tools/perf/util/util.c

   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 static 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 }