xref: /openbmc/linux/tools/perf/util/data.c (revision ab87cc97) 
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 
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 
30 void perf_data__close_dir(struct perf_data *data)
31 {
32 	close_dir(data->dir.files, data->dir.nr);
33 }
34 
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 
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 	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 
130 out_err:
131 	close_dir(files, nr);
132 	return ret;
133 }
134 
135 int 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 
155 static 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 
176 static 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 
210 static 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 
220 static 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 
261 static 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 
276 static 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 
292 static 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 
301 static 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 
325 int 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 
343 void 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 
352 ssize_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 
358 ssize_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 
364 int 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;
400 out:
401 	return ret;
402 }
403 
404 unsigned 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 }
420