1 #include <cstddef>
2 #include <cstdint>
3 #include <cstdio>
4 #include <cstdlib>
5 #include <vector>
6 
7 #include "gwp_asan/stack_trace_compressor.h"
8 
9 constexpr size_t kBytesForLargestVarInt = (sizeof(uintptr_t) * 8) / 7 + 1;
10 
LLVMFuzzerTestOneInput(const uint8_t * Data,size_t Size)11 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
12   size_t BufferSize = kBytesForLargestVarInt * Size / sizeof(uintptr_t);
13   std::vector<uint8_t> Buffer(BufferSize);
14   std::vector<uint8_t> Buffer2(BufferSize);
15 
16   // Unpack the fuzz bytes.
17   gwp_asan::compression::unpack(Data, Size,
18                                 reinterpret_cast<uintptr_t *>(Buffer2.data()),
19                                 BufferSize / sizeof(uintptr_t));
20 
21   // Pack the fuzz bytes.
22   size_t BytesWritten = gwp_asan::compression::pack(
23       reinterpret_cast<const uintptr_t *>(Data), Size / sizeof(uintptr_t),
24       Buffer.data(), BufferSize);
25 
26   // Unpack the compressed buffer.
27   size_t DecodedElements = gwp_asan::compression::unpack(
28       Buffer.data(), BytesWritten,
29       reinterpret_cast<uintptr_t *>(Buffer2.data()),
30       BufferSize / sizeof(uintptr_t));
31 
32   // Ensure that every element was encoded and decoded properly.
33   if (DecodedElements != Size / sizeof(uintptr_t))
34     abort();
35 
36   // Ensure that the compression and uncompression resulted in the same trace.
37   const uintptr_t *FuzzPtrs = reinterpret_cast<const uintptr_t *>(Data);
38   const uintptr_t *DecodedPtrs =
39       reinterpret_cast<const uintptr_t *>(Buffer2.data());
40   for (size_t i = 0; i < Size / sizeof(uintptr_t); ++i) {
41     if (FuzzPtrs[i] != DecodedPtrs[i]) {
42       fprintf(stderr, "FuzzPtrs[%zu] != DecodedPtrs[%zu] (0x%zx vs. 0x%zx)", i,
43               i, FuzzPtrs[i], DecodedPtrs[i]);
44       abort();
45     }
46   }
47 
48   return 0;
49 }
50