xref: /openbmc/linux/tools/perf/util/util.c (revision 08283d30)
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 			ret =  -2;
159 			break;
160 		}
161 
162 		scnprintf(namebuf, sizeof(namebuf), "%s/%s",
163 			  path, d->d_name);
164 
165 		/* We have to check symbolic link itself */
166 		ret = lstat(namebuf, &statbuf);
167 		if (ret < 0) {
168 			pr_debug("stat failed: %s\n", namebuf);
169 			break;
170 		}
171 
172 		if (S_ISDIR(statbuf.st_mode))
173 			ret = depth ? rm_rf_depth_pat(namebuf, depth - 1, pat) : 0;
174 		else
175 			ret = unlink(namebuf);
176 	}
177 	closedir(dir);
178 
179 	if (ret < 0)
180 		return ret;
181 
182 	return rmdir(path);
183 }
184 
185 int rm_rf_perf_data(const char *path)
186 {
187 	const char *pat[] = {
188 		"header",
189 		"data.*",
190 		NULL,
191 	};
192 
193 	return rm_rf_depth_pat(path, 0, pat);
194 }
195 
196 int rm_rf(const char *path)
197 {
198 	return rm_rf_depth_pat(path, INT_MAX, NULL);
199 }
200 
201 /* A filter which removes dot files */
202 bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
203 {
204 	return d->d_name[0] != '.';
205 }
206 
207 /* lsdir reads a directory and store it in strlist */
208 struct strlist *lsdir(const char *name,
209 		      bool (*filter)(const char *, struct dirent *))
210 {
211 	struct strlist *list = NULL;
212 	DIR *dir;
213 	struct dirent *d;
214 
215 	dir = opendir(name);
216 	if (!dir)
217 		return NULL;
218 
219 	list = strlist__new(NULL, NULL);
220 	if (!list) {
221 		errno = ENOMEM;
222 		goto out;
223 	}
224 
225 	while ((d = readdir(dir)) != NULL) {
226 		if (!filter || filter(name, d))
227 			strlist__add(list, d->d_name);
228 	}
229 
230 out:
231 	closedir(dir);
232 	return list;
233 }
234 
235 size_t hex_width(u64 v)
236 {
237 	size_t n = 1;
238 
239 	while ((v >>= 4))
240 		++n;
241 
242 	return n;
243 }
244 
245 int perf_event_paranoid(void)
246 {
247 	int value;
248 
249 	if (sysctl__read_int("kernel/perf_event_paranoid", &value))
250 		return INT_MAX;
251 
252 	return value;
253 }
254 
255 bool perf_event_paranoid_check(int max_level)
256 {
257 	return perf_cap__capable(CAP_SYS_ADMIN) ||
258 			perf_event_paranoid() <= max_level;
259 }
260 
261 static int
262 fetch_ubuntu_kernel_version(unsigned int *puint)
263 {
264 	ssize_t len;
265 	size_t line_len = 0;
266 	char *ptr, *line = NULL;
267 	int version, patchlevel, sublevel, err;
268 	FILE *vsig;
269 
270 	if (!puint)
271 		return 0;
272 
273 	vsig = fopen("/proc/version_signature", "r");
274 	if (!vsig) {
275 		pr_debug("Open /proc/version_signature failed: %s\n",
276 			 strerror(errno));
277 		return -1;
278 	}
279 
280 	len = getline(&line, &line_len, vsig);
281 	fclose(vsig);
282 	err = -1;
283 	if (len <= 0) {
284 		pr_debug("Reading from /proc/version_signature failed: %s\n",
285 			 strerror(errno));
286 		goto errout;
287 	}
288 
289 	ptr = strrchr(line, ' ');
290 	if (!ptr) {
291 		pr_debug("Parsing /proc/version_signature failed: %s\n", line);
292 		goto errout;
293 	}
294 
295 	err = sscanf(ptr + 1, "%d.%d.%d",
296 		     &version, &patchlevel, &sublevel);
297 	if (err != 3) {
298 		pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
299 			 line);
300 		goto errout;
301 	}
302 
303 	*puint = (version << 16) + (patchlevel << 8) + sublevel;
304 	err = 0;
305 errout:
306 	free(line);
307 	return err;
308 }
309 
310 int
311 fetch_kernel_version(unsigned int *puint, char *str,
312 		     size_t str_size)
313 {
314 	struct utsname utsname;
315 	int version, patchlevel, sublevel, err;
316 	bool int_ver_ready = false;
317 
318 	if (access("/proc/version_signature", R_OK) == 0)
319 		if (!fetch_ubuntu_kernel_version(puint))
320 			int_ver_ready = true;
321 
322 	if (uname(&utsname))
323 		return -1;
324 
325 	if (str && str_size) {
326 		strncpy(str, utsname.release, str_size);
327 		str[str_size - 1] = '\0';
328 	}
329 
330 	if (!puint || int_ver_ready)
331 		return 0;
332 
333 	err = sscanf(utsname.release, "%d.%d.%d",
334 		     &version, &patchlevel, &sublevel);
335 
336 	if (err != 3) {
337 		pr_debug("Unable to get kernel version from uname '%s'\n",
338 			 utsname.release);
339 		return -1;
340 	}
341 
342 	*puint = (version << 16) + (patchlevel << 8) + sublevel;
343 	return 0;
344 }
345 
346 const char *perf_tip(const char *dirpath)
347 {
348 	struct strlist *tips;
349 	struct str_node *node;
350 	char *tip = NULL;
351 	struct strlist_config conf = {
352 		.dirname = dirpath,
353 		.file_only = true,
354 	};
355 
356 	tips = strlist__new("tips.txt", &conf);
357 	if (tips == NULL)
358 		return errno == ENOENT ? NULL :
359 			"Tip: check path of tips.txt or get more memory! ;-p";
360 
361 	if (strlist__nr_entries(tips) == 0)
362 		goto out;
363 
364 	node = strlist__entry(tips, random() % strlist__nr_entries(tips));
365 	if (asprintf(&tip, "Tip: %s", node->s) < 0)
366 		tip = (char *)"Tip: get more memory! ;-)";
367 
368 out:
369 	strlist__delete(tips);
370 
371 	return tip;
372 }
373 
374 char *perf_exe(char *buf, int len)
375 {
376 	int n = readlink("/proc/self/exe", buf, len);
377 	if (n > 0) {
378 		buf[n] = 0;
379 		return buf;
380 	}
381 	return strcpy(buf, "perf");
382 }
383