tools/perf/util/util.c

   1 #include "../perf.h"
   2 #include "util.h"
   3 #include "fs.h"
   4 #include <sys/mman.h>
   5 #ifdef HAVE_BACKTRACE_SUPPORT
   6 #include <execinfo.h>
   7 #endif
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <errno.h>
  12 #include <limits.h>
  13 #include <byteswap.h>
  14 #include <linux/kernel.h>
  15
  16 /*
  17  * XXX We need to find a better place for these things...
  18  */
  19 unsigned int page_size;
  20
  21 bool test_attr__enabled;
  22
  23 bool perf_host  = true;
  24 bool perf_guest = false;
  25
  26 char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events";
  27
  28 void event_attr_init(struct perf_event_attr *attr)
  29 {
  30         if (!perf_host)
  31                 attr->exclude_host  = 1;
  32         if (!perf_guest)
  33                 attr->exclude_guest = 1;
  34         /* to capture ABI version */
  35         attr->size = sizeof(*attr);
  36 }
  37
  38 int mkdir_p(char *path, mode_t mode)
  39 {
  40         struct stat st;
  41         int err;
  42         char *d = path;
  43
  44         if (*d != '/')
  45                 return -1;
  46
  47         if (stat(path, &st) == 0)
  48                 return 0;
  49
  50         while (*++d == '/');
  51
  52         while ((d = strchr(d, '/'))) {
  53                 *d = '\0';
  54                 err = stat(path, &st) && mkdir(path, mode);
  55                 *d++ = '/';
  56                 if (err)
  57                         return -1;
  58                 while (*d == '/')
  59                         ++d;
  60         }
  61         return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
  62 }
  63
  64 static int slow_copyfile(const char *from, const char *to, mode_t mode)
  65 {
  66         int err = -1;
  67         char *line = NULL;
  68         size_t n;
  69         FILE *from_fp = fopen(from, "r"), *to_fp;
  70         mode_t old_umask;
  71
  72         if (from_fp == NULL)
  73                 goto out;
  74
  75         old_umask = umask(mode ^ 0777);
  76         to_fp = fopen(to, "w");
  77         umask(old_umask);
  78         if (to_fp == NULL)
  79                 goto out_fclose_from;
  80
  81         while (getline(&line, &n, from_fp) > 0)
  82                 if (fputs(line, to_fp) == EOF)
  83                         goto out_fclose_to;
  84         err = 0;
  85 out_fclose_to:
  86         fclose(to_fp);
  87         free(line);
  88 out_fclose_from:
  89         fclose(from_fp);
  90 out:
  91         return err;
  92 }
  93
  94 int copyfile_mode(const char *from, const char *to, mode_t mode)
  95 {
  96         int fromfd, tofd;
  97         struct stat st;
  98         void *addr;
  99         int err = -1;
 100
 101         if (stat(from, &st))
 102                 goto out;
 103
 104         if (st.st_size == 0) /* /proc? do it slowly... */
 105                 return slow_copyfile(from, to, mode);
 106
 107         fromfd = open(from, O_RDONLY);
 108         if (fromfd < 0)
 109                 goto out;
 110
 111         tofd = creat(to, mode);
 112         if (tofd < 0)
 113                 goto out_close_from;
 114
 115         addr = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fromfd, 0);
 116         if (addr == MAP_FAILED)
 117                 goto out_close_to;
 118
 119         if (write(tofd, addr, st.st_size) == st.st_size)
 120                 err = 0;
 121
 122         munmap(addr, st.st_size);
 123 out_close_to:
 124         close(tofd);
 125         if (err)
 126                 unlink(to);
 127 out_close_from:
 128         close(fromfd);
 129 out:
 130         return err;
 131 }
 132
 133 int copyfile(const char *from, const char *to)
 134 {
 135         return copyfile_mode(from, to, 0755);
 136 }
 137
 138 unsigned long convert_unit(unsigned long value, char *unit)
 139 {
 140         *unit = ' ';
 141
 142         if (value > 1000) {
 143                 value /= 1000;
 144                 *unit = 'K';
 145         }
 146
 147         if (value > 1000) {
 148                 value /= 1000;
 149                 *unit = 'M';
 150         }
 151
 152         if (value > 1000) {
 153                 value /= 1000;
 154                 *unit = 'G';
 155         }
 156
 157         return value;
 158 }
 159
 160 static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
 161 {
 162         void *buf_start = buf;
 163         size_t left = n;
 164
 165         while (left) {
 166                 ssize_t ret = is_read ? read(fd, buf, left) :
 167                                         write(fd, buf, left);
 168
 169                 if (ret <= 0)
 170                         return ret;
 171
 172                 left -= ret;
 173                 buf  += ret;
 174         }
 175
 176         BUG_ON((size_t)(buf - buf_start) != n);
 177         return n;
 178 }
 179
 180 /*
 181  * Read exactly 'n' bytes or return an error.
 182  */
 183 ssize_t readn(int fd, void *buf, size_t n)
 184 {
 185         return ion(true, fd, buf, n);
 186 }
 187
 188 /*
 189  * Write exactly 'n' bytes or return an error.
 190  */
 191 ssize_t writen(int fd, void *buf, size_t n)
 192 {
 193         return ion(false, fd, buf, n);
 194 }
 195
 196 size_t hex_width(u64 v)
 197 {
 198         size_t n = 1;
 199
 200         while ((v >>= 4))
 201                 ++n;
 202
 203         return n;
 204 }
 205
 206 static int hex(char ch)
 207 {
 208         if ((ch >= '0') && (ch <= '9'))
 209                 return ch - '0';
 210         if ((ch >= 'a') && (ch <= 'f'))
 211                 return ch - 'a' + 10;
 212         if ((ch >= 'A') && (ch <= 'F'))
 213                 return ch - 'A' + 10;
 214         return -1;
 215 }
 216
 217 /*
 218  * While we find nice hex chars, build a long_val.
 219  * Return number of chars processed.
 220  */
 221 int hex2u64(const char *ptr, u64 *long_val)
 222 {
 223         const char *p = ptr;
 224         *long_val = 0;
 225
 226         while (*p) {
 227                 const int hex_val = hex(*p);
 228
 229                 if (hex_val < 0)
 230                         break;
 231
 232                 *long_val = (*long_val << 4) | hex_val;
 233                 p++;
 234         }
 235
 236         return p - ptr;
 237 }
 238
 239 /* Obtain a backtrace and print it to stdout. */
 240 #ifdef HAVE_BACKTRACE_SUPPORT
 241 void dump_stack(void)
 242 {
 243         void *array[16];
 244         size_t size = backtrace(array, ARRAY_SIZE(array));
 245         char **strings = backtrace_symbols(array, size);
 246         size_t i;
 247
 248         printf("Obtained %zd stack frames.\n", size);
 249
 250         for (i = 0; i < size; i++)
 251                 printf("%s\n", strings[i]);
 252
 253         free(strings);
 254 }
 255 #else
 256 void dump_stack(void) {}
 257 #endif
 258
 259 void get_term_dimensions(struct winsize *ws)
 260 {
 261         char *s = getenv("LINES");
 262
 263         if (s != NULL) {
 264                 ws->ws_row = atoi(s);
 265                 s = getenv("COLUMNS");
 266                 if (s != NULL) {
 267                         ws->ws_col = atoi(s);
 268                         if (ws->ws_row && ws->ws_col)
 269                                 return;
 270                 }
 271         }
 272 #ifdef TIOCGWINSZ
 273         if (ioctl(1, TIOCGWINSZ, ws) == 0 &&
 274             ws->ws_row && ws->ws_col)
 275                 return;
 276 #endif
 277         ws->ws_row = 25;
 278         ws->ws_col = 80;
 279 }
 280
 281 static void set_tracing_events_path(const char *mountpoint)
 282 {
 283         snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s",
 284                  mountpoint, "tracing/events");
 285 }
 286
 287 const char *perf_debugfs_mount(const char *mountpoint)
 288 {
 289         const char *mnt;
 290
 291         mnt = debugfs_mount(mountpoint);
 292         if (!mnt)
 293                 return NULL;
 294
 295         set_tracing_events_path(mnt);
 296
 297         return mnt;
 298 }
 299
 300 void perf_debugfs_set_path(const char *mntpt)
 301 {
 302         snprintf(debugfs_mountpoint, strlen(debugfs_mountpoint), "%s", mntpt);
 303         set_tracing_events_path(mntpt);
 304 }
 305
 306 static const char *find_debugfs(void)
 307 {
 308         const char *path = perf_debugfs_mount(NULL);
 309
 310         if (!path)
 311                 fprintf(stderr, "Your kernel does not support the debugfs filesystem");
 312
 313         return path;
 314 }
 315
 316 /*
 317  * Finds the path to the debugfs/tracing
 318  * Allocates the string and stores it.
 319  */
 320 const char *find_tracing_dir(void)
 321 {
 322         static char *tracing;
 323         static int tracing_found;
 324         const char *debugfs;
 325
 326         if (tracing_found)
 327                 return tracing;
 328
 329         debugfs = find_debugfs();
 330         if (!debugfs)
 331                 return NULL;
 332
 333         tracing = malloc(strlen(debugfs) + 9);
 334         if (!tracing)
 335                 return NULL;
 336
 337         sprintf(tracing, "%s/tracing", debugfs);
 338
 339         tracing_found = 1;
 340         return tracing;
 341 }
 342
 343 char *get_tracing_file(const char *name)
 344 {
 345         const char *tracing;
 346         char *file;
 347
 348         tracing = find_tracing_dir();
 349         if (!tracing)
 350                 return NULL;
 351
 352         file = malloc(strlen(tracing) + strlen(name) + 2);
 353         if (!file)
 354                 return NULL;
 355
 356         sprintf(file, "%s/%s", tracing, name);
 357         return file;
 358 }
 359
 360 void put_tracing_file(char *file)
 361 {
 362         free(file);
 363 }
 364
 365 int parse_nsec_time(const char *str, u64 *ptime)
 366 {
 367         u64 time_sec, time_nsec;
 368         char *end;
 369
 370         time_sec = strtoul(str, &end, 10);
 371         if (*end != '.' && *end != '\0')
 372                 return -1;
 373
 374         if (*end == '.') {
 375                 int i;
 376                 char nsec_buf[10];
 377
 378                 if (strlen(++end) > 9)
 379                         return -1;
 380
 381                 strncpy(nsec_buf, end, 9);
 382                 nsec_buf[9] = '\0';
 383
 384                 /* make it nsec precision */
 385                 for (i = strlen(nsec_buf); i < 9; i++)
 386                         nsec_buf[i] = '0';
 387
 388                 time_nsec = strtoul(nsec_buf, &end, 10);
 389                 if (*end != '\0')
 390                         return -1;
 391         } else
 392                 time_nsec = 0;
 393
 394         *ptime = time_sec * NSEC_PER_SEC + time_nsec;
 395         return 0;
 396 }
 397
 398 unsigned long parse_tag_value(const char *str, struct parse_tag *tags)
 399 {
 400         struct parse_tag *i = tags;
 401
 402         while (i->tag) {
 403                 char *s;
 404
 405                 s = strchr(str, i->tag);
 406                 if (s) {
 407                         unsigned long int value;
 408                         char *endptr;
 409
 410                         value = strtoul(str, &endptr, 10);
 411                         if (s != endptr)
 412                                 break;
 413
 414                         if (value > ULONG_MAX / i->mult)
 415                                 break;
 416                         value *= i->mult;
 417                         return value;
 418                 }
 419                 i++;
 420         }
 421
 422         return (unsigned long) -1;
 423 }
 424
 425 int filename__read_int(const char *filename, int *value)
 426 {
 427         char line[64];
 428         int fd = open(filename, O_RDONLY), err = -1;
 429
 430         if (fd < 0)
 431                 return -1;
 432
 433         if (read(fd, line, sizeof(line)) > 0) {
 434                 *value = atoi(line);
 435                 err = 0;
 436         }
 437
 438         close(fd);
 439         return err;
 440 }
 441
 442 int filename__read_str(const char *filename, char **buf, size_t *sizep)
 443 {
 444         size_t size = 0, alloc_size = 0;
 445         void *bf = NULL, *nbf;
 446         int fd, n, err = 0;
 447
 448         fd = open(filename, O_RDONLY);
 449         if (fd < 0)
 450                 return -errno;
 451
 452         do {
 453                 if (size == alloc_size) {
 454                         alloc_size += BUFSIZ;
 455                         nbf = realloc(bf, alloc_size);
 456                         if (!nbf) {
 457                                 err = -ENOMEM;
 458                                 break;
 459                         }
 460
 461                         bf = nbf;
 462                 }
 463
 464                 n = read(fd, bf + size, alloc_size - size);
 465                 if (n < 0) {
 466                         if (size) {
 467                                 pr_warning("read failed %d: %s\n",
 468                                            errno, strerror(errno));
 469                                 err = 0;
 470                         } else
 471                                 err = -errno;
 472
 473                         break;
 474                 }
 475
 476                 size += n;
 477         } while (n > 0);
 478
 479         if (!err) {
 480                 *sizep = size;
 481                 *buf   = bf;
 482         } else
 483                 free(bf);
 484
 485         close(fd);
 486         return err;
 487 }
 488
 489 const char *get_filename_for_perf_kvm(void)
 490 {
 491         const char *filename;
 492
 493         if (perf_host && !perf_guest)
 494                 filename = strdup("perf.data.host");
 495         else if (!perf_host && perf_guest)
 496                 filename = strdup("perf.data.guest");
 497         else
 498                 filename = strdup("perf.data.kvm");
 499
 500         return filename;
 501 }
 502
 503 int perf_event_paranoid(void)
 504 {
 505         char path[PATH_MAX];
 506         const char *procfs = procfs__mountpoint();
 507         int value;
 508
 509         if (!procfs)
 510                 return INT_MAX;
 511
 512         scnprintf(path, PATH_MAX, "%s/sys/kernel/perf_event_paranoid", procfs);
 513
 514         if (filename__read_int(path, &value))
 515                 return INT_MAX;
 516
 517         return value;
 518 }
 519
 520 void mem_bswap_32(void *src, int byte_size)
 521 {
 522         u32 *m = src;
 523         while (byte_size > 0) {
 524                 *m = bswap_32(*m);
 525                 byte_size -= sizeof(u32);
 526                 ++m;
 527         }
 528 }
 529
 530 void mem_bswap_64(void *src, int byte_size)
 531 {
 532         u64 *m = src;
 533
 534         while (byte_size > 0) {
 535                 *m = bswap_64(*m);
 536                 byte_size -= sizeof(u64);
 537                 ++m;
 538         }
 539 }