xref: /openbmc/linux/tools/perf/util/util.c (revision 0c874100)
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 
28 bool perf_singlethreaded = true;
29 
30 void perf_set_singlethreaded(void)
31 {
32 	perf_singlethreaded = true;
33 }
34 
35 void perf_set_multithreaded(void)
36 {
37 	perf_singlethreaded = false;
38 }
39 
40 unsigned int page_size;
41 
42 #ifdef _SC_LEVEL1_DCACHE_LINESIZE
43 #define cache_line_size(cacheline_sizep) *cacheline_sizep = sysconf(_SC_LEVEL1_DCACHE_LINESIZE)
44 #else
45 static void cache_line_size(int *cacheline_sizep)
46 {
47 	if (sysfs__read_int("devices/system/cpu/cpu0/cache/index0/coherency_line_size", cacheline_sizep))
48 		pr_debug("cannot determine cache line size");
49 }
50 #endif
51 
52 int cacheline_size(void)
53 {
54 	static int size;
55 
56 	if (!size)
57 		cache_line_size(&size);
58 
59 	return size;
60 }
61 
62 int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
63 int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;
64 
65 int sysctl__max_stack(void)
66 {
67 	int value;
68 
69 	if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
70 		sysctl_perf_event_max_stack = value;
71 
72 	if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
73 		sysctl_perf_event_max_contexts_per_stack = value;
74 
75 	return sysctl_perf_event_max_stack;
76 }
77 
78 bool test_attr__enabled;
79 
80 bool perf_host  = true;
81 bool perf_guest = false;
82 
83 void event_attr_init(struct perf_event_attr *attr)
84 {
85 	if (!perf_host)
86 		attr->exclude_host  = 1;
87 	if (!perf_guest)
88 		attr->exclude_guest = 1;
89 	/* to capture ABI version */
90 	attr->size = sizeof(*attr);
91 }
92 
93 int mkdir_p(char *path, mode_t mode)
94 {
95 	struct stat st;
96 	int err;
97 	char *d = path;
98 
99 	if (*d != '/')
100 		return -1;
101 
102 	if (stat(path, &st) == 0)
103 		return 0;
104 
105 	while (*++d == '/');
106 
107 	while ((d = strchr(d, '/'))) {
108 		*d = '\0';
109 		err = stat(path, &st) && mkdir(path, mode);
110 		*d++ = '/';
111 		if (err)
112 			return -1;
113 		while (*d == '/')
114 			++d;
115 	}
116 	return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
117 }
118 
119 int rm_rf(const char *path)
120 {
121 	DIR *dir;
122 	int ret = 0;
123 	struct dirent *d;
124 	char namebuf[PATH_MAX];
125 
126 	dir = opendir(path);
127 	if (dir == NULL)
128 		return 0;
129 
130 	while ((d = readdir(dir)) != NULL && !ret) {
131 		struct stat statbuf;
132 
133 		if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
134 			continue;
135 
136 		scnprintf(namebuf, sizeof(namebuf), "%s/%s",
137 			  path, d->d_name);
138 
139 		/* We have to check symbolic link itself */
140 		ret = lstat(namebuf, &statbuf);
141 		if (ret < 0) {
142 			pr_debug("stat failed: %s\n", namebuf);
143 			break;
144 		}
145 
146 		if (S_ISDIR(statbuf.st_mode))
147 			ret = rm_rf(namebuf);
148 		else
149 			ret = unlink(namebuf);
150 	}
151 	closedir(dir);
152 
153 	if (ret < 0)
154 		return ret;
155 
156 	return rmdir(path);
157 }
158 
159 /* A filter which removes dot files */
160 bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
161 {
162 	return d->d_name[0] != '.';
163 }
164 
165 /* lsdir reads a directory and store it in strlist */
166 struct strlist *lsdir(const char *name,
167 		      bool (*filter)(const char *, struct dirent *))
168 {
169 	struct strlist *list = NULL;
170 	DIR *dir;
171 	struct dirent *d;
172 
173 	dir = opendir(name);
174 	if (!dir)
175 		return NULL;
176 
177 	list = strlist__new(NULL, NULL);
178 	if (!list) {
179 		errno = ENOMEM;
180 		goto out;
181 	}
182 
183 	while ((d = readdir(dir)) != NULL) {
184 		if (!filter || filter(name, d))
185 			strlist__add(list, d->d_name);
186 	}
187 
188 out:
189 	closedir(dir);
190 	return list;
191 }
192 
193 static int slow_copyfile(const char *from, const char *to, struct nsinfo *nsi)
194 {
195 	int err = -1;
196 	char *line = NULL;
197 	size_t n;
198 	FILE *from_fp, *to_fp;
199 	struct nscookie nsc;
200 
201 	nsinfo__mountns_enter(nsi, &nsc);
202 	from_fp = fopen(from, "r");
203 	nsinfo__mountns_exit(&nsc);
204 	if (from_fp == NULL)
205 		goto out;
206 
207 	to_fp = fopen(to, "w");
208 	if (to_fp == NULL)
209 		goto out_fclose_from;
210 
211 	while (getline(&line, &n, from_fp) > 0)
212 		if (fputs(line, to_fp) == EOF)
213 			goto out_fclose_to;
214 	err = 0;
215 out_fclose_to:
216 	fclose(to_fp);
217 	free(line);
218 out_fclose_from:
219 	fclose(from_fp);
220 out:
221 	return err;
222 }
223 
224 int copyfile_offset(int ifd, loff_t off_in, int ofd, loff_t off_out, u64 size)
225 {
226 	void *ptr;
227 	loff_t pgoff;
228 
229 	pgoff = off_in & ~(page_size - 1);
230 	off_in -= pgoff;
231 
232 	ptr = mmap(NULL, off_in + size, PROT_READ, MAP_PRIVATE, ifd, pgoff);
233 	if (ptr == MAP_FAILED)
234 		return -1;
235 
236 	while (size) {
237 		ssize_t ret = pwrite(ofd, ptr + off_in, size, off_out);
238 		if (ret < 0 && errno == EINTR)
239 			continue;
240 		if (ret <= 0)
241 			break;
242 
243 		size -= ret;
244 		off_in += ret;
245 		off_out += ret;
246 	}
247 	munmap(ptr, off_in + size);
248 
249 	return size ? -1 : 0;
250 }
251 
252 static int copyfile_mode_ns(const char *from, const char *to, mode_t mode,
253 			    struct nsinfo *nsi)
254 {
255 	int fromfd, tofd;
256 	struct stat st;
257 	int err;
258 	char *tmp = NULL, *ptr = NULL;
259 	struct nscookie nsc;
260 
261 	nsinfo__mountns_enter(nsi, &nsc);
262 	err = stat(from, &st);
263 	nsinfo__mountns_exit(&nsc);
264 	if (err)
265 		goto out;
266 	err = -1;
267 
268 	/* extra 'x' at the end is to reserve space for '.' */
269 	if (asprintf(&tmp, "%s.XXXXXXx", to) < 0) {
270 		tmp = NULL;
271 		goto out;
272 	}
273 	ptr = strrchr(tmp, '/');
274 	if (!ptr)
275 		goto out;
276 	ptr = memmove(ptr + 1, ptr, strlen(ptr) - 1);
277 	*ptr = '.';
278 
279 	tofd = mkstemp(tmp);
280 	if (tofd < 0)
281 		goto out;
282 
283 	if (fchmod(tofd, mode))
284 		goto out_close_to;
285 
286 	if (st.st_size == 0) { /* /proc? do it slowly... */
287 		err = slow_copyfile(from, tmp, nsi);
288 		goto out_close_to;
289 	}
290 
291 	nsinfo__mountns_enter(nsi, &nsc);
292 	fromfd = open(from, O_RDONLY);
293 	nsinfo__mountns_exit(&nsc);
294 	if (fromfd < 0)
295 		goto out_close_to;
296 
297 	err = copyfile_offset(fromfd, 0, tofd, 0, st.st_size);
298 
299 	close(fromfd);
300 out_close_to:
301 	close(tofd);
302 	if (!err)
303 		err = link(tmp, to);
304 	unlink(tmp);
305 out:
306 	free(tmp);
307 	return err;
308 }
309 
310 int copyfile_ns(const char *from, const char *to, struct nsinfo *nsi)
311 {
312 	return copyfile_mode_ns(from, to, 0755, nsi);
313 }
314 
315 int copyfile_mode(const char *from, const char *to, mode_t mode)
316 {
317 	return copyfile_mode_ns(from, to, mode, NULL);
318 }
319 
320 int copyfile(const char *from, const char *to)
321 {
322 	return copyfile_mode(from, to, 0755);
323 }
324 
325 static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
326 {
327 	void *buf_start = buf;
328 	size_t left = n;
329 
330 	while (left) {
331 		/* buf must be treated as const if !is_read. */
332 		ssize_t ret = is_read ? read(fd, buf, left) :
333 					write(fd, buf, left);
334 
335 		if (ret < 0 && errno == EINTR)
336 			continue;
337 		if (ret <= 0)
338 			return ret;
339 
340 		left -= ret;
341 		buf  += ret;
342 	}
343 
344 	BUG_ON((size_t)(buf - buf_start) != n);
345 	return n;
346 }
347 
348 /*
349  * Read exactly 'n' bytes or return an error.
350  */
351 ssize_t readn(int fd, void *buf, size_t n)
352 {
353 	return ion(true, fd, buf, n);
354 }
355 
356 /*
357  * Write exactly 'n' bytes or return an error.
358  */
359 ssize_t writen(int fd, const void *buf, size_t n)
360 {
361 	/* ion does not modify buf. */
362 	return ion(false, fd, (void *)buf, n);
363 }
364 
365 size_t hex_width(u64 v)
366 {
367 	size_t n = 1;
368 
369 	while ((v >>= 4))
370 		++n;
371 
372 	return n;
373 }
374 
375 /*
376  * While we find nice hex chars, build a long_val.
377  * Return number of chars processed.
378  */
379 int hex2u64(const char *ptr, u64 *long_val)
380 {
381 	char *p;
382 
383 	*long_val = strtoull(ptr, &p, 16);
384 
385 	return p - ptr;
386 }
387 
388 int perf_event_paranoid(void)
389 {
390 	int value;
391 
392 	if (sysctl__read_int("kernel/perf_event_paranoid", &value))
393 		return INT_MAX;
394 
395 	return value;
396 }
397 static int
398 fetch_ubuntu_kernel_version(unsigned int *puint)
399 {
400 	ssize_t len;
401 	size_t line_len = 0;
402 	char *ptr, *line = NULL;
403 	int version, patchlevel, sublevel, err;
404 	FILE *vsig;
405 
406 	if (!puint)
407 		return 0;
408 
409 	vsig = fopen("/proc/version_signature", "r");
410 	if (!vsig) {
411 		pr_debug("Open /proc/version_signature failed: %s\n",
412 			 strerror(errno));
413 		return -1;
414 	}
415 
416 	len = getline(&line, &line_len, vsig);
417 	fclose(vsig);
418 	err = -1;
419 	if (len <= 0) {
420 		pr_debug("Reading from /proc/version_signature failed: %s\n",
421 			 strerror(errno));
422 		goto errout;
423 	}
424 
425 	ptr = strrchr(line, ' ');
426 	if (!ptr) {
427 		pr_debug("Parsing /proc/version_signature failed: %s\n", line);
428 		goto errout;
429 	}
430 
431 	err = sscanf(ptr + 1, "%d.%d.%d",
432 		     &version, &patchlevel, &sublevel);
433 	if (err != 3) {
434 		pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
435 			 line);
436 		goto errout;
437 	}
438 
439 	*puint = (version << 16) + (patchlevel << 8) + sublevel;
440 	err = 0;
441 errout:
442 	free(line);
443 	return err;
444 }
445 
446 int
447 fetch_kernel_version(unsigned int *puint, char *str,
448 		     size_t str_size)
449 {
450 	struct utsname utsname;
451 	int version, patchlevel, sublevel, err;
452 	bool int_ver_ready = false;
453 
454 	if (access("/proc/version_signature", R_OK) == 0)
455 		if (!fetch_ubuntu_kernel_version(puint))
456 			int_ver_ready = true;
457 
458 	if (uname(&utsname))
459 		return -1;
460 
461 	if (str && str_size) {
462 		strncpy(str, utsname.release, str_size);
463 		str[str_size - 1] = '\0';
464 	}
465 
466 	if (!puint || int_ver_ready)
467 		return 0;
468 
469 	err = sscanf(utsname.release, "%d.%d.%d",
470 		     &version, &patchlevel, &sublevel);
471 
472 	if (err != 3) {
473 		pr_debug("Unable to get kernel version from uname '%s'\n",
474 			 utsname.release);
475 		return -1;
476 	}
477 
478 	*puint = (version << 16) + (patchlevel << 8) + sublevel;
479 	return 0;
480 }
481 
482 const char *perf_tip(const char *dirpath)
483 {
484 	struct strlist *tips;
485 	struct str_node *node;
486 	char *tip = NULL;
487 	struct strlist_config conf = {
488 		.dirname = dirpath,
489 		.file_only = true,
490 	};
491 
492 	tips = strlist__new("tips.txt", &conf);
493 	if (tips == NULL)
494 		return errno == ENOENT ? NULL :
495 			"Tip: check path of tips.txt or get more memory! ;-p";
496 
497 	if (strlist__nr_entries(tips) == 0)
498 		goto out;
499 
500 	node = strlist__entry(tips, random() % strlist__nr_entries(tips));
501 	if (asprintf(&tip, "Tip: %s", node->s) < 0)
502 		tip = (char *)"Tip: get more memory! ;-)";
503 
504 out:
505 	strlist__delete(tips);
506 
507 	return tip;
508 }
509