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 = -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
66 out_err:
67 close_dir(files, i);
68 return ret;
69 }
70
perf_data__open_dir(struct perf_data * data)71 int 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 /*
80 * Directory containing a single regular perf data file which is already
81 * open, means there is nothing more to do here.
82 */
83 if (perf_data__is_single_file(data))
84 return 0;
85
86 if (WARN_ON(!data->is_dir))
87 return -EINVAL;
88
89 /* The version is provided by DIR_FORMAT feature. */
90 if (WARN_ON(data->dir.version != PERF_DIR_VERSION))
91 return -1;
92
93 dir = opendir(data->path);
94 if (!dir)
95 return -EINVAL;
96
97 while ((dent = readdir(dir)) != NULL) {
98 struct perf_data_file *file;
99 char path[PATH_MAX];
100 struct stat st;
101
102 snprintf(path, sizeof(path), "%s/%s", data->path, dent->d_name);
103 if (stat(path, &st))
104 continue;
105
106 if (!S_ISREG(st.st_mode) || strncmp(dent->d_name, "data.", 5))
107 continue;
108
109 ret = -ENOMEM;
110
111 file = realloc(files, (nr + 1) * sizeof(*files));
112 if (!file)
113 goto out_err;
114
115 files = file;
116 file = &files[nr++];
117
118 file->path = strdup(path);
119 if (!file->path)
120 goto out_err;
121
122 ret = open(file->path, O_RDONLY);
123 if (ret < 0)
124 goto out_err;
125
126 file->fd = ret;
127 file->size = st.st_size;
128 }
129
130 if (!files)
131 return -EINVAL;
132
133 data->dir.files = files;
134 data->dir.nr = nr;
135 return 0;
136
137 out_err:
138 close_dir(files, nr);
139 return ret;
140 }
141
perf_data__update_dir(struct perf_data * data)142 int perf_data__update_dir(struct perf_data *data)
143 {
144 int i;
145
146 if (WARN_ON(!data->is_dir))
147 return -EINVAL;
148
149 for (i = 0; i < data->dir.nr; i++) {
150 struct perf_data_file *file = &data->dir.files[i];
151 struct stat st;
152
153 if (fstat(file->fd, &st))
154 return -1;
155
156 file->size = st.st_size;
157 }
158
159 return 0;
160 }
161
check_pipe(struct perf_data * data)162 static bool check_pipe(struct perf_data *data)
163 {
164 struct stat st;
165 bool is_pipe = false;
166 int fd = perf_data__is_read(data) ?
167 STDIN_FILENO : STDOUT_FILENO;
168
169 if (!data->path) {
170 if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
171 is_pipe = true;
172 } else {
173 if (!strcmp(data->path, "-"))
174 is_pipe = true;
175 }
176
177 if (is_pipe)
178 data->file.fd = fd;
179
180 return data->is_pipe = is_pipe;
181 }
182
check_backup(struct perf_data * data)183 static int check_backup(struct perf_data *data)
184 {
185 struct stat st;
186
187 if (perf_data__is_read(data))
188 return 0;
189
190 if (!stat(data->path, &st) && st.st_size) {
191 char oldname[PATH_MAX];
192 int ret;
193
194 snprintf(oldname, sizeof(oldname), "%s.old",
195 data->path);
196
197 ret = rm_rf_perf_data(oldname);
198 if (ret) {
199 pr_err("Can't remove old data: %s (%s)\n",
200 ret == -2 ?
201 "Unknown file found" : strerror(errno),
202 oldname);
203 return -1;
204 }
205
206 if (rename(data->path, oldname)) {
207 pr_err("Can't move data: %s (%s to %s)\n",
208 strerror(errno),
209 data->path, oldname);
210 return -1;
211 }
212 }
213
214 return 0;
215 }
216
is_dir(struct perf_data * data)217 static bool is_dir(struct perf_data *data)
218 {
219 struct stat st;
220
221 if (stat(data->path, &st))
222 return false;
223
224 return (st.st_mode & S_IFMT) == S_IFDIR;
225 }
226
open_file_read(struct perf_data * data)227 static int open_file_read(struct perf_data *data)
228 {
229 struct stat st;
230 int fd;
231 char sbuf[STRERR_BUFSIZE];
232
233 fd = open(data->file.path, O_RDONLY);
234 if (fd < 0) {
235 int err = errno;
236
237 pr_err("failed to open %s: %s", data->file.path,
238 str_error_r(err, sbuf, sizeof(sbuf)));
239 if (err == ENOENT && !strcmp(data->file.path, "perf.data"))
240 pr_err(" (try 'perf record' first)");
241 pr_err("\n");
242 return -err;
243 }
244
245 if (fstat(fd, &st) < 0)
246 goto out_close;
247
248 if (!data->force && st.st_uid && (st.st_uid != geteuid())) {
249 pr_err("File %s not owned by current user or root (use -f to override)\n",
250 data->file.path);
251 goto out_close;
252 }
253
254 if (!st.st_size) {
255 pr_info("zero-sized data (%s), nothing to do!\n",
256 data->file.path);
257 goto out_close;
258 }
259
260 data->file.size = st.st_size;
261 return fd;
262
263 out_close:
264 close(fd);
265 return -1;
266 }
267
open_file_write(struct perf_data * data)268 static int open_file_write(struct perf_data *data)
269 {
270 int fd;
271 char sbuf[STRERR_BUFSIZE];
272
273 fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC,
274 S_IRUSR|S_IWUSR);
275
276 if (fd < 0)
277 pr_err("failed to open %s : %s\n", data->file.path,
278 str_error_r(errno, sbuf, sizeof(sbuf)));
279
280 return fd;
281 }
282
open_file(struct perf_data * data)283 static int open_file(struct perf_data *data)
284 {
285 int fd;
286
287 fd = perf_data__is_read(data) ?
288 open_file_read(data) : open_file_write(data);
289
290 if (fd < 0) {
291 zfree(&data->file.path);
292 return -1;
293 }
294
295 data->file.fd = fd;
296 return 0;
297 }
298
open_file_dup(struct perf_data * data)299 static int open_file_dup(struct perf_data *data)
300 {
301 data->file.path = strdup(data->path);
302 if (!data->file.path)
303 return -ENOMEM;
304
305 return open_file(data);
306 }
307
open_dir(struct perf_data * data)308 static int open_dir(struct perf_data *data)
309 {
310 int ret;
311
312 /*
313 * So far we open only the header, so we can read the data version and
314 * layout.
315 */
316 if (asprintf(&data->file.path, "%s/data", data->path) < 0)
317 return -1;
318
319 if (perf_data__is_write(data) &&
320 mkdir(data->path, S_IRWXU) < 0)
321 return -1;
322
323 ret = open_file(data);
324
325 /* Cleanup whatever we managed to create so far. */
326 if (ret && perf_data__is_write(data))
327 rm_rf_perf_data(data->path);
328
329 return ret;
330 }
331
perf_data__open(struct perf_data * data)332 int perf_data__open(struct perf_data *data)
333 {
334 if (check_pipe(data))
335 return 0;
336
337 if (!data->path)
338 data->path = "perf.data";
339
340 if (check_backup(data))
341 return -1;
342
343 if (perf_data__is_read(data))
344 data->is_dir = is_dir(data);
345
346 return perf_data__is_dir(data) ?
347 open_dir(data) : open_file_dup(data);
348 }
349
perf_data__close(struct perf_data * data)350 void perf_data__close(struct perf_data *data)
351 {
352 if (perf_data__is_dir(data))
353 perf_data__close_dir(data);
354
355 zfree(&data->file.path);
356 close(data->file.fd);
357 }
358
perf_data_file__write(struct perf_data_file * file,void * buf,size_t size)359 ssize_t perf_data_file__write(struct perf_data_file *file,
360 void *buf, size_t size)
361 {
362 return writen(file->fd, buf, size);
363 }
364
perf_data__write(struct perf_data * data,void * buf,size_t size)365 ssize_t perf_data__write(struct perf_data *data,
366 void *buf, size_t size)
367 {
368 return perf_data_file__write(&data->file, buf, size);
369 }
370
perf_data__switch(struct perf_data * data,const char * postfix,size_t pos,bool at_exit,char ** new_filepath)371 int perf_data__switch(struct perf_data *data,
372 const char *postfix,
373 size_t pos, bool at_exit,
374 char **new_filepath)
375 {
376 int ret;
377
378 if (check_pipe(data))
379 return -EINVAL;
380 if (perf_data__is_read(data))
381 return -EINVAL;
382
383 if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)
384 return -ENOMEM;
385
386 /*
387 * Only fire a warning, don't return error, continue fill
388 * original file.
389 */
390 if (rename(data->path, *new_filepath))
391 pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);
392
393 if (!at_exit) {
394 close(data->file.fd);
395 ret = perf_data__open(data);
396 if (ret < 0)
397 goto out;
398
399 if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {
400 ret = -errno;
401 pr_debug("Failed to lseek to %zu: %s",
402 pos, strerror(errno));
403 goto out;
404 }
405 }
406 ret = data->file.fd;
407 out:
408 return ret;
409 }
410
perf_data__size(struct perf_data * data)411 unsigned long perf_data__size(struct perf_data *data)
412 {
413 u64 size = data->file.size;
414 int i;
415
416 if (perf_data__is_single_file(data))
417 return size;
418
419 for (i = 0; i < data->dir.nr; i++) {
420 struct perf_data_file *file = &data->dir.files[i];
421
422 size += file->size;
423 }
424
425 return size;
426 }
427
perf_data__make_kcore_dir(struct perf_data * data,char * buf,size_t buf_sz)428 int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz)
429 {
430 int ret;
431
432 if (!data->is_dir)
433 return -1;
434
435 ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path);
436 if (ret < 0 || (size_t)ret >= buf_sz)
437 return -1;
438
439 return mkdir(buf, S_IRWXU);
440 }
441
perf_data__kallsyms_name(struct perf_data * data)442 char *perf_data__kallsyms_name(struct perf_data *data)
443 {
444 char *kallsyms_name;
445 struct stat st;
446
447 if (!data->is_dir)
448 return NULL;
449
450 if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0)
451 return NULL;
452
453 if (stat(kallsyms_name, &st)) {
454 free(kallsyms_name);
455 return NULL;
456 }
457
458 return kallsyms_name;
459 }
460
