libasan/asan_malloc_win.cc

   1 //===-- asan_malloc_win.cc ------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of AddressSanitizer, an address sanity checker.
   9 //
  10 // Windows-specific malloc interception.
  11 //===----------------------------------------------------------------------===//
  12 #ifdef _WIN32
  13
  14 #include "asan_allocator.h"
  15 #include "asan_interceptors.h"
  16 #include "asan_internal.h"
  17 #include "asan_stack.h"
  18 #include "interception/interception.h"
  19
  20 #include <stddef.h>
  21
  22 // ---------------------- Replacement functions ---------------- {{{1
  23 using namespace __asan;  // NOLINT
  24
  25 // FIXME: Simply defining functions with the same signature in *.obj
  26 // files overrides the standard functions in *.lib
  27 // This works well for simple helloworld-like tests but might need to be
  28 // revisited in the future.
  29
  30 extern "C" {
  31 void free(void *ptr) {
  32   GET_STACK_TRACE_HERE_FOR_FREE(ptr);
  33   return asan_free(ptr, &stack);
  34 }
  35
  36 void _free_dbg(void* ptr, int) {
  37   free(ptr);
  38 }
  39
  40 void cfree(void *ptr) {
  41   CHECK(!"cfree() should not be used on Windows?");
  42 }
  43
  44 void *malloc(size_t size) {
  45   GET_STACK_TRACE_HERE_FOR_MALLOC;
  46   return asan_malloc(size, &stack);
  47 }
  48
  49 void* _malloc_dbg(size_t size, int , const char*, int) {
  50   return malloc(size);
  51 }
  52
  53 void *calloc(size_t nmemb, size_t size) {
  54   GET_STACK_TRACE_HERE_FOR_MALLOC;
  55   return asan_calloc(nmemb, size, &stack);
  56 }
  57
  58 void* _calloc_dbg(size_t n, size_t size, int, const char*, int) {
  59   return calloc(n, size);
  60 }
  61
  62 void *_calloc_impl(size_t nmemb, size_t size, int *errno_tmp) {
  63   return calloc(nmemb, size);
  64 }
  65
  66 void *realloc(void *ptr, size_t size) {
  67   GET_STACK_TRACE_HERE_FOR_MALLOC;
  68   return asan_realloc(ptr, size, &stack);
  69 }
  70
  71 void *_realloc_dbg(void *ptr, size_t size, int) {
  72   CHECK(!"_realloc_dbg should not exist!");
  73   return 0;
  74 }
  75
  76 void* _recalloc(void* p, size_t n, size_t elem_size) {
  77   if (!p)
  78     return calloc(n, elem_size);
  79   const size_t size = n * elem_size;
  80   if (elem_size != 0 && size / elem_size != n)
  81     return 0;
  82   return realloc(p, size);
  83 }
  84
  85 size_t _msize(void *ptr) {
  86   GET_STACK_TRACE_HERE_FOR_MALLOC;
  87   return asan_malloc_usable_size(ptr, &stack);
  88 }
  89
  90 int _CrtDbgReport(int, const char*, int,
  91                   const char*, const char*, ...) {
  92   ShowStatsAndAbort();
  93 }
  94
  95 int _CrtDbgReportW(int reportType, const wchar_t*, int,
  96                    const wchar_t*, const wchar_t*, ...) {
  97   ShowStatsAndAbort();
  98 }
  99
 100 int _CrtSetReportMode(int, int) {
 101   return 0;
 102 }
 103 }  // extern "C"
 104
 105 using __interception::GetRealFunctionAddress;
 106
 107 // We don't want to include "windows.h" in this file to avoid extra attributes
 108 // set on malloc/free etc (e.g. dllimport), so declare a few things manually:
 109 extern "C" int __stdcall VirtualProtect(void* addr, size_t size,
 110                                         DWORD prot, DWORD *old_prot);
 111 const int PAGE_EXECUTE_READWRITE = 0x40;
 112
 113 namespace __asan {
 114 void ReplaceSystemMalloc() {
 115 #if defined(_DLL)
 116 # ifdef _WIN64
 117 #  error ReplaceSystemMalloc was not tested on x64
 118 # endif
 119   char *crt_malloc;
 120   if (GetRealFunctionAddress("malloc", (void**)&crt_malloc)) {
 121     // Replace malloc in the CRT dll with a jump to our malloc.
 122     DWORD old_prot, unused;
 123     CHECK(VirtualProtect(crt_malloc, 16, PAGE_EXECUTE_READWRITE, &old_prot));
 124     REAL(memset)(crt_malloc, 0xCC /* int 3 */, 16);  // just in case.
 125
 126     ptrdiff_t jmp_offset = (char*)malloc - (char*)crt_malloc - 5;
 127     crt_malloc[0] = 0xE9;  // jmp, should be followed by an offset.
 128     REAL(memcpy)(crt_malloc + 1, &jmp_offset, sizeof(jmp_offset));
 129
 130     CHECK(VirtualProtect(crt_malloc, 16, old_prot, &unused));
 131
 132     // FYI: FlushInstructionCache is needed on Itanium etc but not on x86/x64.
 133   }
 134
 135   // FIXME: investigate whether anything else is needed.
 136 #endif
 137 }
 138 }  // namespace __asan
 139
 140 #endif  // _WIN32