xref: /openbmc/linux/tools/perf/util/util.c (revision 82b5d164)
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 
32 void perf_set_singlethreaded(void)
33 {
34 	perf_singlethreaded = true;
35 }
36 
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 
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 
58 bool test_attr__enabled;
59 
60 bool perf_host  = true;
61 bool perf_guest = false;
62 
63 void event_attr_init(struct perf_event_attr *attr)
64 {
65 	if (!perf_host)
66 		attr->exclude_host  = 1;
67 	if (!perf_guest)
68 		attr->exclude_guest = 1;
69 	/* to capture ABI version */
70 	attr->size = sizeof(*attr);
71 }
72 
73 int mkdir_p(char *path, mode_t mode)
74 {
75 	struct stat st;
76 	int err;
77 	char *d = path;
78 
79 	if (*d != '/')
80 		return -1;
81 
82 	if (stat(path, &st) == 0)
83 		return 0;
84 
85 	while (*++d == '/');
86 
87 	while ((d = strchr(d, '/'))) {
88 		*d = '\0';
89 		err = stat(path, &st) && mkdir(path, mode);
90 		*d++ = '/';
91 		if (err)
92 			return -1;
93 		while (*d == '/')
94 			++d;
95 	}
96 	return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
97 }
98 
99 static bool match_pat(char *file, const char **pat)
100 {
101 	int i = 0;
102 
103 	if (!pat)
104 		return true;
105 
106 	while (pat[i]) {
107 		if (strglobmatch(file, pat[i]))
108 			return true;
109 
110 		i++;
111 	}
112 
113 	return false;
114 }
115 
116 /*
117  * The depth specify how deep the removal will go.
118  * 0       - will remove only files under the 'path' directory
119  * 1 .. x  - will dive in x-level deep under the 'path' directory
120  *
121  * If specified the pat is array of string patterns ended with NULL,
122  * which are checked upon every file/directory found. Only matching
123  * ones are removed.
124  *
125  * The function returns:
126  *    0 on success
127  *   -1 on removal failure with errno set
128  *   -2 on pattern failure
129  */
130 static int rm_rf_depth_pat(const char *path, int depth, const char **pat)
131 {
132 	DIR *dir;
133 	int ret;
134 	struct dirent *d;
135 	char namebuf[PATH_MAX];
136 	struct stat statbuf;
137 
138 	/* Do not fail if there's no file. */
139 	ret = lstat(path, &statbuf);
140 	if (ret)
141 		return 0;
142 
143 	/* Try to remove any file we get. */
144 	if (!(statbuf.st_mode & S_IFDIR))
145 		return unlink(path);
146 
147 	/* We have directory in path. */
148 	dir = opendir(path);
149 	if (dir == NULL)
150 		return -1;
151 
152 	while ((d = readdir(dir)) != NULL && !ret) {
153 
154 		if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
155 			continue;
156 
157 		if (!match_pat(d->d_name, pat))
158 			return -2;
159 
160 		scnprintf(namebuf, sizeof(namebuf), "%s/%s",
161 			  path, d->d_name);
162 
163 		/* We have to check symbolic link itself */
164 		ret = lstat(namebuf, &statbuf);
165 		if (ret < 0) {
166 			pr_debug("stat failed: %s\n", namebuf);
167 			break;
168 		}
169 
170 		if (S_ISDIR(statbuf.st_mode))
171 			ret = depth ? rm_rf_depth_pat(namebuf, depth - 1, pat) : 0;
172 		else
173 			ret = unlink(namebuf);
174 	}
175 	closedir(dir);
176 
177 	if (ret < 0)
178 		return ret;
179 
180 	return rmdir(path);
181 }
182 
183 int rm_rf_perf_data(const char *path)
184 {
185 	const char *pat[] = {
186 		"header",
187 		"data.*",
188 		NULL,
189 	};
190 
191 	return rm_rf_depth_pat(path, 0, pat);
192 }
193 
194 int rm_rf(const char *path)
195 {
196 	return rm_rf_depth_pat(path, INT_MAX, NULL);
197 }
198 
199 /* A filter which removes dot files */
200 bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
201 {
202 	return d->d_name[0] != '.';
203 }
204 
205 /* lsdir reads a directory and store it in strlist */
206 struct strlist *lsdir(const char *name,
207 		      bool (*filter)(const char *, struct dirent *))
208 {
209 	struct strlist *list = NULL;
210 	DIR *dir;
211 	struct dirent *d;
212 
213 	dir = opendir(name);
214 	if (!dir)
215 		return NULL;
216 
217 	list = strlist__new(NULL, NULL);
218 	if (!list) {
219 		errno = ENOMEM;
220 		goto out;
221 	}
222 
223 	while ((d = readdir(dir)) != NULL) {
224 		if (!filter || filter(name, d))
225 			strlist__add(list, d->d_name);
226 	}
227 
228 out:
229 	closedir(dir);
230 	return list;
231 }
232 
233 size_t hex_width(u64 v)
234 {
235 	size_t n = 1;
236 
237 	while ((v >>= 4))
238 		++n;
239 
240 	return n;
241 }
242 
243 int perf_event_paranoid(void)
244 {
245 	int value;
246 
247 	if (sysctl__read_int("kernel/perf_event_paranoid", &value))
248 		return INT_MAX;
249 
250 	return value;
251 }
252 
253 bool perf_event_paranoid_check(int max_level)
254 {
255 	return perf_cap__capable(CAP_SYS_ADMIN) ||
256 			perf_event_paranoid() <= max_level;
257 }
258 
259 static int
260 fetch_ubuntu_kernel_version(unsigned int *puint)
261 {
262 	ssize_t len;
263 	size_t line_len = 0;
264 	char *ptr, *line = NULL;
265 	int version, patchlevel, sublevel, err;
266 	FILE *vsig;
267 
268 	if (!puint)
269 		return 0;
270 
271 	vsig = fopen("/proc/version_signature", "r");
272 	if (!vsig) {
273 		pr_debug("Open /proc/version_signature failed: %s\n",
274 			 strerror(errno));
275 		return -1;
276 	}
277 
278 	len = getline(&line, &line_len, vsig);
279 	fclose(vsig);
280 	err = -1;
281 	if (len <= 0) {
282 		pr_debug("Reading from /proc/version_signature failed: %s\n",
283 			 strerror(errno));
284 		goto errout;
285 	}
286 
287 	ptr = strrchr(line, ' ');
288 	if (!ptr) {
289 		pr_debug("Parsing /proc/version_signature failed: %s\n", line);
290 		goto errout;
291 	}
292 
293 	err = sscanf(ptr + 1, "%d.%d.%d",
294 		     &version, &patchlevel, &sublevel);
295 	if (err != 3) {
296 		pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
297 			 line);
298 		goto errout;
299 	}
300 
301 	*puint = (version << 16) + (patchlevel << 8) + sublevel;
302 	err = 0;
303 errout:
304 	free(line);
305 	return err;
306 }
307 
308 int
309 fetch_kernel_version(unsigned int *puint, char *str,
310 		     size_t str_size)
311 {
312 	struct utsname utsname;
313 	int version, patchlevel, sublevel, err;
314 	bool int_ver_ready = false;
315 
316 	if (access("/proc/version_signature", R_OK) == 0)
317 		if (!fetch_ubuntu_kernel_version(puint))
318 			int_ver_ready = true;
319 
320 	if (uname(&utsname))
321 		return -1;
322 
323 	if (str && str_size) {
324 		strncpy(str, utsname.release, str_size);
325 		str[str_size - 1] = '\0';
326 	}
327 
328 	if (!puint || int_ver_ready)
329 		return 0;
330 
331 	err = sscanf(utsname.release, "%d.%d.%d",
332 		     &version, &patchlevel, &sublevel);
333 
334 	if (err != 3) {
335 		pr_debug("Unable to get kernel version from uname '%s'\n",
336 			 utsname.release);
337 		return -1;
338 	}
339 
340 	*puint = (version << 16) + (patchlevel << 8) + sublevel;
341 	return 0;
342 }
343 
344 const char *perf_tip(const char *dirpath)
345 {
346 	struct strlist *tips;
347 	struct str_node *node;
348 	char *tip = NULL;
349 	struct strlist_config conf = {
350 		.dirname = dirpath,
351 		.file_only = true,
352 	};
353 
354 	tips = strlist__new("tips.txt", &conf);
355 	if (tips == NULL)
356 		return errno == ENOENT ? NULL :
357 			"Tip: check path of tips.txt or get more memory! ;-p";
358 
359 	if (strlist__nr_entries(tips) == 0)
360 		goto out;
361 
362 	node = strlist__entry(tips, random() % strlist__nr_entries(tips));
363 	if (asprintf(&tip, "Tip: %s", node->s) < 0)
364 		tip = (char *)"Tip: get more memory! ;-)";
365 
366 out:
367 	strlist__delete(tips);
368 
369 	return tip;
370 }
371 
372 char *perf_exe(char *buf, int len)
373 {
374 	int n = readlink("/proc/self/exe", buf, len);
375 	if (n > 0) {
376 		buf[n] = 0;
377 		return buf;
378 	}
379 	return strcpy(buf, "perf");
380 }
381