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