compiler-rt/test/fuzzer/CustomAllocator.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 // Test whether calling certain libFuzzer's interceptors inside allocators
   6 // does not cause an assertion failure.
   7 #include <assert.h>
   8 #include <cstddef>
   9 #include <cstdint>
  10 #include <cstdlib>
  11 #include <cstring>
  12 #include <iostream>
  13 #include <malloc.h>
  14
  15 static const char *buf1 = "aaaa";
  16 static const char *buf2 = "bbbb";
  17
  18 static void callFuzzerInterceptors(const char *prefix) {
  19   int memcmp_result = memcmp(buf1, buf2, 4);
  20   if (memcmp_result != 0) {
  21     fprintf(stderr, "%s-MEMCMP\n", prefix);
  22   }
  23   int strncmp_result = strncmp(buf1, buf2, 4);
  24   if (strncmp_result != 0) {
  25     fprintf(stderr, "%s-STRNCMP\n", prefix);
  26   }
  27   int strcmp_result = strcmp(buf1, buf2);
  28   if (strcmp_result != 0) {
  29     fprintf(stderr, "%s-STRCMP\n", prefix);
  30   }
  31   const char *strstr_result = strstr(buf1, buf2);
  32   if (strstr_result == nullptr) {
  33     fprintf(stderr, "%s-STRSTR\n", prefix);
  34   }
  35 }
  36
  37 extern "C" void *__libc_calloc(size_t, size_t);
  38
  39 extern "C" void *calloc(size_t n, size_t elem_size) {
  40   static bool CalledOnce = false;
  41   if (!CalledOnce) {
  42     callFuzzerInterceptors("CALLOC");
  43     CalledOnce = true;
  44   }
  45   return __libc_calloc(n, elem_size);
  46 }