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v4.17
  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
 28bool perf_singlethreaded = true;
 29
 30void perf_set_singlethreaded(void)
 31{
 32	perf_singlethreaded = true;
 33}
 34
 35void perf_set_multithreaded(void)
 36{
 37	perf_singlethreaded = false;
 38}
 39
 40unsigned int page_size;
 41int cacheline_size;
 42
 43int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
 44int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;
 45
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 46bool test_attr__enabled;
 47
 48bool perf_host  = true;
 49bool perf_guest = false;
 50
 51void event_attr_init(struct perf_event_attr *attr)
 52{
 53	if (!perf_host)
 54		attr->exclude_host  = 1;
 55	if (!perf_guest)
 56		attr->exclude_guest = 1;
 57	/* to capture ABI version */
 58	attr->size = sizeof(*attr);
 59}
 60
 61int mkdir_p(char *path, mode_t mode)
 62{
 63	struct stat st;
 64	int err;
 65	char *d = path;
 66
 67	if (*d != '/')
 68		return -1;
 69
 70	if (stat(path, &st) == 0)
 71		return 0;
 72
 73	while (*++d == '/');
 74
 75	while ((d = strchr(d, '/'))) {
 76		*d = '\0';
 77		err = stat(path, &st) && mkdir(path, mode);
 78		*d++ = '/';
 79		if (err)
 80			return -1;
 81		while (*d == '/')
 82			++d;
 83	}
 84	return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
 85}
 86
 87int rm_rf(const char *path)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 88{
 89	DIR *dir;
 90	int ret = 0;
 91	struct dirent *d;
 92	char namebuf[PATH_MAX];
 
 
 
 
 
 
 
 
 
 
 93
 
 94	dir = opendir(path);
 95	if (dir == NULL)
 96		return 0;
 97
 98	while ((d = readdir(dir)) != NULL && !ret) {
 99		struct stat statbuf;
100
101		if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
102			continue;
103
 
 
 
 
 
104		scnprintf(namebuf, sizeof(namebuf), "%s/%s",
105			  path, d->d_name);
106
107		/* We have to check symbolic link itself */
108		ret = lstat(namebuf, &statbuf);
109		if (ret < 0) {
110			pr_debug("stat failed: %s\n", namebuf);
111			break;
112		}
113
114		if (S_ISDIR(statbuf.st_mode))
115			ret = rm_rf(namebuf);
116		else
117			ret = unlink(namebuf);
118	}
119	closedir(dir);
120
121	if (ret < 0)
122		return ret;
123
124	return rmdir(path);
125}
126
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
127/* A filter which removes dot files */
128bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
129{
130	return d->d_name[0] != '.';
131}
132
133/* lsdir reads a directory and store it in strlist */
134struct strlist *lsdir(const char *name,
135		      bool (*filter)(const char *, struct dirent *))
136{
137	struct strlist *list = NULL;
138	DIR *dir;
139	struct dirent *d;
140
141	dir = opendir(name);
142	if (!dir)
143		return NULL;
144
145	list = strlist__new(NULL, NULL);
146	if (!list) {
147		errno = ENOMEM;
148		goto out;
149	}
150
151	while ((d = readdir(dir)) != NULL) {
152		if (!filter || filter(name, d))
153			strlist__add(list, d->d_name);
154	}
155
156out:
157	closedir(dir);
158	return list;
159}
160
161static int slow_copyfile(const char *from, const char *to, struct nsinfo *nsi)
162{
163	int err = -1;
164	char *line = NULL;
165	size_t n;
166	FILE *from_fp, *to_fp;
167	struct nscookie nsc;
168
169	nsinfo__mountns_enter(nsi, &nsc);
170	from_fp = fopen(from, "r");
171	nsinfo__mountns_exit(&nsc);
172	if (from_fp == NULL)
173		goto out;
174
175	to_fp = fopen(to, "w");
176	if (to_fp == NULL)
177		goto out_fclose_from;
178
179	while (getline(&line, &n, from_fp) > 0)
180		if (fputs(line, to_fp) == EOF)
181			goto out_fclose_to;
182	err = 0;
183out_fclose_to:
184	fclose(to_fp);
185	free(line);
186out_fclose_from:
187	fclose(from_fp);
188out:
189	return err;
190}
191
192static int copyfile_offset(int ifd, loff_t off_in, int ofd, loff_t off_out, u64 size)
193{
194	void *ptr;
195	loff_t pgoff;
196
197	pgoff = off_in & ~(page_size - 1);
198	off_in -= pgoff;
199
200	ptr = mmap(NULL, off_in + size, PROT_READ, MAP_PRIVATE, ifd, pgoff);
201	if (ptr == MAP_FAILED)
202		return -1;
203
204	while (size) {
205		ssize_t ret = pwrite(ofd, ptr + off_in, size, off_out);
206		if (ret < 0 && errno == EINTR)
207			continue;
208		if (ret <= 0)
209			break;
210
211		size -= ret;
212		off_in += ret;
213		off_out += ret;
214	}
215	munmap(ptr, off_in + size);
216
217	return size ? -1 : 0;
218}
219
220static int copyfile_mode_ns(const char *from, const char *to, mode_t mode,
221			    struct nsinfo *nsi)
222{
223	int fromfd, tofd;
224	struct stat st;
225	int err;
226	char *tmp = NULL, *ptr = NULL;
227	struct nscookie nsc;
228
229	nsinfo__mountns_enter(nsi, &nsc);
230	err = stat(from, &st);
231	nsinfo__mountns_exit(&nsc);
232	if (err)
233		goto out;
234	err = -1;
235
236	/* extra 'x' at the end is to reserve space for '.' */
237	if (asprintf(&tmp, "%s.XXXXXXx", to) < 0) {
238		tmp = NULL;
239		goto out;
240	}
241	ptr = strrchr(tmp, '/');
242	if (!ptr)
243		goto out;
244	ptr = memmove(ptr + 1, ptr, strlen(ptr) - 1);
245	*ptr = '.';
246
247	tofd = mkstemp(tmp);
248	if (tofd < 0)
249		goto out;
250
251	if (fchmod(tofd, mode))
252		goto out_close_to;
253
254	if (st.st_size == 0) { /* /proc? do it slowly... */
255		err = slow_copyfile(from, tmp, nsi);
256		goto out_close_to;
257	}
258
259	nsinfo__mountns_enter(nsi, &nsc);
260	fromfd = open(from, O_RDONLY);
261	nsinfo__mountns_exit(&nsc);
262	if (fromfd < 0)
263		goto out_close_to;
264
265	err = copyfile_offset(fromfd, 0, tofd, 0, st.st_size);
266
267	close(fromfd);
268out_close_to:
269	close(tofd);
270	if (!err)
271		err = link(tmp, to);
272	unlink(tmp);
273out:
274	free(tmp);
275	return err;
276}
277
278int copyfile_ns(const char *from, const char *to, struct nsinfo *nsi)
279{
280	return copyfile_mode_ns(from, to, 0755, nsi);
281}
282
283int copyfile_mode(const char *from, const char *to, mode_t mode)
284{
285	return copyfile_mode_ns(from, to, mode, NULL);
286}
287
288int copyfile(const char *from, const char *to)
289{
290	return copyfile_mode(from, to, 0755);
291}
292
293static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
294{
295	void *buf_start = buf;
296	size_t left = n;
297
298	while (left) {
299		/* buf must be treated as const if !is_read. */
300		ssize_t ret = is_read ? read(fd, buf, left) :
301					write(fd, buf, left);
302
303		if (ret < 0 && errno == EINTR)
304			continue;
305		if (ret <= 0)
306			return ret;
307
308		left -= ret;
309		buf  += ret;
310	}
311
312	BUG_ON((size_t)(buf - buf_start) != n);
313	return n;
314}
315
316/*
317 * Read exactly 'n' bytes or return an error.
318 */
319ssize_t readn(int fd, void *buf, size_t n)
320{
321	return ion(true, fd, buf, n);
322}
323
324/*
325 * Write exactly 'n' bytes or return an error.
326 */
327ssize_t writen(int fd, const void *buf, size_t n)
328{
329	/* ion does not modify buf. */
330	return ion(false, fd, (void *)buf, n);
331}
332
333size_t hex_width(u64 v)
334{
335	size_t n = 1;
336
337	while ((v >>= 4))
338		++n;
339
340	return n;
341}
342
343/*
344 * While we find nice hex chars, build a long_val.
345 * Return number of chars processed.
346 */
347int hex2u64(const char *ptr, u64 *long_val)
348{
349	char *p;
350
351	*long_val = strtoull(ptr, &p, 16);
352
353	return p - ptr;
354}
355
356int perf_event_paranoid(void)
357{
358	int value;
359
360	if (sysctl__read_int("kernel/perf_event_paranoid", &value))
361		return INT_MAX;
362
363	return value;
364}
 
 
 
 
 
 
 
 
365static int
366fetch_ubuntu_kernel_version(unsigned int *puint)
367{
368	ssize_t len;
369	size_t line_len = 0;
370	char *ptr, *line = NULL;
371	int version, patchlevel, sublevel, err;
372	FILE *vsig;
373
374	if (!puint)
375		return 0;
376
377	vsig = fopen("/proc/version_signature", "r");
378	if (!vsig) {
379		pr_debug("Open /proc/version_signature failed: %s\n",
380			 strerror(errno));
381		return -1;
382	}
383
384	len = getline(&line, &line_len, vsig);
385	fclose(vsig);
386	err = -1;
387	if (len <= 0) {
388		pr_debug("Reading from /proc/version_signature failed: %s\n",
389			 strerror(errno));
390		goto errout;
391	}
392
393	ptr = strrchr(line, ' ');
394	if (!ptr) {
395		pr_debug("Parsing /proc/version_signature failed: %s\n", line);
396		goto errout;
397	}
398
399	err = sscanf(ptr + 1, "%d.%d.%d",
400		     &version, &patchlevel, &sublevel);
401	if (err != 3) {
402		pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
403			 line);
404		goto errout;
405	}
406
407	*puint = (version << 16) + (patchlevel << 8) + sublevel;
408	err = 0;
409errout:
410	free(line);
411	return err;
412}
413
414int
415fetch_kernel_version(unsigned int *puint, char *str,
416		     size_t str_size)
417{
418	struct utsname utsname;
419	int version, patchlevel, sublevel, err;
420	bool int_ver_ready = false;
421
422	if (access("/proc/version_signature", R_OK) == 0)
423		if (!fetch_ubuntu_kernel_version(puint))
424			int_ver_ready = true;
425
426	if (uname(&utsname))
427		return -1;
428
429	if (str && str_size) {
430		strncpy(str, utsname.release, str_size);
431		str[str_size - 1] = '\0';
432	}
433
434	if (!puint || int_ver_ready)
435		return 0;
436
437	err = sscanf(utsname.release, "%d.%d.%d",
438		     &version, &patchlevel, &sublevel);
439
440	if (err != 3) {
441		pr_debug("Unable to get kernel version from uname '%s'\n",
442			 utsname.release);
443		return -1;
444	}
445
446	*puint = (version << 16) + (patchlevel << 8) + sublevel;
447	return 0;
448}
449
450const char *perf_tip(const char *dirpath)
451{
452	struct strlist *tips;
453	struct str_node *node;
454	char *tip = NULL;
455	struct strlist_config conf = {
456		.dirname = dirpath,
457		.file_only = true,
458	};
459
460	tips = strlist__new("tips.txt", &conf);
461	if (tips == NULL)
462		return errno == ENOENT ? NULL :
463			"Tip: check path of tips.txt or get more memory! ;-p";
464
465	if (strlist__nr_entries(tips) == 0)
466		goto out;
467
468	node = strlist__entry(tips, random() % strlist__nr_entries(tips));
469	if (asprintf(&tip, "Tip: %s", node->s) < 0)
470		tip = (char *)"Tip: get more memory! ;-)";
471
472out:
473	strlist__delete(tips);
474
475	return tip;
 
 
 
 
 
 
 
 
 
 
476}
v5.9
  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
 30bool perf_singlethreaded = true;
 31
 32void perf_set_singlethreaded(void)
 33{
 34	perf_singlethreaded = true;
 35}
 36
 37void perf_set_multithreaded(void)
 38{
 39	perf_singlethreaded = false;
 40}
 41
 
 
 
 42int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
 43int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;
 44
 45int 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
 58bool 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
 76bool test_attr__enabled;
 77
 78bool perf_host  = true;
 79bool perf_guest = false;
 80
 81void 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
 91int 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
117static 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 */
148static 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
203static 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
218int 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
231int 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 */
237bool 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 */
243struct 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
265out:
266	closedir(dir);
267	return list;
268}
269
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
270size_t hex_width(u64 v)
271{
272	size_t n = 1;
273
274	while ((v >>= 4))
275		++n;
276
277	return n;
278}
279
 
 
 
 
 
 
 
 
 
 
 
 
 
280int 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
290bool 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
297static int
298fetch_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;
341errout:
342	free(line);
343	return err;
344}
345
346int
347fetch_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
382const char *perf_tip(const char *dirpath)
383{
384	struct strlist *tips;
385	struct str_node *node;
386	char *tip = NULL;
387	struct strlist_config conf = {
388		.dirname = dirpath,
389		.file_only = true,
390	};
391
392	tips = strlist__new("tips.txt", &conf);
393	if (tips == NULL)
394		return errno == ENOENT ? NULL :
395			"Tip: check path of tips.txt or get more memory! ;-p";
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(&tip, "Tip: %s", node->s) < 0)
402		tip = (char *)"Tip: get more memory! ;-)";
403
404out:
405	strlist__delete(tips);
406
407	return tip;
408}
409
410char *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}