Loading...
1// SPDX-License-Identifier: GPL-2.0
2#include <errno.h>
3#include <linux/kernel.h>
4#include <linux/types.h>
5#include <inttypes.h>
6#include <stdlib.h>
7#include <unistd.h>
8#include <stdio.h>
9#include <string.h>
10#include <sys/param.h>
11#include <perf/cpumap.h>
12#include <perf/evlist.h>
13
14#include "debug.h"
15#include "dso.h"
16#include "env.h"
17#include "parse-events.h"
18#include "trace-event.h"
19#include "evlist.h"
20#include "evsel.h"
21#include "thread_map.h"
22#include "machine.h"
23#include "map.h"
24#include "symbol.h"
25#include "event.h"
26#include "record.h"
27#include "util/mmap.h"
28#include "util/synthetic-events.h"
29#include "thread.h"
30
31#include "tests.h"
32
33#include <linux/ctype.h>
34
35#define BUFSZ 1024
36#define READLEN 128
37
38struct state {
39 u64 done[1024];
40 size_t done_cnt;
41};
42
43static unsigned int hex(char c)
44{
45 if (c >= '0' && c <= '9')
46 return c - '0';
47 if (c >= 'a' && c <= 'f')
48 return c - 'a' + 10;
49 return c - 'A' + 10;
50}
51
52static size_t read_objdump_chunk(const char **line, unsigned char **buf,
53 size_t *buf_len)
54{
55 size_t bytes_read = 0;
56 unsigned char *chunk_start = *buf;
57
58 /* Read bytes */
59 while (*buf_len > 0) {
60 char c1, c2;
61
62 /* Get 2 hex digits */
63 c1 = *(*line)++;
64 if (!isxdigit(c1))
65 break;
66 c2 = *(*line)++;
67 if (!isxdigit(c2))
68 break;
69
70 /* Store byte and advance buf */
71 **buf = (hex(c1) << 4) | hex(c2);
72 (*buf)++;
73 (*buf_len)--;
74 bytes_read++;
75
76 /* End of chunk? */
77 if (isspace(**line))
78 break;
79 }
80
81 /*
82 * objdump will display raw insn as LE if code endian
83 * is LE and bytes_per_chunk > 1. In that case reverse
84 * the chunk we just read.
85 *
86 * see disassemble_bytes() at binutils/objdump.c for details
87 * how objdump chooses display endian)
88 */
89 if (bytes_read > 1 && !bigendian()) {
90 unsigned char *chunk_end = chunk_start + bytes_read - 1;
91 unsigned char tmp;
92
93 while (chunk_start < chunk_end) {
94 tmp = *chunk_start;
95 *chunk_start = *chunk_end;
96 *chunk_end = tmp;
97 chunk_start++;
98 chunk_end--;
99 }
100 }
101
102 return bytes_read;
103}
104
105static size_t read_objdump_line(const char *line, unsigned char *buf,
106 size_t buf_len)
107{
108 const char *p;
109 size_t ret, bytes_read = 0;
110
111 /* Skip to a colon */
112 p = strchr(line, ':');
113 if (!p)
114 return 0;
115 p++;
116
117 /* Skip initial spaces */
118 while (*p) {
119 if (!isspace(*p))
120 break;
121 p++;
122 }
123
124 do {
125 ret = read_objdump_chunk(&p, &buf, &buf_len);
126 bytes_read += ret;
127 p++;
128 } while (ret > 0);
129
130 /* return number of successfully read bytes */
131 return bytes_read;
132}
133
134static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr)
135{
136 char *line = NULL;
137 size_t line_len, off_last = 0;
138 ssize_t ret;
139 int err = 0;
140 u64 addr, last_addr = start_addr;
141
142 while (off_last < *len) {
143 size_t off, read_bytes, written_bytes;
144 unsigned char tmp[BUFSZ];
145
146 ret = getline(&line, &line_len, f);
147 if (feof(f))
148 break;
149 if (ret < 0) {
150 pr_debug("getline failed\n");
151 err = -1;
152 break;
153 }
154
155 /* read objdump data into temporary buffer */
156 read_bytes = read_objdump_line(line, tmp, sizeof(tmp));
157 if (!read_bytes)
158 continue;
159
160 if (sscanf(line, "%"PRIx64, &addr) != 1)
161 continue;
162 if (addr < last_addr) {
163 pr_debug("addr going backwards, read beyond section?\n");
164 break;
165 }
166 last_addr = addr;
167
168 /* copy it from temporary buffer to 'buf' according
169 * to address on current objdump line */
170 off = addr - start_addr;
171 if (off >= *len)
172 break;
173 written_bytes = MIN(read_bytes, *len - off);
174 memcpy(buf + off, tmp, written_bytes);
175 off_last = off + written_bytes;
176 }
177
178 /* len returns number of bytes that could not be read */
179 *len -= off_last;
180
181 free(line);
182
183 return err;
184}
185
186static int read_via_objdump(const char *filename, u64 addr, void *buf,
187 size_t len)
188{
189 char cmd[PATH_MAX * 2];
190 const char *fmt;
191 FILE *f;
192 int ret;
193
194 fmt = "%s -z -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s";
195 ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len,
196 filename);
197 if (ret <= 0 || (size_t)ret >= sizeof(cmd))
198 return -1;
199
200 pr_debug("Objdump command is: %s\n", cmd);
201
202 /* Ignore objdump errors */
203 strcat(cmd, " 2>/dev/null");
204
205 f = popen(cmd, "r");
206 if (!f) {
207 pr_debug("popen failed\n");
208 return -1;
209 }
210
211 ret = read_objdump_output(f, buf, &len, addr);
212 if (len) {
213 pr_debug("objdump read too few bytes: %zd\n", len);
214 if (!ret)
215 ret = len;
216 }
217
218 pclose(f);
219
220 return ret;
221}
222
223static void dump_buf(unsigned char *buf, size_t len)
224{
225 size_t i;
226
227 for (i = 0; i < len; i++) {
228 pr_debug("0x%02x ", buf[i]);
229 if (i % 16 == 15)
230 pr_debug("\n");
231 }
232 pr_debug("\n");
233}
234
235static int read_object_code(u64 addr, size_t len, u8 cpumode,
236 struct thread *thread, struct state *state)
237{
238 struct addr_location al;
239 unsigned char buf1[BUFSZ];
240 unsigned char buf2[BUFSZ];
241 size_t ret_len;
242 u64 objdump_addr;
243 const char *objdump_name;
244 char decomp_name[KMOD_DECOMP_LEN];
245 bool decomp = false;
246 int ret;
247
248 pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
249
250 if (!thread__find_map(thread, cpumode, addr, &al) || !al.map->dso) {
251 if (cpumode == PERF_RECORD_MISC_HYPERVISOR) {
252 pr_debug("Hypervisor address can not be resolved - skipping\n");
253 return 0;
254 }
255
256 pr_debug("thread__find_map failed\n");
257 return -1;
258 }
259
260 pr_debug("File is: %s\n", al.map->dso->long_name);
261
262 if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
263 !dso__is_kcore(al.map->dso)) {
264 pr_debug("Unexpected kernel address - skipping\n");
265 return 0;
266 }
267
268 pr_debug("On file address is: %#"PRIx64"\n", al.addr);
269
270 if (len > BUFSZ)
271 len = BUFSZ;
272
273 /* Do not go off the map */
274 if (addr + len > al.map->end)
275 len = al.map->end - addr;
276
277 /* Read the object code using perf */
278 ret_len = dso__data_read_offset(al.map->dso, thread->mg->machine,
279 al.addr, buf1, len);
280 if (ret_len != len) {
281 pr_debug("dso__data_read_offset failed\n");
282 return -1;
283 }
284
285 /*
286 * Converting addresses for use by objdump requires more information.
287 * map__load() does that. See map__rip_2objdump() for details.
288 */
289 if (map__load(al.map))
290 return -1;
291
292 /* objdump struggles with kcore - try each map only once */
293 if (dso__is_kcore(al.map->dso)) {
294 size_t d;
295
296 for (d = 0; d < state->done_cnt; d++) {
297 if (state->done[d] == al.map->start) {
298 pr_debug("kcore map tested already");
299 pr_debug(" - skipping\n");
300 return 0;
301 }
302 }
303 if (state->done_cnt >= ARRAY_SIZE(state->done)) {
304 pr_debug("Too many kcore maps - skipping\n");
305 return 0;
306 }
307 state->done[state->done_cnt++] = al.map->start;
308 }
309
310 objdump_name = al.map->dso->long_name;
311 if (dso__needs_decompress(al.map->dso)) {
312 if (dso__decompress_kmodule_path(al.map->dso, objdump_name,
313 decomp_name,
314 sizeof(decomp_name)) < 0) {
315 pr_debug("decompression failed\n");
316 return -1;
317 }
318
319 decomp = true;
320 objdump_name = decomp_name;
321 }
322
323 /* Read the object code using objdump */
324 objdump_addr = map__rip_2objdump(al.map, al.addr);
325 ret = read_via_objdump(objdump_name, objdump_addr, buf2, len);
326
327 if (decomp)
328 unlink(objdump_name);
329
330 if (ret > 0) {
331 /*
332 * The kernel maps are inaccurate - assume objdump is right in
333 * that case.
334 */
335 if (cpumode == PERF_RECORD_MISC_KERNEL ||
336 cpumode == PERF_RECORD_MISC_GUEST_KERNEL) {
337 len -= ret;
338 if (len) {
339 pr_debug("Reducing len to %zu\n", len);
340 } else if (dso__is_kcore(al.map->dso)) {
341 /*
342 * objdump cannot handle very large segments
343 * that may be found in kcore.
344 */
345 pr_debug("objdump failed for kcore");
346 pr_debug(" - skipping\n");
347 return 0;
348 } else {
349 return -1;
350 }
351 }
352 }
353 if (ret < 0) {
354 pr_debug("read_via_objdump failed\n");
355 return -1;
356 }
357
358 /* The results should be identical */
359 if (memcmp(buf1, buf2, len)) {
360 pr_debug("Bytes read differ from those read by objdump\n");
361 pr_debug("buf1 (dso):\n");
362 dump_buf(buf1, len);
363 pr_debug("buf2 (objdump):\n");
364 dump_buf(buf2, len);
365 return -1;
366 }
367 pr_debug("Bytes read match those read by objdump\n");
368
369 return 0;
370}
371
372static int process_sample_event(struct machine *machine,
373 struct evlist *evlist,
374 union perf_event *event, struct state *state)
375{
376 struct perf_sample sample;
377 struct thread *thread;
378 int ret;
379
380 if (perf_evlist__parse_sample(evlist, event, &sample)) {
381 pr_debug("perf_evlist__parse_sample failed\n");
382 return -1;
383 }
384
385 thread = machine__findnew_thread(machine, sample.pid, sample.tid);
386 if (!thread) {
387 pr_debug("machine__findnew_thread failed\n");
388 return -1;
389 }
390
391 ret = read_object_code(sample.ip, READLEN, sample.cpumode, thread, state);
392 thread__put(thread);
393 return ret;
394}
395
396static int process_event(struct machine *machine, struct evlist *evlist,
397 union perf_event *event, struct state *state)
398{
399 if (event->header.type == PERF_RECORD_SAMPLE)
400 return process_sample_event(machine, evlist, event, state);
401
402 if (event->header.type == PERF_RECORD_THROTTLE ||
403 event->header.type == PERF_RECORD_UNTHROTTLE)
404 return 0;
405
406 if (event->header.type < PERF_RECORD_MAX) {
407 int ret;
408
409 ret = machine__process_event(machine, event, NULL);
410 if (ret < 0)
411 pr_debug("machine__process_event failed, event type %u\n",
412 event->header.type);
413 return ret;
414 }
415
416 return 0;
417}
418
419static int process_events(struct machine *machine, struct evlist *evlist,
420 struct state *state)
421{
422 union perf_event *event;
423 struct mmap *md;
424 int i, ret;
425
426 for (i = 0; i < evlist->core.nr_mmaps; i++) {
427 md = &evlist->mmap[i];
428 if (perf_mmap__read_init(md) < 0)
429 continue;
430
431 while ((event = perf_mmap__read_event(md)) != NULL) {
432 ret = process_event(machine, evlist, event, state);
433 perf_mmap__consume(md);
434 if (ret < 0)
435 return ret;
436 }
437 perf_mmap__read_done(md);
438 }
439 return 0;
440}
441
442static int comp(const void *a, const void *b)
443{
444 return *(int *)a - *(int *)b;
445}
446
447static void do_sort_something(void)
448{
449 int buf[40960], i;
450
451 for (i = 0; i < (int)ARRAY_SIZE(buf); i++)
452 buf[i] = ARRAY_SIZE(buf) - i - 1;
453
454 qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp);
455
456 for (i = 0; i < (int)ARRAY_SIZE(buf); i++) {
457 if (buf[i] != i) {
458 pr_debug("qsort failed\n");
459 break;
460 }
461 }
462}
463
464static void sort_something(void)
465{
466 int i;
467
468 for (i = 0; i < 10; i++)
469 do_sort_something();
470}
471
472static void syscall_something(void)
473{
474 int pipefd[2];
475 int i;
476
477 for (i = 0; i < 1000; i++) {
478 if (pipe(pipefd) < 0) {
479 pr_debug("pipe failed\n");
480 break;
481 }
482 close(pipefd[1]);
483 close(pipefd[0]);
484 }
485}
486
487static void fs_something(void)
488{
489 const char *test_file_name = "temp-perf-code-reading-test-file--";
490 FILE *f;
491 int i;
492
493 for (i = 0; i < 1000; i++) {
494 f = fopen(test_file_name, "w+");
495 if (f) {
496 fclose(f);
497 unlink(test_file_name);
498 }
499 }
500}
501
502#ifdef __s390x__
503#include "header.h" // for get_cpuid()
504#endif
505
506static const char *do_determine_event(bool excl_kernel)
507{
508 const char *event = excl_kernel ? "cycles:u" : "cycles";
509
510#ifdef __s390x__
511 char cpuid[128], model[16], model_c[16], cpum_cf_v[16];
512 unsigned int family;
513 int ret, cpum_cf_a;
514
515 if (get_cpuid(cpuid, sizeof(cpuid)))
516 goto out_clocks;
517 ret = sscanf(cpuid, "%*[^,],%u,%[^,],%[^,],%[^,],%x", &family, model_c,
518 model, cpum_cf_v, &cpum_cf_a);
519 if (ret != 5) /* Not available */
520 goto out_clocks;
521 if (excl_kernel && (cpum_cf_a & 4))
522 return event;
523 if (!excl_kernel && (cpum_cf_a & 2))
524 return event;
525
526 /* Fall through: missing authorization */
527out_clocks:
528 event = excl_kernel ? "cpu-clock:u" : "cpu-clock";
529
530#endif
531 return event;
532}
533
534static void do_something(void)
535{
536 fs_something();
537
538 sort_something();
539
540 syscall_something();
541}
542
543enum {
544 TEST_CODE_READING_OK,
545 TEST_CODE_READING_NO_VMLINUX,
546 TEST_CODE_READING_NO_KCORE,
547 TEST_CODE_READING_NO_ACCESS,
548 TEST_CODE_READING_NO_KERNEL_OBJ,
549};
550
551static int do_test_code_reading(bool try_kcore)
552{
553 struct machine *machine;
554 struct thread *thread;
555 struct record_opts opts = {
556 .mmap_pages = UINT_MAX,
557 .user_freq = UINT_MAX,
558 .user_interval = ULLONG_MAX,
559 .freq = 500,
560 .target = {
561 .uses_mmap = true,
562 },
563 };
564 struct state state = {
565 .done_cnt = 0,
566 };
567 struct perf_thread_map *threads = NULL;
568 struct perf_cpu_map *cpus = NULL;
569 struct evlist *evlist = NULL;
570 struct evsel *evsel = NULL;
571 int err = -1, ret;
572 pid_t pid;
573 struct map *map;
574 bool have_vmlinux, have_kcore, excl_kernel = false;
575
576 pid = getpid();
577
578 machine = machine__new_host();
579 machine->env = &perf_env;
580
581 ret = machine__create_kernel_maps(machine);
582 if (ret < 0) {
583 pr_debug("machine__create_kernel_maps failed\n");
584 goto out_err;
585 }
586
587 /* Force the use of kallsyms instead of vmlinux to try kcore */
588 if (try_kcore)
589 symbol_conf.kallsyms_name = "/proc/kallsyms";
590
591 /* Load kernel map */
592 map = machine__kernel_map(machine);
593 ret = map__load(map);
594 if (ret < 0) {
595 pr_debug("map__load failed\n");
596 goto out_err;
597 }
598 have_vmlinux = dso__is_vmlinux(map->dso);
599 have_kcore = dso__is_kcore(map->dso);
600
601 /* 2nd time through we just try kcore */
602 if (try_kcore && !have_kcore)
603 return TEST_CODE_READING_NO_KCORE;
604
605 /* No point getting kernel events if there is no kernel object */
606 if (!have_vmlinux && !have_kcore)
607 excl_kernel = true;
608
609 threads = thread_map__new_by_tid(pid);
610 if (!threads) {
611 pr_debug("thread_map__new_by_tid failed\n");
612 goto out_err;
613 }
614
615 ret = perf_event__synthesize_thread_map(NULL, threads,
616 perf_event__process, machine, false);
617 if (ret < 0) {
618 pr_debug("perf_event__synthesize_thread_map failed\n");
619 goto out_err;
620 }
621
622 thread = machine__findnew_thread(machine, pid, pid);
623 if (!thread) {
624 pr_debug("machine__findnew_thread failed\n");
625 goto out_put;
626 }
627
628 cpus = perf_cpu_map__new(NULL);
629 if (!cpus) {
630 pr_debug("perf_cpu_map__new failed\n");
631 goto out_put;
632 }
633
634 while (1) {
635 const char *str;
636
637 evlist = evlist__new();
638 if (!evlist) {
639 pr_debug("perf_evlist__new failed\n");
640 goto out_put;
641 }
642
643 perf_evlist__set_maps(&evlist->core, cpus, threads);
644
645 str = do_determine_event(excl_kernel);
646 pr_debug("Parsing event '%s'\n", str);
647 ret = parse_events(evlist, str, NULL);
648 if (ret < 0) {
649 pr_debug("parse_events failed\n");
650 goto out_put;
651 }
652
653 perf_evlist__config(evlist, &opts, NULL);
654
655 evsel = evlist__first(evlist);
656
657 evsel->core.attr.comm = 1;
658 evsel->core.attr.disabled = 1;
659 evsel->core.attr.enable_on_exec = 0;
660
661 ret = evlist__open(evlist);
662 if (ret < 0) {
663 if (!excl_kernel) {
664 excl_kernel = true;
665 /*
666 * Both cpus and threads are now owned by evlist
667 * and will be freed by following perf_evlist__set_maps
668 * call. Getting refference to keep them alive.
669 */
670 perf_cpu_map__get(cpus);
671 perf_thread_map__get(threads);
672 perf_evlist__set_maps(&evlist->core, NULL, NULL);
673 evlist__delete(evlist);
674 evlist = NULL;
675 continue;
676 }
677
678 if (verbose > 0) {
679 char errbuf[512];
680 perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf));
681 pr_debug("perf_evlist__open() failed!\n%s\n", errbuf);
682 }
683
684 goto out_put;
685 }
686 break;
687 }
688
689 ret = evlist__mmap(evlist, UINT_MAX);
690 if (ret < 0) {
691 pr_debug("evlist__mmap failed\n");
692 goto out_put;
693 }
694
695 evlist__enable(evlist);
696
697 do_something();
698
699 evlist__disable(evlist);
700
701 ret = process_events(machine, evlist, &state);
702 if (ret < 0)
703 goto out_put;
704
705 if (!have_vmlinux && !have_kcore && !try_kcore)
706 err = TEST_CODE_READING_NO_KERNEL_OBJ;
707 else if (!have_vmlinux && !try_kcore)
708 err = TEST_CODE_READING_NO_VMLINUX;
709 else if (excl_kernel)
710 err = TEST_CODE_READING_NO_ACCESS;
711 else
712 err = TEST_CODE_READING_OK;
713out_put:
714 thread__put(thread);
715out_err:
716
717 if (evlist) {
718 evlist__delete(evlist);
719 } else {
720 perf_cpu_map__put(cpus);
721 perf_thread_map__put(threads);
722 }
723 machine__delete_threads(machine);
724 machine__delete(machine);
725
726 return err;
727}
728
729int test__code_reading(struct test *test __maybe_unused, int subtest __maybe_unused)
730{
731 int ret;
732
733 ret = do_test_code_reading(false);
734 if (!ret)
735 ret = do_test_code_reading(true);
736
737 switch (ret) {
738 case TEST_CODE_READING_OK:
739 return 0;
740 case TEST_CODE_READING_NO_VMLINUX:
741 pr_debug("no vmlinux\n");
742 return 0;
743 case TEST_CODE_READING_NO_KCORE:
744 pr_debug("no kcore\n");
745 return 0;
746 case TEST_CODE_READING_NO_ACCESS:
747 pr_debug("no access\n");
748 return 0;
749 case TEST_CODE_READING_NO_KERNEL_OBJ:
750 pr_debug("no kernel obj\n");
751 return 0;
752 default:
753 return -1;
754 };
755}
1#include <linux/types.h>
2#include <stdlib.h>
3#include <unistd.h>
4#include <stdio.h>
5#include <ctype.h>
6#include <string.h>
7
8#include "parse-events.h"
9#include "evlist.h"
10#include "evsel.h"
11#include "thread_map.h"
12#include "cpumap.h"
13#include "machine.h"
14#include "event.h"
15#include "thread.h"
16
17#include "tests.h"
18
19#define BUFSZ 1024
20#define READLEN 128
21
22struct state {
23 u64 done[1024];
24 size_t done_cnt;
25};
26
27static unsigned int hex(char c)
28{
29 if (c >= '0' && c <= '9')
30 return c - '0';
31 if (c >= 'a' && c <= 'f')
32 return c - 'a' + 10;
33 return c - 'A' + 10;
34}
35
36static size_t read_objdump_chunk(const char **line, unsigned char **buf,
37 size_t *buf_len)
38{
39 size_t bytes_read = 0;
40 unsigned char *chunk_start = *buf;
41
42 /* Read bytes */
43 while (*buf_len > 0) {
44 char c1, c2;
45
46 /* Get 2 hex digits */
47 c1 = *(*line)++;
48 if (!isxdigit(c1))
49 break;
50 c2 = *(*line)++;
51 if (!isxdigit(c2))
52 break;
53
54 /* Store byte and advance buf */
55 **buf = (hex(c1) << 4) | hex(c2);
56 (*buf)++;
57 (*buf_len)--;
58 bytes_read++;
59
60 /* End of chunk? */
61 if (isspace(**line))
62 break;
63 }
64
65 /*
66 * objdump will display raw insn as LE if code endian
67 * is LE and bytes_per_chunk > 1. In that case reverse
68 * the chunk we just read.
69 *
70 * see disassemble_bytes() at binutils/objdump.c for details
71 * how objdump chooses display endian)
72 */
73 if (bytes_read > 1 && !bigendian()) {
74 unsigned char *chunk_end = chunk_start + bytes_read - 1;
75 unsigned char tmp;
76
77 while (chunk_start < chunk_end) {
78 tmp = *chunk_start;
79 *chunk_start = *chunk_end;
80 *chunk_end = tmp;
81 chunk_start++;
82 chunk_end--;
83 }
84 }
85
86 return bytes_read;
87}
88
89static size_t read_objdump_line(const char *line, unsigned char *buf,
90 size_t buf_len)
91{
92 const char *p;
93 size_t ret, bytes_read = 0;
94
95 /* Skip to a colon */
96 p = strchr(line, ':');
97 if (!p)
98 return 0;
99 p++;
100
101 /* Skip initial spaces */
102 while (*p) {
103 if (!isspace(*p))
104 break;
105 p++;
106 }
107
108 do {
109 ret = read_objdump_chunk(&p, &buf, &buf_len);
110 bytes_read += ret;
111 p++;
112 } while (ret > 0);
113
114 /* return number of successfully read bytes */
115 return bytes_read;
116}
117
118static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr)
119{
120 char *line = NULL;
121 size_t line_len, off_last = 0;
122 ssize_t ret;
123 int err = 0;
124 u64 addr, last_addr = start_addr;
125
126 while (off_last < *len) {
127 size_t off, read_bytes, written_bytes;
128 unsigned char tmp[BUFSZ];
129
130 ret = getline(&line, &line_len, f);
131 if (feof(f))
132 break;
133 if (ret < 0) {
134 pr_debug("getline failed\n");
135 err = -1;
136 break;
137 }
138
139 /* read objdump data into temporary buffer */
140 read_bytes = read_objdump_line(line, tmp, sizeof(tmp));
141 if (!read_bytes)
142 continue;
143
144 if (sscanf(line, "%"PRIx64, &addr) != 1)
145 continue;
146 if (addr < last_addr) {
147 pr_debug("addr going backwards, read beyond section?\n");
148 break;
149 }
150 last_addr = addr;
151
152 /* copy it from temporary buffer to 'buf' according
153 * to address on current objdump line */
154 off = addr - start_addr;
155 if (off >= *len)
156 break;
157 written_bytes = MIN(read_bytes, *len - off);
158 memcpy(buf + off, tmp, written_bytes);
159 off_last = off + written_bytes;
160 }
161
162 /* len returns number of bytes that could not be read */
163 *len -= off_last;
164
165 free(line);
166
167 return err;
168}
169
170static int read_via_objdump(const char *filename, u64 addr, void *buf,
171 size_t len)
172{
173 char cmd[PATH_MAX * 2];
174 const char *fmt;
175 FILE *f;
176 int ret;
177
178 fmt = "%s -z -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s";
179 ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len,
180 filename);
181 if (ret <= 0 || (size_t)ret >= sizeof(cmd))
182 return -1;
183
184 pr_debug("Objdump command is: %s\n", cmd);
185
186 /* Ignore objdump errors */
187 strcat(cmd, " 2>/dev/null");
188
189 f = popen(cmd, "r");
190 if (!f) {
191 pr_debug("popen failed\n");
192 return -1;
193 }
194
195 ret = read_objdump_output(f, buf, &len, addr);
196 if (len) {
197 pr_debug("objdump read too few bytes: %zd\n", len);
198 if (!ret)
199 ret = len;
200 }
201
202 pclose(f);
203
204 return ret;
205}
206
207static void dump_buf(unsigned char *buf, size_t len)
208{
209 size_t i;
210
211 for (i = 0; i < len; i++) {
212 pr_debug("0x%02x ", buf[i]);
213 if (i % 16 == 15)
214 pr_debug("\n");
215 }
216 pr_debug("\n");
217}
218
219static int read_object_code(u64 addr, size_t len, u8 cpumode,
220 struct thread *thread, struct state *state)
221{
222 struct addr_location al;
223 unsigned char buf1[BUFSZ];
224 unsigned char buf2[BUFSZ];
225 size_t ret_len;
226 u64 objdump_addr;
227 int ret;
228
229 pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
230
231 thread__find_addr_map(thread, cpumode, MAP__FUNCTION, addr, &al);
232 if (!al.map || !al.map->dso) {
233 pr_debug("thread__find_addr_map failed\n");
234 return -1;
235 }
236
237 pr_debug("File is: %s\n", al.map->dso->long_name);
238
239 if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
240 !dso__is_kcore(al.map->dso)) {
241 pr_debug("Unexpected kernel address - skipping\n");
242 return 0;
243 }
244
245 pr_debug("On file address is: %#"PRIx64"\n", al.addr);
246
247 if (len > BUFSZ)
248 len = BUFSZ;
249
250 /* Do not go off the map */
251 if (addr + len > al.map->end)
252 len = al.map->end - addr;
253
254 /* Read the object code using perf */
255 ret_len = dso__data_read_offset(al.map->dso, thread->mg->machine,
256 al.addr, buf1, len);
257 if (ret_len != len) {
258 pr_debug("dso__data_read_offset failed\n");
259 return -1;
260 }
261
262 /*
263 * Converting addresses for use by objdump requires more information.
264 * map__load() does that. See map__rip_2objdump() for details.
265 */
266 if (map__load(al.map))
267 return -1;
268
269 /* objdump struggles with kcore - try each map only once */
270 if (dso__is_kcore(al.map->dso)) {
271 size_t d;
272
273 for (d = 0; d < state->done_cnt; d++) {
274 if (state->done[d] == al.map->start) {
275 pr_debug("kcore map tested already");
276 pr_debug(" - skipping\n");
277 return 0;
278 }
279 }
280 if (state->done_cnt >= ARRAY_SIZE(state->done)) {
281 pr_debug("Too many kcore maps - skipping\n");
282 return 0;
283 }
284 state->done[state->done_cnt++] = al.map->start;
285 }
286
287 /* Read the object code using objdump */
288 objdump_addr = map__rip_2objdump(al.map, al.addr);
289 ret = read_via_objdump(al.map->dso->long_name, objdump_addr, buf2, len);
290 if (ret > 0) {
291 /*
292 * The kernel maps are inaccurate - assume objdump is right in
293 * that case.
294 */
295 if (cpumode == PERF_RECORD_MISC_KERNEL ||
296 cpumode == PERF_RECORD_MISC_GUEST_KERNEL) {
297 len -= ret;
298 if (len) {
299 pr_debug("Reducing len to %zu\n", len);
300 } else if (dso__is_kcore(al.map->dso)) {
301 /*
302 * objdump cannot handle very large segments
303 * that may be found in kcore.
304 */
305 pr_debug("objdump failed for kcore");
306 pr_debug(" - skipping\n");
307 return 0;
308 } else {
309 return -1;
310 }
311 }
312 }
313 if (ret < 0) {
314 pr_debug("read_via_objdump failed\n");
315 return -1;
316 }
317
318 /* The results should be identical */
319 if (memcmp(buf1, buf2, len)) {
320 pr_debug("Bytes read differ from those read by objdump\n");
321 pr_debug("buf1 (dso):\n");
322 dump_buf(buf1, len);
323 pr_debug("buf2 (objdump):\n");
324 dump_buf(buf2, len);
325 return -1;
326 }
327 pr_debug("Bytes read match those read by objdump\n");
328
329 return 0;
330}
331
332static int process_sample_event(struct machine *machine,
333 struct perf_evlist *evlist,
334 union perf_event *event, struct state *state)
335{
336 struct perf_sample sample;
337 struct thread *thread;
338 int ret;
339
340 if (perf_evlist__parse_sample(evlist, event, &sample)) {
341 pr_debug("perf_evlist__parse_sample failed\n");
342 return -1;
343 }
344
345 thread = machine__findnew_thread(machine, sample.pid, sample.tid);
346 if (!thread) {
347 pr_debug("machine__findnew_thread failed\n");
348 return -1;
349 }
350
351 ret = read_object_code(sample.ip, READLEN, sample.cpumode, thread, state);
352 thread__put(thread);
353 return ret;
354}
355
356static int process_event(struct machine *machine, struct perf_evlist *evlist,
357 union perf_event *event, struct state *state)
358{
359 if (event->header.type == PERF_RECORD_SAMPLE)
360 return process_sample_event(machine, evlist, event, state);
361
362 if (event->header.type == PERF_RECORD_THROTTLE ||
363 event->header.type == PERF_RECORD_UNTHROTTLE)
364 return 0;
365
366 if (event->header.type < PERF_RECORD_MAX) {
367 int ret;
368
369 ret = machine__process_event(machine, event, NULL);
370 if (ret < 0)
371 pr_debug("machine__process_event failed, event type %u\n",
372 event->header.type);
373 return ret;
374 }
375
376 return 0;
377}
378
379static int process_events(struct machine *machine, struct perf_evlist *evlist,
380 struct state *state)
381{
382 union perf_event *event;
383 int i, ret;
384
385 for (i = 0; i < evlist->nr_mmaps; i++) {
386 while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
387 ret = process_event(machine, evlist, event, state);
388 perf_evlist__mmap_consume(evlist, i);
389 if (ret < 0)
390 return ret;
391 }
392 }
393 return 0;
394}
395
396static int comp(const void *a, const void *b)
397{
398 return *(int *)a - *(int *)b;
399}
400
401static void do_sort_something(void)
402{
403 int buf[40960], i;
404
405 for (i = 0; i < (int)ARRAY_SIZE(buf); i++)
406 buf[i] = ARRAY_SIZE(buf) - i - 1;
407
408 qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp);
409
410 for (i = 0; i < (int)ARRAY_SIZE(buf); i++) {
411 if (buf[i] != i) {
412 pr_debug("qsort failed\n");
413 break;
414 }
415 }
416}
417
418static void sort_something(void)
419{
420 int i;
421
422 for (i = 0; i < 10; i++)
423 do_sort_something();
424}
425
426static void syscall_something(void)
427{
428 int pipefd[2];
429 int i;
430
431 for (i = 0; i < 1000; i++) {
432 if (pipe(pipefd) < 0) {
433 pr_debug("pipe failed\n");
434 break;
435 }
436 close(pipefd[1]);
437 close(pipefd[0]);
438 }
439}
440
441static void fs_something(void)
442{
443 const char *test_file_name = "temp-perf-code-reading-test-file--";
444 FILE *f;
445 int i;
446
447 for (i = 0; i < 1000; i++) {
448 f = fopen(test_file_name, "w+");
449 if (f) {
450 fclose(f);
451 unlink(test_file_name);
452 }
453 }
454}
455
456static void do_something(void)
457{
458 fs_something();
459
460 sort_something();
461
462 syscall_something();
463}
464
465enum {
466 TEST_CODE_READING_OK,
467 TEST_CODE_READING_NO_VMLINUX,
468 TEST_CODE_READING_NO_KCORE,
469 TEST_CODE_READING_NO_ACCESS,
470 TEST_CODE_READING_NO_KERNEL_OBJ,
471};
472
473static int do_test_code_reading(bool try_kcore)
474{
475 struct machine *machine;
476 struct thread *thread;
477 struct record_opts opts = {
478 .mmap_pages = UINT_MAX,
479 .user_freq = UINT_MAX,
480 .user_interval = ULLONG_MAX,
481 .freq = 500,
482 .target = {
483 .uses_mmap = true,
484 },
485 };
486 struct state state = {
487 .done_cnt = 0,
488 };
489 struct thread_map *threads = NULL;
490 struct cpu_map *cpus = NULL;
491 struct perf_evlist *evlist = NULL;
492 struct perf_evsel *evsel = NULL;
493 int err = -1, ret;
494 pid_t pid;
495 struct map *map;
496 bool have_vmlinux, have_kcore, excl_kernel = false;
497
498 pid = getpid();
499
500 machine = machine__new_host();
501
502 ret = machine__create_kernel_maps(machine);
503 if (ret < 0) {
504 pr_debug("machine__create_kernel_maps failed\n");
505 goto out_err;
506 }
507
508 /* Force the use of kallsyms instead of vmlinux to try kcore */
509 if (try_kcore)
510 symbol_conf.kallsyms_name = "/proc/kallsyms";
511
512 /* Load kernel map */
513 map = machine__kernel_map(machine);
514 ret = map__load(map);
515 if (ret < 0) {
516 pr_debug("map__load failed\n");
517 goto out_err;
518 }
519 have_vmlinux = dso__is_vmlinux(map->dso);
520 have_kcore = dso__is_kcore(map->dso);
521
522 /* 2nd time through we just try kcore */
523 if (try_kcore && !have_kcore)
524 return TEST_CODE_READING_NO_KCORE;
525
526 /* No point getting kernel events if there is no kernel object */
527 if (!have_vmlinux && !have_kcore)
528 excl_kernel = true;
529
530 threads = thread_map__new_by_tid(pid);
531 if (!threads) {
532 pr_debug("thread_map__new_by_tid failed\n");
533 goto out_err;
534 }
535
536 ret = perf_event__synthesize_thread_map(NULL, threads,
537 perf_event__process, machine, false, 500);
538 if (ret < 0) {
539 pr_debug("perf_event__synthesize_thread_map failed\n");
540 goto out_err;
541 }
542
543 thread = machine__findnew_thread(machine, pid, pid);
544 if (!thread) {
545 pr_debug("machine__findnew_thread failed\n");
546 goto out_put;
547 }
548
549 cpus = cpu_map__new(NULL);
550 if (!cpus) {
551 pr_debug("cpu_map__new failed\n");
552 goto out_put;
553 }
554
555 while (1) {
556 const char *str;
557
558 evlist = perf_evlist__new();
559 if (!evlist) {
560 pr_debug("perf_evlist__new failed\n");
561 goto out_put;
562 }
563
564 perf_evlist__set_maps(evlist, cpus, threads);
565
566 if (excl_kernel)
567 str = "cycles:u";
568 else
569 str = "cycles";
570 pr_debug("Parsing event '%s'\n", str);
571 ret = parse_events(evlist, str, NULL);
572 if (ret < 0) {
573 pr_debug("parse_events failed\n");
574 goto out_put;
575 }
576
577 perf_evlist__config(evlist, &opts, NULL);
578
579 evsel = perf_evlist__first(evlist);
580
581 evsel->attr.comm = 1;
582 evsel->attr.disabled = 1;
583 evsel->attr.enable_on_exec = 0;
584
585 ret = perf_evlist__open(evlist);
586 if (ret < 0) {
587 if (!excl_kernel) {
588 excl_kernel = true;
589 /*
590 * Both cpus and threads are now owned by evlist
591 * and will be freed by following perf_evlist__set_maps
592 * call. Getting refference to keep them alive.
593 */
594 cpu_map__get(cpus);
595 thread_map__get(threads);
596 perf_evlist__set_maps(evlist, NULL, NULL);
597 perf_evlist__delete(evlist);
598 evlist = NULL;
599 continue;
600 }
601
602 if (verbose) {
603 char errbuf[512];
604 perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf));
605 pr_debug("perf_evlist__open() failed!\n%s\n", errbuf);
606 }
607
608 goto out_put;
609 }
610 break;
611 }
612
613 ret = perf_evlist__mmap(evlist, UINT_MAX, false);
614 if (ret < 0) {
615 pr_debug("perf_evlist__mmap failed\n");
616 goto out_put;
617 }
618
619 perf_evlist__enable(evlist);
620
621 do_something();
622
623 perf_evlist__disable(evlist);
624
625 ret = process_events(machine, evlist, &state);
626 if (ret < 0)
627 goto out_put;
628
629 if (!have_vmlinux && !have_kcore && !try_kcore)
630 err = TEST_CODE_READING_NO_KERNEL_OBJ;
631 else if (!have_vmlinux && !try_kcore)
632 err = TEST_CODE_READING_NO_VMLINUX;
633 else if (excl_kernel)
634 err = TEST_CODE_READING_NO_ACCESS;
635 else
636 err = TEST_CODE_READING_OK;
637out_put:
638 thread__put(thread);
639out_err:
640
641 if (evlist) {
642 perf_evlist__delete(evlist);
643 } else {
644 cpu_map__put(cpus);
645 thread_map__put(threads);
646 }
647 machine__delete_threads(machine);
648 machine__delete(machine);
649
650 return err;
651}
652
653int test__code_reading(int subtest __maybe_unused)
654{
655 int ret;
656
657 ret = do_test_code_reading(false);
658 if (!ret)
659 ret = do_test_code_reading(true);
660
661 switch (ret) {
662 case TEST_CODE_READING_OK:
663 return 0;
664 case TEST_CODE_READING_NO_VMLINUX:
665 pr_debug("no vmlinux\n");
666 return 0;
667 case TEST_CODE_READING_NO_KCORE:
668 pr_debug("no kcore\n");
669 return 0;
670 case TEST_CODE_READING_NO_ACCESS:
671 pr_debug("no access\n");
672 return 0;
673 case TEST_CODE_READING_NO_KERNEL_OBJ:
674 pr_debug("no kernel obj\n");
675 return 0;
676 default:
677 return -1;
678 };
679}