compiler-rt/test/fuzzer/SwapCmpTest.cpp

   1 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   2 // See https://llvm.org/LICENSE.txt for license information.
   3 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   4
   5 // The fuzzer must find several constants with swapped bytes.
   6 #include <cstdint>
   7 #include <cstdio>
   8 #include <cstdlib>
   9 #include <cstring>
  10
  11 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
  12   if (Size < 14) return 0;
  13   uint64_t x = 0;
  14   uint32_t y = 0;
  15   uint32_t z = 0;
  16   memcpy(&x, Data, sizeof(x));
  17   memcpy(&y, Data + Size / 2, sizeof(y));
  18   memcpy(&z, Data + Size - sizeof(z), sizeof(z));
  19
  20   x = __builtin_bswap64(x);
  21   y = __builtin_bswap32(y);
  22   z = __builtin_bswap32(z);
  23   const bool k32bit = sizeof(void*) == 4;
  24
  25   if ((k32bit || x == 0x46555A5A5A5A5546ULL) &&
  26       z == 0x4F4B &&
  27       y == 0x66757A7A &&
  28       true
  29       ) {
  30     if (Data[Size - 5] == 'z') {
  31       fprintf(stderr, "BINGO; Found the target\n");
  32       exit(1);
  33     }
  34   }
  35   return 0;
  36 }