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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 <sys/types.h>
7#include <sys/stat.h>
8#include <errno.h>
9#include <fcntl.h>
10#include <unistd.h>
11#include <string.h>
12#include <asm/bug.h>
13#include <dirent.h>
14
15#include "data.h"
16#include "util.h" // rm_rf_perf_data()
17#include "debug.h"
18#include "header.h"
19#include <internal/lib.h>
20
21static void close_dir(struct perf_data_file *files, int nr)
22{
23 while (--nr >= 1) {
24 close(files[nr].fd);
25 zfree(&files[nr].path);
26 }
27 free(files);
28}
29
30void perf_data__close_dir(struct perf_data *data)
31{
32 close_dir(data->dir.files, data->dir.nr);
33}
34
35int perf_data__create_dir(struct perf_data *data, int nr)
36{
37 struct perf_data_file *files = NULL;
38 int i, ret = -1;
39
40 if (WARN_ON(!data->is_dir))
41 return -EINVAL;
42
43 files = zalloc(nr * sizeof(*files));
44 if (!files)
45 return -ENOMEM;
46
47 data->dir.version = PERF_DIR_VERSION;
48 data->dir.files = files;
49 data->dir.nr = nr;
50
51 for (i = 0; i < nr; i++) {
52 struct perf_data_file *file = &files[i];
53
54 if (asprintf(&file->path, "%s/data.%d", data->path, i) < 0)
55 goto out_err;
56
57 ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
58 if (ret < 0)
59 goto out_err;
60
61 file->fd = ret;
62 }
63
64 return 0;
65
66out_err:
67 close_dir(files, i);
68 return ret;
69}
70
71int perf_data__open_dir(struct perf_data *data)
72{
73 struct perf_data_file *files = NULL;
74 struct dirent *dent;
75 int ret = -1;
76 DIR *dir;
77 int nr = 0;
78
79 if (WARN_ON(!data->is_dir))
80 return -EINVAL;
81
82 /* The version is provided by DIR_FORMAT feature. */
83 if (WARN_ON(data->dir.version != PERF_DIR_VERSION))
84 return -1;
85
86 dir = opendir(data->path);
87 if (!dir)
88 return -EINVAL;
89
90 while ((dent = readdir(dir)) != NULL) {
91 struct perf_data_file *file;
92 char path[PATH_MAX];
93 struct stat st;
94
95 snprintf(path, sizeof(path), "%s/%s", data->path, dent->d_name);
96 if (stat(path, &st))
97 continue;
98
99 if (!S_ISREG(st.st_mode) || strncmp(dent->d_name, "data", 4))
100 continue;
101
102 ret = -ENOMEM;
103
104 file = realloc(files, (nr + 1) * sizeof(*files));
105 if (!file)
106 goto out_err;
107
108 files = file;
109 file = &files[nr++];
110
111 file->path = strdup(path);
112 if (!file->path)
113 goto out_err;
114
115 ret = open(file->path, O_RDONLY);
116 if (ret < 0)
117 goto out_err;
118
119 file->fd = ret;
120 file->size = st.st_size;
121 }
122
123 if (!files)
124 return -EINVAL;
125
126 data->dir.files = files;
127 data->dir.nr = nr;
128 return 0;
129
130out_err:
131 close_dir(files, nr);
132 return ret;
133}
134
135int perf_data__update_dir(struct perf_data *data)
136{
137 int i;
138
139 if (WARN_ON(!data->is_dir))
140 return -EINVAL;
141
142 for (i = 0; i < data->dir.nr; i++) {
143 struct perf_data_file *file = &data->dir.files[i];
144 struct stat st;
145
146 if (fstat(file->fd, &st))
147 return -1;
148
149 file->size = st.st_size;
150 }
151
152 return 0;
153}
154
155static bool check_pipe(struct perf_data *data)
156{
157 struct stat st;
158 bool is_pipe = false;
159 int fd = perf_data__is_read(data) ?
160 STDIN_FILENO : STDOUT_FILENO;
161
162 if (!data->path) {
163 if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
164 is_pipe = true;
165 } else {
166 if (!strcmp(data->path, "-"))
167 is_pipe = true;
168 }
169
170 if (is_pipe)
171 data->file.fd = fd;
172
173 return data->is_pipe = is_pipe;
174}
175
176static int check_backup(struct perf_data *data)
177{
178 struct stat st;
179
180 if (perf_data__is_read(data))
181 return 0;
182
183 if (!stat(data->path, &st) && st.st_size) {
184 char oldname[PATH_MAX];
185 int ret;
186
187 snprintf(oldname, sizeof(oldname), "%s.old",
188 data->path);
189
190 ret = rm_rf_perf_data(oldname);
191 if (ret) {
192 pr_err("Can't remove old data: %s (%s)\n",
193 ret == -2 ?
194 "Unknown file found" : strerror(errno),
195 oldname);
196 return -1;
197 }
198
199 if (rename(data->path, oldname)) {
200 pr_err("Can't move data: %s (%s to %s)\n",
201 strerror(errno),
202 data->path, oldname);
203 return -1;
204 }
205 }
206
207 return 0;
208}
209
210static bool is_dir(struct perf_data *data)
211{
212 struct stat st;
213
214 if (stat(data->path, &st))
215 return false;
216
217 return (st.st_mode & S_IFMT) == S_IFDIR;
218}
219
220static int open_file_read(struct perf_data *data)
221{
222 struct stat st;
223 int fd;
224 char sbuf[STRERR_BUFSIZE];
225
226 fd = open(data->file.path, O_RDONLY);
227 if (fd < 0) {
228 int err = errno;
229
230 pr_err("failed to open %s: %s", data->file.path,
231 str_error_r(err, sbuf, sizeof(sbuf)));
232 if (err == ENOENT && !strcmp(data->file.path, "perf.data"))
233 pr_err(" (try 'perf record' first)");
234 pr_err("\n");
235 return -err;
236 }
237
238 if (fstat(fd, &st) < 0)
239 goto out_close;
240
241 if (!data->force && st.st_uid && (st.st_uid != geteuid())) {
242 pr_err("File %s not owned by current user or root (use -f to override)\n",
243 data->file.path);
244 goto out_close;
245 }
246
247 if (!st.st_size) {
248 pr_info("zero-sized data (%s), nothing to do!\n",
249 data->file.path);
250 goto out_close;
251 }
252
253 data->file.size = st.st_size;
254 return fd;
255
256 out_close:
257 close(fd);
258 return -1;
259}
260
261static int open_file_write(struct perf_data *data)
262{
263 int fd;
264 char sbuf[STRERR_BUFSIZE];
265
266 fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC,
267 S_IRUSR|S_IWUSR);
268
269 if (fd < 0)
270 pr_err("failed to open %s : %s\n", data->file.path,
271 str_error_r(errno, sbuf, sizeof(sbuf)));
272
273 return fd;
274}
275
276static int open_file(struct perf_data *data)
277{
278 int fd;
279
280 fd = perf_data__is_read(data) ?
281 open_file_read(data) : open_file_write(data);
282
283 if (fd < 0) {
284 zfree(&data->file.path);
285 return -1;
286 }
287
288 data->file.fd = fd;
289 return 0;
290}
291
292static int open_file_dup(struct perf_data *data)
293{
294 data->file.path = strdup(data->path);
295 if (!data->file.path)
296 return -ENOMEM;
297
298 return open_file(data);
299}
300
301static int open_dir(struct perf_data *data)
302{
303 int ret;
304
305 /*
306 * So far we open only the header, so we can read the data version and
307 * layout.
308 */
309 if (asprintf(&data->file.path, "%s/header", data->path) < 0)
310 return -1;
311
312 if (perf_data__is_write(data) &&
313 mkdir(data->path, S_IRWXU) < 0)
314 return -1;
315
316 ret = open_file(data);
317
318 /* Cleanup whatever we managed to create so far. */
319 if (ret && perf_data__is_write(data))
320 rm_rf_perf_data(data->path);
321
322 return ret;
323}
324
325int perf_data__open(struct perf_data *data)
326{
327 if (check_pipe(data))
328 return 0;
329
330 if (!data->path)
331 data->path = "perf.data";
332
333 if (check_backup(data))
334 return -1;
335
336 if (perf_data__is_read(data))
337 data->is_dir = is_dir(data);
338
339 return perf_data__is_dir(data) ?
340 open_dir(data) : open_file_dup(data);
341}
342
343void perf_data__close(struct perf_data *data)
344{
345 if (perf_data__is_dir(data))
346 perf_data__close_dir(data);
347
348 zfree(&data->file.path);
349 close(data->file.fd);
350}
351
352ssize_t perf_data_file__write(struct perf_data_file *file,
353 void *buf, size_t size)
354{
355 return writen(file->fd, buf, size);
356}
357
358ssize_t perf_data__write(struct perf_data *data,
359 void *buf, size_t size)
360{
361 return perf_data_file__write(&data->file, buf, size);
362}
363
364int perf_data__switch(struct perf_data *data,
365 const char *postfix,
366 size_t pos, bool at_exit,
367 char **new_filepath)
368{
369 int ret;
370
371 if (check_pipe(data))
372 return -EINVAL;
373 if (perf_data__is_read(data))
374 return -EINVAL;
375
376 if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)
377 return -ENOMEM;
378
379 /*
380 * Only fire a warning, don't return error, continue fill
381 * original file.
382 */
383 if (rename(data->path, *new_filepath))
384 pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);
385
386 if (!at_exit) {
387 close(data->file.fd);
388 ret = perf_data__open(data);
389 if (ret < 0)
390 goto out;
391
392 if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {
393 ret = -errno;
394 pr_debug("Failed to lseek to %zu: %s",
395 pos, strerror(errno));
396 goto out;
397 }
398 }
399 ret = data->file.fd;
400out:
401 return ret;
402}
403
404unsigned long perf_data__size(struct perf_data *data)
405{
406 u64 size = data->file.size;
407 int i;
408
409 if (!data->is_dir)
410 return size;
411
412 for (i = 0; i < data->dir.nr; i++) {
413 struct perf_data_file *file = &data->dir.files[i];
414
415 size += file->size;
416 }
417
418 return size;
419}
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
23static 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
32void perf_data__close_dir(struct perf_data *data)
33{
34 close_dir(data->dir.files, data->dir.nr);
35}
36
37int 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
59retry_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
83out_err:
84 close_dir(files, i);
85 return ret;
86}
87
88int 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
155out_err:
156 closedir(dir);
157 close_dir(files, nr);
158 return ret;
159}
160
161int 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
181static 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
215static 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(oldname, sizeof(oldname), "%s.old",
227 data->path);
228
229 ret = rm_rf_perf_data(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
249static 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
259static 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
301static 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
316static 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
332static 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
341static 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(data->path);
361
362 return ret;
363}
364
365int 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
386void 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
399ssize_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
409ssize_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
415ssize_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(&data->file, buf, size);
424}
425
426int 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 (check_pipe(data))
434 return -EINVAL;
435 if (perf_data__is_read(data))
436 return -EINVAL;
437
438 if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)
439 return -ENOMEM;
440
441 /*
442 * Only fire a warning, don't return error, continue fill
443 * original file.
444 */
445 if (rename(data->path, *new_filepath))
446 pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);
447
448 if (!at_exit) {
449 close(data->file.fd);
450 ret = perf_data__open(data);
451 if (ret < 0)
452 goto out;
453
454 if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {
455 ret = -errno;
456 pr_debug("Failed to lseek to %zu: %s",
457 pos, strerror(errno));
458 goto out;
459 }
460 }
461 ret = data->file.fd;
462out:
463 return ret;
464}
465
466unsigned long perf_data__size(struct perf_data *data)
467{
468 u64 size = data->file.size;
469 int i;
470
471 if (perf_data__is_single_file(data))
472 return size;
473
474 for (i = 0; i < data->dir.nr; i++) {
475 struct perf_data_file *file = &data->dir.files[i];
476
477 size += file->size;
478 }
479
480 return size;
481}
482
483int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz)
484{
485 int ret;
486
487 if (!data->is_dir)
488 return -1;
489
490 ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path);
491 if (ret < 0 || (size_t)ret >= buf_sz)
492 return -1;
493
494 return mkdir(buf, S_IRWXU);
495}
496
497bool has_kcore_dir(const char *path)
498{
499 struct dirent *d = ERR_PTR(-EINVAL);
500 const char *name = "kcore_dir";
501 DIR *dir = opendir(path);
502 size_t n = strlen(name);
503 bool result = false;
504
505 if (dir) {
506 while (d && !result) {
507 d = readdir(dir);
508 result = d ? strncmp(d->d_name, name, n) : false;
509 }
510 closedir(dir);
511 }
512
513 return result;
514}
515
516char *perf_data__kallsyms_name(struct perf_data *data)
517{
518 char *kallsyms_name;
519 struct stat st;
520
521 if (!data->is_dir)
522 return NULL;
523
524 if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0)
525 return NULL;
526
527 if (stat(kallsyms_name, &st)) {
528 free(kallsyms_name);
529 return NULL;
530 }
531
532 return kallsyms_name;
533}
534
535char *perf_data__guest_kallsyms_name(struct perf_data *data, pid_t machine_pid)
536{
537 char *kallsyms_name;
538 struct stat st;
539
540 if (!data->is_dir)
541 return NULL;
542
543 if (asprintf(&kallsyms_name, "%s/kcore_dir__%d/kallsyms", data->path, machine_pid) < 0)
544 return NULL;
545
546 if (stat(kallsyms_name, &st)) {
547 free(kallsyms_name);
548 return NULL;
549 }
550
551 return kallsyms_name;
552}
553
554bool is_perf_data(const char *path)
555{
556 bool ret = false;
557 FILE *file;
558 u64 magic;
559
560 file = fopen(path, "r");
561 if (!file)
562 return false;
563
564 if (fread(&magic, 1, 8, file) < 8)
565 goto out;
566
567 ret = is_perf_magic(magic);
568out:
569 fclose(file);
570 return ret;
571}