1439 #else
1440 #error "Don't know how to get a va_list on this platform"
1441 #endif
1442