wimlib.net Git - wimlib/blob - tools/libFuzzer/fault-injection.c

   1 #include "fuzzer.h"
   2
   3 static int64_t num_allocs_remaining;
   4
   5 static void *
   6 faultinject_malloc(size_t size)
   7 {
   8         if (__atomic_sub_fetch(&num_allocs_remaining, 1, __ATOMIC_RELAXED) <= 0)
   9                 return NULL;
  10         return malloc(size);
  11 }
  12
  13 static void
  14 faultinject_free(void *p)
  15 {
  16         free(p);
  17 }
  18
  19 static void *
  20 faultinject_realloc(void *p, size_t size)
  21 {
  22         if (__atomic_sub_fetch(&num_allocs_remaining, 1, __ATOMIC_RELAXED) <= 0)
  23                 return NULL;
  24         return realloc(p, size);
  25 }
  26
  27 bool
  28 setup_fault_nth(const uint8_t **in, size_t *insize, uint16_t *fault_nth)
  29 {
  30         uint16_t n;
  31
  32         if (*insize < 2)
  33                 return false;
  34         memcpy(&n, *in, 2);
  35         wimlib_set_memory_allocator(faultinject_malloc, faultinject_free,
  36                                     faultinject_realloc);
  37         num_allocs_remaining = n ?: INT64_MAX;
  38         *in += 2;
  39         *insize -= 2;
  40         *fault_nth = n;
  41         return true;
  42 }