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 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
  76 bool test_attr__enabled;
  77
  78 bool perf_host  = true;
  79 bool perf_guest = false;
  80
  81 void 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
  91 int 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
 117 static 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  */
 148 static 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
 203 static 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
 218 int 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
 231 int 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 */
 237 bool 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 */
 243 struct 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
 265 out:
 266         closedir(dir);
 267         return list;
 268 }
 269
 270 size_t hex_width(u64 v)
 271 {
 272         size_t n = 1;
 273
 274         while ((v >>= 4))
 275                 ++n;
 276
 277         return n;
 278 }
 279
 280 int 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
 290 bool 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
 297 static int
 298 fetch_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;
 341 errout:
 342         free(line);
 343         return err;
 344 }
 345
 346 int
 347 fetch_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
 382 const 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
 404 out:
 405         strlist__delete(tips);
 406
 407         return tip;
 408 }
 409
 410 char *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 }