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      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 #if SANITIZER_WINDOWS
     17 // Intentionally not including windows.h here, to avoid the risk of
     18 // pulling in conflicting declarations of these functions. (With mingw-w64,
     19 // there's a risk of windows.h pulling in stdint.h.)
     20 typedef int BOOL;
     21 typedef void *HANDLE;
     22 typedef const void *LPCVOID;
     23 typedef void *LPVOID;
     24 
     25 #define HEAP_ZERO_MEMORY           0x00000008
     26 #define HEAP_REALLOC_IN_PLACE_ONLY 0x00000010
     27 
     28 
     29 #include "asan_allocator.h"
     30 #include "asan_interceptors.h"
     31 #include "asan_internal.h"
     32 #include "asan_stack.h"
     33 #include "interception/interception.h"
     34 
     35 #include <stddef.h>
     36 
     37 using namespace __asan;  // NOLINT
     38 
     39 // MT: Simply defining functions with the same signature in *.obj
     40 // files overrides the standard functions in the CRT.
     41 // MD: Memory allocation functions are defined in the CRT .dll,
     42 // so we have to intercept them before they are called for the first time.
     43 
     44 #if ASAN_DYNAMIC
     45 # define ALLOCATION_FUNCTION_ATTRIBUTE
     46 #else
     47 # define ALLOCATION_FUNCTION_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE
     48 #endif
     49 
     50 extern "C" {
     51 ALLOCATION_FUNCTION_ATTRIBUTE
     52 void free(void *ptr) {
     53   GET_STACK_TRACE_FREE;
     54   return asan_free(ptr, &stack, FROM_MALLOC);
     55 }
     56 
     57 ALLOCATION_FUNCTION_ATTRIBUTE
     58 void _free_dbg(void *ptr, int) {
     59   free(ptr);
     60 }
     61 
     62 ALLOCATION_FUNCTION_ATTRIBUTE
     63 void _free_base(void *ptr) {
     64   free(ptr);
     65 }
     66 
     67 ALLOCATION_FUNCTION_ATTRIBUTE
     68 void *malloc(size_t size) {
     69   GET_STACK_TRACE_MALLOC;
     70   return asan_malloc(size, &stack);
     71 }
     72 
     73 ALLOCATION_FUNCTION_ATTRIBUTE
     74 void *_malloc_base(size_t size) {
     75   return malloc(size);
     76 }
     77 
     78 ALLOCATION_FUNCTION_ATTRIBUTE
     79 void *_malloc_dbg(size_t size, int, const char *, int) {
     80   return malloc(size);
     81 }
     82 
     83 ALLOCATION_FUNCTION_ATTRIBUTE
     84 void *calloc(size_t nmemb, size_t size) {
     85   GET_STACK_TRACE_MALLOC;
     86   return asan_calloc(nmemb, size, &stack);
     87 }
     88 
     89 ALLOCATION_FUNCTION_ATTRIBUTE
     90 void *_calloc_base(size_t nmemb, size_t size) {
     91   return calloc(nmemb, size);
     92 }
     93 
     94 ALLOCATION_FUNCTION_ATTRIBUTE
     95 void *_calloc_dbg(size_t nmemb, size_t size, int, const char *, int) {
     96   return calloc(nmemb, size);
     97 }
     98 
     99 ALLOCATION_FUNCTION_ATTRIBUTE
    100 void *_calloc_impl(size_t nmemb, size_t size, int *errno_tmp) {
    101   return calloc(nmemb, size);
    102 }
    103 
    104 ALLOCATION_FUNCTION_ATTRIBUTE
    105 void *realloc(void *ptr, size_t size) {
    106   GET_STACK_TRACE_MALLOC;
    107   return asan_realloc(ptr, size, &stack);
    108 }
    109 
    110 ALLOCATION_FUNCTION_ATTRIBUTE
    111 void *_realloc_dbg(void *ptr, size_t size, int) {
    112   UNREACHABLE("_realloc_dbg should not exist!");
    113   return 0;
    114 }
    115 
    116 ALLOCATION_FUNCTION_ATTRIBUTE
    117 void *_realloc_base(void *ptr, size_t size) {
    118   return realloc(ptr, size);
    119 }
    120 
    121 ALLOCATION_FUNCTION_ATTRIBUTE
    122 void *_recalloc(void *p, size_t n, size_t elem_size) {
    123   if (!p)
    124     return calloc(n, elem_size);
    125   const size_t size = n * elem_size;
    126   if (elem_size != 0 && size / elem_size != n)
    127     return 0;
    128   return realloc(p, size);
    129 }
    130 
    131 ALLOCATION_FUNCTION_ATTRIBUTE
    132 void *_recalloc_base(void *p, size_t n, size_t elem_size) {
    133   return _recalloc(p, n, elem_size);
    134 }
    135 
    136 ALLOCATION_FUNCTION_ATTRIBUTE
    137 size_t _msize(void *ptr) {
    138   GET_CURRENT_PC_BP_SP;
    139   (void)sp;
    140   return asan_malloc_usable_size(ptr, pc, bp);
    141 }
    142 
    143 ALLOCATION_FUNCTION_ATTRIBUTE
    144 size_t _msize_base(void *ptr) {
    145   return _msize(ptr);
    146 }
    147 
    148 ALLOCATION_FUNCTION_ATTRIBUTE
    149 void *_expand(void *memblock, size_t size) {
    150   // _expand is used in realloc-like functions to resize the buffer if possible.
    151   // We don't want memory to stand still while resizing buffers, so return 0.
    152   return 0;
    153 }
    154 
    155 ALLOCATION_FUNCTION_ATTRIBUTE
    156 void *_expand_dbg(void *memblock, size_t size) {
    157   return _expand(memblock, size);
    158 }
    159 
    160 // TODO(timurrrr): Might want to add support for _aligned_* allocation
    161 // functions to detect a bit more bugs.  Those functions seem to wrap malloc().
    162 
    163 int _CrtDbgReport(int, const char*, int,
    164                   const char*, const char*, ...) {
    165   ShowStatsAndAbort();
    166 }
    167 
    168 int _CrtDbgReportW(int reportType, const wchar_t*, int,
    169                    const wchar_t*, const wchar_t*, ...) {
    170   ShowStatsAndAbort();
    171 }
    172 
    173 int _CrtSetReportMode(int, int) {
    174   return 0;
    175 }
    176 }  // extern "C"
    177 
    178 INTERCEPTOR_WINAPI(LPVOID, HeapAlloc, HANDLE hHeap, DWORD dwFlags,
    179                    SIZE_T dwBytes) {
    180   GET_STACK_TRACE_MALLOC;
    181   void *p = asan_malloc(dwBytes, &stack);
    182   // Reading MSDN suggests that the *entire* usable allocation is zeroed out.
    183   // Otherwise it is difficult to HeapReAlloc with HEAP_ZERO_MEMORY.
    184   // https://blogs.msdn.microsoft.com/oldnewthing/20120316-00/?p=8083
    185   if (dwFlags == HEAP_ZERO_MEMORY)
    186     internal_memset(p, 0, asan_mz_size(p));
    187   else
    188     CHECK(dwFlags == 0 && "unsupported heap flags");
    189   return p;
    190 }
    191 
    192 INTERCEPTOR_WINAPI(BOOL, HeapFree, HANDLE hHeap, DWORD dwFlags, LPVOID lpMem) {
    193   CHECK(dwFlags == 0 && "unsupported heap flags");
    194   GET_STACK_TRACE_FREE;
    195   asan_free(lpMem, &stack, FROM_MALLOC);
    196   return true;
    197 }
    198 
    199 INTERCEPTOR_WINAPI(LPVOID, HeapReAlloc, HANDLE hHeap, DWORD dwFlags,
    200                    LPVOID lpMem, SIZE_T dwBytes) {
    201   GET_STACK_TRACE_MALLOC;
    202   // Realloc should never reallocate in place.
    203   if (dwFlags & HEAP_REALLOC_IN_PLACE_ONLY)
    204     return nullptr;
    205   CHECK(dwFlags == 0 && "unsupported heap flags");
    206   return asan_realloc(lpMem, dwBytes, &stack);
    207 }
    208 
    209 INTERCEPTOR_WINAPI(SIZE_T, HeapSize, HANDLE hHeap, DWORD dwFlags,
    210                    LPCVOID lpMem) {
    211   CHECK(dwFlags == 0 && "unsupported heap flags");
    212   GET_CURRENT_PC_BP_SP;
    213   (void)sp;
    214   return asan_malloc_usable_size(lpMem, pc, bp);
    215 }
    216 
    217 namespace __asan {
    218 
    219 static void TryToOverrideFunction(const char *fname, uptr new_func) {
    220   // Failure here is not fatal. The CRT may not be present, and different CRT
    221   // versions use different symbols.
    222   if (!__interception::OverrideFunction(fname, new_func))
    223     VPrintf(2, "Failed to override function %s\n", fname);
    224 }
    225 
    226 void ReplaceSystemMalloc() {
    227 #if defined(ASAN_DYNAMIC)
    228   TryToOverrideFunction("free", (uptr)free);
    229   TryToOverrideFunction("_free_base", (uptr)free);
    230   TryToOverrideFunction("malloc", (uptr)malloc);
    231   TryToOverrideFunction("_malloc_base", (uptr)malloc);
    232   TryToOverrideFunction("_malloc_crt", (uptr)malloc);
    233   TryToOverrideFunction("calloc", (uptr)calloc);
    234   TryToOverrideFunction("_calloc_base", (uptr)calloc);
    235   TryToOverrideFunction("_calloc_crt", (uptr)calloc);
    236   TryToOverrideFunction("realloc", (uptr)realloc);
    237   TryToOverrideFunction("_realloc_base", (uptr)realloc);
    238   TryToOverrideFunction("_realloc_crt", (uptr)realloc);
    239   TryToOverrideFunction("_recalloc", (uptr)_recalloc);
    240   TryToOverrideFunction("_recalloc_base", (uptr)_recalloc);
    241   TryToOverrideFunction("_recalloc_crt", (uptr)_recalloc);
    242   TryToOverrideFunction("_msize", (uptr)_msize);
    243   TryToOverrideFunction("_msize_base", (uptr)_msize);
    244   TryToOverrideFunction("_expand", (uptr)_expand);
    245   TryToOverrideFunction("_expand_base", (uptr)_expand);
    246 
    247   // Recent versions of ucrtbase.dll appear to be built with PGO and LTCG, which
    248   // enable cross-module inlining. This means our _malloc_base hook won't catch
    249   // all CRT allocations. This code here patches the import table of
    250   // ucrtbase.dll so that all attempts to use the lower-level win32 heap
    251   // allocation API will be directed to ASan's heap. We don't currently
    252   // intercept all calls to HeapAlloc. If we did, we would have to check on
    253   // HeapFree whether the pointer came from ASan of from the system.
    254 #define INTERCEPT_UCRT_FUNCTION(func)                                         \
    255   if (!INTERCEPT_FUNCTION_DLLIMPORT("ucrtbase.dll",                           \
    256                                     "api-ms-win-core-heap-l1-1-0.dll", func)) \
    257     VPrintf(2, "Failed to intercept ucrtbase.dll import %s\n", #func);
    258   INTERCEPT_UCRT_FUNCTION(HeapAlloc);
    259   INTERCEPT_UCRT_FUNCTION(HeapFree);
    260   INTERCEPT_UCRT_FUNCTION(HeapReAlloc);
    261   INTERCEPT_UCRT_FUNCTION(HeapSize);
    262 #undef INTERCEPT_UCRT_FUNCTION
    263 #endif
    264 }
    265 }  // namespace __asan
    266 
    267 #endif  // _WIN32
    268