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
perf_set_singlethreaded(void)35 void perf_set_singlethreaded(void)
36 {
37 perf_singlethreaded = true;
38 }
39
perf_set_multithreaded(void)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
sysctl__max_stack(void)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
sysctl__nmi_watchdog_enabled(void)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
event_attr_init(struct perf_event_attr * attr)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
mkdir_p(char * path,mode_t mode)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
match_pat(char * file,const char ** pat)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 */
rm_rf_depth_pat(const char * path,int depth,const char ** pat)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
rm_rf_a_kcore_dir(const char * path,const char * name)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
kcore_dir_filter(const char * name __maybe_unused,struct dirent * d)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
rm_rf_kcore_dir(const char * path)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
rm_rf_perf_data(const char * path)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
rm_rf(const char * path)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 */
lsdir_no_dot_filter(const char * name __maybe_unused,struct dirent * d)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 */
lsdir(const char * name,bool (* filter)(const char *,struct dirent *))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
hex_width(u64 v)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
perf_event_paranoid(void)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
perf_event_paranoid_check(int max_level)326 bool perf_event_paranoid_check(int max_level)
327 {
328 bool used_root;
329
330 if (perf_cap__capable(CAP_SYS_ADMIN, &used_root))
331 return true;
332
333 if (!used_root && perf_cap__capable(CAP_PERFMON, &used_root))
334 return true;
335
336 return perf_event_paranoid() <= max_level;
337 }
338
339 static int
fetch_ubuntu_kernel_version(unsigned int * puint)340 fetch_ubuntu_kernel_version(unsigned int *puint)
341 {
342 ssize_t len;
343 size_t line_len = 0;
344 char *ptr, *line = NULL;
345 int version, patchlevel, sublevel, err;
346 FILE *vsig;
347
348 if (!puint)
349 return 0;
350
351 vsig = fopen("/proc/version_signature", "r");
352 if (!vsig) {
353 pr_debug("Open /proc/version_signature failed: %s\n",
354 strerror(errno));
355 return -1;
356 }
357
358 len = getline(&line, &line_len, vsig);
359 fclose(vsig);
360 err = -1;
361 if (len <= 0) {
362 pr_debug("Reading from /proc/version_signature failed: %s\n",
363 strerror(errno));
364 goto errout;
365 }
366
367 ptr = strrchr(line, ' ');
368 if (!ptr) {
369 pr_debug("Parsing /proc/version_signature failed: %s\n", line);
370 goto errout;
371 }
372
373 err = sscanf(ptr + 1, "%d.%d.%d",
374 &version, &patchlevel, &sublevel);
375 if (err != 3) {
376 pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
377 line);
378 goto errout;
379 }
380
381 *puint = (version << 16) + (patchlevel << 8) + sublevel;
382 err = 0;
383 errout:
384 free(line);
385 return err;
386 }
387
388 int
fetch_kernel_version(unsigned int * puint,char * str,size_t str_size)389 fetch_kernel_version(unsigned int *puint, char *str,
390 size_t str_size)
391 {
392 struct utsname utsname;
393 int version, patchlevel, sublevel, err;
394 bool int_ver_ready = false;
395
396 if (access("/proc/version_signature", R_OK) == 0)
397 if (!fetch_ubuntu_kernel_version(puint))
398 int_ver_ready = true;
399
400 if (uname(&utsname))
401 return -1;
402
403 if (str && str_size) {
404 strncpy(str, utsname.release, str_size);
405 str[str_size - 1] = '\0';
406 }
407
408 if (!puint || int_ver_ready)
409 return 0;
410
411 err = sscanf(utsname.release, "%d.%d.%d",
412 &version, &patchlevel, &sublevel);
413
414 if (err != 3) {
415 pr_debug("Unable to get kernel version from uname '%s'\n",
416 utsname.release);
417 return -1;
418 }
419
420 *puint = (version << 16) + (patchlevel << 8) + sublevel;
421 return 0;
422 }
423
perf_tip(char ** strp,const char * dirpath)424 int perf_tip(char **strp, const char *dirpath)
425 {
426 struct strlist *tips;
427 struct str_node *node;
428 struct strlist_config conf = {
429 .dirname = dirpath,
430 .file_only = true,
431 };
432 int ret = 0;
433
434 *strp = NULL;
435 tips = strlist__new("tips.txt", &conf);
436 if (tips == NULL)
437 return -errno;
438
439 if (strlist__nr_entries(tips) == 0)
440 goto out;
441
442 node = strlist__entry(tips, random() % strlist__nr_entries(tips));
443 if (asprintf(strp, "Tip: %s", node->s) < 0)
444 ret = -ENOMEM;
445
446 out:
447 strlist__delete(tips);
448
449 return ret;
450 }
451
perf_exe(char * buf,int len)452 char *perf_exe(char *buf, int len)
453 {
454 int n = readlink("/proc/self/exe", buf, len);
455 if (n > 0) {
456 buf[n] = 0;
457 return buf;
458 }
459 return strcpy(buf, "perf");
460 }
461
perf_debuginfod_setup(struct perf_debuginfod * di)462 void perf_debuginfod_setup(struct perf_debuginfod *di)
463 {
464 /*
465 * By default '!di->set' we clear DEBUGINFOD_URLS, so debuginfod
466 * processing is not triggered, otherwise we set it to 'di->urls'
467 * value. If 'di->urls' is "system" we keep DEBUGINFOD_URLS value.
468 */
469 if (!di->set)
470 setenv("DEBUGINFOD_URLS", "", 1);
471 else if (di->urls && strcmp(di->urls, "system"))
472 setenv("DEBUGINFOD_URLS", di->urls, 1);
473
474 pr_debug("DEBUGINFOD_URLS=%s\n", getenv("DEBUGINFOD_URLS"));
475
476 #ifndef HAVE_DEBUGINFOD_SUPPORT
477 if (di->set)
478 pr_warning("WARNING: debuginfod support requested, but perf is not built with it\n");
479 #endif
480 }
481
482 /*
483 * Return a new filename prepended with task's root directory if it's in
484 * a chroot. Callers should free the returned string.
485 */
filename_with_chroot(int pid,const char * filename)486 char *filename_with_chroot(int pid, const char *filename)
487 {
488 char buf[PATH_MAX];
489 char proc_root[32];
490 char *new_name = NULL;
491 int ret;
492
493 scnprintf(proc_root, sizeof(proc_root), "/proc/%d/root", pid);
494 ret = readlink(proc_root, buf, sizeof(buf) - 1);
495 if (ret <= 0)
496 return NULL;
497
498 /* readlink(2) does not append a null byte to buf */
499 buf[ret] = '\0';
500
501 if (!strcmp(buf, "/"))
502 return NULL;
503
504 if (strstr(buf, "(deleted)"))
505 return NULL;
506
507 if (asprintf(&new_name, "%s/%s", buf, filename) < 0)
508 return NULL;
509
510 return new_name;
511 }
512
513 /*
514 * Reallocate an array *arr of size *arr_sz so that it is big enough to contain
515 * x elements of size msz, initializing new entries to *init_val or zero if
516 * init_val is NULL
517 */
do_realloc_array_as_needed(void ** arr,size_t * arr_sz,size_t x,size_t msz,const void * init_val)518 int do_realloc_array_as_needed(void **arr, size_t *arr_sz, size_t x, size_t msz, const void *init_val)
519 {
520 size_t new_sz = *arr_sz;
521 void *new_arr;
522 size_t i;
523
524 if (!new_sz)
525 new_sz = msz >= 64 ? 1 : roundup(64, msz); /* Start with at least 64 bytes */
526 while (x >= new_sz) {
527 if (check_mul_overflow(new_sz, (size_t)2, &new_sz))
528 return -ENOMEM;
529 }
530 if (new_sz == *arr_sz)
531 return 0;
532 new_arr = calloc(new_sz, msz);
533 if (!new_arr)
534 return -ENOMEM;
535 if (*arr_sz)
536 memcpy(new_arr, *arr, *arr_sz * msz);
537 if (init_val) {
538 for (i = *arr_sz; i < new_sz; i++)
539 memcpy(new_arr + (i * msz), init_val, msz);
540 }
541 *arr = new_arr;
542 *arr_sz = new_sz;
543 return 0;
544 }
545
546 #ifndef HAVE_SCHED_GETCPU_SUPPORT
sched_getcpu(void)547 int sched_getcpu(void)
548 {
549 #ifdef __NR_getcpu
550 unsigned int cpu;
551 int err = syscall(__NR_getcpu, &cpu, NULL, NULL);
552
553 if (!err)
554 return cpu;
555 #else
556 errno = ENOSYS;
557 #endif
558 return -1;
559 }
560 #endif
561
562 #ifndef HAVE_SCANDIRAT_SUPPORT
scandirat(int dirfd,const char * dirp,struct dirent *** namelist,int (* filter)(const struct dirent *),int (* compar)(const struct dirent **,const struct dirent **))563 int scandirat(int dirfd, const char *dirp,
564 struct dirent ***namelist,
565 int (*filter)(const struct dirent *),
566 int (*compar)(const struct dirent **, const struct dirent **))
567 {
568 char path[PATH_MAX];
569 int err, fd = openat(dirfd, dirp, O_PATH);
570
571 if (fd < 0)
572 return fd;
573
574 snprintf(path, sizeof(path), "/proc/%d/fd/%d", getpid(), fd);
575 err = scandir(path, namelist, filter, compar);
576 close(fd);
577 return err;
578 }
579 #endif
580