1 //===-- bcmp_fuzz.cpp ---------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 /// 9 /// Fuzzing test for llvm-libc bcmp implementation. 10 /// 11 //===----------------------------------------------------------------------===// 12 #include "src/strings/bcmp.h" 13 #include <stddef.h> 14 #include <stdint.h> 15 #include <stdio.h> 16 #include <string.h> 17 18 static int reference_bcmp(const void *pa, const void *pb, size_t count) 19 __attribute__((no_builtin)) { 20 const auto *a = reinterpret_cast<const unsigned char *>(pa); 21 const auto *b = reinterpret_cast<const unsigned char *>(pb); 22 for (size_t i = 0; i < count; ++i, ++a, ++b) 23 if (*a != *b) 24 return 1; 25 return 0; 26 } 27 28 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { 29 const auto normalize = [](int value) -> int { 30 if (value == 0) 31 return 0; 32 return 1; 33 }; 34 // We ignore the last byte is size is odd. 35 const auto count = size / 2; 36 const char *a = reinterpret_cast<const char *>(data); 37 const char *b = reinterpret_cast<const char *>(data) + count; 38 const int actual = LIBC_NAMESPACE::bcmp(a, b, count); 39 const int reference = reference_bcmp(a, b, count); 40 if (normalize(actual) == normalize(reference)) 41 return 0; 42 const auto print = [](const char *msg, const char *buffer, size_t size) { 43 printf("%s\"", msg); 44 for (size_t i = 0; i < size; ++i) 45 printf("\\x%02x", (uint8_t)buffer[i]); 46 printf("\"\n"); 47 }; 48 printf("count : %zu\n", count); 49 print("a : ", a, count); 50 print("b : ", b, count); 51 printf("expected : %d\n", reference); 52 printf("actual : %d\n", actual); 53 __builtin_trap(); 54 } 55