tools/perf/util/util.c

   1 #include "../perf.h"
   2 #include "util.h"
   3 #include <api/fs/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 && errno == EINTR)
 170                         continue;
 171                 if (ret <= 0)
 172                         return ret;
 173
 174                 left -= ret;
 175                 buf  += ret;
 176         }
 177
 178         BUG_ON((size_t)(buf - buf_start) != n);
 179         return n;
 180 }
 181
 182 /*
 183  * Read exactly 'n' bytes or return an error.
 184  */
 185 ssize_t readn(int fd, void *buf, size_t n)
 186 {
 187         return ion(true, fd, buf, n);
 188 }
 189
 190 /*
 191  * Write exactly 'n' bytes or return an error.
 192  */
 193 ssize_t writen(int fd, void *buf, size_t n)
 194 {
 195         return ion(false, fd, buf, n);
 196 }
 197
 198 size_t hex_width(u64 v)
 199 {
 200         size_t n = 1;
 201
 202         while ((v >>= 4))
 203                 ++n;
 204
 205         return n;
 206 }
 207
 208 static int hex(char ch)
 209 {
 210         if ((ch >= '0') && (ch <= '9'))
 211                 return ch - '0';
 212         if ((ch >= 'a') && (ch <= 'f'))
 213                 return ch - 'a' + 10;
 214         if ((ch >= 'A') && (ch <= 'F'))
 215                 return ch - 'A' + 10;
 216         return -1;
 217 }
 218
 219 /*
 220  * While we find nice hex chars, build a long_val.
 221  * Return number of chars processed.
 222  */
 223 int hex2u64(const char *ptr, u64 *long_val)
 224 {
 225         const char *p = ptr;
 226         *long_val = 0;
 227
 228         while (*p) {
 229                 const int hex_val = hex(*p);
 230
 231                 if (hex_val < 0)
 232                         break;
 233
 234                 *long_val = (*long_val << 4) | hex_val;
 235                 p++;
 236         }
 237
 238         return p - ptr;
 239 }
 240
 241 /* Obtain a backtrace and print it to stdout. */
 242 #ifdef HAVE_BACKTRACE_SUPPORT
 243 void dump_stack(void)
 244 {
 245         void *array[16];
 246         size_t size = backtrace(array, ARRAY_SIZE(array));
 247         char **strings = backtrace_symbols(array, size);
 248         size_t i;
 249
 250         printf("Obtained %zd stack frames.\n", size);
 251
 252         for (i = 0; i < size; i++)
 253                 printf("%s\n", strings[i]);
 254
 255         free(strings);
 256 }
 257 #else
 258 void dump_stack(void) {}
 259 #endif
 260
 261 void get_term_dimensions(struct winsize *ws)
 262 {
 263         char *s = getenv("LINES");
 264
 265         if (s != NULL) {
 266                 ws->ws_row = atoi(s);
 267                 s = getenv("COLUMNS");
 268                 if (s != NULL) {
 269                         ws->ws_col = atoi(s);
 270                         if (ws->ws_row && ws->ws_col)
 271                                 return;
 272                 }
 273         }
 274 #ifdef TIOCGWINSZ
 275         if (ioctl(1, TIOCGWINSZ, ws) == 0 &&
 276             ws->ws_row && ws->ws_col)
 277                 return;
 278 #endif
 279         ws->ws_row = 25;
 280         ws->ws_col = 80;
 281 }
 282
 283 static void set_tracing_events_path(const char *mountpoint)
 284 {
 285         snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s",
 286                  mountpoint, "tracing/events");
 287 }
 288
 289 const char *perf_debugfs_mount(const char *mountpoint)
 290 {
 291         const char *mnt;
 292
 293         mnt = debugfs_mount(mountpoint);
 294         if (!mnt)
 295                 return NULL;
 296
 297         set_tracing_events_path(mnt);
 298
 299         return mnt;
 300 }
 301
 302 void perf_debugfs_set_path(const char *mntpt)
 303 {
 304         snprintf(debugfs_mountpoint, strlen(debugfs_mountpoint), "%s", mntpt);
 305         set_tracing_events_path(mntpt);
 306 }
 307
 308 static const char *find_debugfs(void)
 309 {
 310         const char *path = perf_debugfs_mount(NULL);
 311
 312         if (!path)
 313                 fprintf(stderr, "Your kernel does not support the debugfs filesystem");
 314
 315         return path;
 316 }
 317
 318 /*
 319  * Finds the path to the debugfs/tracing
 320  * Allocates the string and stores it.
 321  */
 322 const char *find_tracing_dir(void)
 323 {
 324         static char *tracing;
 325         static int tracing_found;
 326         const char *debugfs;
 327
 328         if (tracing_found)
 329                 return tracing;
 330
 331         debugfs = find_debugfs();
 332         if (!debugfs)
 333                 return NULL;
 334
 335         tracing = malloc(strlen(debugfs) + 9);
 336         if (!tracing)
 337                 return NULL;
 338
 339         sprintf(tracing, "%s/tracing", debugfs);
 340
 341         tracing_found = 1;
 342         return tracing;
 343 }
 344
 345 char *get_tracing_file(const char *name)
 346 {
 347         const char *tracing;
 348         char *file;
 349
 350         tracing = find_tracing_dir();
 351         if (!tracing)
 352                 return NULL;
 353
 354         file = malloc(strlen(tracing) + strlen(name) + 2);
 355         if (!file)
 356                 return NULL;
 357
 358         sprintf(file, "%s/%s", tracing, name);
 359         return file;
 360 }
 361
 362 void put_tracing_file(char *file)
 363 {
 364         free(file);
 365 }
 366
 367 int parse_nsec_time(const char *str, u64 *ptime)
 368 {
 369         u64 time_sec, time_nsec;
 370         char *end;
 371
 372         time_sec = strtoul(str, &end, 10);
 373         if (*end != '.' && *end != '\0')
 374                 return -1;
 375
 376         if (*end == '.') {
 377                 int i;
 378                 char nsec_buf[10];
 379
 380                 if (strlen(++end) > 9)
 381                         return -1;
 382
 383                 strncpy(nsec_buf, end, 9);
 384                 nsec_buf[9] = '\0';
 385
 386                 /* make it nsec precision */
 387                 for (i = strlen(nsec_buf); i < 9; i++)
 388                         nsec_buf[i] = '0';
 389
 390                 time_nsec = strtoul(nsec_buf, &end, 10);
 391                 if (*end != '\0')
 392                         return -1;
 393         } else
 394                 time_nsec = 0;
 395
 396         *ptime = time_sec * NSEC_PER_SEC + time_nsec;
 397         return 0;
 398 }
 399
 400 unsigned long parse_tag_value(const char *str, struct parse_tag *tags)
 401 {
 402         struct parse_tag *i = tags;
 403
 404         while (i->tag) {
 405                 char *s;
 406
 407                 s = strchr(str, i->tag);
 408                 if (s) {
 409                         unsigned long int value;
 410                         char *endptr;
 411
 412                         value = strtoul(str, &endptr, 10);
 413                         if (s != endptr)
 414                                 break;
 415
 416                         if (value > ULONG_MAX / i->mult)
 417                                 break;
 418                         value *= i->mult;
 419                         return value;
 420                 }
 421                 i++;
 422         }
 423
 424         return (unsigned long) -1;
 425 }
 426
 427 int filename__read_int(const char *filename, int *value)
 428 {
 429         char line[64];
 430         int fd = open(filename, O_RDONLY), err = -1;
 431
 432         if (fd < 0)
 433                 return -1;
 434
 435         if (read(fd, line, sizeof(line)) > 0) {
 436                 *value = atoi(line);
 437                 err = 0;
 438         }
 439
 440         close(fd);
 441         return err;
 442 }
 443
 444 int filename__read_str(const char *filename, char **buf, size_t *sizep)
 445 {
 446         size_t size = 0, alloc_size = 0;
 447         void *bf = NULL, *nbf;
 448         int fd, n, err = 0;
 449
 450         fd = open(filename, O_RDONLY);
 451         if (fd < 0)
 452                 return -errno;
 453
 454         do {
 455                 if (size == alloc_size) {
 456                         alloc_size += BUFSIZ;
 457                         nbf = realloc(bf, alloc_size);
 458                         if (!nbf) {
 459                                 err = -ENOMEM;
 460                                 break;
 461                         }
 462
 463                         bf = nbf;
 464                 }
 465
 466                 n = read(fd, bf + size, alloc_size - size);
 467                 if (n < 0) {
 468                         if (size) {
 469                                 pr_warning("read failed %d: %s\n",
 470                                            errno, strerror(errno));
 471                                 err = 0;
 472                         } else
 473                                 err = -errno;
 474
 475                         break;
 476                 }
 477
 478                 size += n;
 479         } while (n > 0);
 480
 481         if (!err) {
 482                 *sizep = size;
 483                 *buf   = bf;
 484         } else
 485                 free(bf);
 486
 487         close(fd);
 488         return err;
 489 }
 490
 491 const char *get_filename_for_perf_kvm(void)
 492 {
 493         const char *filename;
 494
 495         if (perf_host && !perf_guest)
 496                 filename = strdup("perf.data.host");
 497         else if (!perf_host && perf_guest)
 498                 filename = strdup("perf.data.guest");
 499         else
 500                 filename = strdup("perf.data.kvm");
 501
 502         return filename;
 503 }
 504
 505 int perf_event_paranoid(void)
 506 {
 507         char path[PATH_MAX];
 508         const char *procfs = procfs__mountpoint();
 509         int value;
 510
 511         if (!procfs)
 512                 return INT_MAX;
 513
 514         scnprintf(path, PATH_MAX, "%s/sys/kernel/perf_event_paranoid", procfs);
 515
 516         if (filename__read_int(path, &value))
 517                 return INT_MAX;
 518
 519         return value;
 520 }
 521
 522 void mem_bswap_32(void *src, int byte_size)
 523 {
 524         u32 *m = src;
 525         while (byte_size > 0) {
 526                 *m = bswap_32(*m);
 527                 byte_size -= sizeof(u32);
 528                 ++m;
 529         }
 530 }
 531
 532 void mem_bswap_64(void *src, int byte_size)
 533 {
 534         u64 *m = src;
 535
 536         while (byte_size > 0) {
 537                 *m = bswap_64(*m);
 538                 byte_size -= sizeof(u64);
 539                 ++m;
 540         }
 541 }