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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 <sys/types.h>
2#include <stdlib.h>
3#include <unistd.h>
4#include <stdio.h>
5#include <inttypes.h>
6#include <ctype.h>
7#include <string.h>
8
9#include "parse-events.h"
10#include "evlist.h"
11#include "evsel.h"
12#include "thread_map.h"
13#include "cpumap.h"
14#include "machine.h"
15#include "event.h"
16#include "thread.h"
17
18#include "tests.h"
19
20#define BUFSZ 1024
21#define READLEN 128
22
23struct state {
24 u64 done[1024];
25 size_t done_cnt;
26};
27
28static unsigned int hex(char c)
29{
30 if (c >= '0' && c <= '9')
31 return c - '0';
32 if (c >= 'a' && c <= 'f')
33 return c - 'a' + 10;
34 return c - 'A' + 10;
35}
36
37static void read_objdump_line(const char *line, size_t line_len, void **buf,
38 size_t *len)
39{
40 const char *p;
41 size_t i;
42
43 /* Skip to a colon */
44 p = strchr(line, ':');
45 if (!p)
46 return;
47 i = p + 1 - line;
48
49 /* Read bytes */
50 while (*len) {
51 char c1, c2;
52
53 /* Skip spaces */
54 for (; i < line_len; i++) {
55 if (!isspace(line[i]))
56 break;
57 }
58 /* Get 2 hex digits */
59 if (i >= line_len || !isxdigit(line[i]))
60 break;
61 c1 = line[i++];
62 if (i >= line_len || !isxdigit(line[i]))
63 break;
64 c2 = line[i++];
65 /* Followed by a space */
66 if (i < line_len && line[i] && !isspace(line[i]))
67 break;
68 /* Store byte */
69 *(unsigned char *)*buf = (hex(c1) << 4) | hex(c2);
70 *buf += 1;
71 *len -= 1;
72 }
73}
74
75static int read_objdump_output(FILE *f, void **buf, size_t *len)
76{
77 char *line = NULL;
78 size_t line_len;
79 ssize_t ret;
80 int err = 0;
81
82 while (1) {
83 ret = getline(&line, &line_len, f);
84 if (feof(f))
85 break;
86 if (ret < 0) {
87 pr_debug("getline failed\n");
88 err = -1;
89 break;
90 }
91 read_objdump_line(line, ret, buf, len);
92 }
93
94 free(line);
95
96 return err;
97}
98
99static int read_via_objdump(const char *filename, u64 addr, void *buf,
100 size_t len)
101{
102 char cmd[PATH_MAX * 2];
103 const char *fmt;
104 FILE *f;
105 int ret;
106
107 fmt = "%s -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s";
108 ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len,
109 filename);
110 if (ret <= 0 || (size_t)ret >= sizeof(cmd))
111 return -1;
112
113 pr_debug("Objdump command is: %s\n", cmd);
114
115 /* Ignore objdump errors */
116 strcat(cmd, " 2>/dev/null");
117
118 f = popen(cmd, "r");
119 if (!f) {
120 pr_debug("popen failed\n");
121 return -1;
122 }
123
124 ret = read_objdump_output(f, &buf, &len);
125 if (len) {
126 pr_debug("objdump read too few bytes\n");
127 if (!ret)
128 ret = len;
129 }
130
131 pclose(f);
132
133 return ret;
134}
135
136static int read_object_code(u64 addr, size_t len, u8 cpumode,
137 struct thread *thread, struct machine *machine,
138 struct state *state)
139{
140 struct addr_location al;
141 unsigned char buf1[BUFSZ];
142 unsigned char buf2[BUFSZ];
143 size_t ret_len;
144 u64 objdump_addr;
145 int ret;
146
147 pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
148
149 thread__find_addr_map(thread, machine, cpumode, MAP__FUNCTION, addr,
150 &al);
151 if (!al.map || !al.map->dso) {
152 pr_debug("thread__find_addr_map failed\n");
153 return -1;
154 }
155
156 pr_debug("File is: %s\n", al.map->dso->long_name);
157
158 if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
159 !dso__is_kcore(al.map->dso)) {
160 pr_debug("Unexpected kernel address - skipping\n");
161 return 0;
162 }
163
164 pr_debug("On file address is: %#"PRIx64"\n", al.addr);
165
166 if (len > BUFSZ)
167 len = BUFSZ;
168
169 /* Do not go off the map */
170 if (addr + len > al.map->end)
171 len = al.map->end - addr;
172
173 /* Read the object code using perf */
174 ret_len = dso__data_read_offset(al.map->dso, machine, al.addr, buf1,
175 len);
176 if (ret_len != len) {
177 pr_debug("dso__data_read_offset failed\n");
178 return -1;
179 }
180
181 /*
182 * Converting addresses for use by objdump requires more information.
183 * map__load() does that. See map__rip_2objdump() for details.
184 */
185 if (map__load(al.map, NULL))
186 return -1;
187
188 /* objdump struggles with kcore - try each map only once */
189 if (dso__is_kcore(al.map->dso)) {
190 size_t d;
191
192 for (d = 0; d < state->done_cnt; d++) {
193 if (state->done[d] == al.map->start) {
194 pr_debug("kcore map tested already");
195 pr_debug(" - skipping\n");
196 return 0;
197 }
198 }
199 if (state->done_cnt >= ARRAY_SIZE(state->done)) {
200 pr_debug("Too many kcore maps - skipping\n");
201 return 0;
202 }
203 state->done[state->done_cnt++] = al.map->start;
204 }
205
206 /* Read the object code using objdump */
207 objdump_addr = map__rip_2objdump(al.map, al.addr);
208 ret = read_via_objdump(al.map->dso->long_name, objdump_addr, buf2, len);
209 if (ret > 0) {
210 /*
211 * The kernel maps are inaccurate - assume objdump is right in
212 * that case.
213 */
214 if (cpumode == PERF_RECORD_MISC_KERNEL ||
215 cpumode == PERF_RECORD_MISC_GUEST_KERNEL) {
216 len -= ret;
217 if (len) {
218 pr_debug("Reducing len to %zu\n", len);
219 } else if (dso__is_kcore(al.map->dso)) {
220 /*
221 * objdump cannot handle very large segments
222 * that may be found in kcore.
223 */
224 pr_debug("objdump failed for kcore");
225 pr_debug(" - skipping\n");
226 return 0;
227 } else {
228 return -1;
229 }
230 }
231 }
232 if (ret < 0) {
233 pr_debug("read_via_objdump failed\n");
234 return -1;
235 }
236
237 /* The results should be identical */
238 if (memcmp(buf1, buf2, len)) {
239 pr_debug("Bytes read differ from those read by objdump\n");
240 return -1;
241 }
242 pr_debug("Bytes read match those read by objdump\n");
243
244 return 0;
245}
246
247static int process_sample_event(struct machine *machine,
248 struct perf_evlist *evlist,
249 union perf_event *event, struct state *state)
250{
251 struct perf_sample sample;
252 struct thread *thread;
253 u8 cpumode;
254
255 if (perf_evlist__parse_sample(evlist, event, &sample)) {
256 pr_debug("perf_evlist__parse_sample failed\n");
257 return -1;
258 }
259
260 thread = machine__findnew_thread(machine, sample.pid, sample.pid);
261 if (!thread) {
262 pr_debug("machine__findnew_thread failed\n");
263 return -1;
264 }
265
266 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
267
268 return read_object_code(sample.ip, READLEN, cpumode, thread, machine,
269 state);
270}
271
272static int process_event(struct machine *machine, struct perf_evlist *evlist,
273 union perf_event *event, struct state *state)
274{
275 if (event->header.type == PERF_RECORD_SAMPLE)
276 return process_sample_event(machine, evlist, event, state);
277
278 if (event->header.type == PERF_RECORD_THROTTLE ||
279 event->header.type == PERF_RECORD_UNTHROTTLE)
280 return 0;
281
282 if (event->header.type < PERF_RECORD_MAX) {
283 int ret;
284
285 ret = machine__process_event(machine, event, NULL);
286 if (ret < 0)
287 pr_debug("machine__process_event failed, event type %u\n",
288 event->header.type);
289 return ret;
290 }
291
292 return 0;
293}
294
295static int process_events(struct machine *machine, struct perf_evlist *evlist,
296 struct state *state)
297{
298 union perf_event *event;
299 int i, ret;
300
301 for (i = 0; i < evlist->nr_mmaps; i++) {
302 while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
303 ret = process_event(machine, evlist, event, state);
304 perf_evlist__mmap_consume(evlist, i);
305 if (ret < 0)
306 return ret;
307 }
308 }
309 return 0;
310}
311
312static int comp(const void *a, const void *b)
313{
314 return *(int *)a - *(int *)b;
315}
316
317static void do_sort_something(void)
318{
319 int buf[40960], i;
320
321 for (i = 0; i < (int)ARRAY_SIZE(buf); i++)
322 buf[i] = ARRAY_SIZE(buf) - i - 1;
323
324 qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp);
325
326 for (i = 0; i < (int)ARRAY_SIZE(buf); i++) {
327 if (buf[i] != i) {
328 pr_debug("qsort failed\n");
329 break;
330 }
331 }
332}
333
334static void sort_something(void)
335{
336 int i;
337
338 for (i = 0; i < 10; i++)
339 do_sort_something();
340}
341
342static void syscall_something(void)
343{
344 int pipefd[2];
345 int i;
346
347 for (i = 0; i < 1000; i++) {
348 if (pipe(pipefd) < 0) {
349 pr_debug("pipe failed\n");
350 break;
351 }
352 close(pipefd[1]);
353 close(pipefd[0]);
354 }
355}
356
357static void fs_something(void)
358{
359 const char *test_file_name = "temp-perf-code-reading-test-file--";
360 FILE *f;
361 int i;
362
363 for (i = 0; i < 1000; i++) {
364 f = fopen(test_file_name, "w+");
365 if (f) {
366 fclose(f);
367 unlink(test_file_name);
368 }
369 }
370}
371
372static void do_something(void)
373{
374 fs_something();
375
376 sort_something();
377
378 syscall_something();
379}
380
381enum {
382 TEST_CODE_READING_OK,
383 TEST_CODE_READING_NO_VMLINUX,
384 TEST_CODE_READING_NO_KCORE,
385 TEST_CODE_READING_NO_ACCESS,
386 TEST_CODE_READING_NO_KERNEL_OBJ,
387};
388
389static int do_test_code_reading(bool try_kcore)
390{
391 struct machines machines;
392 struct machine *machine;
393 struct thread *thread;
394 struct record_opts opts = {
395 .mmap_pages = UINT_MAX,
396 .user_freq = UINT_MAX,
397 .user_interval = ULLONG_MAX,
398 .freq = 4000,
399 .target = {
400 .uses_mmap = true,
401 },
402 };
403 struct state state = {
404 .done_cnt = 0,
405 };
406 struct thread_map *threads = NULL;
407 struct cpu_map *cpus = NULL;
408 struct perf_evlist *evlist = NULL;
409 struct perf_evsel *evsel = NULL;
410 int err = -1, ret;
411 pid_t pid;
412 struct map *map;
413 bool have_vmlinux, have_kcore, excl_kernel = false;
414
415 pid = getpid();
416
417 machines__init(&machines);
418 machine = &machines.host;
419
420 ret = machine__create_kernel_maps(machine);
421 if (ret < 0) {
422 pr_debug("machine__create_kernel_maps failed\n");
423 goto out_err;
424 }
425
426 /* Force the use of kallsyms instead of vmlinux to try kcore */
427 if (try_kcore)
428 symbol_conf.kallsyms_name = "/proc/kallsyms";
429
430 /* Load kernel map */
431 map = machine->vmlinux_maps[MAP__FUNCTION];
432 ret = map__load(map, NULL);
433 if (ret < 0) {
434 pr_debug("map__load failed\n");
435 goto out_err;
436 }
437 have_vmlinux = dso__is_vmlinux(map->dso);
438 have_kcore = dso__is_kcore(map->dso);
439
440 /* 2nd time through we just try kcore */
441 if (try_kcore && !have_kcore)
442 return TEST_CODE_READING_NO_KCORE;
443
444 /* No point getting kernel events if there is no kernel object */
445 if (!have_vmlinux && !have_kcore)
446 excl_kernel = true;
447
448 threads = thread_map__new_by_tid(pid);
449 if (!threads) {
450 pr_debug("thread_map__new_by_tid failed\n");
451 goto out_err;
452 }
453
454 ret = perf_event__synthesize_thread_map(NULL, threads,
455 perf_event__process, machine, false);
456 if (ret < 0) {
457 pr_debug("perf_event__synthesize_thread_map failed\n");
458 goto out_err;
459 }
460
461 thread = machine__findnew_thread(machine, pid, pid);
462 if (!thread) {
463 pr_debug("machine__findnew_thread failed\n");
464 goto out_err;
465 }
466
467 cpus = cpu_map__new(NULL);
468 if (!cpus) {
469 pr_debug("cpu_map__new failed\n");
470 goto out_err;
471 }
472
473 while (1) {
474 const char *str;
475
476 evlist = perf_evlist__new();
477 if (!evlist) {
478 pr_debug("perf_evlist__new failed\n");
479 goto out_err;
480 }
481
482 perf_evlist__set_maps(evlist, cpus, threads);
483
484 if (excl_kernel)
485 str = "cycles:u";
486 else
487 str = "cycles";
488 pr_debug("Parsing event '%s'\n", str);
489 ret = parse_events(evlist, str);
490 if (ret < 0) {
491 pr_debug("parse_events failed\n");
492 goto out_err;
493 }
494
495 perf_evlist__config(evlist, &opts);
496
497 evsel = perf_evlist__first(evlist);
498
499 evsel->attr.comm = 1;
500 evsel->attr.disabled = 1;
501 evsel->attr.enable_on_exec = 0;
502
503 ret = perf_evlist__open(evlist);
504 if (ret < 0) {
505 if (!excl_kernel) {
506 excl_kernel = true;
507 perf_evlist__set_maps(evlist, NULL, NULL);
508 perf_evlist__delete(evlist);
509 evlist = NULL;
510 continue;
511 }
512 pr_debug("perf_evlist__open failed\n");
513 goto out_err;
514 }
515 break;
516 }
517
518 ret = perf_evlist__mmap(evlist, UINT_MAX, false);
519 if (ret < 0) {
520 pr_debug("perf_evlist__mmap failed\n");
521 goto out_err;
522 }
523
524 perf_evlist__enable(evlist);
525
526 do_something();
527
528 perf_evlist__disable(evlist);
529
530 ret = process_events(machine, evlist, &state);
531 if (ret < 0)
532 goto out_err;
533
534 if (!have_vmlinux && !have_kcore && !try_kcore)
535 err = TEST_CODE_READING_NO_KERNEL_OBJ;
536 else if (!have_vmlinux && !try_kcore)
537 err = TEST_CODE_READING_NO_VMLINUX;
538 else if (excl_kernel)
539 err = TEST_CODE_READING_NO_ACCESS;
540 else
541 err = TEST_CODE_READING_OK;
542out_err:
543 if (evlist) {
544 perf_evlist__delete(evlist);
545 } else {
546 cpu_map__delete(cpus);
547 thread_map__delete(threads);
548 }
549 machines__destroy_kernel_maps(&machines);
550 machine__delete_threads(machine);
551 machines__exit(&machines);
552
553 return err;
554}
555
556int test__code_reading(void)
557{
558 int ret;
559
560 ret = do_test_code_reading(false);
561 if (!ret)
562 ret = do_test_code_reading(true);
563
564 switch (ret) {
565 case TEST_CODE_READING_OK:
566 return 0;
567 case TEST_CODE_READING_NO_VMLINUX:
568 fprintf(stderr, " (no vmlinux)");
569 return 0;
570 case TEST_CODE_READING_NO_KCORE:
571 fprintf(stderr, " (no kcore)");
572 return 0;
573 case TEST_CODE_READING_NO_ACCESS:
574 fprintf(stderr, " (no access)");
575 return 0;
576 case TEST_CODE_READING_NO_KERNEL_OBJ:
577 fprintf(stderr, " (no kernel obj)");
578 return 0;
579 default:
580 return -1;
581 };
582}