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 void read_objdump_line(const char *line, size_t line_len, void **buf,
37 size_t *len)
38{
39 const char *p;
40 size_t i;
41
42
43 p = strchr(line, ':');
44 if (!p)
45 return;
46 i = p + 1 - line;
47
48
49 while (*len) {
50 char c1, c2;
51
52
53 for (; i < line_len; i++) {
54 if (!isspace(line[i]))
55 break;
56 }
57
58 if (i >= line_len || !isxdigit(line[i]))
59 break;
60 c1 = line[i++];
61 if (i >= line_len || !isxdigit(line[i]))
62 break;
63 c2 = line[i++];
64
65 if (i < line_len && line[i] && !isspace(line[i]))
66 break;
67
68 *(unsigned char *)*buf = (hex(c1) << 4) | hex(c2);
69 *buf += 1;
70 *len -= 1;
71 }
72}
73
74static int read_objdump_output(FILE *f, void **buf, size_t *len)
75{
76 char *line = NULL;
77 size_t line_len;
78 ssize_t ret;
79 int err = 0;
80
81 while (1) {
82 ret = getline(&line, &line_len, f);
83 if (feof(f))
84 break;
85 if (ret < 0) {
86 pr_debug("getline failed\n");
87 err = -1;
88 break;
89 }
90 read_objdump_line(line, ret, buf, len);
91 }
92
93 free(line);
94
95 return err;
96}
97
98static int read_via_objdump(const char *filename, u64 addr, void *buf,
99 size_t len)
100{
101 char cmd[PATH_MAX * 2];
102 const char *fmt;
103 FILE *f;
104 int ret;
105
106 fmt = "%s -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s";
107 ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len,
108 filename);
109 if (ret <= 0 || (size_t)ret >= sizeof(cmd))
110 return -1;
111
112 pr_debug("Objdump command is: %s\n", cmd);
113
114
115 strcat(cmd, " 2>/dev/null");
116
117 f = popen(cmd, "r");
118 if (!f) {
119 pr_debug("popen failed\n");
120 return -1;
121 }
122
123 ret = read_objdump_output(f, &buf, &len);
124 if (len) {
125 pr_debug("objdump read too few bytes\n");
126 if (!ret)
127 ret = len;
128 }
129
130 pclose(f);
131
132 return ret;
133}
134
135static int read_object_code(u64 addr, size_t len, u8 cpumode,
136 struct thread *thread, struct state *state)
137{
138 struct addr_location al;
139 unsigned char buf1[BUFSZ];
140 unsigned char buf2[BUFSZ];
141 size_t ret_len;
142 u64 objdump_addr;
143 int ret;
144
145 pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
146
147 thread__find_addr_map(thread, cpumode, MAP__FUNCTION, addr, &al);
148 if (!al.map || !al.map->dso) {
149 pr_debug("thread__find_addr_map failed\n");
150 return -1;
151 }
152
153 pr_debug("File is: %s\n", al.map->dso->long_name);
154
155 if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
156 !dso__is_kcore(al.map->dso)) {
157 pr_debug("Unexpected kernel address - skipping\n");
158 return 0;
159 }
160
161 pr_debug("On file address is: %#"PRIx64"\n", al.addr);
162
163 if (len > BUFSZ)
164 len = BUFSZ;
165
166
167 if (addr + len > al.map->end)
168 len = al.map->end - addr;
169
170
171 ret_len = dso__data_read_offset(al.map->dso, thread->mg->machine,
172 al.addr, buf1, len);
173 if (ret_len != len) {
174 pr_debug("dso__data_read_offset failed\n");
175 return -1;
176 }
177
178
179
180
181
182 if (map__load(al.map, NULL))
183 return -1;
184
185
186 if (dso__is_kcore(al.map->dso)) {
187 size_t d;
188
189 for (d = 0; d < state->done_cnt; d++) {
190 if (state->done[d] == al.map->start) {
191 pr_debug("kcore map tested already");
192 pr_debug(" - skipping\n");
193 return 0;
194 }
195 }
196 if (state->done_cnt >= ARRAY_SIZE(state->done)) {
197 pr_debug("Too many kcore maps - skipping\n");
198 return 0;
199 }
200 state->done[state->done_cnt++] = al.map->start;
201 }
202
203
204 objdump_addr = map__rip_2objdump(al.map, al.addr);
205 ret = read_via_objdump(al.map->dso->long_name, objdump_addr, buf2, len);
206 if (ret > 0) {
207
208
209
210
211 if (cpumode == PERF_RECORD_MISC_KERNEL ||
212 cpumode == PERF_RECORD_MISC_GUEST_KERNEL) {
213 len -= ret;
214 if (len) {
215 pr_debug("Reducing len to %zu\n", len);
216 } else if (dso__is_kcore(al.map->dso)) {
217
218
219
220
221 pr_debug("objdump failed for kcore");
222 pr_debug(" - skipping\n");
223 return 0;
224 } else {
225 return -1;
226 }
227 }
228 }
229 if (ret < 0) {
230 pr_debug("read_via_objdump failed\n");
231 return -1;
232 }
233
234
235 if (memcmp(buf1, buf2, len)) {
236 pr_debug("Bytes read differ from those read by objdump\n");
237 return -1;
238 }
239 pr_debug("Bytes read match those read by objdump\n");
240
241 return 0;
242}
243
244static int process_sample_event(struct machine *machine,
245 struct perf_evlist *evlist,
246 union perf_event *event, struct state *state)
247{
248 struct perf_sample sample;
249 struct thread *thread;
250 u8 cpumode;
251 int ret;
252
253 if (perf_evlist__parse_sample(evlist, event, &sample)) {
254 pr_debug("perf_evlist__parse_sample failed\n");
255 return -1;
256 }
257
258 thread = machine__findnew_thread(machine, sample.pid, sample.tid);
259 if (!thread) {
260 pr_debug("machine__findnew_thread failed\n");
261 return -1;
262 }
263
264 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
265
266 ret = read_object_code(sample.ip, READLEN, cpumode, thread, state);
267 thread__put(thread);
268 return ret;
269}
270
271static int process_event(struct machine *machine, struct perf_evlist *evlist,
272 union perf_event *event, struct state *state)
273{
274 if (event->header.type == PERF_RECORD_SAMPLE)
275 return process_sample_event(machine, evlist, event, state);
276
277 if (event->header.type == PERF_RECORD_THROTTLE ||
278 event->header.type == PERF_RECORD_UNTHROTTLE)
279 return 0;
280
281 if (event->header.type < PERF_RECORD_MAX) {
282 int ret;
283
284 ret = machine__process_event(machine, event, NULL);
285 if (ret < 0)
286 pr_debug("machine__process_event failed, event type %u\n",
287 event->header.type);
288 return ret;
289 }
290
291 return 0;
292}
293
294static int process_events(struct machine *machine, struct perf_evlist *evlist,
295 struct state *state)
296{
297 union perf_event *event;
298 int i, ret;
299
300 for (i = 0; i < evlist->nr_mmaps; i++) {
301 while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
302 ret = process_event(machine, evlist, event, state);
303 perf_evlist__mmap_consume(evlist, i);
304 if (ret < 0)
305 return ret;
306 }
307 }
308 return 0;
309}
310
311static int comp(const void *a, const void *b)
312{
313 return *(int *)a - *(int *)b;
314}
315
316static void do_sort_something(void)
317{
318 int buf[40960], i;
319
320 for (i = 0; i < (int)ARRAY_SIZE(buf); i++)
321 buf[i] = ARRAY_SIZE(buf) - i - 1;
322
323 qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp);
324
325 for (i = 0; i < (int)ARRAY_SIZE(buf); i++) {
326 if (buf[i] != i) {
327 pr_debug("qsort failed\n");
328 break;
329 }
330 }
331}
332
333static void sort_something(void)
334{
335 int i;
336
337 for (i = 0; i < 10; i++)
338 do_sort_something();
339}
340
341static void syscall_something(void)
342{
343 int pipefd[2];
344 int i;
345
346 for (i = 0; i < 1000; i++) {
347 if (pipe(pipefd) < 0) {
348 pr_debug("pipe failed\n");
349 break;
350 }
351 close(pipefd[1]);
352 close(pipefd[0]);
353 }
354}
355
356static void fs_something(void)
357{
358 const char *test_file_name = "temp-perf-code-reading-test-file--";
359 FILE *f;
360 int i;
361
362 for (i = 0; i < 1000; i++) {
363 f = fopen(test_file_name, "w+");
364 if (f) {
365 fclose(f);
366 unlink(test_file_name);
367 }
368 }
369}
370
371static void do_something(void)
372{
373 fs_something();
374
375 sort_something();
376
377 syscall_something();
378}
379
380enum {
381 TEST_CODE_READING_OK,
382 TEST_CODE_READING_NO_VMLINUX,
383 TEST_CODE_READING_NO_KCORE,
384 TEST_CODE_READING_NO_ACCESS,
385 TEST_CODE_READING_NO_KERNEL_OBJ,
386};
387
388static int do_test_code_reading(bool try_kcore)
389{
390 struct machines machines;
391 struct machine *machine;
392 struct thread *thread;
393 struct record_opts opts = {
394 .mmap_pages = UINT_MAX,
395 .user_freq = UINT_MAX,
396 .user_interval = ULLONG_MAX,
397 .freq = 4000,
398 .target = {
399 .uses_mmap = true,
400 },
401 };
402 struct state state = {
403 .done_cnt = 0,
404 };
405 struct thread_map *threads = NULL;
406 struct cpu_map *cpus = NULL;
407 struct perf_evlist *evlist = NULL;
408 struct perf_evsel *evsel = NULL;
409 int err = -1, ret;
410 pid_t pid;
411 struct map *map;
412 bool have_vmlinux, have_kcore, excl_kernel = false;
413
414 pid = getpid();
415
416 machines__init(&machines);
417 machine = &machines.host;
418
419 ret = machine__create_kernel_maps(machine);
420 if (ret < 0) {
421 pr_debug("machine__create_kernel_maps failed\n");
422 goto out_err;
423 }
424
425
426 if (try_kcore)
427 symbol_conf.kallsyms_name = "/proc/kallsyms";
428
429
430 map = machine->vmlinux_maps[MAP__FUNCTION];
431 ret = map__load(map, NULL);
432 if (ret < 0) {
433 pr_debug("map__load failed\n");
434 goto out_err;
435 }
436 have_vmlinux = dso__is_vmlinux(map->dso);
437 have_kcore = dso__is_kcore(map->dso);
438
439
440 if (try_kcore && !have_kcore)
441 return TEST_CODE_READING_NO_KCORE;
442
443
444 if (!have_vmlinux && !have_kcore)
445 excl_kernel = true;
446
447 threads = thread_map__new_by_tid(pid);
448 if (!threads) {
449 pr_debug("thread_map__new_by_tid failed\n");
450 goto out_err;
451 }
452
453 ret = perf_event__synthesize_thread_map(NULL, threads,
454 perf_event__process, machine, false, 500);
455 if (ret < 0) {
456 pr_debug("perf_event__synthesize_thread_map failed\n");
457 goto out_err;
458 }
459
460 thread = machine__findnew_thread(machine, pid, pid);
461 if (!thread) {
462 pr_debug("machine__findnew_thread failed\n");
463 goto out_put;
464 }
465
466 cpus = cpu_map__new(NULL);
467 if (!cpus) {
468 pr_debug("cpu_map__new failed\n");
469 goto out_put;
470 }
471
472 while (1) {
473 const char *str;
474
475 evlist = perf_evlist__new();
476 if (!evlist) {
477 pr_debug("perf_evlist__new failed\n");
478 goto out_put;
479 }
480
481 perf_evlist__set_maps(evlist, cpus, threads);
482
483 if (excl_kernel)
484 str = "cycles:u";
485 else
486 str = "cycles";
487 pr_debug("Parsing event '%s'\n", str);
488 ret = parse_events(evlist, str, NULL);
489 if (ret < 0) {
490 pr_debug("parse_events failed\n");
491 goto out_put;
492 }
493
494 perf_evlist__config(evlist, &opts);
495
496 evsel = perf_evlist__first(evlist);
497
498 evsel->attr.comm = 1;
499 evsel->attr.disabled = 1;
500 evsel->attr.enable_on_exec = 0;
501
502 ret = perf_evlist__open(evlist);
503 if (ret < 0) {
504 if (!excl_kernel) {
505 excl_kernel = true;
506 perf_evlist__set_maps(evlist, NULL, NULL);
507 perf_evlist__delete(evlist);
508 evlist = NULL;
509 continue;
510 }
511 pr_debug("perf_evlist__open failed\n");
512 goto out_put;
513 }
514 break;
515 }
516
517 ret = perf_evlist__mmap(evlist, UINT_MAX, false);
518 if (ret < 0) {
519 pr_debug("perf_evlist__mmap failed\n");
520 goto out_put;
521 }
522
523 perf_evlist__enable(evlist);
524
525 do_something();
526
527 perf_evlist__disable(evlist);
528
529 ret = process_events(machine, evlist, &state);
530 if (ret < 0)
531 goto out_put;
532
533 if (!have_vmlinux && !have_kcore && !try_kcore)
534 err = TEST_CODE_READING_NO_KERNEL_OBJ;
535 else if (!have_vmlinux && !try_kcore)
536 err = TEST_CODE_READING_NO_VMLINUX;
537 else if (excl_kernel)
538 err = TEST_CODE_READING_NO_ACCESS;
539 else
540 err = TEST_CODE_READING_OK;
541out_put:
542 thread__put(thread);
543out_err:
544
545 if (evlist) {
546 perf_evlist__delete(evlist);
547 } else {
548 cpu_map__put(cpus);
549 thread_map__put(threads);
550 }
551 machines__destroy_kernel_maps(&machines);
552 machine__delete_threads(machine);
553 machines__exit(&machines);
554
555 return err;
556}
557
558int test__code_reading(void)
559{
560 int ret;
561
562 ret = do_test_code_reading(false);
563 if (!ret)
564 ret = do_test_code_reading(true);
565
566 switch (ret) {
567 case TEST_CODE_READING_OK:
568 return 0;
569 case TEST_CODE_READING_NO_VMLINUX:
570 fprintf(stderr, " (no vmlinux)");
571 return 0;
572 case TEST_CODE_READING_NO_KCORE:
573 fprintf(stderr, " (no kcore)");
574 return 0;
575 case TEST_CODE_READING_NO_ACCESS:
576 fprintf(stderr, " (no access)");
577 return 0;
578 case TEST_CODE_READING_NO_KERNEL_OBJ:
579 fprintf(stderr, " (no kernel obj)");
580 return 0;
581 default:
582 return -1;
583 };
584}
585
