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1// SPDX-License-Identifier: GPL-2.0
2#include "../perf.h"
3#include "util.h"
4#include "debug.h"
5#include <api/fs/fs.h>
6#include <sys/mman.h>
7#include <sys/stat.h>
8#include <sys/utsname.h>
9#include <dirent.h>
10#include <fcntl.h>
11#include <inttypes.h>
12#include <signal.h>
13#include <stdio.h>
14#include <stdlib.h>
15#include <string.h>
16#include <errno.h>
17#include <limits.h>
18#include <linux/kernel.h>
19#include <linux/log2.h>
20#include <linux/time64.h>
21#include <unistd.h>
22#include "strlist.h"
23
24/*
25 * XXX We need to find a better place for these things...
26 */
27
28bool perf_singlethreaded = true;
29
30void perf_set_singlethreaded(void)
31{
32 perf_singlethreaded = true;
33}
34
35void perf_set_multithreaded(void)
36{
37 perf_singlethreaded = false;
38}
39
40unsigned int page_size;
41int cacheline_size;
42
43int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
44int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;
45
46bool test_attr__enabled;
47
48bool perf_host = true;
49bool perf_guest = false;
50
51void event_attr_init(struct perf_event_attr *attr)
52{
53 if (!perf_host)
54 attr->exclude_host = 1;
55 if (!perf_guest)
56 attr->exclude_guest = 1;
57 /* to capture ABI version */
58 attr->size = sizeof(*attr);
59}
60
61int mkdir_p(char *path, mode_t mode)
62{
63 struct stat st;
64 int err;
65 char *d = path;
66
67 if (*d != '/')
68 return -1;
69
70 if (stat(path, &st) == 0)
71 return 0;
72
73 while (*++d == '/');
74
75 while ((d = strchr(d, '/'))) {
76 *d = '\0';
77 err = stat(path, &st) && mkdir(path, mode);
78 *d++ = '/';
79 if (err)
80 return -1;
81 while (*d == '/')
82 ++d;
83 }
84 return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
85}
86
87int rm_rf(const char *path)
88{
89 DIR *dir;
90 int ret = 0;
91 struct dirent *d;
92 char namebuf[PATH_MAX];
93
94 dir = opendir(path);
95 if (dir == NULL)
96 return 0;
97
98 while ((d = readdir(dir)) != NULL && !ret) {
99 struct stat statbuf;
100
101 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
102 continue;
103
104 scnprintf(namebuf, sizeof(namebuf), "%s/%s",
105 path, d->d_name);
106
107 /* We have to check symbolic link itself */
108 ret = lstat(namebuf, &statbuf);
109 if (ret < 0) {
110 pr_debug("stat failed: %s\n", namebuf);
111 break;
112 }
113
114 if (S_ISDIR(statbuf.st_mode))
115 ret = rm_rf(namebuf);
116 else
117 ret = unlink(namebuf);
118 }
119 closedir(dir);
120
121 if (ret < 0)
122 return ret;
123
124 return rmdir(path);
125}
126
127/* A filter which removes dot files */
128bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
129{
130 return d->d_name[0] != '.';
131}
132
133/* lsdir reads a directory and store it in strlist */
134struct strlist *lsdir(const char *name,
135 bool (*filter)(const char *, struct dirent *))
136{
137 struct strlist *list = NULL;
138 DIR *dir;
139 struct dirent *d;
140
141 dir = opendir(name);
142 if (!dir)
143 return NULL;
144
145 list = strlist__new(NULL, NULL);
146 if (!list) {
147 errno = ENOMEM;
148 goto out;
149 }
150
151 while ((d = readdir(dir)) != NULL) {
152 if (!filter || filter(name, d))
153 strlist__add(list, d->d_name);
154 }
155
156out:
157 closedir(dir);
158 return list;
159}
160
161static int slow_copyfile(const char *from, const char *to, struct nsinfo *nsi)
162{
163 int err = -1;
164 char *line = NULL;
165 size_t n;
166 FILE *from_fp, *to_fp;
167 struct nscookie nsc;
168
169 nsinfo__mountns_enter(nsi, &nsc);
170 from_fp = fopen(from, "r");
171 nsinfo__mountns_exit(&nsc);
172 if (from_fp == NULL)
173 goto out;
174
175 to_fp = fopen(to, "w");
176 if (to_fp == NULL)
177 goto out_fclose_from;
178
179 while (getline(&line, &n, from_fp) > 0)
180 if (fputs(line, to_fp) == EOF)
181 goto out_fclose_to;
182 err = 0;
183out_fclose_to:
184 fclose(to_fp);
185 free(line);
186out_fclose_from:
187 fclose(from_fp);
188out:
189 return err;
190}
191
192static int copyfile_offset(int ifd, loff_t off_in, int ofd, loff_t off_out, u64 size)
193{
194 void *ptr;
195 loff_t pgoff;
196
197 pgoff = off_in & ~(page_size - 1);
198 off_in -= pgoff;
199
200 ptr = mmap(NULL, off_in + size, PROT_READ, MAP_PRIVATE, ifd, pgoff);
201 if (ptr == MAP_FAILED)
202 return -1;
203
204 while (size) {
205 ssize_t ret = pwrite(ofd, ptr + off_in, size, off_out);
206 if (ret < 0 && errno == EINTR)
207 continue;
208 if (ret <= 0)
209 break;
210
211 size -= ret;
212 off_in += ret;
213 off_out += ret;
214 }
215 munmap(ptr, off_in + size);
216
217 return size ? -1 : 0;
218}
219
220static int copyfile_mode_ns(const char *from, const char *to, mode_t mode,
221 struct nsinfo *nsi)
222{
223 int fromfd, tofd;
224 struct stat st;
225 int err;
226 char *tmp = NULL, *ptr = NULL;
227 struct nscookie nsc;
228
229 nsinfo__mountns_enter(nsi, &nsc);
230 err = stat(from, &st);
231 nsinfo__mountns_exit(&nsc);
232 if (err)
233 goto out;
234 err = -1;
235
236 /* extra 'x' at the end is to reserve space for '.' */
237 if (asprintf(&tmp, "%s.XXXXXXx", to) < 0) {
238 tmp = NULL;
239 goto out;
240 }
241 ptr = strrchr(tmp, '/');
242 if (!ptr)
243 goto out;
244 ptr = memmove(ptr + 1, ptr, strlen(ptr) - 1);
245 *ptr = '.';
246
247 tofd = mkstemp(tmp);
248 if (tofd < 0)
249 goto out;
250
251 if (fchmod(tofd, mode))
252 goto out_close_to;
253
254 if (st.st_size == 0) { /* /proc? do it slowly... */
255 err = slow_copyfile(from, tmp, nsi);
256 goto out_close_to;
257 }
258
259 nsinfo__mountns_enter(nsi, &nsc);
260 fromfd = open(from, O_RDONLY);
261 nsinfo__mountns_exit(&nsc);
262 if (fromfd < 0)
263 goto out_close_to;
264
265 err = copyfile_offset(fromfd, 0, tofd, 0, st.st_size);
266
267 close(fromfd);
268out_close_to:
269 close(tofd);
270 if (!err)
271 err = link(tmp, to);
272 unlink(tmp);
273out:
274 free(tmp);
275 return err;
276}
277
278int copyfile_ns(const char *from, const char *to, struct nsinfo *nsi)
279{
280 return copyfile_mode_ns(from, to, 0755, nsi);
281}
282
283int copyfile_mode(const char *from, const char *to, mode_t mode)
284{
285 return copyfile_mode_ns(from, to, mode, NULL);
286}
287
288int copyfile(const char *from, const char *to)
289{
290 return copyfile_mode(from, to, 0755);
291}
292
293static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
294{
295 void *buf_start = buf;
296 size_t left = n;
297
298 while (left) {
299 /* buf must be treated as const if !is_read. */
300 ssize_t ret = is_read ? read(fd, buf, left) :
301 write(fd, buf, left);
302
303 if (ret < 0 && errno == EINTR)
304 continue;
305 if (ret <= 0)
306 return ret;
307
308 left -= ret;
309 buf += ret;
310 }
311
312 BUG_ON((size_t)(buf - buf_start) != n);
313 return n;
314}
315
316/*
317 * Read exactly 'n' bytes or return an error.
318 */
319ssize_t readn(int fd, void *buf, size_t n)
320{
321 return ion(true, fd, buf, n);
322}
323
324/*
325 * Write exactly 'n' bytes or return an error.
326 */
327ssize_t writen(int fd, const void *buf, size_t n)
328{
329 /* ion does not modify buf. */
330 return ion(false, fd, (void *)buf, n);
331}
332
333size_t hex_width(u64 v)
334{
335 size_t n = 1;
336
337 while ((v >>= 4))
338 ++n;
339
340 return n;
341}
342
343/*
344 * While we find nice hex chars, build a long_val.
345 * Return number of chars processed.
346 */
347int hex2u64(const char *ptr, u64 *long_val)
348{
349 char *p;
350
351 *long_val = strtoull(ptr, &p, 16);
352
353 return p - ptr;
354}
355
356int perf_event_paranoid(void)
357{
358 int value;
359
360 if (sysctl__read_int("kernel/perf_event_paranoid", &value))
361 return INT_MAX;
362
363 return value;
364}
365static int
366fetch_ubuntu_kernel_version(unsigned int *puint)
367{
368 ssize_t len;
369 size_t line_len = 0;
370 char *ptr, *line = NULL;
371 int version, patchlevel, sublevel, err;
372 FILE *vsig;
373
374 if (!puint)
375 return 0;
376
377 vsig = fopen("/proc/version_signature", "r");
378 if (!vsig) {
379 pr_debug("Open /proc/version_signature failed: %s\n",
380 strerror(errno));
381 return -1;
382 }
383
384 len = getline(&line, &line_len, vsig);
385 fclose(vsig);
386 err = -1;
387 if (len <= 0) {
388 pr_debug("Reading from /proc/version_signature failed: %s\n",
389 strerror(errno));
390 goto errout;
391 }
392
393 ptr = strrchr(line, ' ');
394 if (!ptr) {
395 pr_debug("Parsing /proc/version_signature failed: %s\n", line);
396 goto errout;
397 }
398
399 err = sscanf(ptr + 1, "%d.%d.%d",
400 &version, &patchlevel, &sublevel);
401 if (err != 3) {
402 pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
403 line);
404 goto errout;
405 }
406
407 *puint = (version << 16) + (patchlevel << 8) + sublevel;
408 err = 0;
409errout:
410 free(line);
411 return err;
412}
413
414int
415fetch_kernel_version(unsigned int *puint, char *str,
416 size_t str_size)
417{
418 struct utsname utsname;
419 int version, patchlevel, sublevel, err;
420 bool int_ver_ready = false;
421
422 if (access("/proc/version_signature", R_OK) == 0)
423 if (!fetch_ubuntu_kernel_version(puint))
424 int_ver_ready = true;
425
426 if (uname(&utsname))
427 return -1;
428
429 if (str && str_size) {
430 strncpy(str, utsname.release, str_size);
431 str[str_size - 1] = '\0';
432 }
433
434 if (!puint || int_ver_ready)
435 return 0;
436
437 err = sscanf(utsname.release, "%d.%d.%d",
438 &version, &patchlevel, &sublevel);
439
440 if (err != 3) {
441 pr_debug("Unable to get kernel version from uname '%s'\n",
442 utsname.release);
443 return -1;
444 }
445
446 *puint = (version << 16) + (patchlevel << 8) + sublevel;
447 return 0;
448}
449
450const char *perf_tip(const char *dirpath)
451{
452 struct strlist *tips;
453 struct str_node *node;
454 char *tip = NULL;
455 struct strlist_config conf = {
456 .dirname = dirpath,
457 .file_only = true,
458 };
459
460 tips = strlist__new("tips.txt", &conf);
461 if (tips == NULL)
462 return errno == ENOENT ? NULL :
463 "Tip: check path of tips.txt or get more memory! ;-p";
464
465 if (strlist__nr_entries(tips) == 0)
466 goto out;
467
468 node = strlist__entry(tips, random() % strlist__nr_entries(tips));
469 if (asprintf(&tip, "Tip: %s", node->s) < 0)
470 tip = (char *)"Tip: get more memory! ;-)";
471
472out:
473 strlist__delete(tips);
474
475 return tip;
476}
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
31bool perf_singlethreaded = true;
32
33void perf_set_singlethreaded(void)
34{
35 perf_singlethreaded = true;
36}
37
38void perf_set_multithreaded(void)
39{
40 perf_singlethreaded = false;
41}
42
43int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
44int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;
45
46int sysctl__max_stack(void)
47{
48 int value;
49
50 if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
51 sysctl_perf_event_max_stack = value;
52
53 if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
54 sysctl_perf_event_max_contexts_per_stack = value;
55
56 return sysctl_perf_event_max_stack;
57}
58
59bool sysctl__nmi_watchdog_enabled(void)
60{
61 static bool cached;
62 static bool nmi_watchdog;
63 int value;
64
65 if (cached)
66 return nmi_watchdog;
67
68 if (sysctl__read_int("kernel/nmi_watchdog", &value) < 0)
69 return false;
70
71 nmi_watchdog = (value > 0) ? true : false;
72 cached = true;
73
74 return nmi_watchdog;
75}
76
77bool test_attr__enabled;
78
79bool perf_host = true;
80bool perf_guest = false;
81
82void event_attr_init(struct perf_event_attr *attr)
83{
84 if (!perf_host)
85 attr->exclude_host = 1;
86 if (!perf_guest)
87 attr->exclude_guest = 1;
88 /* to capture ABI version */
89 attr->size = sizeof(*attr);
90}
91
92int mkdir_p(char *path, mode_t mode)
93{
94 struct stat st;
95 int err;
96 char *d = path;
97
98 if (*d != '/')
99 return -1;
100
101 if (stat(path, &st) == 0)
102 return 0;
103
104 while (*++d == '/');
105
106 while ((d = strchr(d, '/'))) {
107 *d = '\0';
108 err = stat(path, &st) && mkdir(path, mode);
109 *d++ = '/';
110 if (err)
111 return -1;
112 while (*d == '/')
113 ++d;
114 }
115 return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
116}
117
118static bool match_pat(char *file, const char **pat)
119{
120 int i = 0;
121
122 if (!pat)
123 return true;
124
125 while (pat[i]) {
126 if (strglobmatch(file, pat[i]))
127 return true;
128
129 i++;
130 }
131
132 return false;
133}
134
135/*
136 * The depth specify how deep the removal will go.
137 * 0 - will remove only files under the 'path' directory
138 * 1 .. x - will dive in x-level deep under the 'path' directory
139 *
140 * If specified the pat is array of string patterns ended with NULL,
141 * which are checked upon every file/directory found. Only matching
142 * ones are removed.
143 *
144 * The function returns:
145 * 0 on success
146 * -1 on removal failure with errno set
147 * -2 on pattern failure
148 */
149static int rm_rf_depth_pat(const char *path, int depth, const char **pat)
150{
151 DIR *dir;
152 int ret;
153 struct dirent *d;
154 char namebuf[PATH_MAX];
155 struct stat statbuf;
156
157 /* Do not fail if there's no file. */
158 ret = lstat(path, &statbuf);
159 if (ret)
160 return 0;
161
162 /* Try to remove any file we get. */
163 if (!(statbuf.st_mode & S_IFDIR))
164 return unlink(path);
165
166 /* We have directory in path. */
167 dir = opendir(path);
168 if (dir == NULL)
169 return -1;
170
171 while ((d = readdir(dir)) != NULL && !ret) {
172
173 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
174 continue;
175
176 if (!match_pat(d->d_name, pat)) {
177 ret = -2;
178 break;
179 }
180
181 scnprintf(namebuf, sizeof(namebuf), "%s/%s",
182 path, d->d_name);
183
184 /* We have to check symbolic link itself */
185 ret = lstat(namebuf, &statbuf);
186 if (ret < 0) {
187 pr_debug("stat failed: %s\n", namebuf);
188 break;
189 }
190
191 if (S_ISDIR(statbuf.st_mode))
192 ret = depth ? rm_rf_depth_pat(namebuf, depth - 1, pat) : 0;
193 else
194 ret = unlink(namebuf);
195 }
196 closedir(dir);
197
198 if (ret < 0)
199 return ret;
200
201 return rmdir(path);
202}
203
204static int rm_rf_a_kcore_dir(const char *path, const char *name)
205{
206 char kcore_dir_path[PATH_MAX];
207 const char *pat[] = {
208 "kcore",
209 "kallsyms",
210 "modules",
211 NULL,
212 };
213
214 snprintf(kcore_dir_path, sizeof(kcore_dir_path), "%s/%s", path, name);
215
216 return rm_rf_depth_pat(kcore_dir_path, 0, pat);
217}
218
219static bool kcore_dir_filter(const char *name __maybe_unused, struct dirent *d)
220{
221 const char *pat[] = {
222 "kcore_dir",
223 "kcore_dir__[1-9]*",
224 NULL,
225 };
226
227 return match_pat(d->d_name, pat);
228}
229
230static int rm_rf_kcore_dir(const char *path)
231{
232 struct strlist *kcore_dirs;
233 struct str_node *nd;
234 int ret;
235
236 kcore_dirs = lsdir(path, kcore_dir_filter);
237
238 if (!kcore_dirs)
239 return 0;
240
241 strlist__for_each_entry(nd, kcore_dirs) {
242 ret = rm_rf_a_kcore_dir(path, nd->s);
243 if (ret)
244 return ret;
245 }
246
247 strlist__delete(kcore_dirs);
248
249 return 0;
250}
251
252int rm_rf_perf_data(const char *path)
253{
254 const char *pat[] = {
255 "data",
256 "data.*",
257 NULL,
258 };
259
260 rm_rf_kcore_dir(path);
261
262 return rm_rf_depth_pat(path, 0, pat);
263}
264
265int rm_rf(const char *path)
266{
267 return rm_rf_depth_pat(path, INT_MAX, NULL);
268}
269
270/* A filter which removes dot files */
271bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
272{
273 return d->d_name[0] != '.';
274}
275
276/* lsdir reads a directory and store it in strlist */
277struct strlist *lsdir(const char *name,
278 bool (*filter)(const char *, struct dirent *))
279{
280 struct strlist *list = NULL;
281 DIR *dir;
282 struct dirent *d;
283
284 dir = opendir(name);
285 if (!dir)
286 return NULL;
287
288 list = strlist__new(NULL, NULL);
289 if (!list) {
290 errno = ENOMEM;
291 goto out;
292 }
293
294 while ((d = readdir(dir)) != NULL) {
295 if (!filter || filter(name, d))
296 strlist__add(list, d->d_name);
297 }
298
299out:
300 closedir(dir);
301 return list;
302}
303
304size_t hex_width(u64 v)
305{
306 size_t n = 1;
307
308 while ((v >>= 4))
309 ++n;
310
311 return n;
312}
313
314int perf_event_paranoid(void)
315{
316 int value;
317
318 if (sysctl__read_int("kernel/perf_event_paranoid", &value))
319 return INT_MAX;
320
321 return value;
322}
323
324bool perf_event_paranoid_check(int max_level)
325{
326 return perf_cap__capable(CAP_SYS_ADMIN) ||
327 perf_cap__capable(CAP_PERFMON) ||
328 perf_event_paranoid() <= max_level;
329}
330
331static int
332fetch_ubuntu_kernel_version(unsigned int *puint)
333{
334 ssize_t len;
335 size_t line_len = 0;
336 char *ptr, *line = NULL;
337 int version, patchlevel, sublevel, err;
338 FILE *vsig;
339
340 if (!puint)
341 return 0;
342
343 vsig = fopen("/proc/version_signature", "r");
344 if (!vsig) {
345 pr_debug("Open /proc/version_signature failed: %s\n",
346 strerror(errno));
347 return -1;
348 }
349
350 len = getline(&line, &line_len, vsig);
351 fclose(vsig);
352 err = -1;
353 if (len <= 0) {
354 pr_debug("Reading from /proc/version_signature failed: %s\n",
355 strerror(errno));
356 goto errout;
357 }
358
359 ptr = strrchr(line, ' ');
360 if (!ptr) {
361 pr_debug("Parsing /proc/version_signature failed: %s\n", line);
362 goto errout;
363 }
364
365 err = sscanf(ptr + 1, "%d.%d.%d",
366 &version, &patchlevel, &sublevel);
367 if (err != 3) {
368 pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
369 line);
370 goto errout;
371 }
372
373 *puint = (version << 16) + (patchlevel << 8) + sublevel;
374 err = 0;
375errout:
376 free(line);
377 return err;
378}
379
380int
381fetch_kernel_version(unsigned int *puint, char *str,
382 size_t str_size)
383{
384 struct utsname utsname;
385 int version, patchlevel, sublevel, err;
386 bool int_ver_ready = false;
387
388 if (access("/proc/version_signature", R_OK) == 0)
389 if (!fetch_ubuntu_kernel_version(puint))
390 int_ver_ready = true;
391
392 if (uname(&utsname))
393 return -1;
394
395 if (str && str_size) {
396 strncpy(str, utsname.release, str_size);
397 str[str_size - 1] = '\0';
398 }
399
400 if (!puint || int_ver_ready)
401 return 0;
402
403 err = sscanf(utsname.release, "%d.%d.%d",
404 &version, &patchlevel, &sublevel);
405
406 if (err != 3) {
407 pr_debug("Unable to get kernel version from uname '%s'\n",
408 utsname.release);
409 return -1;
410 }
411
412 *puint = (version << 16) + (patchlevel << 8) + sublevel;
413 return 0;
414}
415
416int perf_tip(char **strp, const char *dirpath)
417{
418 struct strlist *tips;
419 struct str_node *node;
420 struct strlist_config conf = {
421 .dirname = dirpath,
422 .file_only = true,
423 };
424 int ret = 0;
425
426 *strp = NULL;
427 tips = strlist__new("tips.txt", &conf);
428 if (tips == NULL)
429 return -errno;
430
431 if (strlist__nr_entries(tips) == 0)
432 goto out;
433
434 node = strlist__entry(tips, random() % strlist__nr_entries(tips));
435 if (asprintf(strp, "Tip: %s", node->s) < 0)
436 ret = -ENOMEM;
437
438out:
439 strlist__delete(tips);
440
441 return ret;
442}
443
444char *perf_exe(char *buf, int len)
445{
446 int n = readlink("/proc/self/exe", buf, len);
447 if (n > 0) {
448 buf[n] = 0;
449 return buf;
450 }
451 return strcpy(buf, "perf");
452}
453
454void perf_debuginfod_setup(struct perf_debuginfod *di)
455{
456 /*
457 * By default '!di->set' we clear DEBUGINFOD_URLS, so debuginfod
458 * processing is not triggered, otherwise we set it to 'di->urls'
459 * value. If 'di->urls' is "system" we keep DEBUGINFOD_URLS value.
460 */
461 if (!di->set)
462 setenv("DEBUGINFOD_URLS", "", 1);
463 else if (di->urls && strcmp(di->urls, "system"))
464 setenv("DEBUGINFOD_URLS", di->urls, 1);
465
466 pr_debug("DEBUGINFOD_URLS=%s\n", getenv("DEBUGINFOD_URLS"));
467
468#ifndef HAVE_DEBUGINFOD_SUPPORT
469 if (di->set)
470 pr_warning("WARNING: debuginfod support requested, but perf is not built with it\n");
471#endif
472}
473
474/*
475 * Return a new filename prepended with task's root directory if it's in
476 * a chroot. Callers should free the returned string.
477 */
478char *filename_with_chroot(int pid, const char *filename)
479{
480 char buf[PATH_MAX];
481 char proc_root[32];
482 char *new_name = NULL;
483 int ret;
484
485 scnprintf(proc_root, sizeof(proc_root), "/proc/%d/root", pid);
486 ret = readlink(proc_root, buf, sizeof(buf) - 1);
487 if (ret <= 0)
488 return NULL;
489
490 /* readlink(2) does not append a null byte to buf */
491 buf[ret] = '\0';
492
493 if (!strcmp(buf, "/"))
494 return NULL;
495
496 if (strstr(buf, "(deleted)"))
497 return NULL;
498
499 if (asprintf(&new_name, "%s/%s", buf, filename) < 0)
500 return NULL;
501
502 return new_name;
503}
504
505/*
506 * Reallocate an array *arr of size *arr_sz so that it is big enough to contain
507 * x elements of size msz, initializing new entries to *init_val or zero if
508 * init_val is NULL
509 */
510int do_realloc_array_as_needed(void **arr, size_t *arr_sz, size_t x, size_t msz, const void *init_val)
511{
512 size_t new_sz = *arr_sz;
513 void *new_arr;
514 size_t i;
515
516 if (!new_sz)
517 new_sz = msz >= 64 ? 1 : roundup(64, msz); /* Start with at least 64 bytes */
518 while (x >= new_sz) {
519 if (check_mul_overflow(new_sz, (size_t)2, &new_sz))
520 return -ENOMEM;
521 }
522 if (new_sz == *arr_sz)
523 return 0;
524 new_arr = calloc(new_sz, msz);
525 if (!new_arr)
526 return -ENOMEM;
527 memcpy(new_arr, *arr, *arr_sz * msz);
528 if (init_val) {
529 for (i = *arr_sz; i < new_sz; i++)
530 memcpy(new_arr + (i * msz), init_val, msz);
531 }
532 *arr = new_arr;
533 *arr_sz = new_sz;
534 return 0;
535}