tools/perf/util/util.c

   1 #include "../perf.h"
   2 #include "util.h"
   3 #include "debug.h"
   4 #include <api/fs/fs.h>
   5 #include <sys/mman.h>
   6 #include <sys/stat.h>
   7 #include <sys/utsname.h>
   8 #include <dirent.h>
   9 #include <inttypes.h>
  10 #include <signal.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <errno.h>
  15 #include <limits.h>
  16 #include <linux/kernel.h>
  17 #include <linux/log2.h>
  18 #include <linux/time64.h>
  19 #include <unistd.h>
  20 #include "strlist.h"
  21
  22 /*
  23  * XXX We need to find a better place for these things...
  24  */
  25 unsigned int page_size;
  26 int cacheline_size;
  27
  28 int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
  29 int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;
  30
  31 bool test_attr__enabled;
  32
  33 bool perf_host  = true;
  34 bool perf_guest = false;
  35
  36 void event_attr_init(struct perf_event_attr *attr)
  37 {
  38         if (!perf_host)
  39                 attr->exclude_host  = 1;
  40         if (!perf_guest)
  41                 attr->exclude_guest = 1;
  42         /* to capture ABI version */
  43         attr->size = sizeof(*attr);
  44 }
  45
  46 int mkdir_p(char *path, mode_t mode)
  47 {
  48         struct stat st;
  49         int err;
  50         char *d = path;
  51
  52         if (*d != '/')
  53                 return -1;
  54
  55         if (stat(path, &st) == 0)
  56                 return 0;
  57
  58         while (*++d == '/');
  59
  60         while ((d = strchr(d, '/'))) {
  61                 *d = '\0';
  62                 err = stat(path, &st) && mkdir(path, mode);
  63                 *d++ = '/';
  64                 if (err)
  65                         return -1;
  66                 while (*d == '/')
  67                         ++d;
  68         }
  69         return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
  70 }
  71
  72 int rm_rf(const char *path)
  73 {
  74         DIR *dir;
  75         int ret = 0;
  76         struct dirent *d;
  77         char namebuf[PATH_MAX];
  78
  79         dir = opendir(path);
  80         if (dir == NULL)
  81                 return 0;
  82
  83         while ((d = readdir(dir)) != NULL && !ret) {
  84                 struct stat statbuf;
  85
  86                 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
  87                         continue;
  88
  89                 scnprintf(namebuf, sizeof(namebuf), "%s/%s",
  90                           path, d->d_name);
  91
  92                 /* We have to check symbolic link itself */
  93                 ret = lstat(namebuf, &statbuf);
  94                 if (ret < 0) {
  95                         pr_debug("stat failed: %s\n", namebuf);
  96                         break;
  97                 }
  98
  99                 if (S_ISDIR(statbuf.st_mode))
 100                         ret = rm_rf(namebuf);
 101                 else
 102                         ret = unlink(namebuf);
 103         }
 104         closedir(dir);
 105
 106         if (ret < 0)
 107                 return ret;
 108
 109         return rmdir(path);
 110 }
 111
 112 /* A filter which removes dot files */
 113 bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
 114 {
 115         return d->d_name[0] != '.';
 116 }
 117
 118 /* lsdir reads a directory and store it in strlist */
 119 struct strlist *lsdir(const char *name,
 120                       bool (*filter)(const char *, struct dirent *))
 121 {
 122         struct strlist *list = NULL;
 123         DIR *dir;
 124         struct dirent *d;
 125
 126         dir = opendir(name);
 127         if (!dir)
 128                 return NULL;
 129
 130         list = strlist__new(NULL, NULL);
 131         if (!list) {
 132                 errno = ENOMEM;
 133                 goto out;
 134         }
 135
 136         while ((d = readdir(dir)) != NULL) {
 137                 if (!filter || filter(name, d))
 138                         strlist__add(list, d->d_name);
 139         }
 140
 141 out:
 142         closedir(dir);
 143         return list;
 144 }
 145
 146 static int slow_copyfile(const char *from, const char *to, struct nsinfo *nsi)
 147 {
 148         int err = -1;
 149         char *line = NULL;
 150         size_t n;
 151         FILE *from_fp, *to_fp;
 152         struct nscookie nsc;
 153
 154         nsinfo__mountns_enter(nsi, &nsc);
 155         from_fp = fopen(from, "r");
 156         nsinfo__mountns_exit(&nsc);
 157         if (from_fp == NULL)
 158                 goto out;
 159
 160         to_fp = fopen(to, "w");
 161         if (to_fp == NULL)
 162                 goto out_fclose_from;
 163
 164         while (getline(&line, &n, from_fp) > 0)
 165                 if (fputs(line, to_fp) == EOF)
 166                         goto out_fclose_to;
 167         err = 0;
 168 out_fclose_to:
 169         fclose(to_fp);
 170         free(line);
 171 out_fclose_from:
 172         fclose(from_fp);
 173 out:
 174         return err;
 175 }
 176
 177 int copyfile_offset(int ifd, loff_t off_in, int ofd, loff_t off_out, u64 size)
 178 {
 179         void *ptr;
 180         loff_t pgoff;
 181
 182         pgoff = off_in & ~(page_size - 1);
 183         off_in -= pgoff;
 184
 185         ptr = mmap(NULL, off_in + size, PROT_READ, MAP_PRIVATE, ifd, pgoff);
 186         if (ptr == MAP_FAILED)
 187                 return -1;
 188
 189         while (size) {
 190                 ssize_t ret = pwrite(ofd, ptr + off_in, size, off_out);
 191                 if (ret < 0 && errno == EINTR)
 192                         continue;
 193                 if (ret <= 0)
 194                         break;
 195
 196                 size -= ret;
 197                 off_in += ret;
 198                 off_out -= ret;
 199         }
 200         munmap(ptr, off_in + size);
 201
 202         return size ? -1 : 0;
 203 }
 204
 205 static int copyfile_mode_ns(const char *from, const char *to, mode_t mode,
 206                             struct nsinfo *nsi)
 207 {
 208         int fromfd, tofd;
 209         struct stat st;
 210         int err;
 211         char *tmp = NULL, *ptr = NULL;
 212         struct nscookie nsc;
 213
 214         nsinfo__mountns_enter(nsi, &nsc);
 215         err = stat(from, &st);
 216         nsinfo__mountns_exit(&nsc);
 217         if (err)
 218                 goto out;
 219         err = -1;
 220
 221         /* extra 'x' at the end is to reserve space for '.' */
 222         if (asprintf(&tmp, "%s.XXXXXXx", to) < 0) {
 223                 tmp = NULL;
 224                 goto out;
 225         }
 226         ptr = strrchr(tmp, '/');
 227         if (!ptr)
 228                 goto out;
 229         ptr = memmove(ptr + 1, ptr, strlen(ptr) - 1);
 230         *ptr = '.';
 231
 232         tofd = mkstemp(tmp);
 233         if (tofd < 0)
 234                 goto out;
 235
 236         if (fchmod(tofd, mode))
 237                 goto out_close_to;
 238
 239         if (st.st_size == 0) { /* /proc? do it slowly... */
 240                 err = slow_copyfile(from, tmp, nsi);
 241                 goto out_close_to;
 242         }
 243
 244         nsinfo__mountns_enter(nsi, &nsc);
 245         fromfd = open(from, O_RDONLY);
 246         nsinfo__mountns_exit(&nsc);
 247         if (fromfd < 0)
 248                 goto out_close_to;
 249
 250         err = copyfile_offset(fromfd, 0, tofd, 0, st.st_size);
 251
 252         close(fromfd);
 253 out_close_to:
 254         close(tofd);
 255         if (!err)
 256                 err = link(tmp, to);
 257         unlink(tmp);
 258 out:
 259         free(tmp);
 260         return err;
 261 }
 262
 263 int copyfile_ns(const char *from, const char *to, struct nsinfo *nsi)
 264 {
 265         return copyfile_mode_ns(from, to, 0755, nsi);
 266 }
 267
 268 int copyfile_mode(const char *from, const char *to, mode_t mode)
 269 {
 270         return copyfile_mode_ns(from, to, mode, NULL);
 271 }
 272
 273 int copyfile(const char *from, const char *to)
 274 {
 275         return copyfile_mode(from, to, 0755);
 276 }
 277
 278 static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
 279 {
 280         void *buf_start = buf;
 281         size_t left = n;
 282
 283         while (left) {
 284                 /* buf must be treated as const if !is_read. */
 285                 ssize_t ret = is_read ? read(fd, buf, left) :
 286                                         write(fd, buf, left);
 287
 288                 if (ret < 0 && errno == EINTR)
 289                         continue;
 290                 if (ret <= 0)
 291                         return ret;
 292
 293                 left -= ret;
 294                 buf  += ret;
 295         }
 296
 297         BUG_ON((size_t)(buf - buf_start) != n);
 298         return n;
 299 }
 300
 301 /*
 302  * Read exactly 'n' bytes or return an error.
 303  */
 304 ssize_t readn(int fd, void *buf, size_t n)
 305 {
 306         return ion(true, fd, buf, n);
 307 }
 308
 309 /*
 310  * Write exactly 'n' bytes or return an error.
 311  */
 312 ssize_t writen(int fd, const void *buf, size_t n)
 313 {
 314         /* ion does not modify buf. */
 315         return ion(false, fd, (void *)buf, n);
 316 }
 317
 318 size_t hex_width(u64 v)
 319 {
 320         size_t n = 1;
 321
 322         while ((v >>= 4))
 323                 ++n;
 324
 325         return n;
 326 }
 327
 328 static int hex(char ch)
 329 {
 330         if ((ch >= '0') && (ch <= '9'))
 331                 return ch - '0';
 332         if ((ch >= 'a') && (ch <= 'f'))
 333                 return ch - 'a' + 10;
 334         if ((ch >= 'A') && (ch <= 'F'))
 335                 return ch - 'A' + 10;
 336         return -1;
 337 }
 338
 339 /*
 340  * While we find nice hex chars, build a long_val.
 341  * Return number of chars processed.
 342  */
 343 int hex2u64(const char *ptr, u64 *long_val)
 344 {
 345         const char *p = ptr;
 346         *long_val = 0;
 347
 348         while (*p) {
 349                 const int hex_val = hex(*p);
 350
 351                 if (hex_val < 0)
 352                         break;
 353
 354                 *long_val = (*long_val << 4) | hex_val;
 355                 p++;
 356         }
 357
 358         return p - ptr;
 359 }
 360
 361 int perf_event_paranoid(void)
 362 {
 363         int value;
 364
 365         if (sysctl__read_int("kernel/perf_event_paranoid", &value))
 366                 return INT_MAX;
 367
 368         return value;
 369 }
 370 static int
 371 fetch_ubuntu_kernel_version(unsigned int *puint)
 372 {
 373         ssize_t len;
 374         size_t line_len = 0;
 375         char *ptr, *line = NULL;
 376         int version, patchlevel, sublevel, err;
 377         FILE *vsig;
 378
 379         if (!puint)
 380                 return 0;
 381
 382         vsig = fopen("/proc/version_signature", "r");
 383         if (!vsig) {
 384                 pr_debug("Open /proc/version_signature failed: %s\n",
 385                          strerror(errno));
 386                 return -1;
 387         }
 388
 389         len = getline(&line, &line_len, vsig);
 390         fclose(vsig);
 391         err = -1;
 392         if (len <= 0) {
 393                 pr_debug("Reading from /proc/version_signature failed: %s\n",
 394                          strerror(errno));
 395                 goto errout;
 396         }
 397
 398         ptr = strrchr(line, ' ');
 399         if (!ptr) {
 400                 pr_debug("Parsing /proc/version_signature failed: %s\n", line);
 401                 goto errout;
 402         }
 403
 404         err = sscanf(ptr + 1, "%d.%d.%d",
 405                      &version, &patchlevel, &sublevel);
 406         if (err != 3) {
 407                 pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
 408                          line);
 409                 goto errout;
 410         }
 411
 412         *puint = (version << 16) + (patchlevel << 8) + sublevel;
 413         err = 0;
 414 errout:
 415         free(line);
 416         return err;
 417 }
 418
 419 int
 420 fetch_kernel_version(unsigned int *puint, char *str,
 421                      size_t str_size)
 422 {
 423         struct utsname utsname;
 424         int version, patchlevel, sublevel, err;
 425         bool int_ver_ready = false;
 426
 427         if (access("/proc/version_signature", R_OK) == 0)
 428                 if (!fetch_ubuntu_kernel_version(puint))
 429                         int_ver_ready = true;
 430
 431         if (uname(&utsname))
 432                 return -1;
 433
 434         if (str && str_size) {
 435                 strncpy(str, utsname.release, str_size);
 436                 str[str_size - 1] = '\0';
 437         }
 438
 439         if (!puint || int_ver_ready)
 440                 return 0;
 441
 442         err = sscanf(utsname.release, "%d.%d.%d",
 443                      &version, &patchlevel, &sublevel);
 444
 445         if (err != 3) {
 446                 pr_debug("Unable to get kernel version from uname '%s'\n",
 447                          utsname.release);
 448                 return -1;
 449         }
 450
 451         *puint = (version << 16) + (patchlevel << 8) + sublevel;
 452         return 0;
 453 }
 454
 455 const char *perf_tip(const char *dirpath)
 456 {
 457         struct strlist *tips;
 458         struct str_node *node;
 459         char *tip = NULL;
 460         struct strlist_config conf = {
 461                 .dirname = dirpath,
 462                 .file_only = true,
 463         };
 464
 465         tips = strlist__new("tips.txt", &conf);
 466         if (tips == NULL)
 467                 return errno == ENOENT ? NULL :
 468                         "Tip: check path of tips.txt or get more memory! ;-p";
 469
 470         if (strlist__nr_entries(tips) == 0)
 471                 goto out;
 472
 473         node = strlist__entry(tips, random() % strlist__nr_entries(tips));
 474         if (asprintf(&tip, "Tip: %s", node->s) < 0)
 475                 tip = (char *)"Tip: get more memory! ;-)";
 476
 477 out:
 478         strlist__delete(tips);
 479
 480         return tip;
 481 }