1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include <linux/compiler.h> |
3 | #include <linux/kernel.h> |
4 | #include <linux/string.h> |
5 | #include <linux/zalloc.h> |
6 | #include <linux/err.h> |
7 | #include <sys/types.h> |
8 | #include <sys/stat.h> |
9 | #include <errno.h> |
10 | #include <fcntl.h> |
11 | #include <unistd.h> |
12 | #include <string.h> |
13 | #include <asm/bug.h> |
14 | #include <dirent.h> |
15 | |
16 | #include "data.h" |
17 | #include "util.h" // rm_rf_perf_data() |
18 | #include "debug.h" |
19 | #include "header.h" |
20 | #include "rlimit.h" |
21 | #include <internal/lib.h> |
22 | |
23 | static void close_dir(struct perf_data_file *files, int nr) |
24 | { |
25 | while (--nr >= 0) { |
26 | close(files[nr].fd); |
27 | zfree(&files[nr].path); |
28 | } |
29 | free(files); |
30 | } |
31 | |
32 | void perf_data__close_dir(struct perf_data *data) |
33 | { |
34 | close_dir(files: data->dir.files, nr: data->dir.nr); |
35 | } |
36 | |
37 | int perf_data__create_dir(struct perf_data *data, int nr) |
38 | { |
39 | enum rlimit_action set_rlimit = NO_CHANGE; |
40 | struct perf_data_file *files = NULL; |
41 | int i, ret; |
42 | |
43 | if (WARN_ON(!data->is_dir)) |
44 | return -EINVAL; |
45 | |
46 | files = zalloc(nr * sizeof(*files)); |
47 | if (!files) |
48 | return -ENOMEM; |
49 | |
50 | for (i = 0; i < nr; i++) { |
51 | struct perf_data_file *file = &files[i]; |
52 | |
53 | ret = asprintf(&file->path, "%s/data.%d" , data->path, i); |
54 | if (ret < 0) { |
55 | ret = -ENOMEM; |
56 | goto out_err; |
57 | } |
58 | |
59 | retry_open: |
60 | ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR); |
61 | if (ret < 0) { |
62 | /* |
63 | * If using parallel threads to collect data, |
64 | * perf record needs at least 6 fds per CPU. |
65 | * When we run out of them try to increase the limits. |
66 | */ |
67 | if (errno == EMFILE && rlimit__increase_nofile(set_rlimit: &set_rlimit)) |
68 | goto retry_open; |
69 | |
70 | ret = -errno; |
71 | goto out_err; |
72 | } |
73 | set_rlimit = NO_CHANGE; |
74 | |
75 | file->fd = ret; |
76 | } |
77 | |
78 | data->dir.version = PERF_DIR_VERSION; |
79 | data->dir.files = files; |
80 | data->dir.nr = nr; |
81 | return 0; |
82 | |
83 | out_err: |
84 | close_dir(files, nr: i); |
85 | return ret; |
86 | } |
87 | |
88 | int perf_data__open_dir(struct perf_data *data) |
89 | { |
90 | struct perf_data_file *files = NULL; |
91 | struct dirent *dent; |
92 | int ret = -1; |
93 | DIR *dir; |
94 | int nr = 0; |
95 | |
96 | /* |
97 | * Directory containing a single regular perf data file which is already |
98 | * open, means there is nothing more to do here. |
99 | */ |
100 | if (perf_data__is_single_file(data)) |
101 | return 0; |
102 | |
103 | if (WARN_ON(!data->is_dir)) |
104 | return -EINVAL; |
105 | |
106 | /* The version is provided by DIR_FORMAT feature. */ |
107 | if (WARN_ON(data->dir.version != PERF_DIR_VERSION)) |
108 | return -1; |
109 | |
110 | dir = opendir(data->path); |
111 | if (!dir) |
112 | return -EINVAL; |
113 | |
114 | while ((dent = readdir(dir)) != NULL) { |
115 | struct perf_data_file *file; |
116 | char path[PATH_MAX]; |
117 | struct stat st; |
118 | |
119 | snprintf(buf: path, size: sizeof(path), fmt: "%s/%s" , data->path, dent->d_name); |
120 | if (stat(path, &st)) |
121 | continue; |
122 | |
123 | if (!S_ISREG(st.st_mode) || strncmp(dent->d_name, "data." , 5)) |
124 | continue; |
125 | |
126 | ret = -ENOMEM; |
127 | |
128 | file = realloc(files, (nr + 1) * sizeof(*files)); |
129 | if (!file) |
130 | goto out_err; |
131 | |
132 | files = file; |
133 | file = &files[nr++]; |
134 | |
135 | file->path = strdup(path); |
136 | if (!file->path) |
137 | goto out_err; |
138 | |
139 | ret = open(file->path, O_RDONLY); |
140 | if (ret < 0) |
141 | goto out_err; |
142 | |
143 | file->fd = ret; |
144 | file->size = st.st_size; |
145 | } |
146 | |
147 | closedir(dir); |
148 | if (!files) |
149 | return -EINVAL; |
150 | |
151 | data->dir.files = files; |
152 | data->dir.nr = nr; |
153 | return 0; |
154 | |
155 | out_err: |
156 | closedir(dir); |
157 | close_dir(files, nr); |
158 | return ret; |
159 | } |
160 | |
161 | int perf_data__update_dir(struct perf_data *data) |
162 | { |
163 | int i; |
164 | |
165 | if (WARN_ON(!data->is_dir)) |
166 | return -EINVAL; |
167 | |
168 | for (i = 0; i < data->dir.nr; i++) { |
169 | struct perf_data_file *file = &data->dir.files[i]; |
170 | struct stat st; |
171 | |
172 | if (fstat(file->fd, &st)) |
173 | return -1; |
174 | |
175 | file->size = st.st_size; |
176 | } |
177 | |
178 | return 0; |
179 | } |
180 | |
181 | static bool check_pipe(struct perf_data *data) |
182 | { |
183 | struct stat st; |
184 | bool is_pipe = false; |
185 | int fd = perf_data__is_read(data) ? |
186 | STDIN_FILENO : STDOUT_FILENO; |
187 | |
188 | if (!data->path) { |
189 | if (!fstat(fd, &st) && S_ISFIFO(st.st_mode)) |
190 | is_pipe = true; |
191 | } else { |
192 | if (!strcmp(data->path, "-" )) |
193 | is_pipe = true; |
194 | } |
195 | |
196 | if (is_pipe) { |
197 | if (data->use_stdio) { |
198 | const char *mode; |
199 | |
200 | mode = perf_data__is_read(data) ? "r" : "w" ; |
201 | data->file.fptr = fdopen(fd, mode); |
202 | |
203 | if (data->file.fptr == NULL) { |
204 | data->file.fd = fd; |
205 | data->use_stdio = false; |
206 | } |
207 | } else { |
208 | data->file.fd = fd; |
209 | } |
210 | } |
211 | |
212 | return data->is_pipe = is_pipe; |
213 | } |
214 | |
215 | static int check_backup(struct perf_data *data) |
216 | { |
217 | struct stat st; |
218 | |
219 | if (perf_data__is_read(data)) |
220 | return 0; |
221 | |
222 | if (!stat(data->path, &st) && st.st_size) { |
223 | char oldname[PATH_MAX]; |
224 | int ret; |
225 | |
226 | snprintf(buf: oldname, size: sizeof(oldname), fmt: "%s.old" , |
227 | data->path); |
228 | |
229 | ret = rm_rf_perf_data(path: oldname); |
230 | if (ret) { |
231 | pr_err("Can't remove old data: %s (%s)\n" , |
232 | ret == -2 ? |
233 | "Unknown file found" : strerror(errno), |
234 | oldname); |
235 | return -1; |
236 | } |
237 | |
238 | if (rename(data->path, oldname)) { |
239 | pr_err("Can't move data: %s (%s to %s)\n" , |
240 | strerror(errno), |
241 | data->path, oldname); |
242 | return -1; |
243 | } |
244 | } |
245 | |
246 | return 0; |
247 | } |
248 | |
249 | static bool is_dir(struct perf_data *data) |
250 | { |
251 | struct stat st; |
252 | |
253 | if (stat(data->path, &st)) |
254 | return false; |
255 | |
256 | return (st.st_mode & S_IFMT) == S_IFDIR; |
257 | } |
258 | |
259 | static int open_file_read(struct perf_data *data) |
260 | { |
261 | int flags = data->in_place_update ? O_RDWR : O_RDONLY; |
262 | struct stat st; |
263 | int fd; |
264 | char sbuf[STRERR_BUFSIZE]; |
265 | |
266 | fd = open(data->file.path, flags); |
267 | if (fd < 0) { |
268 | int err = errno; |
269 | |
270 | pr_err("failed to open %s: %s" , data->file.path, |
271 | str_error_r(err, sbuf, sizeof(sbuf))); |
272 | if (err == ENOENT && !strcmp(data->file.path, "perf.data" )) |
273 | pr_err(" (try 'perf record' first)" ); |
274 | pr_err("\n" ); |
275 | return -err; |
276 | } |
277 | |
278 | if (fstat(fd, &st) < 0) |
279 | goto out_close; |
280 | |
281 | if (!data->force && st.st_uid && (st.st_uid != geteuid())) { |
282 | pr_err("File %s not owned by current user or root (use -f to override)\n" , |
283 | data->file.path); |
284 | goto out_close; |
285 | } |
286 | |
287 | if (!st.st_size) { |
288 | pr_info("zero-sized data (%s), nothing to do!\n" , |
289 | data->file.path); |
290 | goto out_close; |
291 | } |
292 | |
293 | data->file.size = st.st_size; |
294 | return fd; |
295 | |
296 | out_close: |
297 | close(fd); |
298 | return -1; |
299 | } |
300 | |
301 | static int open_file_write(struct perf_data *data) |
302 | { |
303 | int fd; |
304 | char sbuf[STRERR_BUFSIZE]; |
305 | |
306 | fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC, |
307 | S_IRUSR|S_IWUSR); |
308 | |
309 | if (fd < 0) |
310 | pr_err("failed to open %s : %s\n" , data->file.path, |
311 | str_error_r(errno, sbuf, sizeof(sbuf))); |
312 | |
313 | return fd; |
314 | } |
315 | |
316 | static int open_file(struct perf_data *data) |
317 | { |
318 | int fd; |
319 | |
320 | fd = perf_data__is_read(data) ? |
321 | open_file_read(data) : open_file_write(data); |
322 | |
323 | if (fd < 0) { |
324 | zfree(&data->file.path); |
325 | return -1; |
326 | } |
327 | |
328 | data->file.fd = fd; |
329 | return 0; |
330 | } |
331 | |
332 | static int open_file_dup(struct perf_data *data) |
333 | { |
334 | data->file.path = strdup(data->path); |
335 | if (!data->file.path) |
336 | return -ENOMEM; |
337 | |
338 | return open_file(data); |
339 | } |
340 | |
341 | static int open_dir(struct perf_data *data) |
342 | { |
343 | int ret; |
344 | |
345 | /* |
346 | * So far we open only the header, so we can read the data version and |
347 | * layout. |
348 | */ |
349 | if (asprintf(&data->file.path, "%s/data" , data->path) < 0) |
350 | return -1; |
351 | |
352 | if (perf_data__is_write(data) && |
353 | mkdir(data->path, S_IRWXU) < 0) |
354 | return -1; |
355 | |
356 | ret = open_file(data); |
357 | |
358 | /* Cleanup whatever we managed to create so far. */ |
359 | if (ret && perf_data__is_write(data)) |
360 | rm_rf_perf_data(path: data->path); |
361 | |
362 | return ret; |
363 | } |
364 | |
365 | int perf_data__open(struct perf_data *data) |
366 | { |
367 | if (check_pipe(data)) |
368 | return 0; |
369 | |
370 | /* currently it allows stdio for pipe only */ |
371 | data->use_stdio = false; |
372 | |
373 | if (!data->path) |
374 | data->path = "perf.data" ; |
375 | |
376 | if (check_backup(data)) |
377 | return -1; |
378 | |
379 | if (perf_data__is_read(data)) |
380 | data->is_dir = is_dir(data); |
381 | |
382 | return perf_data__is_dir(data) ? |
383 | open_dir(data) : open_file_dup(data); |
384 | } |
385 | |
386 | void perf_data__close(struct perf_data *data) |
387 | { |
388 | if (perf_data__is_dir(data)) |
389 | perf_data__close_dir(data); |
390 | |
391 | zfree(&data->file.path); |
392 | |
393 | if (data->use_stdio) |
394 | fclose(data->file.fptr); |
395 | else |
396 | close(data->file.fd); |
397 | } |
398 | |
399 | ssize_t perf_data__read(struct perf_data *data, void *buf, size_t size) |
400 | { |
401 | if (data->use_stdio) { |
402 | if (fread(buf, size, 1, data->file.fptr) == 1) |
403 | return size; |
404 | return feof(data->file.fptr) ? 0 : -1; |
405 | } |
406 | return readn(data->file.fd, buf, size); |
407 | } |
408 | |
409 | ssize_t perf_data_file__write(struct perf_data_file *file, |
410 | void *buf, size_t size) |
411 | { |
412 | return writen(file->fd, buf, size); |
413 | } |
414 | |
415 | ssize_t perf_data__write(struct perf_data *data, |
416 | void *buf, size_t size) |
417 | { |
418 | if (data->use_stdio) { |
419 | if (fwrite(buf, size, 1, data->file.fptr) == 1) |
420 | return size; |
421 | return -1; |
422 | } |
423 | return perf_data_file__write(file: &data->file, buf, size); |
424 | } |
425 | |
426 | int perf_data__switch(struct perf_data *data, |
427 | const char *postfix, |
428 | size_t pos, bool at_exit, |
429 | char **new_filepath) |
430 | { |
431 | int ret; |
432 | |
433 | if (perf_data__is_read(data)) |
434 | return -EINVAL; |
435 | |
436 | if (asprintf(new_filepath, "%s.%s" , data->path, postfix) < 0) |
437 | return -ENOMEM; |
438 | |
439 | /* |
440 | * Only fire a warning, don't return error, continue fill |
441 | * original file. |
442 | */ |
443 | if (rename(data->path, *new_filepath)) |
444 | pr_warning("Failed to rename %s to %s\n" , data->path, *new_filepath); |
445 | |
446 | if (!at_exit) { |
447 | close(data->file.fd); |
448 | ret = perf_data__open(data); |
449 | if (ret < 0) |
450 | goto out; |
451 | |
452 | if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) { |
453 | ret = -errno; |
454 | pr_debug("Failed to lseek to %zu: %s" , |
455 | pos, strerror(errno)); |
456 | goto out; |
457 | } |
458 | } |
459 | ret = data->file.fd; |
460 | out: |
461 | return ret; |
462 | } |
463 | |
464 | unsigned long perf_data__size(struct perf_data *data) |
465 | { |
466 | u64 size = data->file.size; |
467 | int i; |
468 | |
469 | if (perf_data__is_single_file(data)) |
470 | return size; |
471 | |
472 | for (i = 0; i < data->dir.nr; i++) { |
473 | struct perf_data_file *file = &data->dir.files[i]; |
474 | |
475 | size += file->size; |
476 | } |
477 | |
478 | return size; |
479 | } |
480 | |
481 | int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz) |
482 | { |
483 | int ret; |
484 | |
485 | if (!data->is_dir) |
486 | return -1; |
487 | |
488 | ret = snprintf(buf, size: buf_sz, fmt: "%s/kcore_dir" , data->path); |
489 | if (ret < 0 || (size_t)ret >= buf_sz) |
490 | return -1; |
491 | |
492 | return mkdir(buf, S_IRWXU); |
493 | } |
494 | |
495 | bool has_kcore_dir(const char *path) |
496 | { |
497 | struct dirent *d = ERR_PTR(error: -EINVAL); |
498 | const char *name = "kcore_dir" ; |
499 | DIR *dir = opendir(path); |
500 | size_t n = strlen(name); |
501 | bool result = false; |
502 | |
503 | if (dir) { |
504 | while (d && !result) { |
505 | d = readdir(dir); |
506 | result = d ? strncmp(d->d_name, name, n) : false; |
507 | } |
508 | closedir(dir); |
509 | } |
510 | |
511 | return result; |
512 | } |
513 | |
514 | char *perf_data__kallsyms_name(struct perf_data *data) |
515 | { |
516 | char *kallsyms_name; |
517 | struct stat st; |
518 | |
519 | if (!data->is_dir) |
520 | return NULL; |
521 | |
522 | if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms" , data->path) < 0) |
523 | return NULL; |
524 | |
525 | if (stat(kallsyms_name, &st)) { |
526 | free(kallsyms_name); |
527 | return NULL; |
528 | } |
529 | |
530 | return kallsyms_name; |
531 | } |
532 | |
533 | char *perf_data__guest_kallsyms_name(struct perf_data *data, pid_t machine_pid) |
534 | { |
535 | char *kallsyms_name; |
536 | struct stat st; |
537 | |
538 | if (!data->is_dir) |
539 | return NULL; |
540 | |
541 | if (asprintf(&kallsyms_name, "%s/kcore_dir__%d/kallsyms" , data->path, machine_pid) < 0) |
542 | return NULL; |
543 | |
544 | if (stat(kallsyms_name, &st)) { |
545 | free(kallsyms_name); |
546 | return NULL; |
547 | } |
548 | |
549 | return kallsyms_name; |
550 | } |
551 | |
552 | bool is_perf_data(const char *path) |
553 | { |
554 | bool ret = false; |
555 | FILE *file; |
556 | u64 magic; |
557 | |
558 | file = fopen(path, "r" ); |
559 | if (!file) |
560 | return false; |
561 | |
562 | if (fread(&magic, 1, 8, file) < 8) |
563 | goto out; |
564 | |
565 | ret = is_perf_magic(magic); |
566 | out: |
567 | fclose(file); |
568 | return ret; |
569 | } |
570 | |