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 <unistd.h>
22 #include "cap.h"
23 #include "strlist.h"
24 #include "string2.h"
25
26 /*
27 * XXX We need to find a better place for these things...
28 */
29
30 bool perf_singlethreaded = true;
31
perf_set_singlethreaded(void)32 void perf_set_singlethreaded(void)
33 {
34 perf_singlethreaded = true;
35 }
36
perf_set_multithreaded(void)37 void perf_set_multithreaded(void)
38 {
39 perf_singlethreaded = false;
40 }
41
42 int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
43 int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;
44
sysctl__max_stack(void)45 int sysctl__max_stack(void)
46 {
47 int value;
48
49 if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
50 sysctl_perf_event_max_stack = value;
51
52 if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
53 sysctl_perf_event_max_contexts_per_stack = value;
54
55 return sysctl_perf_event_max_stack;
56 }
57
sysctl__nmi_watchdog_enabled(void)58 bool sysctl__nmi_watchdog_enabled(void)
59 {
60 static bool cached;
61 static bool nmi_watchdog;
62 int value;
63
64 if (cached)
65 return nmi_watchdog;
66
67 if (sysctl__read_int("kernel/nmi_watchdog", &value) < 0)
68 return false;
69
70 nmi_watchdog = (value > 0) ? true : false;
71 cached = true;
72
73 return nmi_watchdog;
74 }
75
76 bool test_attr__enabled;
77
78 bool perf_host = true;
79 bool perf_guest = false;
80
event_attr_init(struct perf_event_attr * attr)81 void event_attr_init(struct perf_event_attr *attr)
82 {
83 if (!perf_host)
84 attr->exclude_host = 1;
85 if (!perf_guest)
86 attr->exclude_guest = 1;
87 /* to capture ABI version */
88 attr->size = sizeof(*attr);
89 }
90
mkdir_p(char * path,mode_t mode)91 int mkdir_p(char *path, mode_t mode)
92 {
93 struct stat st;
94 int err;
95 char *d = path;
96
97 if (*d != '/')
98 return -1;
99
100 if (stat(path, &st) == 0)
101 return 0;
102
103 while (*++d == '/');
104
105 while ((d = strchr(d, '/'))) {
106 *d = '\0';
107 err = stat(path, &st) && mkdir(path, mode);
108 *d++ = '/';
109 if (err)
110 return -1;
111 while (*d == '/')
112 ++d;
113 }
114 return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
115 }
116
match_pat(char * file,const char ** pat)117 static bool match_pat(char *file, const char **pat)
118 {
119 int i = 0;
120
121 if (!pat)
122 return true;
123
124 while (pat[i]) {
125 if (strglobmatch(file, pat[i]))
126 return true;
127
128 i++;
129 }
130
131 return false;
132 }
133
134 /*
135 * The depth specify how deep the removal will go.
136 * 0 - will remove only files under the 'path' directory
137 * 1 .. x - will dive in x-level deep under the 'path' directory
138 *
139 * If specified the pat is array of string patterns ended with NULL,
140 * which are checked upon every file/directory found. Only matching
141 * ones are removed.
142 *
143 * The function returns:
144 * 0 on success
145 * -1 on removal failure with errno set
146 * -2 on pattern failure
147 */
rm_rf_depth_pat(const char * path,int depth,const char ** pat)148 static int rm_rf_depth_pat(const char *path, int depth, const char **pat)
149 {
150 DIR *dir;
151 int ret;
152 struct dirent *d;
153 char namebuf[PATH_MAX];
154 struct stat statbuf;
155
156 /* Do not fail if there's no file. */
157 ret = lstat(path, &statbuf);
158 if (ret)
159 return 0;
160
161 /* Try to remove any file we get. */
162 if (!(statbuf.st_mode & S_IFDIR))
163 return unlink(path);
164
165 /* We have directory in path. */
166 dir = opendir(path);
167 if (dir == NULL)
168 return -1;
169
170 while ((d = readdir(dir)) != NULL && !ret) {
171
172 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
173 continue;
174
175 if (!match_pat(d->d_name, pat)) {
176 ret = -2;
177 break;
178 }
179
180 scnprintf(namebuf, sizeof(namebuf), "%s/%s",
181 path, d->d_name);
182
183 /* We have to check symbolic link itself */
184 ret = lstat(namebuf, &statbuf);
185 if (ret < 0) {
186 pr_debug("stat failed: %s\n", namebuf);
187 break;
188 }
189
190 if (S_ISDIR(statbuf.st_mode))
191 ret = depth ? rm_rf_depth_pat(namebuf, depth - 1, pat) : 0;
192 else
193 ret = unlink(namebuf);
194 }
195 closedir(dir);
196
197 if (ret < 0)
198 return ret;
199
200 return rmdir(path);
201 }
202
rm_rf_kcore_dir(const char * path)203 static int rm_rf_kcore_dir(const char *path)
204 {
205 char kcore_dir_path[PATH_MAX];
206 const char *pat[] = {
207 "kcore",
208 "kallsyms",
209 "modules",
210 NULL,
211 };
212
213 snprintf(kcore_dir_path, sizeof(kcore_dir_path), "%s/kcore_dir", path);
214
215 return rm_rf_depth_pat(kcore_dir_path, 0, pat);
216 }
217
rm_rf_perf_data(const char * path)218 int rm_rf_perf_data(const char *path)
219 {
220 const char *pat[] = {
221 "data",
222 "data.*",
223 NULL,
224 };
225
226 rm_rf_kcore_dir(path);
227
228 return rm_rf_depth_pat(path, 0, pat);
229 }
230
rm_rf(const char * path)231 int rm_rf(const char *path)
232 {
233 return rm_rf_depth_pat(path, INT_MAX, NULL);
234 }
235
236 /* A filter which removes dot files */
lsdir_no_dot_filter(const char * name __maybe_unused,struct dirent * d)237 bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
238 {
239 return d->d_name[0] != '.';
240 }
241
242 /* lsdir reads a directory and store it in strlist */
lsdir(const char * name,bool (* filter)(const char *,struct dirent *))243 struct strlist *lsdir(const char *name,
244 bool (*filter)(const char *, struct dirent *))
245 {
246 struct strlist *list = NULL;
247 DIR *dir;
248 struct dirent *d;
249
250 dir = opendir(name);
251 if (!dir)
252 return NULL;
253
254 list = strlist__new(NULL, NULL);
255 if (!list) {
256 errno = ENOMEM;
257 goto out;
258 }
259
260 while ((d = readdir(dir)) != NULL) {
261 if (!filter || filter(name, d))
262 strlist__add(list, d->d_name);
263 }
264
265 out:
266 closedir(dir);
267 return list;
268 }
269
hex_width(u64 v)270 size_t hex_width(u64 v)
271 {
272 size_t n = 1;
273
274 while ((v >>= 4))
275 ++n;
276
277 return n;
278 }
279
perf_event_paranoid(void)280 int perf_event_paranoid(void)
281 {
282 int value;
283
284 if (sysctl__read_int("kernel/perf_event_paranoid", &value))
285 return INT_MAX;
286
287 return value;
288 }
289
perf_event_paranoid_check(int max_level)290 bool perf_event_paranoid_check(int max_level)
291 {
292 return perf_cap__capable(CAP_SYS_ADMIN) ||
293 perf_cap__capable(CAP_PERFMON) ||
294 perf_event_paranoid() <= max_level;
295 }
296
297 static int
fetch_ubuntu_kernel_version(unsigned int * puint)298 fetch_ubuntu_kernel_version(unsigned int *puint)
299 {
300 ssize_t len;
301 size_t line_len = 0;
302 char *ptr, *line = NULL;
303 int version, patchlevel, sublevel, err;
304 FILE *vsig;
305
306 if (!puint)
307 return 0;
308
309 vsig = fopen("/proc/version_signature", "r");
310 if (!vsig) {
311 pr_debug("Open /proc/version_signature failed: %s\n",
312 strerror(errno));
313 return -1;
314 }
315
316 len = getline(&line, &line_len, vsig);
317 fclose(vsig);
318 err = -1;
319 if (len <= 0) {
320 pr_debug("Reading from /proc/version_signature failed: %s\n",
321 strerror(errno));
322 goto errout;
323 }
324
325 ptr = strrchr(line, ' ');
326 if (!ptr) {
327 pr_debug("Parsing /proc/version_signature failed: %s\n", line);
328 goto errout;
329 }
330
331 err = sscanf(ptr + 1, "%d.%d.%d",
332 &version, &patchlevel, &sublevel);
333 if (err != 3) {
334 pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
335 line);
336 goto errout;
337 }
338
339 *puint = (version << 16) + (patchlevel << 8) + sublevel;
340 err = 0;
341 errout:
342 free(line);
343 return err;
344 }
345
346 int
fetch_kernel_version(unsigned int * puint,char * str,size_t str_size)347 fetch_kernel_version(unsigned int *puint, char *str,
348 size_t str_size)
349 {
350 struct utsname utsname;
351 int version, patchlevel, sublevel, err;
352 bool int_ver_ready = false;
353
354 if (access("/proc/version_signature", R_OK) == 0)
355 if (!fetch_ubuntu_kernel_version(puint))
356 int_ver_ready = true;
357
358 if (uname(&utsname))
359 return -1;
360
361 if (str && str_size) {
362 strncpy(str, utsname.release, str_size);
363 str[str_size - 1] = '\0';
364 }
365
366 if (!puint || int_ver_ready)
367 return 0;
368
369 err = sscanf(utsname.release, "%d.%d.%d",
370 &version, &patchlevel, &sublevel);
371
372 if (err != 3) {
373 pr_debug("Unable to get kernel version from uname '%s'\n",
374 utsname.release);
375 return -1;
376 }
377
378 *puint = (version << 16) + (patchlevel << 8) + sublevel;
379 return 0;
380 }
381
perf_tip(char ** strp,const char * dirpath)382 int perf_tip(char **strp, const char *dirpath)
383 {
384 struct strlist *tips;
385 struct str_node *node;
386 struct strlist_config conf = {
387 .dirname = dirpath,
388 .file_only = true,
389 };
390 int ret = 0;
391
392 *strp = NULL;
393 tips = strlist__new("tips.txt", &conf);
394 if (tips == NULL)
395 return -errno;
396
397 if (strlist__nr_entries(tips) == 0)
398 goto out;
399
400 node = strlist__entry(tips, random() % strlist__nr_entries(tips));
401 if (asprintf(strp, "Tip: %s", node->s) < 0)
402 ret = -ENOMEM;
403
404 out:
405 strlist__delete(tips);
406
407 return ret;
408 }
409
perf_exe(char * buf,int len)410 char *perf_exe(char *buf, int len)
411 {
412 int n = readlink("/proc/self/exe", buf, len);
413 if (n > 0) {
414 buf[n] = 0;
415 return buf;
416 }
417 return strcpy(buf, "perf");
418 }
419