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 int cacheline_size;
  42
  43 int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
  44 int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;
  45
  46 bool test_attr__enabled;
  47
  48 bool perf_host  = true;
  49 bool perf_guest = false;
  50
  51 void 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
  61 int 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
  87 int 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 */
 128 bool 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 */
 134 struct 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
 156 out:
 157         closedir(dir);
 158         return list;
 159 }
 160
 161 static 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;
 183 out_fclose_to:
 184         fclose(to_fp);
 185         free(line);
 186 out_fclose_from:
 187         fclose(from_fp);
 188 out:
 189         return err;
 190 }
 191
 192 static 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
 220 static 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);
 268 out_close_to:
 269         close(tofd);
 270         if (!err)
 271                 err = link(tmp, to);
 272         unlink(tmp);
 273 out:
 274         free(tmp);
 275         return err;
 276 }
 277
 278 int copyfile_ns(const char *from, const char *to, struct nsinfo *nsi)
 279 {
 280         return copyfile_mode_ns(from, to, 0755, nsi);
 281 }
 282
 283 int copyfile_mode(const char *from, const char *to, mode_t mode)
 284 {
 285         return copyfile_mode_ns(from, to, mode, NULL);
 286 }
 287
 288 int copyfile(const char *from, const char *to)
 289 {
 290         return copyfile_mode(from, to, 0755);
 291 }
 292
 293 static 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  */
 319 ssize_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  */
 327 ssize_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
 333 size_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  */
 347 int 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
 356 int 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 }
 365 static int
 366 fetch_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;
 409 errout:
 410         free(line);
 411         return err;
 412 }
 413
 414 int
 415 fetch_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
 450 const 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
 472 out:
 473         strlist__delete(tips);
 474
 475         return tip;
 476 }