libsanitizer/asan/asan_interceptors_memintrinsics.h

   1 //===-- asan_interceptors_memintrinsics.h -----------------------*- C++ -*-===//
   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 // ASan-private header for asan_memintrin.cc
  11 //===---------------------------------------------------------------------===//
  12 #ifndef ASAN_MEMINTRIN_H
  13 #define ASAN_MEMINTRIN_H
  14
  15 #include "asan_interface_internal.h"
  16 #include "asan_internal.h"
  17 #include "asan_mapping.h"
  18 #include "interception/interception.h"
  19
  20 DECLARE_REAL(void*, memcpy, void *to, const void *from, uptr size)
  21 DECLARE_REAL(void*, memset, void *block, int c, uptr size)
  22
  23 namespace __asan {
  24
  25 // Return true if we can quickly decide that the region is unpoisoned.
  26 // We assume that a redzone is at least 16 bytes.
  27 static inline bool QuickCheckForUnpoisonedRegion(uptr beg, uptr size) {
  28   if (size == 0) return true;
  29   if (size <= 32)
  30     return !AddressIsPoisoned(beg) &&
  31            !AddressIsPoisoned(beg + size - 1) &&
  32            !AddressIsPoisoned(beg + size / 2);
  33   if (size <= 64)
  34     return !AddressIsPoisoned(beg) &&
  35            !AddressIsPoisoned(beg + size / 4) &&
  36            !AddressIsPoisoned(beg + size - 1) &&
  37            !AddressIsPoisoned(beg + 3 * size / 4) &&
  38            !AddressIsPoisoned(beg + size / 2);
  39   return false;
  40 }
  41
  42 struct AsanInterceptorContext {
  43   const char *interceptor_name;
  44 };
  45
  46 // We implement ACCESS_MEMORY_RANGE, ASAN_READ_RANGE,
  47 // and ASAN_WRITE_RANGE as macro instead of function so
  48 // that no extra frames are created, and stack trace contains
  49 // relevant information only.
  50 // We check all shadow bytes.
  51 #define ACCESS_MEMORY_RANGE(ctx, offset, size, isWrite) do {            \
  52     uptr __offset = (uptr)(offset);                                     \
  53     uptr __size = (uptr)(size);                                         \
  54     uptr __bad = 0;                                                     \
  55     if (__offset > __offset + __size) {                                 \
  56       GET_STACK_TRACE_FATAL_HERE;                                       \
  57       ReportStringFunctionSizeOverflow(__offset, __size, &stack);       \
  58     }                                                                   \
  59     if (!QuickCheckForUnpoisonedRegion(__offset, __size) &&             \
  60         (__bad = __asan_region_is_poisoned(__offset, __size))) {        \
  61       AsanInterceptorContext *_ctx = (AsanInterceptorContext *)ctx;     \
  62       bool suppressed = false;                                          \
  63       if (_ctx) {                                                       \
  64         suppressed = IsInterceptorSuppressed(_ctx->interceptor_name);   \
  65         if (!suppressed && HaveStackTraceBasedSuppressions()) {         \
  66           GET_STACK_TRACE_FATAL_HERE;                                   \
  67           suppressed = IsStackTraceSuppressed(&stack);                  \
  68         }                                                               \
  69       }                                                                 \
  70       if (!suppressed) {                                                \
  71         GET_CURRENT_PC_BP_SP;                                           \
  72         ReportGenericError(pc, bp, sp, __bad, isWrite, __size, 0, false);\
  73       }                                                                 \
  74     }                                                                   \
  75   } while (0)
  76
  77 // memcpy is called during __asan_init() from the internals of printf(...).
  78 // We do not treat memcpy with to==from as a bug.
  79 // See http://llvm.org/bugs/show_bug.cgi?id=11763.
  80 #define ASAN_MEMCPY_IMPL(ctx, to, from, size)                           \
  81   do {                                                                  \
  82     if (UNLIKELY(!asan_inited)) return internal_memcpy(to, from, size); \
  83     if (asan_init_is_running) {                                         \
  84       return REAL(memcpy)(to, from, size);                              \
  85     }                                                                   \
  86     ENSURE_ASAN_INITED();                                               \
  87     if (flags()->replace_intrin) {                                      \
  88       if (to != from) {                                                 \
  89         CHECK_RANGES_OVERLAP("memcpy", to, size, from, size);           \
  90       }                                                                 \
  91       ASAN_READ_RANGE(ctx, from, size);                                 \
  92       ASAN_WRITE_RANGE(ctx, to, size);                                  \
  93     }                                                                   \
  94     return REAL(memcpy)(to, from, size);                                \
  95   } while (0)
  96
  97 // memset is called inside Printf.
  98 #define ASAN_MEMSET_IMPL(ctx, block, c, size)                           \
  99   do {                                                                  \
 100     if (UNLIKELY(!asan_inited)) return internal_memset(block, c, size); \
 101     if (asan_init_is_running) {                                         \
 102       return REAL(memset)(block, c, size);                              \
 103     }                                                                   \
 104     ENSURE_ASAN_INITED();                                               \
 105     if (flags()->replace_intrin) {                                      \
 106       ASAN_WRITE_RANGE(ctx, block, size);                               \
 107     }                                                                   \
 108     return REAL(memset)(block, c, size);                                \
 109   } while (0)
 110
 111 #define ASAN_MEMMOVE_IMPL(ctx, to, from, size)                           \
 112   do {                                                                   \
 113     if (UNLIKELY(!asan_inited)) return internal_memmove(to, from, size); \
 114     ENSURE_ASAN_INITED();                                                \
 115     if (flags()->replace_intrin) {                                       \
 116       ASAN_READ_RANGE(ctx, from, size);                                  \
 117       ASAN_WRITE_RANGE(ctx, to, size);                                   \
 118     }                                                                    \
 119     return internal_memmove(to, from, size);                             \
 120   } while (0)
 121
 122 #define ASAN_READ_RANGE(ctx, offset, size) \
 123   ACCESS_MEMORY_RANGE(ctx, offset, size, false)
 124 #define ASAN_WRITE_RANGE(ctx, offset, size) \
 125   ACCESS_MEMORY_RANGE(ctx, offset, size, true)
 126
 127 // Behavior of functions like "memcpy" or "strcpy" is undefined
 128 // if memory intervals overlap. We report error in this case.
 129 // Macro is used to avoid creation of new frames.
 130 static inline bool RangesOverlap(const char *offset1, uptr length1,
 131                                  const char *offset2, uptr length2) {
 132   return !((offset1 + length1 <= offset2) || (offset2 + length2 <= offset1));
 133 }
 134 #define CHECK_RANGES_OVERLAP(name, _offset1, length1, _offset2, length2) do { \
 135   const char *offset1 = (const char*)_offset1; \
 136   const char *offset2 = (const char*)_offset2; \
 137   if (RangesOverlap(offset1, length1, offset2, length2)) { \
 138     GET_STACK_TRACE_FATAL_HERE; \
 139     ReportStringFunctionMemoryRangesOverlap(name, offset1, length1, \
 140                                             offset2, length2, &stack); \
 141   } \
 142 } while (0)
 143
 144 }  // namespace __asan
 145
 146 #endif  // ASAN_MEMINTRIN_H