lib/dfsan/dfsan_custom.cc

   1 //===-- dfsan.cc ----------------------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file is a part of DataFlowSanitizer.
  11 //
  12 // This file defines the custom functions listed in done_abilist.txt.
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "sanitizer_common/sanitizer_internal_defs.h"
  16 #include "sanitizer_common/sanitizer_linux.h"
  17
  18 #include "dfsan/dfsan.h"
  19
  20 #include <arpa/inet.h>
  21 #include <ctype.h>
  22 #include <dlfcn.h>
  23 #include <link.h>
  24 #include <poll.h>
  25 #include <pthread.h>
  26 #include <pwd.h>
  27 #include <sched.h>
  28 #include <signal.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <sys/resource.h>
  33 #include <sys/select.h>
  34 #include <sys/stat.h>
  35 #include <sys/time.h>
  36 #include <sys/types.h>
  37 #include <time.h>
  38 #include <unistd.h>
  39
  40 using namespace __dfsan;
  41
  42 extern "C" {
  43 SANITIZER_INTERFACE_ATTRIBUTE int
  44 __dfsw_stat(const char *path, struct stat *buf, dfsan_label path_label,
  45             dfsan_label buf_label, dfsan_label *ret_label) {
  46   int ret = stat(path, buf);
  47   if (ret == 0)
  48     dfsan_set_label(0, buf, sizeof(struct stat));
  49   *ret_label = 0;
  50   return ret;
  51 }
  52
  53 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_fstat(int fd, struct stat *buf,
  54                                                dfsan_label fd_label,
  55                                                dfsan_label buf_label,
  56                                                dfsan_label *ret_label) {
  57   int ret = fstat(fd, buf);
  58   if (ret == 0)
  59     dfsan_set_label(0, buf, sizeof(struct stat));
  60   *ret_label = 0;
  61   return ret;
  62 }
  63
  64 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strchr(const char *s, int c,
  65                                                   dfsan_label s_label,
  66                                                   dfsan_label c_label,
  67                                                   dfsan_label *ret_label) {
  68   for (size_t i = 0;; ++i) {
  69     if (s[i] == c || s[i] == 0) {
  70       if (flags().strict_data_dependencies) {
  71         *ret_label = s_label;
  72       } else {
  73         *ret_label = dfsan_union(dfsan_read_label(s, i + 1),
  74                                  dfsan_union(s_label, c_label));
  75       }
  76       return s[i] == 0 ? 0 : const_cast<char *>(s+i);
  77     }
  78   }
  79 }
  80
  81 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_memcmp(const void *s1, const void *s2,
  82                                                 size_t n, dfsan_label s1_label,
  83                                                 dfsan_label s2_label,
  84                                                 dfsan_label n_label,
  85                                                 dfsan_label *ret_label) {
  86   const char *cs1 = (const char *) s1, *cs2 = (const char *) s2;
  87   for (size_t i = 0; i != n; ++i) {
  88     if (cs1[i] != cs2[i]) {
  89       if (flags().strict_data_dependencies) {
  90         *ret_label = 0;
  91       } else {
  92         *ret_label = dfsan_union(dfsan_read_label(cs1, i + 1),
  93                                  dfsan_read_label(cs2, i + 1));
  94       }
  95       return cs1[i] - cs2[i];
  96     }
  97   }
  98
  99   if (flags().strict_data_dependencies) {
 100     *ret_label = 0;
 101   } else {
 102     *ret_label = dfsan_union(dfsan_read_label(cs1, n),
 103                              dfsan_read_label(cs2, n));
 104   }
 105   return 0;
 106 }
 107
 108 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strcmp(const char *s1, const char *s2,
 109                                                 dfsan_label s1_label,
 110                                                 dfsan_label s2_label,
 111                                                 dfsan_label *ret_label) {
 112   for (size_t i = 0;; ++i) {
 113     if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0) {
 114       if (flags().strict_data_dependencies) {
 115         *ret_label = 0;
 116       } else {
 117         *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
 118                                  dfsan_read_label(s2, i + 1));
 119       }
 120       return s1[i] - s2[i];
 121     }
 122   }
 123   return 0;
 124 }
 125
 126 SANITIZER_INTERFACE_ATTRIBUTE int
 127 __dfsw_strcasecmp(const char *s1, const char *s2, dfsan_label s1_label,
 128                   dfsan_label s2_label, dfsan_label *ret_label) {
 129   for (size_t i = 0;; ++i) {
 130     if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0) {
 131       if (flags().strict_data_dependencies) {
 132         *ret_label = 0;
 133       } else {
 134         *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
 135                                  dfsan_read_label(s2, i + 1));
 136       }
 137       return s1[i] - s2[i];
 138     }
 139   }
 140   return 0;
 141 }
 142
 143 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strncmp(const char *s1, const char *s2,
 144                                                  size_t n, dfsan_label s1_label,
 145                                                  dfsan_label s2_label,
 146                                                  dfsan_label n_label,
 147                                                  dfsan_label *ret_label) {
 148   if (n == 0) {
 149     *ret_label = 0;
 150     return 0;
 151   }
 152
 153   for (size_t i = 0;; ++i) {
 154     if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0 || i == n - 1) {
 155       if (flags().strict_data_dependencies) {
 156         *ret_label = 0;
 157       } else {
 158         *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
 159                                  dfsan_read_label(s2, i + 1));
 160       }
 161       return s1[i] - s2[i];
 162     }
 163   }
 164   return 0;
 165 }
 166
 167 SANITIZER_INTERFACE_ATTRIBUTE int
 168 __dfsw_strncasecmp(const char *s1, const char *s2, size_t n,
 169                    dfsan_label s1_label, dfsan_label s2_label,
 170                    dfsan_label n_label, dfsan_label *ret_label) {
 171   if (n == 0) {
 172     *ret_label = 0;
 173     return 0;
 174   }
 175
 176   for (size_t i = 0;; ++i) {
 177     if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0 ||
 178         i == n - 1) {
 179       if (flags().strict_data_dependencies) {
 180         *ret_label = 0;
 181       } else {
 182         *ret_label = dfsan_union(dfsan_read_label(s1, i + 1),
 183                                  dfsan_read_label(s2, i + 1));
 184       }
 185       return s1[i] - s2[i];
 186     }
 187   }
 188   return 0;
 189 }
 190
 191 SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_calloc(size_t nmemb, size_t size,
 192                                                   dfsan_label nmemb_label,
 193                                                   dfsan_label size_label,
 194                                                   dfsan_label *ret_label) {
 195   void *p = calloc(nmemb, size);
 196   dfsan_set_label(0, p, nmemb * size);
 197   *ret_label = 0;
 198   return p;
 199 }
 200
 201 SANITIZER_INTERFACE_ATTRIBUTE size_t
 202 __dfsw_strlen(const char *s, dfsan_label s_label, dfsan_label *ret_label) {
 203   size_t ret = strlen(s);
 204   if (flags().strict_data_dependencies) {
 205     *ret_label = 0;
 206   } else {
 207     *ret_label = dfsan_read_label(s, ret + 1);
 208   }
 209   return ret;
 210 }
 211
 212
 213 static void *dfsan_memcpy(void *dest, const void *src, size_t n) {
 214   dfsan_label *sdest = shadow_for(dest), *ssrc = shadow_for((void *)src);
 215   internal_memcpy((void *)sdest, (void *)ssrc, n * sizeof(dfsan_label));
 216   return internal_memcpy(dest, src, n);
 217 }
 218
 219 static void dfsan_memset(void *s, int c, dfsan_label c_label, size_t n) {
 220   internal_memset(s, c, n);
 221   dfsan_set_label(c_label, s, n);
 222 }
 223
 224 SANITIZER_INTERFACE_ATTRIBUTE
 225 void *__dfsw_memcpy(void *dest, const void *src, size_t n,
 226                     dfsan_label dest_label, dfsan_label src_label,
 227                     dfsan_label n_label, dfsan_label *ret_label) {
 228   *ret_label = dest_label;
 229   return dfsan_memcpy(dest, src, n);
 230 }
 231
 232 SANITIZER_INTERFACE_ATTRIBUTE
 233 void *__dfsw_memset(void *s, int c, size_t n,
 234                     dfsan_label s_label, dfsan_label c_label,
 235                     dfsan_label n_label, dfsan_label *ret_label) {
 236   dfsan_memset(s, c, c_label, n);
 237   *ret_label = s_label;
 238   return s;
 239 }
 240
 241 SANITIZER_INTERFACE_ATTRIBUTE char *
 242 __dfsw_strdup(const char *s, dfsan_label s_label, dfsan_label *ret_label) {
 243   size_t len = strlen(s);
 244   void *p = malloc(len+1);
 245   dfsan_memcpy(p, s, len+1);
 246   *ret_label = 0;
 247   return static_cast<char *>(p);
 248 }
 249
 250 SANITIZER_INTERFACE_ATTRIBUTE char *
 251 __dfsw_strncpy(char *s1, const char *s2, size_t n, dfsan_label s1_label,
 252                dfsan_label s2_label, dfsan_label n_label,
 253                dfsan_label *ret_label) {
 254   size_t len = strlen(s2);
 255   if (len < n) {
 256     dfsan_memcpy(s1, s2, len+1);
 257     dfsan_memset(s1+len+1, 0, 0, n-len-1);
 258   } else {
 259     dfsan_memcpy(s1, s2, n);
 260   }
 261
 262   *ret_label = s1_label;
 263   return s1;
 264 }
 265
 266 SANITIZER_INTERFACE_ATTRIBUTE ssize_t
 267 __dfsw_pread(int fd, void *buf, size_t count, off_t offset,
 268              dfsan_label fd_label, dfsan_label buf_label,
 269              dfsan_label count_label, dfsan_label offset_label,
 270              dfsan_label *ret_label) {
 271   ssize_t ret = pread(fd, buf, count, offset);
 272   if (ret > 0)
 273     dfsan_set_label(0, buf, ret);
 274   *ret_label = 0;
 275   return ret;
 276 }
 277
 278 SANITIZER_INTERFACE_ATTRIBUTE ssize_t
 279 __dfsw_read(int fd, void *buf, size_t count,
 280              dfsan_label fd_label, dfsan_label buf_label,
 281              dfsan_label count_label,
 282              dfsan_label *ret_label) {
 283   ssize_t ret = read(fd, buf, count);
 284   if (ret > 0)
 285     dfsan_set_label(0, buf, ret);
 286   *ret_label = 0;
 287   return ret;
 288 }
 289
 290 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_clock_gettime(clockid_t clk_id,
 291                                                        struct timespec *tp,
 292                                                        dfsan_label clk_id_label,
 293                                                        dfsan_label tp_label,
 294                                                        dfsan_label *ret_label) {
 295   int ret = clock_gettime(clk_id, tp);
 296   if (ret == 0)
 297     dfsan_set_label(0, tp, sizeof(struct timespec));
 298   *ret_label = 0;
 299   return ret;
 300 }
 301
 302 static void unpoison(const void *ptr, uptr size) {
 303   dfsan_set_label(0, const_cast<void *>(ptr), size);
 304 }
 305
 306 // dlopen() ultimately calls mmap() down inside the loader, which generally
 307 // doesn't participate in dynamic symbol resolution.  Therefore we won't
 308 // intercept its calls to mmap, and we have to hook it here.
 309 SANITIZER_INTERFACE_ATTRIBUTE void *
 310 __dfsw_dlopen(const char *filename, int flag, dfsan_label filename_label,
 311               dfsan_label flag_label, dfsan_label *ret_label) {
 312   link_map *map = (link_map *)dlopen(filename, flag);
 313   if (map)
 314     ForEachMappedRegion(map, unpoison);
 315   *ret_label = 0;
 316   return (void *)map;
 317 }
 318
 319 struct pthread_create_info {
 320   void *(*start_routine_trampoline)(void *, void *, dfsan_label, dfsan_label *);
 321   void *start_routine;
 322   void *arg;
 323 };
 324
 325 static void *pthread_create_cb(void *p) {
 326   pthread_create_info pci(*(pthread_create_info *)p);
 327   free(p);
 328   dfsan_label ret_label;
 329   return pci.start_routine_trampoline(pci.start_routine, pci.arg, 0,
 330                                       &ret_label);
 331 }
 332
 333 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_create(
 334     pthread_t *thread, const pthread_attr_t *attr,
 335     void *(*start_routine_trampoline)(void *, void *, dfsan_label,
 336                                       dfsan_label *),
 337     void *start_routine, void *arg, dfsan_label thread_label,
 338     dfsan_label attr_label, dfsan_label start_routine_label,
 339     dfsan_label arg_label, dfsan_label *ret_label) {
 340   pthread_create_info *pci =
 341       (pthread_create_info *)malloc(sizeof(pthread_create_info));
 342   pci->start_routine_trampoline = start_routine_trampoline;
 343   pci->start_routine = start_routine;
 344   pci->arg = arg;
 345   int rv = pthread_create(thread, attr, pthread_create_cb, (void *)pci);
 346   if (rv != 0)
 347     free(pci);
 348   *ret_label = 0;
 349   return rv;
 350 }
 351
 352 struct dl_iterate_phdr_info {
 353   int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
 354                              size_t size, void *data, dfsan_label info_label,
 355                              dfsan_label size_label, dfsan_label data_label,
 356                              dfsan_label *ret_label);
 357   void *callback;
 358   void *data;
 359 };
 360
 361 int dl_iterate_phdr_cb(struct dl_phdr_info *info, size_t size, void *data) {
 362   dl_iterate_phdr_info *dipi = (dl_iterate_phdr_info *)data;
 363   dfsan_set_label(0, *info);
 364   dfsan_set_label(0, (void *)info->dlpi_name, strlen(info->dlpi_name) + 1);
 365   dfsan_set_label(0, (void *)info->dlpi_phdr,
 366                   sizeof(*info->dlpi_phdr) * info->dlpi_phnum);
 367   dfsan_label ret_label;
 368   return dipi->callback_trampoline(dipi->callback, info, size, dipi->data, 0, 0,
 369                                    0, &ret_label);
 370 }
 371
 372 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_dl_iterate_phdr(
 373     int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
 374                                size_t size, void *data, dfsan_label info_label,
 375                                dfsan_label size_label, dfsan_label data_label,
 376                                dfsan_label *ret_label),
 377     void *callback, void *data, dfsan_label callback_label,
 378     dfsan_label data_label, dfsan_label *ret_label) {
 379   dl_iterate_phdr_info dipi = { callback_trampoline, callback, data };
 380   *ret_label = 0;
 381   return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi);
 382 }
 383
 384 SANITIZER_INTERFACE_ATTRIBUTE
 385 char *__dfsw_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label,
 386                      dfsan_label buf_label, dfsan_label *ret_label) {
 387   char *ret = ctime_r(timep, buf);
 388   if (ret) {
 389     dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), buf,
 390                     strlen(buf) + 1);
 391     *ret_label = buf_label;
 392   } else {
 393     *ret_label = 0;
 394   }
 395   return ret;
 396 }
 397
 398 SANITIZER_INTERFACE_ATTRIBUTE
 399 char *__dfsw_fgets(char *s, int size, FILE *stream, dfsan_label s_label,
 400                    dfsan_label size_label, dfsan_label stream_label,
 401                    dfsan_label *ret_label) {
 402   char *ret = fgets(s, size, stream);
 403   if (ret) {
 404     dfsan_set_label(0, ret, strlen(ret) + 1);
 405     *ret_label = s_label;
 406   } else {
 407     *ret_label = 0;
 408   }
 409   return ret;
 410 }
 411
 412 SANITIZER_INTERFACE_ATTRIBUTE
 413 char *__dfsw_getcwd(char *buf, size_t size, dfsan_label buf_label,
 414                     dfsan_label size_label, dfsan_label *ret_label) {
 415   char *ret = getcwd(buf, size);
 416   if (ret) {
 417     dfsan_set_label(0, ret, strlen(ret) + 1);
 418     *ret_label = buf_label;
 419   } else {
 420     *ret_label = 0;
 421   }
 422   return ret;
 423 }
 424
 425 SANITIZER_INTERFACE_ATTRIBUTE
 426 char *__dfsw_get_current_dir_name(dfsan_label *ret_label) {
 427   char *ret = get_current_dir_name();
 428   if (ret) {
 429     dfsan_set_label(0, ret, strlen(ret) + 1);
 430   }
 431   *ret_label = 0;
 432   return ret;
 433 }
 434
 435 SANITIZER_INTERFACE_ATTRIBUTE
 436 int __dfsw_gethostname(char *name, size_t len, dfsan_label name_label,
 437                        dfsan_label len_label, dfsan_label *ret_label) {
 438   int ret = gethostname(name, len);
 439   if (ret == 0) {
 440     dfsan_set_label(0, name, strlen(name) + 1);
 441   }
 442   *ret_label = 0;
 443   return ret;
 444 }
 445
 446 SANITIZER_INTERFACE_ATTRIBUTE
 447 int __dfsw_getrlimit(int resource, struct rlimit *rlim,
 448                      dfsan_label resource_label, dfsan_label rlim_label,
 449                      dfsan_label *ret_label) {
 450   int ret = getrlimit(resource, rlim);
 451   if (ret == 0) {
 452     dfsan_set_label(0, rlim, sizeof(struct rlimit));
 453   }
 454   *ret_label = 0;
 455   return ret;
 456 }
 457
 458 SANITIZER_INTERFACE_ATTRIBUTE
 459 int __dfsw_getrusage(int who, struct rusage *usage, dfsan_label who_label,
 460                      dfsan_label usage_label, dfsan_label *ret_label) {
 461   int ret = getrusage(who, usage);
 462   if (ret == 0) {
 463     dfsan_set_label(0, usage, sizeof(struct rusage));
 464   }
 465   *ret_label = 0;
 466   return ret;
 467 }
 468
 469 SANITIZER_INTERFACE_ATTRIBUTE
 470 char *__dfsw_strcpy(char *dest, const char *src, dfsan_label dst_label,
 471                     dfsan_label src_label, dfsan_label *ret_label) {
 472   char *ret = strcpy(dest, src);
 473   if (ret) {
 474     internal_memcpy(shadow_for(dest), shadow_for(src),
 475                     sizeof(dfsan_label) * (strlen(src) + 1));
 476   }
 477   *ret_label = dst_label;
 478   return ret;
 479 }
 480
 481 SANITIZER_INTERFACE_ATTRIBUTE
 482 long int __dfsw_strtol(const char *nptr, char **endptr, int base,
 483                        dfsan_label nptr_label, dfsan_label endptr_label,
 484                        dfsan_label base_label, dfsan_label *ret_label) {
 485   char *tmp_endptr;
 486   long int ret = strtol(nptr, &tmp_endptr, base);
 487   if (endptr) {
 488     *endptr = tmp_endptr;
 489   }
 490   if (tmp_endptr > nptr) {
 491     // If *tmp_endptr is '\0' include its label as well.
 492     *ret_label = dfsan_union(
 493         base_label,
 494         dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
 495   } else {
 496     *ret_label = 0;
 497   }
 498   return ret;
 499 }
 500
 501 SANITIZER_INTERFACE_ATTRIBUTE
 502 double __dfsw_strtod(const char *nptr, char **endptr,
 503                        dfsan_label nptr_label, dfsan_label endptr_label,
 504                        dfsan_label *ret_label) {
 505   char *tmp_endptr;
 506   double ret = strtod(nptr, &tmp_endptr);
 507   if (endptr) {
 508     *endptr = tmp_endptr;
 509   }
 510   if (tmp_endptr > nptr) {
 511     // If *tmp_endptr is '\0' include its label as well.
 512     *ret_label = dfsan_read_label(
 513         nptr,
 514         tmp_endptr - nptr + (*tmp_endptr ? 0 : 1));
 515   } else {
 516     *ret_label = 0;
 517   }
 518   return ret;
 519 }
 520
 521 SANITIZER_INTERFACE_ATTRIBUTE
 522 long long int __dfsw_strtoll(const char *nptr, char **endptr, int base,
 523                        dfsan_label nptr_label, dfsan_label endptr_label,
 524                        dfsan_label base_label, dfsan_label *ret_label) {
 525   char *tmp_endptr;
 526   long long int ret = strtoll(nptr, &tmp_endptr, base);
 527   if (endptr) {
 528     *endptr = tmp_endptr;
 529   }
 530   if (tmp_endptr > nptr) {
 531     // If *tmp_endptr is '\0' include its label as well.
 532     *ret_label = dfsan_union(
 533         base_label,
 534         dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
 535   } else {
 536     *ret_label = 0;
 537   }
 538   return ret;
 539 }
 540
 541 SANITIZER_INTERFACE_ATTRIBUTE
 542 unsigned long int __dfsw_strtoul(const char *nptr, char **endptr, int base,
 543                        dfsan_label nptr_label, dfsan_label endptr_label,
 544                        dfsan_label base_label, dfsan_label *ret_label) {
 545   char *tmp_endptr;
 546   unsigned long int ret = strtoul(nptr, &tmp_endptr, base);
 547   if (endptr) {
 548     *endptr = tmp_endptr;
 549   }
 550   if (tmp_endptr > nptr) {
 551     // If *tmp_endptr is '\0' include its label as well.
 552     *ret_label = dfsan_union(
 553         base_label,
 554         dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
 555   } else {
 556     *ret_label = 0;
 557   }
 558   return ret;
 559 }
 560
 561 SANITIZER_INTERFACE_ATTRIBUTE
 562 long long unsigned int __dfsw_strtoull(const char *nptr, char **endptr,
 563                                        dfsan_label nptr_label,
 564                                        int base, dfsan_label endptr_label,
 565                                        dfsan_label base_label,
 566                                        dfsan_label *ret_label) {
 567   char *tmp_endptr;
 568   long long unsigned int ret = strtoull(nptr, &tmp_endptr, base);
 569   if (endptr) {
 570     *endptr = tmp_endptr;
 571   }
 572   if (tmp_endptr > nptr) {
 573     // If *tmp_endptr is '\0' include its label as well.
 574     *ret_label = dfsan_union(
 575         base_label,
 576         dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
 577   } else {
 578     *ret_label = 0;
 579   }
 580   return ret;
 581 }
 582
 583 SANITIZER_INTERFACE_ATTRIBUTE
 584 time_t __dfsw_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label) {
 585   time_t ret = time(t);
 586   if (ret != (time_t) -1 && t) {
 587     dfsan_set_label(0, t, sizeof(time_t));
 588   }
 589   *ret_label = 0;
 590   return ret;
 591 }
 592
 593 SANITIZER_INTERFACE_ATTRIBUTE
 594 int __dfsw_inet_pton(int af, const char *src, void *dst, dfsan_label af_label,
 595                      dfsan_label src_label, dfsan_label dst_label,
 596                      dfsan_label *ret_label) {
 597   int ret = inet_pton(af, src, dst);
 598   if (ret == 1) {
 599     dfsan_set_label(dfsan_read_label(src, strlen(src) + 1), dst,
 600                     af == AF_INET ? sizeof(struct in_addr) : sizeof(in6_addr));
 601   }
 602   *ret_label = 0;
 603   return ret;
 604 }
 605
 606 SANITIZER_INTERFACE_ATTRIBUTE
 607 struct tm *__dfsw_localtime_r(const time_t *timep, struct tm *result,
 608                               dfsan_label timep_label, dfsan_label result_label,
 609                               dfsan_label *ret_label) {
 610   struct tm *ret = localtime_r(timep, result);
 611   if (ret) {
 612     dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), result,
 613                     sizeof(struct tm));
 614     *ret_label = result_label;
 615   } else {
 616     *ret_label = 0;
 617   }
 618   return ret;
 619 }
 620
 621 SANITIZER_INTERFACE_ATTRIBUTE
 622 int __dfsw_getpwuid_r(id_t uid, struct passwd *pwd,
 623                       char *buf, size_t buflen, struct passwd **result,
 624                       dfsan_label uid_label, dfsan_label pwd_label,
 625                       dfsan_label buf_label, dfsan_label buflen_label,
 626                       dfsan_label result_label, dfsan_label *ret_label) {
 627   // Store the data in pwd, the strings referenced from pwd in buf, and the
 628   // address of pwd in *result.  On failure, NULL is stored in *result.
 629   int ret = getpwuid_r(uid, pwd, buf, buflen, result);
 630   if (ret == 0) {
 631     dfsan_set_label(0, pwd, sizeof(struct passwd));
 632     dfsan_set_label(0, buf, strlen(buf) + 1);
 633   }
 634   *ret_label = 0;
 635   dfsan_set_label(0, result, sizeof(struct passwd*));
 636   return ret;
 637 }
 638
 639 SANITIZER_INTERFACE_ATTRIBUTE
 640 int __dfsw_poll(struct pollfd *fds, nfds_t nfds, int timeout,
 641                 dfsan_label dfs_label, dfsan_label nfds_label,
 642                 dfsan_label timeout_label, dfsan_label *ret_label) {
 643   int ret = poll(fds, nfds, timeout);
 644   if (ret >= 0) {
 645     for (; nfds > 0; --nfds) {
 646       dfsan_set_label(0, &fds[nfds - 1].revents, sizeof(fds[nfds - 1].revents));
 647     }
 648   }
 649   *ret_label = 0;
 650   return ret;
 651 }
 652
 653 SANITIZER_INTERFACE_ATTRIBUTE
 654 int __dfsw_select(int nfds, fd_set *readfds, fd_set *writefds,
 655                   fd_set *exceptfds, struct timeval *timeout,
 656                   dfsan_label nfds_label, dfsan_label readfds_label,
 657                   dfsan_label writefds_label, dfsan_label exceptfds_label,
 658                   dfsan_label timeout_label, dfsan_label *ret_label) {
 659   int ret = select(nfds, readfds, writefds, exceptfds, timeout);
 660   // Clear everything (also on error) since their content is either set or
 661   // undefined.
 662   if (readfds) {
 663     dfsan_set_label(0, readfds, sizeof(fd_set));
 664   }
 665   if (writefds) {
 666     dfsan_set_label(0, writefds, sizeof(fd_set));
 667   }
 668   if (exceptfds) {
 669     dfsan_set_label(0, exceptfds, sizeof(fd_set));
 670   }
 671   dfsan_set_label(0, timeout, sizeof(struct timeval));
 672   *ret_label = 0;
 673   return ret;
 674 }
 675
 676 SANITIZER_INTERFACE_ATTRIBUTE
 677 int __dfsw_sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask,
 678                              dfsan_label pid_label,
 679                              dfsan_label cpusetsize_label,
 680                              dfsan_label mask_label, dfsan_label *ret_label) {
 681   int ret = sched_getaffinity(pid, cpusetsize, mask);
 682   if (ret == 0) {
 683     dfsan_set_label(0, mask, cpusetsize);
 684   }
 685   *ret_label = 0;
 686   return ret;
 687 }
 688
 689 SANITIZER_INTERFACE_ATTRIBUTE
 690 int __dfsw_sigemptyset(sigset_t *set, dfsan_label set_label,
 691                        dfsan_label *ret_label) {
 692   int ret = sigemptyset(set);
 693   dfsan_set_label(0, set, sizeof(sigset_t));
 694   return ret;
 695 }
 696
 697 SANITIZER_INTERFACE_ATTRIBUTE
 698 int __dfsw_sigaction(int signum, const struct sigaction *act,
 699                      struct sigaction *oldact, dfsan_label signum_label,
 700                      dfsan_label act_label, dfsan_label oldact_label,
 701                      dfsan_label *ret_label) {
 702   int ret = sigaction(signum, act, oldact);
 703   if (oldact) {
 704     dfsan_set_label(0, oldact, sizeof(struct sigaction));
 705   }
 706   *ret_label = 0;
 707   return ret;
 708 }
 709
 710 SANITIZER_INTERFACE_ATTRIBUTE
 711 int __dfsw_gettimeofday(struct timeval *tv, struct timezone *tz,
 712                         dfsan_label tv_label, dfsan_label tz_label,
 713                         dfsan_label *ret_label) {
 714   int ret = gettimeofday(tv, tz);
 715   if (tv) {
 716     dfsan_set_label(0, tv, sizeof(struct timeval));
 717   }
 718   if (tz) {
 719     dfsan_set_label(0, tz, sizeof(struct timezone));
 720   }
 721   *ret_label = 0;
 722   return ret;
 723 }
 724
 725 SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_memchr(void *s, int c, size_t n,
 726                                                   dfsan_label s_label,
 727                                                   dfsan_label c_label,
 728                                                   dfsan_label n_label,
 729                                                   dfsan_label *ret_label) {
 730   void *ret = memchr(s, c, n);
 731   if (flags().strict_data_dependencies) {
 732     *ret_label = ret ? s_label : 0;
 733   } else {
 734     size_t len =
 735         ret ? reinterpret_cast<char *>(ret) - reinterpret_cast<char *>(s) + 1
 736             : n;
 737     *ret_label =
 738         dfsan_union(dfsan_read_label(s, len), dfsan_union(s_label, c_label));
 739   }
 740   return ret;
 741 }
 742
 743 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strrchr(char *s, int c,
 744                                                    dfsan_label s_label,
 745                                                    dfsan_label c_label,
 746                                                    dfsan_label *ret_label) {
 747   char *ret = strrchr(s, c);
 748   if (flags().strict_data_dependencies) {
 749     *ret_label = ret ? s_label : 0;
 750   } else {
 751     *ret_label =
 752         dfsan_union(dfsan_read_label(s, strlen(s) + 1),
 753                     dfsan_union(s_label, c_label));
 754   }
 755
 756   return ret;
 757 }
 758
 759 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strstr(char *haystack, char *needle,
 760                                                   dfsan_label haystack_label,
 761                                                   dfsan_label needle_label,
 762                                                   dfsan_label *ret_label) {
 763   char *ret = strstr(haystack, needle);
 764   if (flags().strict_data_dependencies) {
 765     *ret_label = ret ? haystack_label : 0;
 766   } else {
 767     size_t len = ret ? ret + strlen(needle) - haystack : strlen(haystack) + 1;
 768     *ret_label =
 769         dfsan_union(dfsan_read_label(haystack, len),
 770                     dfsan_union(dfsan_read_label(needle, strlen(needle) + 1),
 771                                 dfsan_union(haystack_label, needle_label)));
 772   }
 773
 774   return ret;
 775 }
 776
 777 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_nanosleep(const struct timespec *req,
 778                                                    struct timespec *rem,
 779                                                    dfsan_label req_label,
 780                                                    dfsan_label rem_label,
 781                                                    dfsan_label *ret_label) {
 782   int ret = nanosleep(req, rem);
 783   *ret_label = 0;
 784   if (ret == -1) {
 785     // Interrupted by a signal, rem is filled with the remaining time.
 786     dfsan_set_label(0, rem, sizeof(struct timespec));
 787   }
 788   return ret;
 789 }
 790
 791 SANITIZER_INTERFACE_ATTRIBUTE int
 792 __dfsw_socketpair(int domain, int type, int protocol, int sv[2],
 793                   dfsan_label domain_label, dfsan_label type_label,
 794                   dfsan_label protocol_label, dfsan_label sv_label,
 795                   dfsan_label *ret_label) {
 796   int ret = socketpair(domain, type, protocol, sv);
 797   *ret_label = 0;
 798   if (ret == 0) {
 799     dfsan_set_label(0, sv, sizeof(*sv) * 2);
 800   }
 801   return ret;
 802 }
 803
 804 // Type of the trampoline function passed to the custom version of
 805 // dfsan_set_write_callback.
 806 typedef void (*write_trampoline_t)(
 807     void *callback,
 808     int fd, const void *buf, ssize_t count,
 809     dfsan_label fd_label, dfsan_label buf_label, dfsan_label count_label);
 810
 811 // Calls to dfsan_set_write_callback() set the values in this struct.
 812 // Calls to the custom version of write() read (and invoke) them.
 813 static struct {
 814   write_trampoline_t write_callback_trampoline = NULL;
 815   void *write_callback = NULL;
 816 } write_callback_info;
 817
 818 SANITIZER_INTERFACE_ATTRIBUTE void
 819 __dfsw_dfsan_set_write_callback(
 820     write_trampoline_t write_callback_trampoline,
 821     void *write_callback,
 822     dfsan_label write_callback_label,
 823     dfsan_label *ret_label) {
 824   write_callback_info.write_callback_trampoline = write_callback_trampoline;
 825   write_callback_info.write_callback = write_callback;
 826 }
 827
 828 SANITIZER_INTERFACE_ATTRIBUTE int
 829 __dfsw_write(int fd, const void *buf, size_t count,
 830              dfsan_label fd_label, dfsan_label buf_label,
 831              dfsan_label count_label, dfsan_label *ret_label) {
 832   if (write_callback_info.write_callback != NULL) {
 833     write_callback_info.write_callback_trampoline(
 834         write_callback_info.write_callback,
 835         fd, buf, count,
 836         fd_label, buf_label, count_label);
 837   }
 838
 839   *ret_label = 0;
 840   return write(fd, buf, count);
 841 }
 842 }