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1#include <ctype.h>
2#include <errno.h>
3#include <limits.h>
4#include <stdbool.h>
5#include <stdio.h>
6#include <stdlib.h>
7#include <string.h>
8#include <sys/vfs.h>
9#include <sys/types.h>
10#include <sys/stat.h>
11#include <fcntl.h>
12#include <unistd.h>
13#include <sys/mount.h>
14
15#include "fs.h"
16#include "debug-internal.h"
17
18#define _STR(x) #x
19#define STR(x) _STR(x)
20
21#ifndef SYSFS_MAGIC
22#define SYSFS_MAGIC 0x62656572
23#endif
24
25#ifndef PROC_SUPER_MAGIC
26#define PROC_SUPER_MAGIC 0x9fa0
27#endif
28
29#ifndef DEBUGFS_MAGIC
30#define DEBUGFS_MAGIC 0x64626720
31#endif
32
33#ifndef TRACEFS_MAGIC
34#define TRACEFS_MAGIC 0x74726163
35#endif
36
37#ifndef HUGETLBFS_MAGIC
38#define HUGETLBFS_MAGIC 0x958458f6
39#endif
40
41static const char * const sysfs__fs_known_mountpoints[] = {
42 "/sys",
43 0,
44};
45
46static const char * const procfs__known_mountpoints[] = {
47 "/proc",
48 0,
49};
50
51#ifndef DEBUGFS_DEFAULT_PATH
52#define DEBUGFS_DEFAULT_PATH "/sys/kernel/debug"
53#endif
54
55static const char * const debugfs__known_mountpoints[] = {
56 DEBUGFS_DEFAULT_PATH,
57 "/debug",
58 0,
59};
60
61
62#ifndef TRACEFS_DEFAULT_PATH
63#define TRACEFS_DEFAULT_PATH "/sys/kernel/tracing"
64#endif
65
66static const char * const tracefs__known_mountpoints[] = {
67 TRACEFS_DEFAULT_PATH,
68 "/sys/kernel/debug/tracing",
69 "/tracing",
70 "/trace",
71 0,
72};
73
74static const char * const hugetlbfs__known_mountpoints[] = {
75 0,
76};
77
78struct fs {
79 const char *name;
80 const char * const *mounts;
81 char path[PATH_MAX];
82 bool found;
83 long magic;
84};
85
86enum {
87 FS__SYSFS = 0,
88 FS__PROCFS = 1,
89 FS__DEBUGFS = 2,
90 FS__TRACEFS = 3,
91 FS__HUGETLBFS = 4,
92};
93
94#ifndef TRACEFS_MAGIC
95#define TRACEFS_MAGIC 0x74726163
96#endif
97
98static struct fs fs__entries[] = {
99 [FS__SYSFS] = {
100 .name = "sysfs",
101 .mounts = sysfs__fs_known_mountpoints,
102 .magic = SYSFS_MAGIC,
103 },
104 [FS__PROCFS] = {
105 .name = "proc",
106 .mounts = procfs__known_mountpoints,
107 .magic = PROC_SUPER_MAGIC,
108 },
109 [FS__DEBUGFS] = {
110 .name = "debugfs",
111 .mounts = debugfs__known_mountpoints,
112 .magic = DEBUGFS_MAGIC,
113 },
114 [FS__TRACEFS] = {
115 .name = "tracefs",
116 .mounts = tracefs__known_mountpoints,
117 .magic = TRACEFS_MAGIC,
118 },
119 [FS__HUGETLBFS] = {
120 .name = "hugetlbfs",
121 .mounts = hugetlbfs__known_mountpoints,
122 .magic = HUGETLBFS_MAGIC,
123 },
124};
125
126static bool fs__read_mounts(struct fs *fs)
127{
128 bool found = false;
129 char type[100];
130 FILE *fp;
131
132 fp = fopen("/proc/mounts", "r");
133 if (fp == NULL)
134 return NULL;
135
136 while (!found &&
137 fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
138 fs->path, type) == 2) {
139
140 if (strcmp(type, fs->name) == 0)
141 found = true;
142 }
143
144 fclose(fp);
145 return fs->found = found;
146}
147
148static int fs__valid_mount(const char *fs, long magic)
149{
150 struct statfs st_fs;
151
152 if (statfs(fs, &st_fs) < 0)
153 return -ENOENT;
154 else if ((long)st_fs.f_type != magic)
155 return -ENOENT;
156
157 return 0;
158}
159
160static bool fs__check_mounts(struct fs *fs)
161{
162 const char * const *ptr;
163
164 ptr = fs->mounts;
165 while (*ptr) {
166 if (fs__valid_mount(*ptr, fs->magic) == 0) {
167 fs->found = true;
168 strcpy(fs->path, *ptr);
169 return true;
170 }
171 ptr++;
172 }
173
174 return false;
175}
176
177static void mem_toupper(char *f, size_t len)
178{
179 while (len) {
180 *f = toupper(*f);
181 f++;
182 len--;
183 }
184}
185
186/*
187 * Check for "NAME_PATH" environment variable to override fs location (for
188 * testing). This matches the recommendation in Documentation/sysfs-rules.txt
189 * for SYSFS_PATH.
190 */
191static bool fs__env_override(struct fs *fs)
192{
193 char *override_path;
194 size_t name_len = strlen(fs->name);
195 /* name + "_PATH" + '\0' */
196 char upper_name[name_len + 5 + 1];
197 memcpy(upper_name, fs->name, name_len);
198 mem_toupper(upper_name, name_len);
199 strcpy(&upper_name[name_len], "_PATH");
200
201 override_path = getenv(upper_name);
202 if (!override_path)
203 return false;
204
205 fs->found = true;
206 strncpy(fs->path, override_path, sizeof(fs->path));
207 return true;
208}
209
210static const char *fs__get_mountpoint(struct fs *fs)
211{
212 if (fs__env_override(fs))
213 return fs->path;
214
215 if (fs__check_mounts(fs))
216 return fs->path;
217
218 if (fs__read_mounts(fs))
219 return fs->path;
220
221 return NULL;
222}
223
224static const char *fs__mountpoint(int idx)
225{
226 struct fs *fs = &fs__entries[idx];
227
228 if (fs->found)
229 return (const char *)fs->path;
230
231 return fs__get_mountpoint(fs);
232}
233
234static const char *mount_overload(struct fs *fs)
235{
236 size_t name_len = strlen(fs->name);
237 /* "PERF_" + name + "_ENVIRONMENT" + '\0' */
238 char upper_name[5 + name_len + 12 + 1];
239
240 snprintf(upper_name, name_len, "PERF_%s_ENVIRONMENT", fs->name);
241 mem_toupper(upper_name, name_len);
242
243 return getenv(upper_name) ?: *fs->mounts;
244}
245
246static const char *fs__mount(int idx)
247{
248 struct fs *fs = &fs__entries[idx];
249 const char *mountpoint;
250
251 if (fs__mountpoint(idx))
252 return (const char *)fs->path;
253
254 mountpoint = mount_overload(fs);
255
256 if (mount(NULL, mountpoint, fs->name, 0, NULL) < 0)
257 return NULL;
258
259 return fs__check_mounts(fs) ? fs->path : NULL;
260}
261
262#define FS(name, idx) \
263const char *name##__mountpoint(void) \
264{ \
265 return fs__mountpoint(idx); \
266} \
267 \
268const char *name##__mount(void) \
269{ \
270 return fs__mount(idx); \
271} \
272 \
273bool name##__configured(void) \
274{ \
275 return name##__mountpoint() != NULL; \
276}
277
278FS(sysfs, FS__SYSFS);
279FS(procfs, FS__PROCFS);
280FS(debugfs, FS__DEBUGFS);
281FS(tracefs, FS__TRACEFS);
282FS(hugetlbfs, FS__HUGETLBFS);
283
284int filename__read_int(const char *filename, int *value)
285{
286 char line[64];
287 int fd = open(filename, O_RDONLY), err = -1;
288
289 if (fd < 0)
290 return -1;
291
292 if (read(fd, line, sizeof(line)) > 0) {
293 *value = atoi(line);
294 err = 0;
295 }
296
297 close(fd);
298 return err;
299}
300
301/*
302 * Parses @value out of @filename with strtoull.
303 * By using 0 for base, the strtoull detects the
304 * base automatically (see man strtoull).
305 */
306int filename__read_ull(const char *filename, unsigned long long *value)
307{
308 char line[64];
309 int fd = open(filename, O_RDONLY), err = -1;
310
311 if (fd < 0)
312 return -1;
313
314 if (read(fd, line, sizeof(line)) > 0) {
315 *value = strtoull(line, NULL, 0);
316 if (*value != ULLONG_MAX)
317 err = 0;
318 }
319
320 close(fd);
321 return err;
322}
323
324#define STRERR_BUFSIZE 128 /* For the buffer size of strerror_r */
325
326int filename__read_str(const char *filename, char **buf, size_t *sizep)
327{
328 size_t size = 0, alloc_size = 0;
329 void *bf = NULL, *nbf;
330 int fd, n, err = 0;
331 char sbuf[STRERR_BUFSIZE];
332
333 fd = open(filename, O_RDONLY);
334 if (fd < 0)
335 return -errno;
336
337 do {
338 if (size == alloc_size) {
339 alloc_size += BUFSIZ;
340 nbf = realloc(bf, alloc_size);
341 if (!nbf) {
342 err = -ENOMEM;
343 break;
344 }
345
346 bf = nbf;
347 }
348
349 n = read(fd, bf + size, alloc_size - size);
350 if (n < 0) {
351 if (size) {
352 pr_warning("read failed %d: %s\n", errno,
353 strerror_r(errno, sbuf, sizeof(sbuf)));
354 err = 0;
355 } else
356 err = -errno;
357
358 break;
359 }
360
361 size += n;
362 } while (n > 0);
363
364 if (!err) {
365 *sizep = size;
366 *buf = bf;
367 } else
368 free(bf);
369
370 close(fd);
371 return err;
372}
373
374int procfs__read_str(const char *entry, char **buf, size_t *sizep)
375{
376 char path[PATH_MAX];
377 const char *procfs = procfs__mountpoint();
378
379 if (!procfs)
380 return -1;
381
382 snprintf(path, sizeof(path), "%s/%s", procfs, entry);
383
384 return filename__read_str(path, buf, sizep);
385}
386
387int sysfs__read_ull(const char *entry, unsigned long long *value)
388{
389 char path[PATH_MAX];
390 const char *sysfs = sysfs__mountpoint();
391
392 if (!sysfs)
393 return -1;
394
395 snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
396
397 return filename__read_ull(path, value);
398}
399
400int sysfs__read_int(const char *entry, int *value)
401{
402 char path[PATH_MAX];
403 const char *sysfs = sysfs__mountpoint();
404
405 if (!sysfs)
406 return -1;
407
408 snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
409
410 return filename__read_int(path, value);
411}
412
413int sysfs__read_str(const char *entry, char **buf, size_t *sizep)
414{
415 char path[PATH_MAX];
416 const char *sysfs = sysfs__mountpoint();
417
418 if (!sysfs)
419 return -1;
420
421 snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
422
423 return filename__read_str(path, buf, sizep);
424}
425
426int sysctl__read_int(const char *sysctl, int *value)
427{
428 char path[PATH_MAX];
429 const char *procfs = procfs__mountpoint();
430
431 if (!procfs)
432 return -1;
433
434 snprintf(path, sizeof(path), "%s/sys/%s", procfs, sysctl);
435
436 return filename__read_int(path, value);
437}
1// SPDX-License-Identifier: GPL-2.0
2#include <ctype.h>
3#include <errno.h>
4#include <limits.h>
5#include <stdbool.h>
6#include <stdio.h>
7#include <stdlib.h>
8#include <string.h>
9#include <sys/vfs.h>
10#include <sys/types.h>
11#include <sys/stat.h>
12#include <fcntl.h>
13#include <unistd.h>
14#include <sys/mount.h>
15
16#include "fs.h"
17#include "debug-internal.h"
18
19#define _STR(x) #x
20#define STR(x) _STR(x)
21
22#ifndef SYSFS_MAGIC
23#define SYSFS_MAGIC 0x62656572
24#endif
25
26#ifndef PROC_SUPER_MAGIC
27#define PROC_SUPER_MAGIC 0x9fa0
28#endif
29
30#ifndef DEBUGFS_MAGIC
31#define DEBUGFS_MAGIC 0x64626720
32#endif
33
34#ifndef TRACEFS_MAGIC
35#define TRACEFS_MAGIC 0x74726163
36#endif
37
38#ifndef HUGETLBFS_MAGIC
39#define HUGETLBFS_MAGIC 0x958458f6
40#endif
41
42#ifndef BPF_FS_MAGIC
43#define BPF_FS_MAGIC 0xcafe4a11
44#endif
45
46static const char * const sysfs__fs_known_mountpoints[] = {
47 "/sys",
48 0,
49};
50
51static const char * const procfs__known_mountpoints[] = {
52 "/proc",
53 0,
54};
55
56#ifndef DEBUGFS_DEFAULT_PATH
57#define DEBUGFS_DEFAULT_PATH "/sys/kernel/debug"
58#endif
59
60static const char * const debugfs__known_mountpoints[] = {
61 DEBUGFS_DEFAULT_PATH,
62 "/debug",
63 0,
64};
65
66
67#ifndef TRACEFS_DEFAULT_PATH
68#define TRACEFS_DEFAULT_PATH "/sys/kernel/tracing"
69#endif
70
71static const char * const tracefs__known_mountpoints[] = {
72 TRACEFS_DEFAULT_PATH,
73 "/sys/kernel/debug/tracing",
74 "/tracing",
75 "/trace",
76 0,
77};
78
79static const char * const hugetlbfs__known_mountpoints[] = {
80 0,
81};
82
83static const char * const bpf_fs__known_mountpoints[] = {
84 "/sys/fs/bpf",
85 0,
86};
87
88struct fs {
89 const char *name;
90 const char * const *mounts;
91 char path[PATH_MAX];
92 bool found;
93 bool checked;
94 long magic;
95};
96
97enum {
98 FS__SYSFS = 0,
99 FS__PROCFS = 1,
100 FS__DEBUGFS = 2,
101 FS__TRACEFS = 3,
102 FS__HUGETLBFS = 4,
103 FS__BPF_FS = 5,
104};
105
106#ifndef TRACEFS_MAGIC
107#define TRACEFS_MAGIC 0x74726163
108#endif
109
110static struct fs fs__entries[] = {
111 [FS__SYSFS] = {
112 .name = "sysfs",
113 .mounts = sysfs__fs_known_mountpoints,
114 .magic = SYSFS_MAGIC,
115 .checked = false,
116 },
117 [FS__PROCFS] = {
118 .name = "proc",
119 .mounts = procfs__known_mountpoints,
120 .magic = PROC_SUPER_MAGIC,
121 .checked = false,
122 },
123 [FS__DEBUGFS] = {
124 .name = "debugfs",
125 .mounts = debugfs__known_mountpoints,
126 .magic = DEBUGFS_MAGIC,
127 .checked = false,
128 },
129 [FS__TRACEFS] = {
130 .name = "tracefs",
131 .mounts = tracefs__known_mountpoints,
132 .magic = TRACEFS_MAGIC,
133 .checked = false,
134 },
135 [FS__HUGETLBFS] = {
136 .name = "hugetlbfs",
137 .mounts = hugetlbfs__known_mountpoints,
138 .magic = HUGETLBFS_MAGIC,
139 .checked = false,
140 },
141 [FS__BPF_FS] = {
142 .name = "bpf",
143 .mounts = bpf_fs__known_mountpoints,
144 .magic = BPF_FS_MAGIC,
145 .checked = false,
146 },
147};
148
149static bool fs__read_mounts(struct fs *fs)
150{
151 bool found = false;
152 char type[100];
153 FILE *fp;
154
155 fp = fopen("/proc/mounts", "r");
156 if (fp == NULL)
157 return NULL;
158
159 while (!found &&
160 fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
161 fs->path, type) == 2) {
162
163 if (strcmp(type, fs->name) == 0)
164 found = true;
165 }
166
167 fclose(fp);
168 fs->checked = true;
169 return fs->found = found;
170}
171
172static int fs__valid_mount(const char *fs, long magic)
173{
174 struct statfs st_fs;
175
176 if (statfs(fs, &st_fs) < 0)
177 return -ENOENT;
178 else if ((long)st_fs.f_type != magic)
179 return -ENOENT;
180
181 return 0;
182}
183
184static bool fs__check_mounts(struct fs *fs)
185{
186 const char * const *ptr;
187
188 ptr = fs->mounts;
189 while (*ptr) {
190 if (fs__valid_mount(*ptr, fs->magic) == 0) {
191 fs->found = true;
192 strcpy(fs->path, *ptr);
193 return true;
194 }
195 ptr++;
196 }
197
198 return false;
199}
200
201static void mem_toupper(char *f, size_t len)
202{
203 while (len) {
204 *f = toupper(*f);
205 f++;
206 len--;
207 }
208}
209
210/*
211 * Check for "NAME_PATH" environment variable to override fs location (for
212 * testing). This matches the recommendation in Documentation/admin-guide/sysfs-rules.rst
213 * for SYSFS_PATH.
214 */
215static bool fs__env_override(struct fs *fs)
216{
217 char *override_path;
218 size_t name_len = strlen(fs->name);
219 /* name + "_PATH" + '\0' */
220 char upper_name[name_len + 5 + 1];
221
222 memcpy(upper_name, fs->name, name_len);
223 mem_toupper(upper_name, name_len);
224 strcpy(&upper_name[name_len], "_PATH");
225
226 override_path = getenv(upper_name);
227 if (!override_path)
228 return false;
229
230 fs->found = true;
231 fs->checked = true;
232 strncpy(fs->path, override_path, sizeof(fs->path) - 1);
233 fs->path[sizeof(fs->path) - 1] = '\0';
234 return true;
235}
236
237static const char *fs__get_mountpoint(struct fs *fs)
238{
239 if (fs__env_override(fs))
240 return fs->path;
241
242 if (fs__check_mounts(fs))
243 return fs->path;
244
245 if (fs__read_mounts(fs))
246 return fs->path;
247
248 return NULL;
249}
250
251static const char *fs__mountpoint(int idx)
252{
253 struct fs *fs = &fs__entries[idx];
254
255 if (fs->found)
256 return (const char *)fs->path;
257
258 /* the mount point was already checked for the mount point
259 * but and did not exist, so return NULL to avoid scanning again.
260 * This makes the found and not found paths cost equivalent
261 * in case of multiple calls.
262 */
263 if (fs->checked)
264 return NULL;
265
266 return fs__get_mountpoint(fs);
267}
268
269static const char *mount_overload(struct fs *fs)
270{
271 size_t name_len = strlen(fs->name);
272 /* "PERF_" + name + "_ENVIRONMENT" + '\0' */
273 char upper_name[5 + name_len + 12 + 1];
274
275 snprintf(upper_name, name_len, "PERF_%s_ENVIRONMENT", fs->name);
276 mem_toupper(upper_name, name_len);
277
278 return getenv(upper_name) ?: *fs->mounts;
279}
280
281static const char *fs__mount(int idx)
282{
283 struct fs *fs = &fs__entries[idx];
284 const char *mountpoint;
285
286 if (fs__mountpoint(idx))
287 return (const char *)fs->path;
288
289 mountpoint = mount_overload(fs);
290
291 if (mount(NULL, mountpoint, fs->name, 0, NULL) < 0)
292 return NULL;
293
294 return fs__check_mounts(fs) ? fs->path : NULL;
295}
296
297#define FS(name, idx) \
298const char *name##__mountpoint(void) \
299{ \
300 return fs__mountpoint(idx); \
301} \
302 \
303const char *name##__mount(void) \
304{ \
305 return fs__mount(idx); \
306} \
307 \
308bool name##__configured(void) \
309{ \
310 return name##__mountpoint() != NULL; \
311}
312
313FS(sysfs, FS__SYSFS);
314FS(procfs, FS__PROCFS);
315FS(debugfs, FS__DEBUGFS);
316FS(tracefs, FS__TRACEFS);
317FS(hugetlbfs, FS__HUGETLBFS);
318FS(bpf_fs, FS__BPF_FS);
319
320int filename__read_int(const char *filename, int *value)
321{
322 char line[64];
323 int fd = open(filename, O_RDONLY), err = -1;
324
325 if (fd < 0)
326 return -1;
327
328 if (read(fd, line, sizeof(line)) > 0) {
329 *value = atoi(line);
330 err = 0;
331 }
332
333 close(fd);
334 return err;
335}
336
337static int filename__read_ull_base(const char *filename,
338 unsigned long long *value, int base)
339{
340 char line[64];
341 int fd = open(filename, O_RDONLY), err = -1;
342
343 if (fd < 0)
344 return -1;
345
346 if (read(fd, line, sizeof(line)) > 0) {
347 *value = strtoull(line, NULL, base);
348 if (*value != ULLONG_MAX)
349 err = 0;
350 }
351
352 close(fd);
353 return err;
354}
355
356/*
357 * Parses @value out of @filename with strtoull.
358 * By using 16 for base to treat the number as hex.
359 */
360int filename__read_xll(const char *filename, unsigned long long *value)
361{
362 return filename__read_ull_base(filename, value, 16);
363}
364
365/*
366 * Parses @value out of @filename with strtoull.
367 * By using 0 for base, the strtoull detects the
368 * base automatically (see man strtoull).
369 */
370int filename__read_ull(const char *filename, unsigned long long *value)
371{
372 return filename__read_ull_base(filename, value, 0);
373}
374
375#define STRERR_BUFSIZE 128 /* For the buffer size of strerror_r */
376
377int filename__read_str(const char *filename, char **buf, size_t *sizep)
378{
379 size_t size = 0, alloc_size = 0;
380 void *bf = NULL, *nbf;
381 int fd, n, err = 0;
382 char sbuf[STRERR_BUFSIZE];
383
384 fd = open(filename, O_RDONLY);
385 if (fd < 0)
386 return -errno;
387
388 do {
389 if (size == alloc_size) {
390 alloc_size += BUFSIZ;
391 nbf = realloc(bf, alloc_size);
392 if (!nbf) {
393 err = -ENOMEM;
394 break;
395 }
396
397 bf = nbf;
398 }
399
400 n = read(fd, bf + size, alloc_size - size);
401 if (n < 0) {
402 if (size) {
403 pr_warn("read failed %d: %s\n", errno,
404 strerror_r(errno, sbuf, sizeof(sbuf)));
405 err = 0;
406 } else
407 err = -errno;
408
409 break;
410 }
411
412 size += n;
413 } while (n > 0);
414
415 if (!err) {
416 *sizep = size;
417 *buf = bf;
418 } else
419 free(bf);
420
421 close(fd);
422 return err;
423}
424
425int filename__write_int(const char *filename, int value)
426{
427 int fd = open(filename, O_WRONLY), err = -1;
428 char buf[64];
429
430 if (fd < 0)
431 return err;
432
433 sprintf(buf, "%d", value);
434 if (write(fd, buf, sizeof(buf)) == sizeof(buf))
435 err = 0;
436
437 close(fd);
438 return err;
439}
440
441int procfs__read_str(const char *entry, char **buf, size_t *sizep)
442{
443 char path[PATH_MAX];
444 const char *procfs = procfs__mountpoint();
445
446 if (!procfs)
447 return -1;
448
449 snprintf(path, sizeof(path), "%s/%s", procfs, entry);
450
451 return filename__read_str(path, buf, sizep);
452}
453
454static int sysfs__read_ull_base(const char *entry,
455 unsigned long long *value, int base)
456{
457 char path[PATH_MAX];
458 const char *sysfs = sysfs__mountpoint();
459
460 if (!sysfs)
461 return -1;
462
463 snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
464
465 return filename__read_ull_base(path, value, base);
466}
467
468int sysfs__read_xll(const char *entry, unsigned long long *value)
469{
470 return sysfs__read_ull_base(entry, value, 16);
471}
472
473int sysfs__read_ull(const char *entry, unsigned long long *value)
474{
475 return sysfs__read_ull_base(entry, value, 0);
476}
477
478int sysfs__read_int(const char *entry, int *value)
479{
480 char path[PATH_MAX];
481 const char *sysfs = sysfs__mountpoint();
482
483 if (!sysfs)
484 return -1;
485
486 snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
487
488 return filename__read_int(path, value);
489}
490
491int sysfs__read_str(const char *entry, char **buf, size_t *sizep)
492{
493 char path[PATH_MAX];
494 const char *sysfs = sysfs__mountpoint();
495
496 if (!sysfs)
497 return -1;
498
499 snprintf(path, sizeof(path), "%s/%s", sysfs, entry);
500
501 return filename__read_str(path, buf, sizep);
502}
503
504int sysfs__read_bool(const char *entry, bool *value)
505{
506 char *buf;
507 size_t size;
508 int ret;
509
510 ret = sysfs__read_str(entry, &buf, &size);
511 if (ret < 0)
512 return ret;
513
514 switch (buf[0]) {
515 case '1':
516 case 'y':
517 case 'Y':
518 *value = true;
519 break;
520 case '0':
521 case 'n':
522 case 'N':
523 *value = false;
524 break;
525 default:
526 ret = -1;
527 }
528
529 free(buf);
530
531 return ret;
532}
533int sysctl__read_int(const char *sysctl, int *value)
534{
535 char path[PATH_MAX];
536 const char *procfs = procfs__mountpoint();
537
538 if (!procfs)
539 return -1;
540
541 snprintf(path, sizeof(path), "%s/sys/%s", procfs, sysctl);
542
543 return filename__read_int(path, value);
544}
545
546int sysfs__write_int(const char *entry, int value)
547{
548 char path[PATH_MAX];
549 const char *sysfs = sysfs__mountpoint();
550
551 if (!sysfs)
552 return -1;
553
554 if (snprintf(path, sizeof(path), "%s/%s", sysfs, entry) >= PATH_MAX)
555 return -1;
556
557 return filename__write_int(path, value);
558}