contrib/compiler-rt/lib/asan/asan_interceptors_memintrinsics.h

   1 //===-- asan_interceptors_memintrinsics.h -----------------------*- C++ -*-===//
   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 // ASan-private header for asan_memintrin.cc
  13 //===---------------------------------------------------------------------===//
  14 #ifndef ASAN_MEMINTRIN_H
  15 #define ASAN_MEMINTRIN_H
  16
  17 #include "asan_interface_internal.h"
  18 #include "asan_internal.h"
  19 #include "asan_mapping.h"
  20 #include "interception/interception.h"
  21
  22 DECLARE_REAL(void*, memcpy, void *to, const void *from, uptr size)
  23 DECLARE_REAL(void*, memset, void *block, int c, uptr size)
  24
  25 namespace __asan {
  26
  27 // Return true if we can quickly decide that the region is unpoisoned.
  28 // We assume that a redzone is at least 16 bytes.
  29 static inline bool QuickCheckForUnpoisonedRegion(uptr beg, uptr size) {
  30   if (size == 0) return true;
  31   if (size <= 32)
  32     return !AddressIsPoisoned(beg) &&
  33            !AddressIsPoisoned(beg + size - 1) &&
  34            !AddressIsPoisoned(beg + size / 2);
  35   if (size <= 64)
  36     return !AddressIsPoisoned(beg) &&
  37            !AddressIsPoisoned(beg + size / 4) &&
  38            !AddressIsPoisoned(beg + size - 1) &&
  39            !AddressIsPoisoned(beg + 3 * size / 4) &&
  40            !AddressIsPoisoned(beg + size / 2);
  41   return false;
  42 }
  43
  44 struct AsanInterceptorContext {
  45   const char *interceptor_name;
  46 };
  47
  48 // We implement ACCESS_MEMORY_RANGE, ASAN_READ_RANGE,
  49 // and ASAN_WRITE_RANGE as macro instead of function so
  50 // that no extra frames are created, and stack trace contains
  51 // relevant information only.
  52 // We check all shadow bytes.
  53 #define ACCESS_MEMORY_RANGE(ctx, offset, size, isWrite) do {            \
  54     uptr __offset = (uptr)(offset);                                     \
  55     uptr __size = (uptr)(size);                                         \
  56     uptr __bad = 0;                                                     \
  57     if (__offset > __offset + __size) {                                 \
  58       GET_STACK_TRACE_FATAL_HERE;                                       \
  59       ReportStringFunctionSizeOverflow(__offset, __size, &stack);       \
  60     }                                                                   \
  61     if (!QuickCheckForUnpoisonedRegion(__offset, __size) &&             \
  62         (__bad = __asan_region_is_poisoned(__offset, __size))) {        \
  63       AsanInterceptorContext *_ctx = (AsanInterceptorContext *)ctx;     \
  64       bool suppressed = false;                                          \
  65       if (_ctx) {                                                       \
  66         suppressed = IsInterceptorSuppressed(_ctx->interceptor_name);   \
  67         if (!suppressed && HaveStackTraceBasedSuppressions()) {         \
  68           GET_STACK_TRACE_FATAL_HERE;                                   \
  69           suppressed = IsStackTraceSuppressed(&stack);                  \
  70         }                                                               \
  71       }                                                                 \
  72       if (!suppressed) {                                                \
  73         GET_CURRENT_PC_BP_SP;                                           \
  74         ReportGenericError(pc, bp, sp, __bad, isWrite, __size, 0, false);\
  75       }                                                                 \
  76     }                                                                   \
  77   } while (0)
  78
  79 // memcpy is called during __asan_init() from the internals of printf(...).
  80 // We do not treat memcpy with to==from as a bug.
  81 // See http://llvm.org/bugs/show_bug.cgi?id=11763.
  82 #define ASAN_MEMCPY_IMPL(ctx, to, from, size)                           \
  83   do {                                                                  \
  84     if (UNLIKELY(!asan_inited)) return internal_memcpy(to, from, size); \
  85     if (asan_init_is_running) {                                         \
  86       return REAL(memcpy)(to, from, size);                              \
  87     }                                                                   \
  88     ENSURE_ASAN_INITED();                                               \
  89     if (flags()->replace_intrin) {                                      \
  90       if (to != from) {                                                 \
  91         CHECK_RANGES_OVERLAP("memcpy", to, size, from, size);           \
  92       }                                                                 \
  93       ASAN_READ_RANGE(ctx, from, size);                                 \
  94       ASAN_WRITE_RANGE(ctx, to, size);                                  \
  95     }                                                                   \
  96     return REAL(memcpy)(to, from, size);                                \
  97   } while (0)
  98
  99 // memset is called inside Printf.
 100 #define ASAN_MEMSET_IMPL(ctx, block, c, size)                           \
 101   do {                                                                  \
 102     if (UNLIKELY(!asan_inited)) return internal_memset(block, c, size); \
 103     if (asan_init_is_running) {                                         \
 104       return REAL(memset)(block, c, size);                              \
 105     }                                                                   \
 106     ENSURE_ASAN_INITED();                                               \
 107     if (flags()->replace_intrin) {                                      \
 108       ASAN_WRITE_RANGE(ctx, block, size);                               \
 109     }                                                                   \
 110     return REAL(memset)(block, c, size);                                \
 111   } while (0)
 112
 113 #define ASAN_MEMMOVE_IMPL(ctx, to, from, size)                           \
 114   do {                                                                   \
 115     if (UNLIKELY(!asan_inited)) return internal_memmove(to, from, size); \
 116     ENSURE_ASAN_INITED();                                                \
 117     if (flags()->replace_intrin) {                                       \
 118       ASAN_READ_RANGE(ctx, from, size);                                  \
 119       ASAN_WRITE_RANGE(ctx, to, size);                                   \
 120     }                                                                    \
 121     return internal_memmove(to, from, size);                             \
 122   } while (0)
 123
 124 #define ASAN_READ_RANGE(ctx, offset, size) \
 125   ACCESS_MEMORY_RANGE(ctx, offset, size, false)
 126 #define ASAN_WRITE_RANGE(ctx, offset, size) \
 127   ACCESS_MEMORY_RANGE(ctx, offset, size, true)
 128
 129 // Behavior of functions like "memcpy" or "strcpy" is undefined
 130 // if memory intervals overlap. We report error in this case.
 131 // Macro is used to avoid creation of new frames.
 132 static inline bool RangesOverlap(const char *offset1, uptr length1,
 133                                  const char *offset2, uptr length2) {
 134   return !((offset1 + length1 <= offset2) || (offset2 + length2 <= offset1));
 135 }
 136 #define CHECK_RANGES_OVERLAP(name, _offset1, length1, _offset2, length2)   \
 137   do {                                                                     \
 138     const char *offset1 = (const char *)_offset1;                          \
 139     const char *offset2 = (const char *)_offset2;                          \
 140     if (RangesOverlap(offset1, length1, offset2, length2)) {               \
 141       GET_STACK_TRACE_FATAL_HERE;                                          \
 142       bool suppressed = IsInterceptorSuppressed(name);                     \
 143       if (!suppressed && HaveStackTraceBasedSuppressions()) {              \
 144         suppressed = IsStackTraceSuppressed(&stack);                       \
 145       }                                                                    \
 146       if (!suppressed) {                                                   \
 147         ReportStringFunctionMemoryRangesOverlap(name, offset1, length1,    \
 148                                                 offset2, length2, &stack); \
 149       }                                                                    \
 150     }                                                                      \
 151   } while (0)
 152
 153 }  // namespace __asan
 154
 155 #endif  // ASAN_MEMINTRIN_H