compiler-rt/lib/dfsan/dfsan_platform.h

   1 //===-- dfsan_platform.h ----------------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is a part of DataFlowSanitizer.
  10 //
  11 // Platform specific information for DFSan.
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef DFSAN_PLATFORM_H
  15 #define DFSAN_PLATFORM_H
  16
  17 #include "sanitizer_common/sanitizer_common.h"
  18 #include "sanitizer_common/sanitizer_platform.h"
  19
  20 namespace __dfsan {
  21
  22 using __sanitizer::uptr;
  23
  24 // TODO: The memory mapping code to setup a 1:1 shadow is based on msan.
  25 // Consider refactoring these into a shared implementation.
  26
  27 struct MappingDesc {
  28   uptr start;
  29   uptr end;
  30   enum Type { INVALID, APP, SHADOW, ORIGIN } type;
  31   const char *name;
  32 };
  33
  34 #if SANITIZER_LINUX && SANITIZER_WORDSIZE == 64
  35
  36 // All of the following configurations are supported.
  37 // ASLR disabled: main executable and DSOs at 0x555550000000
  38 // PIE and ASLR: main executable and DSOs at 0x7f0000000000
  39 // non-PIE: main executable below 0x100000000, DSOs at 0x7f0000000000
  40 // Heap at 0x700000000000.
  41 const MappingDesc kMemoryLayout[] = {
  42     {0x000000000000ULL, 0x010000000000ULL, MappingDesc::APP, "app-1"},
  43     {0x010000000000ULL, 0x100000000000ULL, MappingDesc::SHADOW, "shadow-2"},
  44     {0x100000000000ULL, 0x110000000000ULL, MappingDesc::INVALID, "invalid"},
  45     {0x110000000000ULL, 0x200000000000ULL, MappingDesc::ORIGIN, "origin-2"},
  46     {0x200000000000ULL, 0x300000000000ULL, MappingDesc::SHADOW, "shadow-3"},
  47     {0x300000000000ULL, 0x400000000000ULL, MappingDesc::ORIGIN, "origin-3"},
  48     {0x400000000000ULL, 0x500000000000ULL, MappingDesc::INVALID, "invalid"},
  49     {0x500000000000ULL, 0x510000000000ULL, MappingDesc::SHADOW, "shadow-1"},
  50     {0x510000000000ULL, 0x600000000000ULL, MappingDesc::APP, "app-2"},
  51     {0x600000000000ULL, 0x610000000000ULL, MappingDesc::ORIGIN, "origin-1"},
  52     {0x610000000000ULL, 0x700000000000ULL, MappingDesc::INVALID, "invalid"},
  53     {0x700000000000ULL, 0x800000000000ULL, MappingDesc::APP, "app-3"}};
  54 #  define MEM_TO_SHADOW(mem) (((uptr)(mem)) ^ 0x500000000000ULL)
  55 #  define SHADOW_TO_ORIGIN(mem) (((uptr)(mem)) + 0x100000000000ULL)
  56
  57 #else
  58 #  error "Unsupported platform"
  59 #endif
  60
  61 const uptr kMemoryLayoutSize = sizeof(kMemoryLayout) / sizeof(kMemoryLayout[0]);
  62
  63 #define MEM_TO_ORIGIN(mem) (SHADOW_TO_ORIGIN(MEM_TO_SHADOW((mem))))
  64
  65 #ifndef __clang__
  66 __attribute__((optimize("unroll-loops")))
  67 #endif
  68 inline bool
  69 addr_is_type(uptr addr, MappingDesc::Type mapping_type) {
  70 // It is critical for performance that this loop is unrolled (because then it is
  71 // simplified into just a few constant comparisons).
  72 #ifdef __clang__
  73 #  pragma unroll
  74 #endif
  75   for (unsigned i = 0; i < kMemoryLayoutSize; ++i)
  76     if (kMemoryLayout[i].type == mapping_type &&
  77         addr >= kMemoryLayout[i].start && addr < kMemoryLayout[i].end)
  78       return true;
  79   return false;
  80 }
  81
  82 #define MEM_IS_APP(mem) addr_is_type((uptr)(mem), MappingDesc::APP)
  83 #define MEM_IS_SHADOW(mem) addr_is_type((uptr)(mem), MappingDesc::SHADOW)
  84 #define MEM_IS_ORIGIN(mem) addr_is_type((uptr)(mem), MappingDesc::ORIGIN)
  85
  86 }  // namespace __dfsan
  87
  88 #endif