2 #include <linux/kernel.h>
3 #include <linux/types.h>
11 #include "parse-events.h"
14 #include "thread_map.h"
22 #include "sane_ctype.h"
32 static unsigned int hex(char c)
34 if (c >= '0' && c <= '9')
36 if (c >= 'a' && c <= 'f')
41 static size_t read_objdump_chunk(const char **line, unsigned char **buf,
44 size_t bytes_read = 0;
45 unsigned char *chunk_start = *buf;
48 while (*buf_len > 0) {
51 /* Get 2 hex digits */
59 /* Store byte and advance buf */
60 **buf = (hex(c1) << 4) | hex(c2);
71 * objdump will display raw insn as LE if code endian
72 * is LE and bytes_per_chunk > 1. In that case reverse
73 * the chunk we just read.
75 * see disassemble_bytes() at binutils/objdump.c for details
76 * how objdump chooses display endian)
78 if (bytes_read > 1 && !bigendian()) {
79 unsigned char *chunk_end = chunk_start + bytes_read - 1;
82 while (chunk_start < chunk_end) {
84 *chunk_start = *chunk_end;
94 static size_t read_objdump_line(const char *line, unsigned char *buf,
98 size_t ret, bytes_read = 0;
100 /* Skip to a colon */
101 p = strchr(line, ':');
106 /* Skip initial spaces */
114 ret = read_objdump_chunk(&p, &buf, &buf_len);
119 /* return number of successfully read bytes */
123 static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr)
126 size_t line_len, off_last = 0;
129 u64 addr, last_addr = start_addr;
131 while (off_last < *len) {
132 size_t off, read_bytes, written_bytes;
133 unsigned char tmp[BUFSZ];
135 ret = getline(&line, &line_len, f);
139 pr_debug("getline failed\n");
144 /* read objdump data into temporary buffer */
145 read_bytes = read_objdump_line(line, tmp, sizeof(tmp));
149 if (sscanf(line, "%"PRIx64, &addr) != 1)
151 if (addr < last_addr) {
152 pr_debug("addr going backwards, read beyond section?\n");
157 /* copy it from temporary buffer to 'buf' according
158 * to address on current objdump line */
159 off = addr - start_addr;
162 written_bytes = MIN(read_bytes, *len - off);
163 memcpy(buf + off, tmp, written_bytes);
164 off_last = off + written_bytes;
167 /* len returns number of bytes that could not be read */
175 static int read_via_objdump(const char *filename, u64 addr, void *buf,
178 char cmd[PATH_MAX * 2];
183 fmt = "%s -z -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s";
184 ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len,
186 if (ret <= 0 || (size_t)ret >= sizeof(cmd))
189 pr_debug("Objdump command is: %s\n", cmd);
191 /* Ignore objdump errors */
192 strcat(cmd, " 2>/dev/null");
196 pr_debug("popen failed\n");
200 ret = read_objdump_output(f, buf, &len, addr);
202 pr_debug("objdump read too few bytes: %zd\n", len);
212 static void dump_buf(unsigned char *buf, size_t len)
216 for (i = 0; i < len; i++) {
217 pr_debug("0x%02x ", buf[i]);
224 static int read_object_code(u64 addr, size_t len, u8 cpumode,
225 struct thread *thread, struct state *state)
227 struct addr_location al;
228 unsigned char buf1[BUFSZ];
229 unsigned char buf2[BUFSZ];
234 pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
236 thread__find_addr_map(thread, cpumode, MAP__FUNCTION, addr, &al);
237 if (!al.map || !al.map->dso) {
238 pr_debug("thread__find_addr_map failed\n");
242 pr_debug("File is: %s\n", al.map->dso->long_name);
244 if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
245 !dso__is_kcore(al.map->dso)) {
246 pr_debug("Unexpected kernel address - skipping\n");
250 pr_debug("On file address is: %#"PRIx64"\n", al.addr);
255 /* Do not go off the map */
256 if (addr + len > al.map->end)
257 len = al.map->end - addr;
259 /* Read the object code using perf */
260 ret_len = dso__data_read_offset(al.map->dso, thread->mg->machine,
262 if (ret_len != len) {
263 pr_debug("dso__data_read_offset failed\n");
268 * Converting addresses for use by objdump requires more information.
269 * map__load() does that. See map__rip_2objdump() for details.
271 if (map__load(al.map))
274 /* objdump struggles with kcore - try each map only once */
275 if (dso__is_kcore(al.map->dso)) {
278 for (d = 0; d < state->done_cnt; d++) {
279 if (state->done[d] == al.map->start) {
280 pr_debug("kcore map tested already");
281 pr_debug(" - skipping\n");
285 if (state->done_cnt >= ARRAY_SIZE(state->done)) {
286 pr_debug("Too many kcore maps - skipping\n");
289 state->done[state->done_cnt++] = al.map->start;
292 /* Read the object code using objdump */
293 objdump_addr = map__rip_2objdump(al.map, al.addr);
294 ret = read_via_objdump(al.map->dso->long_name, objdump_addr, buf2, len);
297 * The kernel maps are inaccurate - assume objdump is right in
300 if (cpumode == PERF_RECORD_MISC_KERNEL ||
301 cpumode == PERF_RECORD_MISC_GUEST_KERNEL) {
304 pr_debug("Reducing len to %zu\n", len);
305 } else if (dso__is_kcore(al.map->dso)) {
307 * objdump cannot handle very large segments
308 * that may be found in kcore.
310 pr_debug("objdump failed for kcore");
311 pr_debug(" - skipping\n");
319 pr_debug("read_via_objdump failed\n");
323 /* The results should be identical */
324 if (memcmp(buf1, buf2, len)) {
325 pr_debug("Bytes read differ from those read by objdump\n");
326 pr_debug("buf1 (dso):\n");
328 pr_debug("buf2 (objdump):\n");
332 pr_debug("Bytes read match those read by objdump\n");
337 static int process_sample_event(struct machine *machine,
338 struct perf_evlist *evlist,
339 union perf_event *event, struct state *state)
341 struct perf_sample sample;
342 struct thread *thread;
345 if (perf_evlist__parse_sample(evlist, event, &sample)) {
346 pr_debug("perf_evlist__parse_sample failed\n");
350 thread = machine__findnew_thread(machine, sample.pid, sample.tid);
352 pr_debug("machine__findnew_thread failed\n");
356 ret = read_object_code(sample.ip, READLEN, sample.cpumode, thread, state);
361 static int process_event(struct machine *machine, struct perf_evlist *evlist,
362 union perf_event *event, struct state *state)
364 if (event->header.type == PERF_RECORD_SAMPLE)
365 return process_sample_event(machine, evlist, event, state);
367 if (event->header.type == PERF_RECORD_THROTTLE ||
368 event->header.type == PERF_RECORD_UNTHROTTLE)
371 if (event->header.type < PERF_RECORD_MAX) {
374 ret = machine__process_event(machine, event, NULL);
376 pr_debug("machine__process_event failed, event type %u\n",
384 static int process_events(struct machine *machine, struct perf_evlist *evlist,
387 union perf_event *event;
390 for (i = 0; i < evlist->nr_mmaps; i++) {
391 while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
392 ret = process_event(machine, evlist, event, state);
393 perf_evlist__mmap_consume(evlist, i);
401 static int comp(const void *a, const void *b)
403 return *(int *)a - *(int *)b;
406 static void do_sort_something(void)
410 for (i = 0; i < (int)ARRAY_SIZE(buf); i++)
411 buf[i] = ARRAY_SIZE(buf) - i - 1;
413 qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp);
415 for (i = 0; i < (int)ARRAY_SIZE(buf); i++) {
417 pr_debug("qsort failed\n");
423 static void sort_something(void)
427 for (i = 0; i < 10; i++)
431 static void syscall_something(void)
436 for (i = 0; i < 1000; i++) {
437 if (pipe(pipefd) < 0) {
438 pr_debug("pipe failed\n");
446 static void fs_something(void)
448 const char *test_file_name = "temp-perf-code-reading-test-file--";
452 for (i = 0; i < 1000; i++) {
453 f = fopen(test_file_name, "w+");
456 unlink(test_file_name);
461 static void do_something(void)
471 TEST_CODE_READING_OK,
472 TEST_CODE_READING_NO_VMLINUX,
473 TEST_CODE_READING_NO_KCORE,
474 TEST_CODE_READING_NO_ACCESS,
475 TEST_CODE_READING_NO_KERNEL_OBJ,
478 static int do_test_code_reading(bool try_kcore)
480 struct machine *machine;
481 struct thread *thread;
482 struct record_opts opts = {
483 .mmap_pages = UINT_MAX,
484 .user_freq = UINT_MAX,
485 .user_interval = ULLONG_MAX,
491 struct state state = {
494 struct thread_map *threads = NULL;
495 struct cpu_map *cpus = NULL;
496 struct perf_evlist *evlist = NULL;
497 struct perf_evsel *evsel = NULL;
501 bool have_vmlinux, have_kcore, excl_kernel = false;
505 machine = machine__new_host();
507 ret = machine__create_kernel_maps(machine);
509 pr_debug("machine__create_kernel_maps failed\n");
513 /* Force the use of kallsyms instead of vmlinux to try kcore */
515 symbol_conf.kallsyms_name = "/proc/kallsyms";
517 /* Load kernel map */
518 map = machine__kernel_map(machine);
519 ret = map__load(map);
521 pr_debug("map__load failed\n");
524 have_vmlinux = dso__is_vmlinux(map->dso);
525 have_kcore = dso__is_kcore(map->dso);
527 /* 2nd time through we just try kcore */
528 if (try_kcore && !have_kcore)
529 return TEST_CODE_READING_NO_KCORE;
531 /* No point getting kernel events if there is no kernel object */
532 if (!have_vmlinux && !have_kcore)
535 threads = thread_map__new_by_tid(pid);
537 pr_debug("thread_map__new_by_tid failed\n");
541 ret = perf_event__synthesize_thread_map(NULL, threads,
542 perf_event__process, machine, false, 500);
544 pr_debug("perf_event__synthesize_thread_map failed\n");
548 thread = machine__findnew_thread(machine, pid, pid);
550 pr_debug("machine__findnew_thread failed\n");
554 cpus = cpu_map__new(NULL);
556 pr_debug("cpu_map__new failed\n");
563 evlist = perf_evlist__new();
565 pr_debug("perf_evlist__new failed\n");
569 perf_evlist__set_maps(evlist, cpus, threads);
575 pr_debug("Parsing event '%s'\n", str);
576 ret = parse_events(evlist, str, NULL);
578 pr_debug("parse_events failed\n");
582 perf_evlist__config(evlist, &opts, NULL);
584 evsel = perf_evlist__first(evlist);
586 evsel->attr.comm = 1;
587 evsel->attr.disabled = 1;
588 evsel->attr.enable_on_exec = 0;
590 ret = perf_evlist__open(evlist);
595 * Both cpus and threads are now owned by evlist
596 * and will be freed by following perf_evlist__set_maps
597 * call. Getting refference to keep them alive.
600 thread_map__get(threads);
601 perf_evlist__set_maps(evlist, NULL, NULL);
602 perf_evlist__delete(evlist);
609 perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf));
610 pr_debug("perf_evlist__open() failed!\n%s\n", errbuf);
618 ret = perf_evlist__mmap(evlist, UINT_MAX, false);
620 pr_debug("perf_evlist__mmap failed\n");
624 perf_evlist__enable(evlist);
628 perf_evlist__disable(evlist);
630 ret = process_events(machine, evlist, &state);
634 if (!have_vmlinux && !have_kcore && !try_kcore)
635 err = TEST_CODE_READING_NO_KERNEL_OBJ;
636 else if (!have_vmlinux && !try_kcore)
637 err = TEST_CODE_READING_NO_VMLINUX;
638 else if (excl_kernel)
639 err = TEST_CODE_READING_NO_ACCESS;
641 err = TEST_CODE_READING_OK;
647 perf_evlist__delete(evlist);
650 thread_map__put(threads);
652 machine__delete_threads(machine);
653 machine__delete(machine);
658 int test__code_reading(int subtest __maybe_unused)
662 ret = do_test_code_reading(false);
664 ret = do_test_code_reading(true);
667 case TEST_CODE_READING_OK:
669 case TEST_CODE_READING_NO_VMLINUX:
670 pr_debug("no vmlinux\n");
672 case TEST_CODE_READING_NO_KCORE:
673 pr_debug("no kcore\n");
675 case TEST_CODE_READING_NO_ACCESS:
676 pr_debug("no access\n");
678 case TEST_CODE_READING_NO_KERNEL_OBJ:
679 pr_debug("no kernel obj\n");