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 {
  31     INVALID = 1,
  32     ALLOCATOR = 2,
  33     APP = 4,
  34     SHADOW = 8,
  35     ORIGIN = 16,
  36   } type;
  37   const char *name;
  38 };
  39
  40 // Note: MappingDesc::ALLOCATOR entries are only used to check for memory
  41 // layout compatibility. The actual allocation settings are in
  42 // dfsan_allocator.cpp, which need to be kept in sync.
  43 #if SANITIZER_LINUX && SANITIZER_WORDSIZE == 64
  44
  45 #  if defined(__aarch64__)
  46 // The mapping assumes 48-bit VMA. AArch64 maps:
  47 // - 0x0000000000000-0x0100000000000: 39/42/48-bits program own segments
  48 // - 0x0a00000000000-0x0b00000000000: 48-bits PIE program segments
  49 //   Ideally, this would extend to 0x0c00000000000 (2^45 bytes - the
  50 //   maximum ASLR region for 48-bit VMA) but it is too hard to fit in
  51 //   the larger app/shadow/origin regions.
  52 // - 0x0e00000000000-0x1000000000000: 48-bits libraries segments
  53 const MappingDesc kMemoryLayout[] = {
  54     {0X0000000000000, 0X0100000000000, MappingDesc::APP, "app-10-13"},
  55     {0X0100000000000, 0X0200000000000, MappingDesc::SHADOW, "shadow-14"},
  56     {0X0200000000000, 0X0300000000000, MappingDesc::INVALID, "invalid"},
  57     {0X0300000000000, 0X0400000000000, MappingDesc::ORIGIN, "origin-14"},
  58     {0X0400000000000, 0X0600000000000, MappingDesc::SHADOW, "shadow-15"},
  59     {0X0600000000000, 0X0800000000000, MappingDesc::ORIGIN, "origin-15"},
  60     {0X0800000000000, 0X0A00000000000, MappingDesc::INVALID, "invalid"},
  61     {0X0A00000000000, 0X0B00000000000, MappingDesc::APP, "app-14"},
  62     {0X0B00000000000, 0X0C00000000000, MappingDesc::SHADOW, "shadow-10-13"},
  63     {0X0C00000000000, 0X0D00000000000, MappingDesc::INVALID, "invalid"},
  64     {0X0D00000000000, 0X0E00000000000, MappingDesc::ORIGIN, "origin-10-13"},
  65     {0X0E00000000000, 0X0E40000000000, MappingDesc::ALLOCATOR, "allocator"},
  66     {0X0E40000000000, 0X1000000000000, MappingDesc::APP, "app-15"},
  67 };
  68 #    define MEM_TO_SHADOW(mem) ((uptr)mem ^ 0xB00000000000ULL)
  69 #    define SHADOW_TO_ORIGIN(shadow) (((uptr)(shadow)) + 0x200000000000ULL)
  70
  71 #  else
  72 // All of the following configurations are supported.
  73 // ASLR disabled: main executable and DSOs at 0x555550000000
  74 // PIE and ASLR: main executable and DSOs at 0x7f0000000000
  75 // non-PIE: main executable below 0x100000000, DSOs at 0x7f0000000000
  76 // Heap at 0x700000000000.
  77 const MappingDesc kMemoryLayout[] = {
  78     {0x000000000000ULL, 0x010000000000ULL, MappingDesc::APP, "app-1"},
  79     {0x010000000000ULL, 0x100000000000ULL, MappingDesc::SHADOW, "shadow-2"},
  80     {0x100000000000ULL, 0x110000000000ULL, MappingDesc::INVALID, "invalid"},
  81     {0x110000000000ULL, 0x200000000000ULL, MappingDesc::ORIGIN, "origin-2"},
  82     {0x200000000000ULL, 0x300000000000ULL, MappingDesc::SHADOW, "shadow-3"},
  83     {0x300000000000ULL, 0x400000000000ULL, MappingDesc::ORIGIN, "origin-3"},
  84     {0x400000000000ULL, 0x500000000000ULL, MappingDesc::INVALID, "invalid"},
  85     {0x500000000000ULL, 0x510000000000ULL, MappingDesc::SHADOW, "shadow-1"},
  86     {0x510000000000ULL, 0x600000000000ULL, MappingDesc::APP, "app-2"},
  87     {0x600000000000ULL, 0x610000000000ULL, MappingDesc::ORIGIN, "origin-1"},
  88     {0x610000000000ULL, 0x700000000000ULL, MappingDesc::INVALID, "invalid"},
  89     {0x700000000000ULL, 0x740000000000ULL, MappingDesc::ALLOCATOR, "allocator"},
  90     {0x740000000000ULL, 0x800000000000ULL, MappingDesc::APP, "app-3"}};
  91 #    define MEM_TO_SHADOW(mem) (((uptr)(mem)) ^ 0x500000000000ULL)
  92 #    define SHADOW_TO_ORIGIN(mem) (((uptr)(mem)) + 0x100000000000ULL)
  93 #  endif
  94
  95 #else
  96 #  error "Unsupported platform"
  97 #endif
  98
  99 const uptr kMemoryLayoutSize = sizeof(kMemoryLayout) / sizeof(kMemoryLayout[0]);
 100
 101 #define MEM_TO_ORIGIN(mem) (SHADOW_TO_ORIGIN(MEM_TO_SHADOW((mem))))
 102
 103 #ifndef __clang__
 104 __attribute__((optimize("unroll-loops")))
 105 #endif
 106 inline bool
 107 addr_is_type(uptr addr, int mapping_types) {
 108 // It is critical for performance that this loop is unrolled (because then it is
 109 // simplified into just a few constant comparisons).
 110 #ifdef __clang__
 111 #  pragma unroll
 112 #endif
 113   for (unsigned i = 0; i < kMemoryLayoutSize; ++i)
 114     if ((kMemoryLayout[i].type & mapping_types) &&
 115         addr >= kMemoryLayout[i].start && addr < kMemoryLayout[i].end)
 116       return true;
 117   return false;
 118 }
 119
 120 #define MEM_IS_APP(mem) \
 121   (addr_is_type((uptr)(mem), MappingDesc::APP | MappingDesc::ALLOCATOR))
 122 #define MEM_IS_SHADOW(mem) addr_is_type((uptr)(mem), MappingDesc::SHADOW)
 123 #define MEM_IS_ORIGIN(mem) addr_is_type((uptr)(mem), MappingDesc::ORIGIN)
 124
 125 }  // namespace __dfsan
 126
 127 #endif