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