xref: /openbmc/linux/tools/perf/util/util.c (revision 9a6b55ac)
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 static int rm_rf_kcore_dir(const char *path)
186 {
187 	char kcore_dir_path[PATH_MAX];
188 	const char *pat[] = {
189 		"kcore",
190 		"kallsyms",
191 		"modules",
192 		NULL,
193 	};
194 
195 	snprintf(kcore_dir_path, sizeof(kcore_dir_path), "%s/kcore_dir", path);
196 
197 	return rm_rf_depth_pat(kcore_dir_path, 0, pat);
198 }
199 
200 int rm_rf_perf_data(const char *path)
201 {
202 	const char *pat[] = {
203 		"data",
204 		"data.*",
205 		NULL,
206 	};
207 
208 	rm_rf_kcore_dir(path);
209 
210 	return rm_rf_depth_pat(path, 0, pat);
211 }
212 
213 int rm_rf(const char *path)
214 {
215 	return rm_rf_depth_pat(path, INT_MAX, NULL);
216 }
217 
218 /* A filter which removes dot files */
219 bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
220 {
221 	return d->d_name[0] != '.';
222 }
223 
224 /* lsdir reads a directory and store it in strlist */
225 struct strlist *lsdir(const char *name,
226 		      bool (*filter)(const char *, struct dirent *))
227 {
228 	struct strlist *list = NULL;
229 	DIR *dir;
230 	struct dirent *d;
231 
232 	dir = opendir(name);
233 	if (!dir)
234 		return NULL;
235 
236 	list = strlist__new(NULL, NULL);
237 	if (!list) {
238 		errno = ENOMEM;
239 		goto out;
240 	}
241 
242 	while ((d = readdir(dir)) != NULL) {
243 		if (!filter || filter(name, d))
244 			strlist__add(list, d->d_name);
245 	}
246 
247 out:
248 	closedir(dir);
249 	return list;
250 }
251 
252 size_t hex_width(u64 v)
253 {
254 	size_t n = 1;
255 
256 	while ((v >>= 4))
257 		++n;
258 
259 	return n;
260 }
261 
262 int perf_event_paranoid(void)
263 {
264 	int value;
265 
266 	if (sysctl__read_int("kernel/perf_event_paranoid", &value))
267 		return INT_MAX;
268 
269 	return value;
270 }
271 
272 bool perf_event_paranoid_check(int max_level)
273 {
274 	return perf_cap__capable(CAP_SYS_ADMIN) ||
275 			perf_event_paranoid() <= max_level;
276 }
277 
278 static int
279 fetch_ubuntu_kernel_version(unsigned int *puint)
280 {
281 	ssize_t len;
282 	size_t line_len = 0;
283 	char *ptr, *line = NULL;
284 	int version, patchlevel, sublevel, err;
285 	FILE *vsig;
286 
287 	if (!puint)
288 		return 0;
289 
290 	vsig = fopen("/proc/version_signature", "r");
291 	if (!vsig) {
292 		pr_debug("Open /proc/version_signature failed: %s\n",
293 			 strerror(errno));
294 		return -1;
295 	}
296 
297 	len = getline(&line, &line_len, vsig);
298 	fclose(vsig);
299 	err = -1;
300 	if (len <= 0) {
301 		pr_debug("Reading from /proc/version_signature failed: %s\n",
302 			 strerror(errno));
303 		goto errout;
304 	}
305 
306 	ptr = strrchr(line, ' ');
307 	if (!ptr) {
308 		pr_debug("Parsing /proc/version_signature failed: %s\n", line);
309 		goto errout;
310 	}
311 
312 	err = sscanf(ptr + 1, "%d.%d.%d",
313 		     &version, &patchlevel, &sublevel);
314 	if (err != 3) {
315 		pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
316 			 line);
317 		goto errout;
318 	}
319 
320 	*puint = (version << 16) + (patchlevel << 8) + sublevel;
321 	err = 0;
322 errout:
323 	free(line);
324 	return err;
325 }
326 
327 int
328 fetch_kernel_version(unsigned int *puint, char *str,
329 		     size_t str_size)
330 {
331 	struct utsname utsname;
332 	int version, patchlevel, sublevel, err;
333 	bool int_ver_ready = false;
334 
335 	if (access("/proc/version_signature", R_OK) == 0)
336 		if (!fetch_ubuntu_kernel_version(puint))
337 			int_ver_ready = true;
338 
339 	if (uname(&utsname))
340 		return -1;
341 
342 	if (str && str_size) {
343 		strncpy(str, utsname.release, str_size);
344 		str[str_size - 1] = '\0';
345 	}
346 
347 	if (!puint || int_ver_ready)
348 		return 0;
349 
350 	err = sscanf(utsname.release, "%d.%d.%d",
351 		     &version, &patchlevel, &sublevel);
352 
353 	if (err != 3) {
354 		pr_debug("Unable to get kernel version from uname '%s'\n",
355 			 utsname.release);
356 		return -1;
357 	}
358 
359 	*puint = (version << 16) + (patchlevel << 8) + sublevel;
360 	return 0;
361 }
362 
363 const char *perf_tip(const char *dirpath)
364 {
365 	struct strlist *tips;
366 	struct str_node *node;
367 	char *tip = NULL;
368 	struct strlist_config conf = {
369 		.dirname = dirpath,
370 		.file_only = true,
371 	};
372 
373 	tips = strlist__new("tips.txt", &conf);
374 	if (tips == NULL)
375 		return errno == ENOENT ? NULL :
376 			"Tip: check path of tips.txt or get more memory! ;-p";
377 
378 	if (strlist__nr_entries(tips) == 0)
379 		goto out;
380 
381 	node = strlist__entry(tips, random() % strlist__nr_entries(tips));
382 	if (asprintf(&tip, "Tip: %s", node->s) < 0)
383 		tip = (char *)"Tip: get more memory! ;-)";
384 
385 out:
386 	strlist__delete(tips);
387 
388 	return tip;
389 }
390 
391 char *perf_exe(char *buf, int len)
392 {
393 	int n = readlink("/proc/self/exe", buf, len);
394 	if (n > 0) {
395 		buf[n] = 0;
396 		return buf;
397 	}
398 	return strcpy(buf, "perf");
399 }
400