asan_malloc_win.cc revision 24e13723f8477d8c42ab8b2a7f4f69fc089842f1 
1//===-- asan_malloc_win.cc ------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file is a part of AddressSanitizer, an address sanity checker.
11//
12// Windows-specific malloc interception.
13//===----------------------------------------------------------------------===//
14
15#include "sanitizer_common/sanitizer_platform.h"
16#ifdef _WIN32
17
18#include "asan_allocator.h"
19#include "asan_interceptors.h"
20#include "asan_internal.h"
21#include "asan_stack.h"
22#include "interception/interception.h"
23
24#include <stddef.h>
25
26// ---------------------- Replacement functions ---------------- {{{1
27using namespace __asan;  // NOLINT
28
29// FIXME: Simply defining functions with the same signature in *.obj
30// files overrides the standard functions in *.lib
31// This works well for simple helloworld-like tests but might need to be
32// revisited in the future.
33
34extern "C" {
35void free(void *ptr) {
36  GET_STACK_TRACE_FREE;
37  return asan_free(ptr, &stack, FROM_MALLOC);
38}
39
40void _free_dbg(void* ptr, int) {
41  free(ptr);
42}
43
44void cfree(void *ptr) {
45  CHECK(!"cfree() should not be used on Windows?");
46}
47
48void *malloc(size_t size) {
49  GET_STACK_TRACE_MALLOC;
50  return asan_malloc(size, &stack);
51}
52
53void* _malloc_dbg(size_t size, int , const char*, int) {
54  return malloc(size);
55}
56
57void *calloc(size_t nmemb, size_t size) {
58  GET_STACK_TRACE_MALLOC;
59  return asan_calloc(nmemb, size, &stack);
60}
61
62void* _calloc_dbg(size_t n, size_t size, int, const char*, int) {
63  return calloc(n, size);
64}
65
66void *_calloc_impl(size_t nmemb, size_t size, int *errno_tmp) {
67  return calloc(nmemb, size);
68}
69
70void *realloc(void *ptr, size_t size) {
71  GET_STACK_TRACE_MALLOC;
72  return asan_realloc(ptr, size, &stack);
73}
74
75void *_realloc_dbg(void *ptr, size_t size, int) {
76  CHECK(!"_realloc_dbg should not exist!");
77  return 0;
78}
79
80void* _recalloc(void* p, size_t n, size_t elem_size) {
81  if (!p)
82    return calloc(n, elem_size);
83  const size_t size = n * elem_size;
84  if (elem_size != 0 && size / elem_size != n)
85    return 0;
86  return realloc(p, size);
87}
88
89size_t _msize(void *ptr) {
90  GET_STACK_TRACE_MALLOC;
91  return asan_malloc_usable_size(ptr, &stack);
92}
93
94int _CrtDbgReport(int, const char*, int,
95                  const char*, const char*, ...) {
96  ShowStatsAndAbort();
97}
98
99int _CrtDbgReportW(int reportType, const wchar_t*, int,
100                   const wchar_t*, const wchar_t*, ...) {
101  ShowStatsAndAbort();
102}
103
104int _CrtSetReportMode(int, int) {
105  return 0;
106}
107}  // extern "C"
108
109using __interception::GetRealFunctionAddress;
110
111// We don't want to include "windows.h" in this file to avoid extra attributes
112// set on malloc/free etc (e.g. dllimport), so declare a few things manually:
113extern "C" int __stdcall VirtualProtect(void* addr, size_t size,
114                                        DWORD prot, DWORD *old_prot);
115const int PAGE_EXECUTE_READWRITE = 0x40;
116
117namespace __asan {
118void ReplaceSystemMalloc() {
119#if defined(_DLL)
120# ifdef _WIN64
121#  error ReplaceSystemMalloc was not tested on x64
122# endif
123  char *crt_malloc;
124  if (GetRealFunctionAddress("malloc", (void**)&crt_malloc)) {
125    // Replace malloc in the CRT dll with a jump to our malloc.
126    DWORD old_prot, unused;
127    CHECK(VirtualProtect(crt_malloc, 16, PAGE_EXECUTE_READWRITE, &old_prot));
128    REAL(memset)(crt_malloc, 0xCC /* int 3 */, 16);  // just in case.
129
130    ptrdiff_t jmp_offset = (char*)malloc - (char*)crt_malloc - 5;
131    crt_malloc[0] = 0xE9;  // jmp, should be followed by an offset.
132    REAL(memcpy)(crt_malloc + 1, &jmp_offset, sizeof(jmp_offset));
133
134    CHECK(VirtualProtect(crt_malloc, 16, old_prot, &unused));
135
136    // FYI: FlushInstructionCache is needed on Itanium etc but not on x86/x64.
137  }
138
139  // FIXME: investigate whether anything else is needed.
140#endif
141}
142}  // namespace __asan
143
144#endif  // _WIN32
145