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