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 (check_pipe(data))
422 		return -EINVAL;
423 	if (perf_data__is_read(data))
424 		return -EINVAL;
425 
426 	if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)
427 		return -ENOMEM;
428 
429 	/*
430 	 * Only fire a warning, don't return error, continue fill
431 	 * original file.
432 	 */
433 	if (rename(data->path, *new_filepath))
434 		pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);
435 
436 	if (!at_exit) {
437 		close(data->file.fd);
438 		ret = perf_data__open(data);
439 		if (ret < 0)
440 			goto out;
441 
442 		if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {
443 			ret = -errno;
444 			pr_debug("Failed to lseek to %zu: %s",
445 				 pos, strerror(errno));
446 			goto out;
447 		}
448 	}
449 	ret = data->file.fd;
450 out:
451 	return ret;
452 }
453 
perf_data__size(struct perf_data * data)454 unsigned long perf_data__size(struct perf_data *data)
455 {
456 	u64 size = data->file.size;
457 	int i;
458 
459 	if (perf_data__is_single_file(data))
460 		return size;
461 
462 	for (i = 0; i < data->dir.nr; i++) {
463 		struct perf_data_file *file = &data->dir.files[i];
464 
465 		size += file->size;
466 	}
467 
468 	return size;
469 }
470 
perf_data__make_kcore_dir(struct perf_data * data,char * buf,size_t buf_sz)471 int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz)
472 {
473 	int ret;
474 
475 	if (!data->is_dir)
476 		return -1;
477 
478 	ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path);
479 	if (ret < 0 || (size_t)ret >= buf_sz)
480 		return -1;
481 
482 	return mkdir(buf, S_IRWXU);
483 }
484 
has_kcore_dir(const char * path)485 bool has_kcore_dir(const char *path)
486 {
487 	struct dirent *d = ERR_PTR(-EINVAL);
488 	const char *name = "kcore_dir";
489 	DIR *dir = opendir(path);
490 	size_t n = strlen(name);
491 	bool result = false;
492 
493 	if (dir) {
494 		while (d && !result) {
495 			d = readdir(dir);
496 			result = d ? strncmp(d->d_name, name, n) : false;
497 		}
498 		closedir(dir);
499 	}
500 
501 	return result;
502 }
503 
perf_data__kallsyms_name(struct perf_data * data)504 char *perf_data__kallsyms_name(struct perf_data *data)
505 {
506 	char *kallsyms_name;
507 	struct stat st;
508 
509 	if (!data->is_dir)
510 		return NULL;
511 
512 	if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0)
513 		return NULL;
514 
515 	if (stat(kallsyms_name, &st)) {
516 		free(kallsyms_name);
517 		return NULL;
518 	}
519 
520 	return kallsyms_name;
521 }
522 
perf_data__guest_kallsyms_name(struct perf_data * data,pid_t machine_pid)523 char *perf_data__guest_kallsyms_name(struct perf_data *data, pid_t machine_pid)
524 {
525 	char *kallsyms_name;
526 	struct stat st;
527 
528 	if (!data->is_dir)
529 		return NULL;
530 
531 	if (asprintf(&kallsyms_name, "%s/kcore_dir__%d/kallsyms", data->path, machine_pid) < 0)
532 		return NULL;
533 
534 	if (stat(kallsyms_name, &st)) {
535 		free(kallsyms_name);
536 		return NULL;
537 	}
538 
539 	return kallsyms_name;
540 }
541 
is_perf_data(const char * path)542 bool is_perf_data(const char *path)
543 {
544 	bool ret = false;
545 	FILE *file;
546 	u64 magic;
547 
548 	file = fopen(path, "r");
549 	if (!file)
550 		return false;
551 
552 	if (fread(&magic, 1, 8, file) < 8)
553 		goto out;
554 
555 	ret = is_perf_magic(magic);
556 out:
557 	fclose(file);
558 	return ret;
559 }
560