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 int cacheline_size;
  21
  22 bool test_attr__enabled;
  23
  24 bool perf_host  = true;
  25 bool perf_guest = false;
  26
  27 char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events";
  28
  29 void event_attr_init(struct perf_event_attr *attr)
  30 {
  31         if (!perf_host)
  32                 attr->exclude_host  = 1;
  33         if (!perf_guest)
  34                 attr->exclude_guest = 1;
  35         /* to capture ABI version */
  36         attr->size = sizeof(*attr);
  37 }
  38
  39 int mkdir_p(char *path, mode_t mode)
  40 {
  41         struct stat st;
  42         int err;
  43         char *d = path;
  44
  45         if (*d != '/')
  46                 return -1;
  47
  48         if (stat(path, &st) == 0)
  49                 return 0;
  50
  51         while (*++d == '/');
  52
  53         while ((d = strchr(d, '/'))) {
  54                 *d = '\0';
  55                 err = stat(path, &st) && mkdir(path, mode);
  56                 *d++ = '/';
  57                 if (err)
  58                         return -1;
  59                 while (*d == '/')
  60                         ++d;
  61         }
  62         return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
  63 }
  64
  65 static int slow_copyfile(const char *from, const char *to, mode_t mode)
  66 {
  67         int err = -1;
  68         char *line = NULL;
  69         size_t n;
  70         FILE *from_fp = fopen(from, "r"), *to_fp;
  71         mode_t old_umask;
  72
  73         if (from_fp == NULL)
  74                 goto out;
  75
  76         old_umask = umask(mode ^ 0777);
  77         to_fp = fopen(to, "w");
  78         umask(old_umask);
  79         if (to_fp == NULL)
  80                 goto out_fclose_from;
  81
  82         while (getline(&line, &n, from_fp) > 0)
  83                 if (fputs(line, to_fp) == EOF)
  84                         goto out_fclose_to;
  85         err = 0;
  86 out_fclose_to:
  87         fclose(to_fp);
  88         free(line);
  89 out_fclose_from:
  90         fclose(from_fp);
  91 out:
  92         return err;
  93 }
  94
  95 int copyfile_mode(const char *from, const char *to, mode_t mode)
  96 {
  97         int fromfd, tofd;
  98         struct stat st;
  99         void *addr;
 100         int err = -1;
 101
 102         if (stat(from, &st))
 103                 goto out;
 104
 105         if (st.st_size == 0) /* /proc? do it slowly... */
 106                 return slow_copyfile(from, to, mode);
 107
 108         fromfd = open(from, O_RDONLY);
 109         if (fromfd < 0)
 110                 goto out;
 111
 112         tofd = creat(to, mode);
 113         if (tofd < 0)
 114                 goto out_close_from;
 115
 116         addr = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fromfd, 0);
 117         if (addr == MAP_FAILED)
 118                 goto out_close_to;
 119
 120         if (write(tofd, addr, st.st_size) == st.st_size)
 121                 err = 0;
 122
 123         munmap(addr, st.st_size);
 124 out_close_to:
 125         close(tofd);
 126         if (err)
 127                 unlink(to);
 128 out_close_from:
 129         close(fromfd);
 130 out:
 131         return err;
 132 }
 133
 134 int copyfile(const char *from, const char *to)
 135 {
 136         return copyfile_mode(from, to, 0755);
 137 }
 138
 139 unsigned long convert_unit(unsigned long value, char *unit)
 140 {
 141         *unit = ' ';
 142
 143         if (value > 1000) {
 144                 value /= 1000;
 145                 *unit = 'K';
 146         }
 147
 148         if (value > 1000) {
 149                 value /= 1000;
 150                 *unit = 'M';
 151         }
 152
 153         if (value > 1000) {
 154                 value /= 1000;
 155                 *unit = 'G';
 156         }
 157
 158         return value;
 159 }
 160
 161 static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
 162 {
 163         void *buf_start = buf;
 164         size_t left = n;
 165
 166         while (left) {
 167                 ssize_t ret = is_read ? read(fd, buf, left) :
 168                                         write(fd, buf, left);
 169
 170                 if (ret < 0 && errno == EINTR)
 171                         continue;
 172                 if (ret <= 0)
 173                         return ret;
 174
 175                 left -= ret;
 176                 buf  += ret;
 177         }
 178
 179         BUG_ON((size_t)(buf - buf_start) != n);
 180         return n;
 181 }
 182
 183 /*
 184  * Read exactly 'n' bytes or return an error.
 185  */
 186 ssize_t readn(int fd, void *buf, size_t n)
 187 {
 188         return ion(true, fd, buf, n);
 189 }
 190
 191 /*
 192  * Write exactly 'n' bytes or return an error.
 193  */
 194 ssize_t writen(int fd, void *buf, size_t n)
 195 {
 196         return ion(false, fd, buf, n);
 197 }
 198
 199 size_t hex_width(u64 v)
 200 {
 201         size_t n = 1;
 202
 203         while ((v >>= 4))
 204                 ++n;
 205
 206         return n;
 207 }
 208
 209 static int hex(char ch)
 210 {
 211         if ((ch >= '0') && (ch <= '9'))
 212                 return ch - '0';
 213         if ((ch >= 'a') && (ch <= 'f'))
 214                 return ch - 'a' + 10;
 215         if ((ch >= 'A') && (ch <= 'F'))
 216                 return ch - 'A' + 10;
 217         return -1;
 218 }
 219
 220 /*
 221  * While we find nice hex chars, build a long_val.
 222  * Return number of chars processed.
 223  */
 224 int hex2u64(const char *ptr, u64 *long_val)
 225 {
 226         const char *p = ptr;
 227         *long_val = 0;
 228
 229         while (*p) {
 230                 const int hex_val = hex(*p);
 231
 232                 if (hex_val < 0)
 233                         break;
 234
 235                 *long_val = (*long_val << 4) | hex_val;
 236                 p++;
 237         }
 238
 239         return p - ptr;
 240 }
 241
 242 /* Obtain a backtrace and print it to stdout. */
 243 #ifdef HAVE_BACKTRACE_SUPPORT
 244 void dump_stack(void)
 245 {
 246         void *array[16];
 247         size_t size = backtrace(array, ARRAY_SIZE(array));
 248         char **strings = backtrace_symbols(array, size);
 249         size_t i;
 250
 251         printf("Obtained %zd stack frames.\n", size);
 252
 253         for (i = 0; i < size; i++)
 254                 printf("%s\n", strings[i]);
 255
 256         free(strings);
 257 }
 258 #else
 259 void dump_stack(void) {}
 260 #endif
 261
 262 void get_term_dimensions(struct winsize *ws)
 263 {
 264         char *s = getenv("LINES");
 265
 266         if (s != NULL) {
 267                 ws->ws_row = atoi(s);
 268                 s = getenv("COLUMNS");
 269                 if (s != NULL) {
 270                         ws->ws_col = atoi(s);
 271                         if (ws->ws_row && ws->ws_col)
 272                                 return;
 273                 }
 274         }
 275 #ifdef TIOCGWINSZ
 276         if (ioctl(1, TIOCGWINSZ, ws) == 0 &&
 277             ws->ws_row && ws->ws_col)
 278                 return;
 279 #endif
 280         ws->ws_row = 25;
 281         ws->ws_col = 80;
 282 }
 283
 284 static void set_tracing_events_path(const char *mountpoint)
 285 {
 286         snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s",
 287                  mountpoint, "tracing/events");
 288 }
 289
 290 const char *perf_debugfs_mount(const char *mountpoint)
 291 {
 292         const char *mnt;
 293
 294         mnt = debugfs_mount(mountpoint);
 295         if (!mnt)
 296                 return NULL;
 297
 298         set_tracing_events_path(mnt);
 299
 300         return mnt;
 301 }
 302
 303 void perf_debugfs_set_path(const char *mntpt)
 304 {
 305         snprintf(debugfs_mountpoint, strlen(debugfs_mountpoint), "%s", mntpt);
 306         set_tracing_events_path(mntpt);
 307 }
 308
 309 static const char *find_debugfs(void)
 310 {
 311         const char *path = perf_debugfs_mount(NULL);
 312
 313         if (!path)
 314                 fprintf(stderr, "Your kernel does not support the debugfs filesystem");
 315
 316         return path;
 317 }
 318
 319 /*
 320  * Finds the path to the debugfs/tracing
 321  * Allocates the string and stores it.
 322  */
 323 const char *find_tracing_dir(void)
 324 {
 325         static char *tracing;
 326         static int tracing_found;
 327         const char *debugfs;
 328
 329         if (tracing_found)
 330                 return tracing;
 331
 332         debugfs = find_debugfs();
 333         if (!debugfs)
 334                 return NULL;
 335
 336         tracing = malloc(strlen(debugfs) + 9);
 337         if (!tracing)
 338                 return NULL;
 339
 340         sprintf(tracing, "%s/tracing", debugfs);
 341
 342         tracing_found = 1;
 343         return tracing;
 344 }
 345
 346 char *get_tracing_file(const char *name)
 347 {
 348         const char *tracing;
 349         char *file;
 350
 351         tracing = find_tracing_dir();
 352         if (!tracing)
 353                 return NULL;
 354
 355         file = malloc(strlen(tracing) + strlen(name) + 2);
 356         if (!file)
 357                 return NULL;
 358
 359         sprintf(file, "%s/%s", tracing, name);
 360         return file;
 361 }
 362
 363 void put_tracing_file(char *file)
 364 {
 365         free(file);
 366 }
 367
 368 int parse_nsec_time(const char *str, u64 *ptime)
 369 {
 370         u64 time_sec, time_nsec;
 371         char *end;
 372
 373         time_sec = strtoul(str, &end, 10);
 374         if (*end != '.' && *end != '\0')
 375                 return -1;
 376
 377         if (*end == '.') {
 378                 int i;
 379                 char nsec_buf[10];
 380
 381                 if (strlen(++end) > 9)
 382                         return -1;
 383
 384                 strncpy(nsec_buf, end, 9);
 385                 nsec_buf[9] = '\0';
 386
 387                 /* make it nsec precision */
 388                 for (i = strlen(nsec_buf); i < 9; i++)
 389                         nsec_buf[i] = '0';
 390
 391                 time_nsec = strtoul(nsec_buf, &end, 10);
 392                 if (*end != '\0')
 393                         return -1;
 394         } else
 395                 time_nsec = 0;
 396
 397         *ptime = time_sec * NSEC_PER_SEC + time_nsec;
 398         return 0;
 399 }
 400
 401 unsigned long parse_tag_value(const char *str, struct parse_tag *tags)
 402 {
 403         struct parse_tag *i = tags;
 404
 405         while (i->tag) {
 406                 char *s;
 407
 408                 s = strchr(str, i->tag);
 409                 if (s) {
 410                         unsigned long int value;
 411                         char *endptr;
 412
 413                         value = strtoul(str, &endptr, 10);
 414                         if (s != endptr)
 415                                 break;
 416
 417                         if (value > ULONG_MAX / i->mult)
 418                                 break;
 419                         value *= i->mult;
 420                         return value;
 421                 }
 422                 i++;
 423         }
 424
 425         return (unsigned long) -1;
 426 }
 427
 428 int filename__read_int(const char *filename, int *value)
 429 {
 430         char line[64];
 431         int fd = open(filename, O_RDONLY), err = -1;
 432
 433         if (fd < 0)
 434                 return -1;
 435
 436         if (read(fd, line, sizeof(line)) > 0) {
 437                 *value = atoi(line);
 438                 err = 0;
 439         }
 440
 441         close(fd);
 442         return err;
 443 }
 444
 445 int filename__read_str(const char *filename, char **buf, size_t *sizep)
 446 {
 447         size_t size = 0, alloc_size = 0;
 448         void *bf = NULL, *nbf;
 449         int fd, n, err = 0;
 450
 451         fd = open(filename, O_RDONLY);
 452         if (fd < 0)
 453                 return -errno;
 454
 455         do {
 456                 if (size == alloc_size) {
 457                         alloc_size += BUFSIZ;
 458                         nbf = realloc(bf, alloc_size);
 459                         if (!nbf) {
 460                                 err = -ENOMEM;
 461                                 break;
 462                         }
 463
 464                         bf = nbf;
 465                 }
 466
 467                 n = read(fd, bf + size, alloc_size - size);
 468                 if (n < 0) {
 469                         if (size) {
 470                                 pr_warning("read failed %d: %s\n",
 471                                            errno, strerror(errno));
 472                                 err = 0;
 473                         } else
 474                                 err = -errno;
 475
 476                         break;
 477                 }
 478
 479                 size += n;
 480         } while (n > 0);
 481
 482         if (!err) {
 483                 *sizep = size;
 484                 *buf   = bf;
 485         } else
 486                 free(bf);
 487
 488         close(fd);
 489         return err;
 490 }
 491
 492 const char *get_filename_for_perf_kvm(void)
 493 {
 494         const char *filename;
 495
 496         if (perf_host && !perf_guest)
 497                 filename = strdup("perf.data.host");
 498         else if (!perf_host && perf_guest)
 499                 filename = strdup("perf.data.guest");
 500         else
 501                 filename = strdup("perf.data.kvm");
 502
 503         return filename;
 504 }
 505
 506 int perf_event_paranoid(void)
 507 {
 508         char path[PATH_MAX];
 509         const char *procfs = procfs__mountpoint();
 510         int value;
 511
 512         if (!procfs)
 513                 return INT_MAX;
 514
 515         scnprintf(path, PATH_MAX, "%s/sys/kernel/perf_event_paranoid", procfs);
 516
 517         if (filename__read_int(path, &value))
 518                 return INT_MAX;
 519
 520         return value;
 521 }
 522
 523 void mem_bswap_32(void *src, int byte_size)
 524 {
 525         u32 *m = src;
 526         while (byte_size > 0) {
 527                 *m = bswap_32(*m);
 528                 byte_size -= sizeof(u32);
 529                 ++m;
 530         }
 531 }
 532
 533 void mem_bswap_64(void *src, int byte_size)
 534 {
 535         u64 *m = src;
 536
 537         while (byte_size > 0) {
 538                 *m = bswap_64(*m);
 539                 byte_size -= sizeof(u64);
 540                 ++m;
 541         }
 542 }