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 <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/kernel.h>
  18 #include <linux/log2.h>
  19 #include <linux/time64.h>
  20 #include <unistd.h>
  21 #include "strlist.h"
  22
  23 /*
  24  * XXX We need to find a better place for these things...
  25  */
  26 unsigned int page_size;
  27 int cacheline_size;
  28
  29 int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
  30 int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;
  31
  32 bool test_attr__enabled;
  33
  34 bool perf_host  = true;
  35 bool perf_guest = false;
  36
  37 void event_attr_init(struct perf_event_attr *attr)
  38 {
  39         if (!perf_host)
  40                 attr->exclude_host  = 1;
  41         if (!perf_guest)
  42                 attr->exclude_guest = 1;
  43         /* to capture ABI version */
  44         attr->size = sizeof(*attr);
  45 }
  46
  47 int mkdir_p(char *path, mode_t mode)
  48 {
  49         struct stat st;
  50         int err;
  51         char *d = path;
  52
  53         if (*d != '/')
  54                 return -1;
  55
  56         if (stat(path, &st) == 0)
  57                 return 0;
  58
  59         while (*++d == '/');
  60
  61         while ((d = strchr(d, '/'))) {
  62                 *d = '\0';
  63                 err = stat(path, &st) && mkdir(path, mode);
  64                 *d++ = '/';
  65                 if (err)
  66                         return -1;
  67                 while (*d == '/')
  68                         ++d;
  69         }
  70         return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
  71 }
  72
  73 int rm_rf(const char *path)
  74 {
  75         DIR *dir;
  76         int ret = 0;
  77         struct dirent *d;
  78         char namebuf[PATH_MAX];
  79
  80         dir = opendir(path);
  81         if (dir == NULL)
  82                 return 0;
  83
  84         while ((d = readdir(dir)) != NULL && !ret) {
  85                 struct stat statbuf;
  86
  87                 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
  88                         continue;
  89
  90                 scnprintf(namebuf, sizeof(namebuf), "%s/%s",
  91                           path, d->d_name);
  92
  93                 /* We have to check symbolic link itself */
  94                 ret = lstat(namebuf, &statbuf);
  95                 if (ret < 0) {
  96                         pr_debug("stat failed: %s\n", namebuf);
  97                         break;
  98                 }
  99
 100                 if (S_ISDIR(statbuf.st_mode))
 101                         ret = rm_rf(namebuf);
 102                 else
 103                         ret = unlink(namebuf);
 104         }
 105         closedir(dir);
 106
 107         if (ret < 0)
 108                 return ret;
 109
 110         return rmdir(path);
 111 }
 112
 113 /* A filter which removes dot files */
 114 bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
 115 {
 116         return d->d_name[0] != '.';
 117 }
 118
 119 /* lsdir reads a directory and store it in strlist */
 120 struct strlist *lsdir(const char *name,
 121                       bool (*filter)(const char *, struct dirent *))
 122 {
 123         struct strlist *list = NULL;
 124         DIR *dir;
 125         struct dirent *d;
 126
 127         dir = opendir(name);
 128         if (!dir)
 129                 return NULL;
 130
 131         list = strlist__new(NULL, NULL);
 132         if (!list) {
 133                 errno = ENOMEM;
 134                 goto out;
 135         }
 136
 137         while ((d = readdir(dir)) != NULL) {
 138                 if (!filter || filter(name, d))
 139                         strlist__add(list, d->d_name);
 140         }
 141
 142 out:
 143         closedir(dir);
 144         return list;
 145 }
 146
 147 static int slow_copyfile(const char *from, const char *to, struct nsinfo *nsi)
 148 {
 149         int err = -1;
 150         char *line = NULL;
 151         size_t n;
 152         FILE *from_fp, *to_fp;
 153         struct nscookie nsc;
 154
 155         nsinfo__mountns_enter(nsi, &nsc);
 156         from_fp = fopen(from, "r");
 157         nsinfo__mountns_exit(&nsc);
 158         if (from_fp == NULL)
 159                 goto out;
 160
 161         to_fp = fopen(to, "w");
 162         if (to_fp == NULL)
 163                 goto out_fclose_from;
 164
 165         while (getline(&line, &n, from_fp) > 0)
 166                 if (fputs(line, to_fp) == EOF)
 167                         goto out_fclose_to;
 168         err = 0;
 169 out_fclose_to:
 170         fclose(to_fp);
 171         free(line);
 172 out_fclose_from:
 173         fclose(from_fp);
 174 out:
 175         return err;
 176 }
 177
 178 int copyfile_offset(int ifd, loff_t off_in, int ofd, loff_t off_out, u64 size)
 179 {
 180         void *ptr;
 181         loff_t pgoff;
 182
 183         pgoff = off_in & ~(page_size - 1);
 184         off_in -= pgoff;
 185
 186         ptr = mmap(NULL, off_in + size, PROT_READ, MAP_PRIVATE, ifd, pgoff);
 187         if (ptr == MAP_FAILED)
 188                 return -1;
 189
 190         while (size) {
 191                 ssize_t ret = pwrite(ofd, ptr + off_in, size, off_out);
 192                 if (ret < 0 && errno == EINTR)
 193                         continue;
 194                 if (ret <= 0)
 195                         break;
 196
 197                 size -= ret;
 198                 off_in += ret;
 199                 off_out -= ret;
 200         }
 201         munmap(ptr, off_in + size);
 202
 203         return size ? -1 : 0;
 204 }
 205
 206 static int copyfile_mode_ns(const char *from, const char *to, mode_t mode,
 207                             struct nsinfo *nsi)
 208 {
 209         int fromfd, tofd;
 210         struct stat st;
 211         int err;
 212         char *tmp = NULL, *ptr = NULL;
 213         struct nscookie nsc;
 214
 215         nsinfo__mountns_enter(nsi, &nsc);
 216         err = stat(from, &st);
 217         nsinfo__mountns_exit(&nsc);
 218         if (err)
 219                 goto out;
 220         err = -1;
 221
 222         /* extra 'x' at the end is to reserve space for '.' */
 223         if (asprintf(&tmp, "%s.XXXXXXx", to) < 0) {
 224                 tmp = NULL;
 225                 goto out;
 226         }
 227         ptr = strrchr(tmp, '/');
 228         if (!ptr)
 229                 goto out;
 230         ptr = memmove(ptr + 1, ptr, strlen(ptr) - 1);
 231         *ptr = '.';
 232
 233         tofd = mkstemp(tmp);
 234         if (tofd < 0)
 235                 goto out;
 236
 237         if (fchmod(tofd, mode))
 238                 goto out_close_to;
 239
 240         if (st.st_size == 0) { /* /proc? do it slowly... */
 241                 err = slow_copyfile(from, tmp, nsi);
 242                 goto out_close_to;
 243         }
 244
 245         nsinfo__mountns_enter(nsi, &nsc);
 246         fromfd = open(from, O_RDONLY);
 247         nsinfo__mountns_exit(&nsc);
 248         if (fromfd < 0)
 249                 goto out_close_to;
 250
 251         err = copyfile_offset(fromfd, 0, tofd, 0, st.st_size);
 252
 253         close(fromfd);
 254 out_close_to:
 255         close(tofd);
 256         if (!err)
 257                 err = link(tmp, to);
 258         unlink(tmp);
 259 out:
 260         free(tmp);
 261         return err;
 262 }
 263
 264 int copyfile_ns(const char *from, const char *to, struct nsinfo *nsi)
 265 {
 266         return copyfile_mode_ns(from, to, 0755, nsi);
 267 }
 268
 269 int copyfile_mode(const char *from, const char *to, mode_t mode)
 270 {
 271         return copyfile_mode_ns(from, to, mode, NULL);
 272 }
 273
 274 int copyfile(const char *from, const char *to)
 275 {
 276         return copyfile_mode(from, to, 0755);
 277 }
 278
 279 static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
 280 {
 281         void *buf_start = buf;
 282         size_t left = n;
 283
 284         while (left) {
 285                 /* buf must be treated as const if !is_read. */
 286                 ssize_t ret = is_read ? read(fd, buf, left) :
 287                                         write(fd, buf, left);
 288
 289                 if (ret < 0 && errno == EINTR)
 290                         continue;
 291                 if (ret <= 0)
 292                         return ret;
 293
 294                 left -= ret;
 295                 buf  += ret;
 296         }
 297
 298         BUG_ON((size_t)(buf - buf_start) != n);
 299         return n;
 300 }
 301
 302 /*
 303  * Read exactly 'n' bytes or return an error.
 304  */
 305 ssize_t readn(int fd, void *buf, size_t n)
 306 {
 307         return ion(true, fd, buf, n);
 308 }
 309
 310 /*
 311  * Write exactly 'n' bytes or return an error.
 312  */
 313 ssize_t writen(int fd, const void *buf, size_t n)
 314 {
 315         /* ion does not modify buf. */
 316         return ion(false, fd, (void *)buf, n);
 317 }
 318
 319 size_t hex_width(u64 v)
 320 {
 321         size_t n = 1;
 322
 323         while ((v >>= 4))
 324                 ++n;
 325
 326         return n;
 327 }
 328
 329 static int hex(char ch)
 330 {
 331         if ((ch >= '0') && (ch <= '9'))
 332                 return ch - '0';
 333         if ((ch >= 'a') && (ch <= 'f'))
 334                 return ch - 'a' + 10;
 335         if ((ch >= 'A') && (ch <= 'F'))
 336                 return ch - 'A' + 10;
 337         return -1;
 338 }
 339
 340 /*
 341  * While we find nice hex chars, build a long_val.
 342  * Return number of chars processed.
 343  */
 344 int hex2u64(const char *ptr, u64 *long_val)
 345 {
 346         const char *p = ptr;
 347         *long_val = 0;
 348
 349         while (*p) {
 350                 const int hex_val = hex(*p);
 351
 352                 if (hex_val < 0)
 353                         break;
 354
 355                 *long_val = (*long_val << 4) | hex_val;
 356                 p++;
 357         }
 358
 359         return p - ptr;
 360 }
 361
 362 int perf_event_paranoid(void)
 363 {
 364         int value;
 365
 366         if (sysctl__read_int("kernel/perf_event_paranoid", &value))
 367                 return INT_MAX;
 368
 369         return value;
 370 }
 371 static int
 372 fetch_ubuntu_kernel_version(unsigned int *puint)
 373 {
 374         ssize_t len;
 375         size_t line_len = 0;
 376         char *ptr, *line = NULL;
 377         int version, patchlevel, sublevel, err;
 378         FILE *vsig;
 379
 380         if (!puint)
 381                 return 0;
 382
 383         vsig = fopen("/proc/version_signature", "r");
 384         if (!vsig) {
 385                 pr_debug("Open /proc/version_signature failed: %s\n",
 386                          strerror(errno));
 387                 return -1;
 388         }
 389
 390         len = getline(&line, &line_len, vsig);
 391         fclose(vsig);
 392         err = -1;
 393         if (len <= 0) {
 394                 pr_debug("Reading from /proc/version_signature failed: %s\n",
 395                          strerror(errno));
 396                 goto errout;
 397         }
 398
 399         ptr = strrchr(line, ' ');
 400         if (!ptr) {
 401                 pr_debug("Parsing /proc/version_signature failed: %s\n", line);
 402                 goto errout;
 403         }
 404
 405         err = sscanf(ptr + 1, "%d.%d.%d",
 406                      &version, &patchlevel, &sublevel);
 407         if (err != 3) {
 408                 pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
 409                          line);
 410                 goto errout;
 411         }
 412
 413         *puint = (version << 16) + (patchlevel << 8) + sublevel;
 414         err = 0;
 415 errout:
 416         free(line);
 417         return err;
 418 }
 419
 420 int
 421 fetch_kernel_version(unsigned int *puint, char *str,
 422                      size_t str_size)
 423 {
 424         struct utsname utsname;
 425         int version, patchlevel, sublevel, err;
 426         bool int_ver_ready = false;
 427
 428         if (access("/proc/version_signature", R_OK) == 0)
 429                 if (!fetch_ubuntu_kernel_version(puint))
 430                         int_ver_ready = true;
 431
 432         if (uname(&utsname))
 433                 return -1;
 434
 435         if (str && str_size) {
 436                 strncpy(str, utsname.release, str_size);
 437                 str[str_size - 1] = '\0';
 438         }
 439
 440         if (!puint || int_ver_ready)
 441                 return 0;
 442
 443         err = sscanf(utsname.release, "%d.%d.%d",
 444                      &version, &patchlevel, &sublevel);
 445
 446         if (err != 3) {
 447                 pr_debug("Unable to get kernel version from uname '%s'\n",
 448                          utsname.release);
 449                 return -1;
 450         }
 451
 452         *puint = (version << 16) + (patchlevel << 8) + sublevel;
 453         return 0;
 454 }
 455
 456 const char *perf_tip(const char *dirpath)
 457 {
 458         struct strlist *tips;
 459         struct str_node *node;
 460         char *tip = NULL;
 461         struct strlist_config conf = {
 462                 .dirname = dirpath,
 463                 .file_only = true,
 464         };
 465
 466         tips = strlist__new("tips.txt", &conf);
 467         if (tips == NULL)
 468                 return errno == ENOENT ? NULL :
 469                         "Tip: check path of tips.txt or get more memory! ;-p";
 470
 471         if (strlist__nr_entries(tips) == 0)
 472                 goto out;
 473
 474         node = strlist__entry(tips, random() % strlist__nr_entries(tips));
 475         if (asprintf(&tip, "Tip: %s", node->s) < 0)
 476                 tip = (char *)"Tip: get more memory! ;-)";
 477
 478 out:
 479         strlist__delete(tips);
 480
 481         return tip;
 482 }