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