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 "namespaces.h"
   6 #include <api/fs/fs.h>
   7 #include <sys/mman.h>
   8 #include <sys/stat.h>
   9 #include <sys/utsname.h>
  10 #include <dirent.h>
  11 #include <fcntl.h>
  12 #include <inttypes.h>
  13 #include <signal.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <errno.h>
  18 #include <limits.h>
  19 #include <linux/kernel.h>
  20 #include <linux/log2.h>
  21 #include <linux/time64.h>
  22 #include <unistd.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 unsigned int page_size;
  43
  44 #ifdef _SC_LEVEL1_DCACHE_LINESIZE
  45 #define cache_line_size(cacheline_sizep) *cacheline_sizep = sysconf(_SC_LEVEL1_DCACHE_LINESIZE)
  46 #else
  47 static void cache_line_size(int *cacheline_sizep)
  48 {
  49         if (sysfs__read_int("devices/system/cpu/cpu0/cache/index0/coherency_line_size", cacheline_sizep))
  50                 pr_debug("cannot determine cache line size");
  51 }
  52 #endif
  53
  54 int cacheline_size(void)
  55 {
  56         static int size;
  57
  58         if (!size)
  59                 cache_line_size(&size);
  60
  61         return size;
  62 }
  63
  64 int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
  65 int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;
  66
  67 int sysctl__max_stack(void)
  68 {
  69         int value;
  70
  71         if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
  72                 sysctl_perf_event_max_stack = value;
  73
  74         if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
  75                 sysctl_perf_event_max_contexts_per_stack = value;
  76
  77         return sysctl_perf_event_max_stack;
  78 }
  79
  80 bool test_attr__enabled;
  81
  82 bool perf_host  = true;
  83 bool perf_guest = false;
  84
  85 void event_attr_init(struct perf_event_attr *attr)
  86 {
  87         if (!perf_host)
  88                 attr->exclude_host  = 1;
  89         if (!perf_guest)
  90                 attr->exclude_guest = 1;
  91         /* to capture ABI version */
  92         attr->size = sizeof(*attr);
  93 }
  94
  95 int mkdir_p(char *path, mode_t mode)
  96 {
  97         struct stat st;
  98         int err;
  99         char *d = path;
 100
 101         if (*d != '/')
 102                 return -1;
 103
 104         if (stat(path, &st) == 0)
 105                 return 0;
 106
 107         while (*++d == '/');
 108
 109         while ((d = strchr(d, '/'))) {
 110                 *d = '\0';
 111                 err = stat(path, &st) && mkdir(path, mode);
 112                 *d++ = '/';
 113                 if (err)
 114                         return -1;
 115                 while (*d == '/')
 116                         ++d;
 117         }
 118         return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
 119 }
 120
 121 static bool match_pat(char *file, const char **pat)
 122 {
 123         int i = 0;
 124
 125         if (!pat)
 126                 return true;
 127
 128         while (pat[i]) {
 129                 if (strglobmatch(file, pat[i]))
 130                         return true;
 131
 132                 i++;
 133         }
 134
 135         return false;
 136 }
 137
 138 /*
 139  * The depth specify how deep the removal will go.
 140  * 0       - will remove only files under the 'path' directory
 141  * 1 .. x  - will dive in x-level deep under the 'path' directory
 142  *
 143  * If specified the pat is array of string patterns ended with NULL,
 144  * which are checked upon every file/directory found. Only matching
 145  * ones are removed.
 146  *
 147  * The function returns:
 148  *    0 on success
 149  *   -1 on removal failure with errno set
 150  *   -2 on pattern failure
 151  */
 152 static int rm_rf_depth_pat(const char *path, int depth, const char **pat)
 153 {
 154         DIR *dir;
 155         int ret;
 156         struct dirent *d;
 157         char namebuf[PATH_MAX];
 158         struct stat statbuf;
 159
 160         /* Do not fail if there's no file. */
 161         ret = lstat(path, &statbuf);
 162         if (ret)
 163                 return 0;
 164
 165         /* Try to remove any file we get. */
 166         if (!(statbuf.st_mode & S_IFDIR))
 167                 return unlink(path);
 168
 169         /* We have directory in path. */
 170         dir = opendir(path);
 171         if (dir == NULL)
 172                 return -1;
 173
 174         while ((d = readdir(dir)) != NULL && !ret) {
 175
 176                 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
 177                         continue;
 178
 179                 if (!match_pat(d->d_name, pat))
 180                         return -2;
 181
 182                 scnprintf(namebuf, sizeof(namebuf), "%s/%s",
 183                           path, d->d_name);
 184
 185                 /* We have to check symbolic link itself */
 186                 ret = lstat(namebuf, &statbuf);
 187                 if (ret < 0) {
 188                         pr_debug("stat failed: %s\n", namebuf);
 189                         break;
 190                 }
 191
 192                 if (S_ISDIR(statbuf.st_mode))
 193                         ret = depth ? rm_rf_depth_pat(namebuf, depth - 1, pat) : 0;
 194                 else
 195                         ret = unlink(namebuf);
 196         }
 197         closedir(dir);
 198
 199         if (ret < 0)
 200                 return ret;
 201
 202         return rmdir(path);
 203 }
 204
 205 int rm_rf_perf_data(const char *path)
 206 {
 207         const char *pat[] = {
 208                 "header",
 209                 "data.*",
 210                 NULL,
 211         };
 212
 213         return rm_rf_depth_pat(path, 0, pat);
 214 }
 215
 216 int rm_rf(const char *path)
 217 {
 218         return rm_rf_depth_pat(path, INT_MAX, NULL);
 219 }
 220
 221 /* A filter which removes dot files */
 222 bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
 223 {
 224         return d->d_name[0] != '.';
 225 }
 226
 227 /* lsdir reads a directory and store it in strlist */
 228 struct strlist *lsdir(const char *name,
 229                       bool (*filter)(const char *, struct dirent *))
 230 {
 231         struct strlist *list = NULL;
 232         DIR *dir;
 233         struct dirent *d;
 234
 235         dir = opendir(name);
 236         if (!dir)
 237                 return NULL;
 238
 239         list = strlist__new(NULL, NULL);
 240         if (!list) {
 241                 errno = ENOMEM;
 242                 goto out;
 243         }
 244
 245         while ((d = readdir(dir)) != NULL) {
 246                 if (!filter || filter(name, d))
 247                         strlist__add(list, d->d_name);
 248         }
 249
 250 out:
 251         closedir(dir);
 252         return list;
 253 }
 254
 255 static int slow_copyfile(const char *from, const char *to, struct nsinfo *nsi)
 256 {
 257         int err = -1;
 258         char *line = NULL;
 259         size_t n;
 260         FILE *from_fp, *to_fp;
 261         struct nscookie nsc;
 262
 263         nsinfo__mountns_enter(nsi, &nsc);
 264         from_fp = fopen(from, "r");
 265         nsinfo__mountns_exit(&nsc);
 266         if (from_fp == NULL)
 267                 goto out;
 268
 269         to_fp = fopen(to, "w");
 270         if (to_fp == NULL)
 271                 goto out_fclose_from;
 272
 273         while (getline(&line, &n, from_fp) > 0)
 274                 if (fputs(line, to_fp) == EOF)
 275                         goto out_fclose_to;
 276         err = 0;
 277 out_fclose_to:
 278         fclose(to_fp);
 279         free(line);
 280 out_fclose_from:
 281         fclose(from_fp);
 282 out:
 283         return err;
 284 }
 285
 286 int copyfile_offset(int ifd, loff_t off_in, int ofd, loff_t off_out, u64 size)
 287 {
 288         void *ptr;
 289         loff_t pgoff;
 290
 291         pgoff = off_in & ~(page_size - 1);
 292         off_in -= pgoff;
 293
 294         ptr = mmap(NULL, off_in + size, PROT_READ, MAP_PRIVATE, ifd, pgoff);
 295         if (ptr == MAP_FAILED)
 296                 return -1;
 297
 298         while (size) {
 299                 ssize_t ret = pwrite(ofd, ptr + off_in, size, off_out);
 300                 if (ret < 0 && errno == EINTR)
 301                         continue;
 302                 if (ret <= 0)
 303                         break;
 304
 305                 size -= ret;
 306                 off_in += ret;
 307                 off_out += ret;
 308         }
 309         munmap(ptr, off_in + size);
 310
 311         return size ? -1 : 0;
 312 }
 313
 314 static int copyfile_mode_ns(const char *from, const char *to, mode_t mode,
 315                             struct nsinfo *nsi)
 316 {
 317         int fromfd, tofd;
 318         struct stat st;
 319         int err;
 320         char *tmp = NULL, *ptr = NULL;
 321         struct nscookie nsc;
 322
 323         nsinfo__mountns_enter(nsi, &nsc);
 324         err = stat(from, &st);
 325         nsinfo__mountns_exit(&nsc);
 326         if (err)
 327                 goto out;
 328         err = -1;
 329
 330         /* extra 'x' at the end is to reserve space for '.' */
 331         if (asprintf(&tmp, "%s.XXXXXXx", to) < 0) {
 332                 tmp = NULL;
 333                 goto out;
 334         }
 335         ptr = strrchr(tmp, '/');
 336         if (!ptr)
 337                 goto out;
 338         ptr = memmove(ptr + 1, ptr, strlen(ptr) - 1);
 339         *ptr = '.';
 340
 341         tofd = mkstemp(tmp);
 342         if (tofd < 0)
 343                 goto out;
 344
 345         if (fchmod(tofd, mode))
 346                 goto out_close_to;
 347
 348         if (st.st_size == 0) { /* /proc? do it slowly... */
 349                 err = slow_copyfile(from, tmp, nsi);
 350                 goto out_close_to;
 351         }
 352
 353         nsinfo__mountns_enter(nsi, &nsc);
 354         fromfd = open(from, O_RDONLY);
 355         nsinfo__mountns_exit(&nsc);
 356         if (fromfd < 0)
 357                 goto out_close_to;
 358
 359         err = copyfile_offset(fromfd, 0, tofd, 0, st.st_size);
 360
 361         close(fromfd);
 362 out_close_to:
 363         close(tofd);
 364         if (!err)
 365                 err = link(tmp, to);
 366         unlink(tmp);
 367 out:
 368         free(tmp);
 369         return err;
 370 }
 371
 372 int copyfile_ns(const char *from, const char *to, struct nsinfo *nsi)
 373 {
 374         return copyfile_mode_ns(from, to, 0755, nsi);
 375 }
 376
 377 int copyfile_mode(const char *from, const char *to, mode_t mode)
 378 {
 379         return copyfile_mode_ns(from, to, mode, NULL);
 380 }
 381
 382 int copyfile(const char *from, const char *to)
 383 {
 384         return copyfile_mode(from, to, 0755);
 385 }
 386
 387 static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
 388 {
 389         void *buf_start = buf;
 390         size_t left = n;
 391
 392         while (left) {
 393                 /* buf must be treated as const if !is_read. */
 394                 ssize_t ret = is_read ? read(fd, buf, left) :
 395                                         write(fd, buf, left);
 396
 397                 if (ret < 0 && errno == EINTR)
 398                         continue;
 399                 if (ret <= 0)
 400                         return ret;
 401
 402                 left -= ret;
 403                 buf  += ret;
 404         }
 405
 406         BUG_ON((size_t)(buf - buf_start) != n);
 407         return n;
 408 }
 409
 410 /*
 411  * Read exactly 'n' bytes or return an error.
 412  */
 413 ssize_t readn(int fd, void *buf, size_t n)
 414 {
 415         return ion(true, fd, buf, n);
 416 }
 417
 418 /*
 419  * Write exactly 'n' bytes or return an error.
 420  */
 421 ssize_t writen(int fd, const void *buf, size_t n)
 422 {
 423         /* ion does not modify buf. */
 424         return ion(false, fd, (void *)buf, n);
 425 }
 426
 427 size_t hex_width(u64 v)
 428 {
 429         size_t n = 1;
 430
 431         while ((v >>= 4))
 432                 ++n;
 433
 434         return n;
 435 }
 436
 437 /*
 438  * While we find nice hex chars, build a long_val.
 439  * Return number of chars processed.
 440  */
 441 int hex2u64(const char *ptr, u64 *long_val)
 442 {
 443         char *p;
 444
 445         *long_val = strtoull(ptr, &p, 16);
 446
 447         return p - ptr;
 448 }
 449
 450 int perf_event_paranoid(void)
 451 {
 452         int value;
 453
 454         if (sysctl__read_int("kernel/perf_event_paranoid", &value))
 455                 return INT_MAX;
 456
 457         return value;
 458 }
 459 static int
 460 fetch_ubuntu_kernel_version(unsigned int *puint)
 461 {
 462         ssize_t len;
 463         size_t line_len = 0;
 464         char *ptr, *line = NULL;
 465         int version, patchlevel, sublevel, err;
 466         FILE *vsig;
 467
 468         if (!puint)
 469                 return 0;
 470
 471         vsig = fopen("/proc/version_signature", "r");
 472         if (!vsig) {
 473                 pr_debug("Open /proc/version_signature failed: %s\n",
 474                          strerror(errno));
 475                 return -1;
 476         }
 477
 478         len = getline(&line, &line_len, vsig);
 479         fclose(vsig);
 480         err = -1;
 481         if (len <= 0) {
 482                 pr_debug("Reading from /proc/version_signature failed: %s\n",
 483                          strerror(errno));
 484                 goto errout;
 485         }
 486
 487         ptr = strrchr(line, ' ');
 488         if (!ptr) {
 489                 pr_debug("Parsing /proc/version_signature failed: %s\n", line);
 490                 goto errout;
 491         }
 492
 493         err = sscanf(ptr + 1, "%d.%d.%d",
 494                      &version, &patchlevel, &sublevel);
 495         if (err != 3) {
 496                 pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
 497                          line);
 498                 goto errout;
 499         }
 500
 501         *puint = (version << 16) + (patchlevel << 8) + sublevel;
 502         err = 0;
 503 errout:
 504         free(line);
 505         return err;
 506 }
 507
 508 int
 509 fetch_kernel_version(unsigned int *puint, char *str,
 510                      size_t str_size)
 511 {
 512         struct utsname utsname;
 513         int version, patchlevel, sublevel, err;
 514         bool int_ver_ready = false;
 515
 516         if (access("/proc/version_signature", R_OK) == 0)
 517                 if (!fetch_ubuntu_kernel_version(puint))
 518                         int_ver_ready = true;
 519
 520         if (uname(&utsname))
 521                 return -1;
 522
 523         if (str && str_size) {
 524                 strncpy(str, utsname.release, str_size);
 525                 str[str_size - 1] = '\0';
 526         }
 527
 528         if (!puint || int_ver_ready)
 529                 return 0;
 530
 531         err = sscanf(utsname.release, "%d.%d.%d",
 532                      &version, &patchlevel, &sublevel);
 533
 534         if (err != 3) {
 535                 pr_debug("Unable to get kernel version from uname '%s'\n",
 536                          utsname.release);
 537                 return -1;
 538         }
 539
 540         *puint = (version << 16) + (patchlevel << 8) + sublevel;
 541         return 0;
 542 }
 543
 544 const char *perf_tip(const char *dirpath)
 545 {
 546         struct strlist *tips;
 547         struct str_node *node;
 548         char *tip = NULL;
 549         struct strlist_config conf = {
 550                 .dirname = dirpath,
 551                 .file_only = true,
 552         };
 553
 554         tips = strlist__new("tips.txt", &conf);
 555         if (tips == NULL)
 556                 return errno == ENOENT ? NULL :
 557                         "Tip: check path of tips.txt or get more memory! ;-p";
 558
 559         if (strlist__nr_entries(tips) == 0)
 560                 goto out;
 561
 562         node = strlist__entry(tips, random() % strlist__nr_entries(tips));
 563         if (asprintf(&tip, "Tip: %s", node->s) < 0)
 564                 tip = (char *)"Tip: get more memory! ;-)";
 565
 566 out:
 567         strlist__delete(tips);
 568
 569         return tip;
 570 }
 571
 572 char *perf_exe(char *buf, int len)
 573 {
 574         int n = readlink("/proc/self/exe", buf, len);
 575         if (n > 0) {
 576                 buf[n] = 0;
 577                 return buf;
 578         }
 579         return strcpy(buf, "perf");
 580 }