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
close_dir(struct perf_data_file * files,int nr)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
perf_data__close_dir(struct perf_data * data)32 void perf_data__close_dir(struct perf_data *data)
33 {
34 close_dir(data->dir.files, data->dir.nr);
35 }
36
perf_data__create_dir(struct perf_data * data,int nr)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))
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, i);
85 return ret;
86 }
87
perf_data__open_dir(struct perf_data * data)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(path, sizeof(path), "%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
check_pipe(struct perf_data * data)161 static bool check_pipe(struct perf_data *data)
162 {
163 struct stat st;
164 bool is_pipe = false;
165 int fd = perf_data__is_read(data) ?
166 STDIN_FILENO : STDOUT_FILENO;
167
168 if (!data->path) {
169 if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
170 is_pipe = true;
171 } else {
172 if (!strcmp(data->path, "-"))
173 is_pipe = true;
174 }
175
176 if (is_pipe) {
177 if (data->use_stdio) {
178 const char *mode;
179
180 mode = perf_data__is_read(data) ? "r" : "w";
181 data->file.fptr = fdopen(fd, mode);
182
183 if (data->file.fptr == NULL) {
184 data->file.fd = fd;
185 data->use_stdio = false;
186 }
187
188 /*
189 * When is_pipe and data->file.fd is given, use given fd
190 * instead of STDIN_FILENO or STDOUT_FILENO
191 */
192 } else if (data->file.fd <= 0) {
193 data->file.fd = fd;
194 }
195 }
196
197 return data->is_pipe = is_pipe;
198 }
199
check_backup(struct perf_data * data)200 static int check_backup(struct perf_data *data)
201 {
202 struct stat st;
203
204 if (perf_data__is_read(data))
205 return 0;
206
207 if (!stat(data->path, &st) && st.st_size) {
208 char oldname[PATH_MAX];
209 int ret;
210
211 snprintf(oldname, sizeof(oldname), "%s.old",
212 data->path);
213
214 ret = rm_rf_perf_data(oldname);
215 if (ret) {
216 if (ret == -2)
217 pr_err("Can't remove old data: Unknown file found (%s)\n", oldname);
218 else
219 pr_err("Can't remove old data: %m (%s)\n", oldname);
220 return -1;
221 }
222
223 if (rename(data->path, oldname)) {
224 pr_err("Can't move data: %m (%s to %s)\n", data->path, oldname);
225 return -1;
226 }
227 }
228
229 return 0;
230 }
231
is_dir(struct perf_data * data)232 static bool is_dir(struct perf_data *data)
233 {
234 struct stat st;
235
236 if (stat(data->path, &st))
237 return false;
238
239 return (st.st_mode & S_IFMT) == S_IFDIR;
240 }
241
open_file_read(struct perf_data * data)242 static int open_file_read(struct perf_data *data)
243 {
244 int flags = data->in_place_update ? O_RDWR : O_RDONLY;
245 struct stat st;
246 int fd;
247
248 fd = open(data->file.path, flags);
249 if (fd < 0) {
250 int err = errno;
251
252 pr_err("failed to open %s: %m", data->file.path);
253 if (err == ENOENT && !strcmp(data->file.path, "perf.data"))
254 pr_err(" (try 'perf record' first)");
255 pr_err("\n");
256 return -err;
257 }
258
259 if (fstat(fd, &st) < 0)
260 goto out_close;
261
262 if (!data->force && st.st_uid && (st.st_uid != geteuid())) {
263 pr_err("File %s not owned by current user or root (use -f to override)\n",
264 data->file.path);
265 goto out_close;
266 }
267
268 if (!st.st_size) {
269 pr_info("zero-sized data (%s), nothing to do!\n",
270 data->file.path);
271 goto out_close;
272 }
273
274 data->file.size = st.st_size;
275 return fd;
276
277 out_close:
278 close(fd);
279 return -1;
280 }
281
open_file_write(struct perf_data * data)282 static int open_file_write(struct perf_data *data)
283 {
284 int fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC, S_IRUSR|S_IWUSR);
285
286 if (fd < 0)
287 pr_err("failed to open %s : %m\n", data->file.path);
288
289 return fd;
290 }
291
open_file(struct perf_data * data)292 static int open_file(struct perf_data *data)
293 {
294 int fd;
295
296 fd = perf_data__is_read(data) ?
297 open_file_read(data) : open_file_write(data);
298
299 if (fd < 0) {
300 zfree(&data->file.path);
301 return -1;
302 }
303
304 data->file.fd = fd;
305 return 0;
306 }
307
open_file_dup(struct perf_data * data)308 static int open_file_dup(struct perf_data *data)
309 {
310 data->file.path = strdup(data->path);
311 if (!data->file.path)
312 return -ENOMEM;
313
314 return open_file(data);
315 }
316
open_dir(struct perf_data * data)317 static int open_dir(struct perf_data *data)
318 {
319 int ret;
320
321 /*
322 * So far we open only the header, so we can read the data version and
323 * layout.
324 */
325 if (asprintf(&data->file.path, "%s/data", data->path) < 0)
326 return -1;
327
328 if (perf_data__is_write(data) &&
329 mkdir(data->path, S_IRWXU) < 0)
330 return -1;
331
332 ret = open_file(data);
333
334 /* Cleanup whatever we managed to create so far. */
335 if (ret && perf_data__is_write(data))
336 rm_rf_perf_data(data->path);
337
338 return ret;
339 }
340
perf_data__open(struct perf_data * data)341 int perf_data__open(struct perf_data *data)
342 {
343 if (check_pipe(data))
344 return 0;
345
346 /* currently it allows stdio for pipe only */
347 data->use_stdio = false;
348
349 if (!data->path)
350 data->path = "perf.data";
351
352 if (check_backup(data))
353 return -1;
354
355 if (perf_data__is_read(data))
356 data->is_dir = is_dir(data);
357
358 return perf_data__is_dir(data) ?
359 open_dir(data) : open_file_dup(data);
360 }
361
perf_data__close(struct perf_data * data)362 void perf_data__close(struct perf_data *data)
363 {
364 if (perf_data__is_dir(data))
365 perf_data__close_dir(data);
366
367 zfree(&data->file.path);
368
369 if (data->use_stdio)
370 fclose(data->file.fptr);
371 else
372 close(data->file.fd);
373 }
374
perf_data__read(struct perf_data * data,void * buf,size_t size)375 ssize_t perf_data__read(struct perf_data *data, void *buf, size_t size)
376 {
377 if (data->use_stdio) {
378 if (fread(buf, size, 1, data->file.fptr) == 1)
379 return size;
380 return feof(data->file.fptr) ? 0 : -1;
381 }
382 return readn(data->file.fd, buf, size);
383 }
384
perf_data_file__write(struct perf_data_file * file,void * buf,size_t size)385 ssize_t perf_data_file__write(struct perf_data_file *file,
386 void *buf, size_t size)
387 {
388 return writen(file->fd, buf, size);
389 }
390
perf_data__write(struct perf_data * data,void * buf,size_t size)391 ssize_t perf_data__write(struct perf_data *data,
392 void *buf, size_t size)
393 {
394 if (data->use_stdio) {
395 if (fwrite(buf, size, 1, data->file.fptr) == 1)
396 return size;
397 return -1;
398 }
399 return perf_data_file__write(&data->file, buf, size);
400 }
401
perf_data__switch(struct perf_data * data,const char * postfix,size_t pos,bool at_exit,char ** new_filepath)402 int perf_data__switch(struct perf_data *data,
403 const char *postfix,
404 size_t pos, bool at_exit,
405 char **new_filepath)
406 {
407 int ret;
408
409 if (perf_data__is_read(data))
410 return -EINVAL;
411
412 if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)
413 return -ENOMEM;
414
415 /*
416 * Only fire a warning, don't return error, continue fill
417 * original file.
418 */
419 if (rename(data->path, *new_filepath))
420 pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);
421
422 if (!at_exit) {
423 close(data->file.fd);
424 ret = perf_data__open(data);
425 if (ret < 0)
426 goto out;
427
428 if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {
429 ret = -errno;
430 pr_debug("Failed to lseek to %zu: %m\n",
431 pos);
432 goto out;
433 }
434 }
435 ret = data->file.fd;
436 out:
437 return ret;
438 }
439
perf_data__size(struct perf_data * data)440 unsigned long perf_data__size(struct perf_data *data)
441 {
442 u64 size = data->file.size;
443 int i;
444
445 if (perf_data__is_single_file(data))
446 return size;
447
448 for (i = 0; i < data->dir.nr; i++) {
449 struct perf_data_file *file = &data->dir.files[i];
450
451 size += file->size;
452 }
453
454 return size;
455 }
456
perf_data__make_kcore_dir(struct perf_data * data,char * buf,size_t buf_sz)457 int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz)
458 {
459 int ret;
460
461 if (!data->is_dir)
462 return -1;
463
464 ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path);
465 if (ret < 0 || (size_t)ret >= buf_sz)
466 return -1;
467
468 return mkdir(buf, S_IRWXU);
469 }
470
has_kcore_dir(const char * path)471 bool has_kcore_dir(const char *path)
472 {
473 struct dirent *d = ERR_PTR(-EINVAL);
474 const char *name = "kcore_dir";
475 DIR *dir = opendir(path);
476 size_t n = strlen(name);
477 bool result = false;
478
479 if (dir) {
480 while (d && !result) {
481 d = readdir(dir);
482 result = d ? strncmp(d->d_name, name, n) : false;
483 }
484 closedir(dir);
485 }
486
487 return result;
488 }
489
perf_data__kallsyms_name(struct perf_data * data)490 char *perf_data__kallsyms_name(struct perf_data *data)
491 {
492 char *kallsyms_name;
493 struct stat st;
494
495 if (!data->is_dir)
496 return NULL;
497
498 if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0)
499 return NULL;
500
501 if (stat(kallsyms_name, &st)) {
502 free(kallsyms_name);
503 return NULL;
504 }
505
506 return kallsyms_name;
507 }
508
perf_data__guest_kallsyms_name(struct perf_data * data,pid_t machine_pid)509 char *perf_data__guest_kallsyms_name(struct perf_data *data, pid_t machine_pid)
510 {
511 char *kallsyms_name;
512 struct stat st;
513
514 if (!data->is_dir)
515 return NULL;
516
517 if (asprintf(&kallsyms_name, "%s/kcore_dir__%d/kallsyms", data->path, machine_pid) < 0)
518 return NULL;
519
520 if (stat(kallsyms_name, &st)) {
521 free(kallsyms_name);
522 return NULL;
523 }
524
525 return kallsyms_name;
526 }
527
is_perf_data(const char * path)528 bool is_perf_data(const char *path)
529 {
530 bool ret = false;
531 FILE *file;
532 u64 magic;
533
534 file = fopen(path, "r");
535 if (!file)
536 return false;
537
538 if (fread(&magic, 1, 8, file) < 8)
539 goto out;
540
541 ret = is_perf_magic(magic);
542 out:
543 fclose(file);
544 return ret;
545 }
546