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
close_dir(struct perf_data_file * files,int nr)21 static 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
perf_data__close_dir(struct perf_data * data)30 void perf_data__close_dir(struct perf_data *data)
31 {
32 close_dir(data->dir.files, data->dir.nr);
33 }
34
perf_data__create_dir(struct perf_data * data,int nr)35 int perf_data__create_dir(struct perf_data *data, int nr)
36 {
37 struct perf_data_file *files = NULL;
38 int i, ret;
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 ret = asprintf(&file->path, "%s/data.%d", data->path, i);
55 if (ret < 0)
56 goto out_err;
57
58 ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
59 if (ret < 0)
60 goto out_err;
61
62 file->fd = ret;
63 }
64
65 return 0;
66
67 out_err:
68 close_dir(files, i);
69 return ret;
70 }
71
perf_data__open_dir(struct perf_data * data)72 int perf_data__open_dir(struct perf_data *data)
73 {
74 struct perf_data_file *files = NULL;
75 struct dirent *dent;
76 int ret = -1;
77 DIR *dir;
78 int nr = 0;
79
80 /*
81 * Directory containing a single regular perf data file which is already
82 * open, means there is nothing more to do here.
83 */
84 if (perf_data__is_single_file(data))
85 return 0;
86
87 if (WARN_ON(!data->is_dir))
88 return -EINVAL;
89
90 /* The version is provided by DIR_FORMAT feature. */
91 if (WARN_ON(data->dir.version != PERF_DIR_VERSION))
92 return -1;
93
94 dir = opendir(data->path);
95 if (!dir)
96 return -EINVAL;
97
98 while ((dent = readdir(dir)) != NULL) {
99 struct perf_data_file *file;
100 char path[PATH_MAX];
101 struct stat st;
102
103 snprintf(path, sizeof(path), "%s/%s", data->path, dent->d_name);
104 if (stat(path, &st))
105 continue;
106
107 if (!S_ISREG(st.st_mode) || strncmp(dent->d_name, "data.", 5))
108 continue;
109
110 ret = -ENOMEM;
111
112 file = realloc(files, (nr + 1) * sizeof(*files));
113 if (!file)
114 goto out_err;
115
116 files = file;
117 file = &files[nr++];
118
119 file->path = strdup(path);
120 if (!file->path)
121 goto out_err;
122
123 ret = open(file->path, O_RDONLY);
124 if (ret < 0)
125 goto out_err;
126
127 file->fd = ret;
128 file->size = st.st_size;
129 }
130
131 if (!files)
132 return -EINVAL;
133
134 data->dir.files = files;
135 data->dir.nr = nr;
136 return 0;
137
138 out_err:
139 close_dir(files, nr);
140 return ret;
141 }
142
perf_data__update_dir(struct perf_data * data)143 int perf_data__update_dir(struct perf_data *data)
144 {
145 int i;
146
147 if (WARN_ON(!data->is_dir))
148 return -EINVAL;
149
150 for (i = 0; i < data->dir.nr; i++) {
151 struct perf_data_file *file = &data->dir.files[i];
152 struct stat st;
153
154 if (fstat(file->fd, &st))
155 return -1;
156
157 file->size = st.st_size;
158 }
159
160 return 0;
161 }
162
check_pipe(struct perf_data * data)163 static bool check_pipe(struct perf_data *data)
164 {
165 struct stat st;
166 bool is_pipe = false;
167 int fd = perf_data__is_read(data) ?
168 STDIN_FILENO : STDOUT_FILENO;
169
170 if (!data->path) {
171 if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
172 is_pipe = true;
173 } else {
174 if (!strcmp(data->path, "-"))
175 is_pipe = true;
176 }
177
178 if (is_pipe) {
179 if (data->use_stdio) {
180 const char *mode;
181
182 mode = perf_data__is_read(data) ? "r" : "w";
183 data->file.fptr = fdopen(fd, mode);
184
185 if (data->file.fptr == NULL) {
186 data->file.fd = fd;
187 data->use_stdio = false;
188 }
189 } else {
190 data->file.fd = fd;
191 }
192 }
193
194 return data->is_pipe = is_pipe;
195 }
196
check_backup(struct perf_data * data)197 static int check_backup(struct perf_data *data)
198 {
199 struct stat st;
200
201 if (perf_data__is_read(data))
202 return 0;
203
204 if (!stat(data->path, &st) && st.st_size) {
205 char oldname[PATH_MAX];
206 int ret;
207
208 snprintf(oldname, sizeof(oldname), "%s.old",
209 data->path);
210
211 ret = rm_rf_perf_data(oldname);
212 if (ret) {
213 pr_err("Can't remove old data: %s (%s)\n",
214 ret == -2 ?
215 "Unknown file found" : strerror(errno),
216 oldname);
217 return -1;
218 }
219
220 if (rename(data->path, oldname)) {
221 pr_err("Can't move data: %s (%s to %s)\n",
222 strerror(errno),
223 data->path, oldname);
224 return -1;
225 }
226 }
227
228 return 0;
229 }
230
is_dir(struct perf_data * data)231 static bool is_dir(struct perf_data *data)
232 {
233 struct stat st;
234
235 if (stat(data->path, &st))
236 return false;
237
238 return (st.st_mode & S_IFMT) == S_IFDIR;
239 }
240
open_file_read(struct perf_data * data)241 static int open_file_read(struct perf_data *data)
242 {
243 struct stat st;
244 int fd;
245 char sbuf[STRERR_BUFSIZE];
246
247 fd = open(data->file.path, O_RDONLY);
248 if (fd < 0) {
249 int err = errno;
250
251 pr_err("failed to open %s: %s", data->file.path,
252 str_error_r(err, sbuf, sizeof(sbuf)));
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;
285 char sbuf[STRERR_BUFSIZE];
286
287 fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC,
288 S_IRUSR|S_IWUSR);
289
290 if (fd < 0)
291 pr_err("failed to open %s : %s\n", data->file.path,
292 str_error_r(errno, sbuf, sizeof(sbuf)));
293
294 return fd;
295 }
296
open_file(struct perf_data * data)297 static int open_file(struct perf_data *data)
298 {
299 int fd;
300
301 fd = perf_data__is_read(data) ?
302 open_file_read(data) : open_file_write(data);
303
304 if (fd < 0) {
305 zfree(&data->file.path);
306 return -1;
307 }
308
309 data->file.fd = fd;
310 return 0;
311 }
312
open_file_dup(struct perf_data * data)313 static int open_file_dup(struct perf_data *data)
314 {
315 data->file.path = strdup(data->path);
316 if (!data->file.path)
317 return -ENOMEM;
318
319 return open_file(data);
320 }
321
open_dir(struct perf_data * data)322 static int open_dir(struct perf_data *data)
323 {
324 int ret;
325
326 /*
327 * So far we open only the header, so we can read the data version and
328 * layout.
329 */
330 if (asprintf(&data->file.path, "%s/data", data->path) < 0)
331 return -1;
332
333 if (perf_data__is_write(data) &&
334 mkdir(data->path, S_IRWXU) < 0)
335 return -1;
336
337 ret = open_file(data);
338
339 /* Cleanup whatever we managed to create so far. */
340 if (ret && perf_data__is_write(data))
341 rm_rf_perf_data(data->path);
342
343 return ret;
344 }
345
perf_data__open(struct perf_data * data)346 int perf_data__open(struct perf_data *data)
347 {
348 if (check_pipe(data))
349 return 0;
350
351 /* currently it allows stdio for pipe only */
352 data->use_stdio = false;
353
354 if (!data->path)
355 data->path = "perf.data";
356
357 if (check_backup(data))
358 return -1;
359
360 if (perf_data__is_read(data))
361 data->is_dir = is_dir(data);
362
363 return perf_data__is_dir(data) ?
364 open_dir(data) : open_file_dup(data);
365 }
366
perf_data__close(struct perf_data * data)367 void perf_data__close(struct perf_data *data)
368 {
369 if (perf_data__is_dir(data))
370 perf_data__close_dir(data);
371
372 zfree(&data->file.path);
373
374 if (data->use_stdio)
375 fclose(data->file.fptr);
376 else
377 close(data->file.fd);
378 }
379
perf_data__read(struct perf_data * data,void * buf,size_t size)380 ssize_t perf_data__read(struct perf_data *data, void *buf, size_t size)
381 {
382 if (data->use_stdio) {
383 if (fread(buf, size, 1, data->file.fptr) == 1)
384 return size;
385 return feof(data->file.fptr) ? 0 : -1;
386 }
387 return readn(data->file.fd, buf, size);
388 }
389
perf_data_file__write(struct perf_data_file * file,void * buf,size_t size)390 ssize_t perf_data_file__write(struct perf_data_file *file,
391 void *buf, size_t size)
392 {
393 return writen(file->fd, buf, size);
394 }
395
perf_data__write(struct perf_data * data,void * buf,size_t size)396 ssize_t perf_data__write(struct perf_data *data,
397 void *buf, size_t size)
398 {
399 if (data->use_stdio) {
400 if (fwrite(buf, size, 1, data->file.fptr) == 1)
401 return size;
402 return -1;
403 }
404 return perf_data_file__write(&data->file, buf, size);
405 }
406
perf_data__switch(struct perf_data * data,const char * postfix,size_t pos,bool at_exit,char ** new_filepath)407 int perf_data__switch(struct perf_data *data,
408 const char *postfix,
409 size_t pos, bool at_exit,
410 char **new_filepath)
411 {
412 int ret;
413
414 if (check_pipe(data))
415 return -EINVAL;
416 if (perf_data__is_read(data))
417 return -EINVAL;
418
419 if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)
420 return -ENOMEM;
421
422 /*
423 * Only fire a warning, don't return error, continue fill
424 * original file.
425 */
426 if (rename(data->path, *new_filepath))
427 pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);
428
429 if (!at_exit) {
430 close(data->file.fd);
431 ret = perf_data__open(data);
432 if (ret < 0)
433 goto out;
434
435 if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {
436 ret = -errno;
437 pr_debug("Failed to lseek to %zu: %s",
438 pos, strerror(errno));
439 goto out;
440 }
441 }
442 ret = data->file.fd;
443 out:
444 return ret;
445 }
446
perf_data__size(struct perf_data * data)447 unsigned long perf_data__size(struct perf_data *data)
448 {
449 u64 size = data->file.size;
450 int i;
451
452 if (perf_data__is_single_file(data))
453 return size;
454
455 for (i = 0; i < data->dir.nr; i++) {
456 struct perf_data_file *file = &data->dir.files[i];
457
458 size += file->size;
459 }
460
461 return size;
462 }
463
perf_data__make_kcore_dir(struct perf_data * data,char * buf,size_t buf_sz)464 int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz)
465 {
466 int ret;
467
468 if (!data->is_dir)
469 return -1;
470
471 ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path);
472 if (ret < 0 || (size_t)ret >= buf_sz)
473 return -1;
474
475 return mkdir(buf, S_IRWXU);
476 }
477
perf_data__kallsyms_name(struct perf_data * data)478 char *perf_data__kallsyms_name(struct perf_data *data)
479 {
480 char *kallsyms_name;
481 struct stat st;
482
483 if (!data->is_dir)
484 return NULL;
485
486 if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0)
487 return NULL;
488
489 if (stat(kallsyms_name, &st)) {
490 free(kallsyms_name);
491 return NULL;
492 }
493
494 return kallsyms_name;
495 }
496
is_perf_data(const char * path)497 bool is_perf_data(const char *path)
498 {
499 bool ret = false;
500 FILE *file;
501 u64 magic;
502
503 file = fopen(path, "r");
504 if (!file)
505 return false;
506
507 if (fread(&magic, 1, 8, file) < 8)
508 goto out;
509
510 ret = is_perf_magic(magic);
511 out:
512 fclose(file);
513 return ret;
514 }
515