tools/perf/util/util.c

   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 }