1 // SPDX-License-Identifier: GPL-2.0
2 #include "util.h"
3 #include "debug.h"
4 #include "event.h"
5 #include <api/fs/fs.h>
6 #include <sys/stat.h>
7 #include <sys/utsname.h>
8 #include <dirent.h>
9 #include <fcntl.h>
10 #include <inttypes.h>
11 #include <signal.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <errno.h>
16 #include <limits.h>
17 #include <linux/capability.h>
18 #include <linux/kernel.h>
19 #include <linux/log2.h>
20 #include <linux/time64.h>
21 #include <linux/overflow.h>
22 #include <unistd.h>
23 #include "cap.h"
24 #include "strlist.h"
25 #include "string2.h"
26
27 /*
28 * XXX We need to find a better place for these things...
29 */
30
31 const char *input_name;
32
33 bool perf_singlethreaded = true;
34
35 void perf_set_singlethreaded(void)
36 {
37 perf_singlethreaded = true;
38 }
39
40 void perf_set_multithreaded(void)
41 {
42 perf_singlethreaded = false;
43 }
44
45 int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
46 int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;
47
48 int sysctl__max_stack(void)
49 {
50 int value;
51
52 if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
53 sysctl_perf_event_max_stack = value;
54
55 if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
56 sysctl_perf_event_max_contexts_per_stack = value;
57
58 return sysctl_perf_event_max_stack;
59 }
60
61 bool sysctl__nmi_watchdog_enabled(void)
62 {
63 static bool cached;
64 static bool nmi_watchdog;
65 int value;
66
67 if (cached)
68 return nmi_watchdog;
69
70 if (sysctl__read_int("kernel/nmi_watchdog", &value) < 0)
71 return false;
72
73 nmi_watchdog = (value > 0) ? true : false;
74 cached = true;
75
76 return nmi_watchdog;
77 }
78
79 bool test_attr__enabled;
80
81 bool perf_host = true;
82 bool perf_guest = false;
83
84 void event_attr_init(struct perf_event_attr *attr)
85 {
86 if (!perf_host)
87 attr->exclude_host = 1;
88 if (!perf_guest)
89 attr->exclude_guest = 1;
90 /* to capture ABI version */
91 attr->size = sizeof(*attr);
92 }
93
94 int mkdir_p(char *path, mode_t mode)
95 {
96 struct stat st;
97 int err;
98 char *d = path;
99
100 if (*d != '/')
101 return -1;
102
103 if (stat(path, &st) == 0)
104 return 0;
105
106 while (*++d == '/');
107
108 while ((d = strchr(d, '/'))) {
109 *d = '\0';
110 err = stat(path, &st) && mkdir(path, mode);
111 *d++ = '/';
112 if (err)
113 return -1;
114 while (*d == '/')
115 ++d;
116 }
117 return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
118 }
119
120 static bool match_pat(char *file, const char **pat)
121 {
122 int i = 0;
123
124 if (!pat)
125 return true;
126
127 while (pat[i]) {
128 if (strglobmatch(file, pat[i]))
129 return true;
130
131 i++;
132 }
133
134 return false;
135 }
136
137 /*
138 * The depth specify how deep the removal will go.
139 * 0 - will remove only files under the 'path' directory
140 * 1 .. x - will dive in x-level deep under the 'path' directory
141 *
142 * If specified the pat is array of string patterns ended with NULL,
143 * which are checked upon every file/directory found. Only matching
144 * ones are removed.
145 *
146 * The function returns:
147 * 0 on success
148 * -1 on removal failure with errno set
149 * -2 on pattern failure
150 */
151 static int rm_rf_depth_pat(const char *path, int depth, const char **pat)
152 {
153 DIR *dir;
154 int ret;
155 struct dirent *d;
156 char namebuf[PATH_MAX];
157 struct stat statbuf;
158
159 /* Do not fail if there's no file. */
160 ret = lstat(path, &statbuf);
161 if (ret)
162 return 0;
163
164 /* Try to remove any file we get. */
165 if (!(statbuf.st_mode & S_IFDIR))
166 return unlink(path);
167
168 /* We have directory in path. */
169 dir = opendir(path);
170 if (dir == NULL)
171 return -1;
172
173 while ((d = readdir(dir)) != NULL && !ret) {
174
175 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
176 continue;
177
178 if (!match_pat(d->d_name, pat)) {
179 ret = -2;
180 break;
181 }
182
183 scnprintf(namebuf, sizeof(namebuf), "%s/%s",
184 path, d->d_name);
185
186 /* We have to check symbolic link itself */
187 ret = lstat(namebuf, &statbuf);
188 if (ret < 0) {
189 pr_debug("stat failed: %s\n", namebuf);
190 break;
191 }
192
193 if (S_ISDIR(statbuf.st_mode))
194 ret = depth ? rm_rf_depth_pat(namebuf, depth - 1, pat) : 0;
195 else
196 ret = unlink(namebuf);
197 }
198 closedir(dir);
199
200 if (ret < 0)
201 return ret;
202
203 return rmdir(path);
204 }
205
206 static int rm_rf_a_kcore_dir(const char *path, const char *name)
207 {
208 char kcore_dir_path[PATH_MAX];
209 const char *pat[] = {
210 "kcore",
211 "kallsyms",
212 "modules",
213 NULL,
214 };
215
216 snprintf(kcore_dir_path, sizeof(kcore_dir_path), "%s/%s", path, name);
217
218 return rm_rf_depth_pat(kcore_dir_path, 0, pat);
219 }
220
221 static bool kcore_dir_filter(const char *name __maybe_unused, struct dirent *d)
222 {
223 const char *pat[] = {
224 "kcore_dir",
225 "kcore_dir__[1-9]*",
226 NULL,
227 };
228
229 return match_pat(d->d_name, pat);
230 }
231
232 static int rm_rf_kcore_dir(const char *path)
233 {
234 struct strlist *kcore_dirs;
235 struct str_node *nd;
236 int ret;
237
238 kcore_dirs = lsdir(path, kcore_dir_filter);
239
240 if (!kcore_dirs)
241 return 0;
242
243 strlist__for_each_entry(nd, kcore_dirs) {
244 ret = rm_rf_a_kcore_dir(path, nd->s);
245 if (ret)
246 return ret;
247 }
248
249 strlist__delete(kcore_dirs);
250
251 return 0;
252 }
253
254 int rm_rf_perf_data(const char *path)
255 {
256 const char *pat[] = {
257 "data",
258 "data.*",
259 NULL,
260 };
261
262 rm_rf_kcore_dir(path);
263
264 return rm_rf_depth_pat(path, 0, pat);
265 }
266
267 int rm_rf(const char *path)
268 {
269 return rm_rf_depth_pat(path, INT_MAX, NULL);
270 }
271
272 /* A filter which removes dot files */
273 bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
274 {
275 return d->d_name[0] != '.';
276 }
277
278 /* lsdir reads a directory and store it in strlist */
279 struct strlist *lsdir(const char *name,
280 bool (*filter)(const char *, struct dirent *))
281 {
282 struct strlist *list = NULL;
283 DIR *dir;
284 struct dirent *d;
285
286 dir = opendir(name);
287 if (!dir)
288 return NULL;
289
290 list = strlist__new(NULL, NULL);
291 if (!list) {
292 errno = ENOMEM;
293 goto out;
294 }
295
296 while ((d = readdir(dir)) != NULL) {
297 if (!filter || filter(name, d))
298 strlist__add(list, d->d_name);
299 }
300
301 out:
302 closedir(dir);
303 return list;
304 }
305
306 size_t hex_width(u64 v)
307 {
308 size_t n = 1;
309
310 while ((v >>= 4))
311 ++n;
312
313 return n;
314 }
315
316 int perf_event_paranoid(void)
317 {
318 int value;
319
320 if (sysctl__read_int("kernel/perf_event_paranoid", &value))
321 return INT_MAX;
322
323 return value;
324 }
325
326 bool perf_event_paranoid_check(int max_level)
327 {
328 return perf_cap__capable(CAP_SYS_ADMIN) ||
329 perf_cap__capable(CAP_PERFMON) ||
330 perf_event_paranoid() <= max_level;
331 }
332
333 static int
334 fetch_ubuntu_kernel_version(unsigned int *puint)
335 {
336 ssize_t len;
337 size_t line_len = 0;
338 char *ptr, *line = NULL;
339 int version, patchlevel, sublevel, err;
340 FILE *vsig;
341
342 if (!puint)
343 return 0;
344
345 vsig = fopen("/proc/version_signature", "r");
346 if (!vsig) {
347 pr_debug("Open /proc/version_signature failed: %s\n",
348 strerror(errno));
349 return -1;
350 }
351
352 len = getline(&line, &line_len, vsig);
353 fclose(vsig);
354 err = -1;
355 if (len <= 0) {
356 pr_debug("Reading from /proc/version_signature failed: %s\n",
357 strerror(errno));
358 goto errout;
359 }
360
361 ptr = strrchr(line, ' ');
362 if (!ptr) {
363 pr_debug("Parsing /proc/version_signature failed: %s\n", line);
364 goto errout;
365 }
366
367 err = sscanf(ptr + 1, "%d.%d.%d",
368 &version, &patchlevel, &sublevel);
369 if (err != 3) {
370 pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
371 line);
372 goto errout;
373 }
374
375 *puint = (version << 16) + (patchlevel << 8) + sublevel;
376 err = 0;
377 errout:
378 free(line);
379 return err;
380 }
381
382 int
383 fetch_kernel_version(unsigned int *puint, char *str,
384 size_t str_size)
385 {
386 struct utsname utsname;
387 int version, patchlevel, sublevel, err;
388 bool int_ver_ready = false;
389
390 if (access("/proc/version_signature", R_OK) == 0)
391 if (!fetch_ubuntu_kernel_version(puint))
392 int_ver_ready = true;
393
394 if (uname(&utsname))
395 return -1;
396
397 if (str && str_size) {
398 strncpy(str, utsname.release, str_size);
399 str[str_size - 1] = '\0';
400 }
401
402 if (!puint || int_ver_ready)
403 return 0;
404
405 err = sscanf(utsname.release, "%d.%d.%d",
406 &version, &patchlevel, &sublevel);
407
408 if (err != 3) {
409 pr_debug("Unable to get kernel version from uname '%s'\n",
410 utsname.release);
411 return -1;
412 }
413
414 *puint = (version << 16) + (patchlevel << 8) + sublevel;
415 return 0;
416 }
417
418 int perf_tip(char **strp, const char *dirpath)
419 {
420 struct strlist *tips;
421 struct str_node *node;
422 struct strlist_config conf = {
423 .dirname = dirpath,
424 .file_only = true,
425 };
426 int ret = 0;
427
428 *strp = NULL;
429 tips = strlist__new("tips.txt", &conf);
430 if (tips == NULL)
431 return -errno;
432
433 if (strlist__nr_entries(tips) == 0)
434 goto out;
435
436 node = strlist__entry(tips, random() % strlist__nr_entries(tips));
437 if (asprintf(strp, "Tip: %s", node->s) < 0)
438 ret = -ENOMEM;
439
440 out:
441 strlist__delete(tips);
442
443 return ret;
444 }
445
446 char *perf_exe(char *buf, int len)
447 {
448 int n = readlink("/proc/self/exe", buf, len);
449 if (n > 0) {
450 buf[n] = 0;
451 return buf;
452 }
453 return strcpy(buf, "perf");
454 }
455
456 void perf_debuginfod_setup(struct perf_debuginfod *di)
457 {
458 /*
459 * By default '!di->set' we clear DEBUGINFOD_URLS, so debuginfod
460 * processing is not triggered, otherwise we set it to 'di->urls'
461 * value. If 'di->urls' is "system" we keep DEBUGINFOD_URLS value.
462 */
463 if (!di->set)
464 setenv("DEBUGINFOD_URLS", "", 1);
465 else if (di->urls && strcmp(di->urls, "system"))
466 setenv("DEBUGINFOD_URLS", di->urls, 1);
467
468 pr_debug("DEBUGINFOD_URLS=%s\n", getenv("DEBUGINFOD_URLS"));
469
470 #ifndef HAVE_DEBUGINFOD_SUPPORT
471 if (di->set)
472 pr_warning("WARNING: debuginfod support requested, but perf is not built with it\n");
473 #endif
474 }
475
476 /*
477 * Return a new filename prepended with task's root directory if it's in
478 * a chroot. Callers should free the returned string.
479 */
480 char *filename_with_chroot(int pid, const char *filename)
481 {
482 char buf[PATH_MAX];
483 char proc_root[32];
484 char *new_name = NULL;
485 int ret;
486
487 scnprintf(proc_root, sizeof(proc_root), "/proc/%d/root", pid);
488 ret = readlink(proc_root, buf, sizeof(buf) - 1);
489 if (ret <= 0)
490 return NULL;
491
492 /* readlink(2) does not append a null byte to buf */
493 buf[ret] = '\0';
494
495 if (!strcmp(buf, "/"))
496 return NULL;
497
498 if (strstr(buf, "(deleted)"))
499 return NULL;
500
501 if (asprintf(&new_name, "%s/%s", buf, filename) < 0)
502 return NULL;
503
504 return new_name;
505 }
506
507 /*
508 * Reallocate an array *arr of size *arr_sz so that it is big enough to contain
509 * x elements of size msz, initializing new entries to *init_val or zero if
510 * init_val is NULL
511 */
512 int do_realloc_array_as_needed(void **arr, size_t *arr_sz, size_t x, size_t msz, const void *init_val)
513 {
514 size_t new_sz = *arr_sz;
515 void *new_arr;
516 size_t i;
517
518 if (!new_sz)
519 new_sz = msz >= 64 ? 1 : roundup(64, msz); /* Start with at least 64 bytes */
520 while (x >= new_sz) {
521 if (check_mul_overflow(new_sz, (size_t)2, &new_sz))
522 return -ENOMEM;
523 }
524 if (new_sz == *arr_sz)
525 return 0;
526 new_arr = calloc(new_sz, msz);
527 if (!new_arr)
528 return -ENOMEM;
529 if (*arr_sz)
530 memcpy(new_arr, *arr, *arr_sz * msz);
531 if (init_val) {
532 for (i = *arr_sz; i < new_sz; i++)
533 memcpy(new_arr + (i * msz), init_val, msz);
534 }
535 *arr = new_arr;
536 *arr_sz = new_sz;
537 return 0;
538 }
539
540 #ifndef HAVE_SCHED_GETCPU_SUPPORT
541 int sched_getcpu(void)
542 {
543 #ifdef __NR_getcpu
544 unsigned int cpu;
545 int err = syscall(__NR_getcpu, &cpu, NULL, NULL);
546
547 if (!err)
548 return cpu;
549 #else
550 errno = ENOSYS;
551 #endif
552 return -1;
553 }
554 #endif
555
556 #ifndef HAVE_SCANDIRAT_SUPPORT
557 int scandirat(int dirfd, const char *dirp,
558 struct dirent ***namelist,
559 int (*filter)(const struct dirent *),
560 int (*compar)(const struct dirent **, const struct dirent **))
561 {
562 char path[PATH_MAX];
563 int err, fd = openat(dirfd, dirp, O_PATH);
564
565 if (fd < 0)
566 return fd;
567
568 snprintf(path, sizeof(path), "/proc/%d/fd/%d", getpid(), fd);
569 err = scandir(path, namelist, filter, compar);
570 close(fd);
571 return err;
572 }
573 #endif
574
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