llvm/compiler-rt/lib/dfsan/dfsan_platform.h

//===-- dfsan_platform.h ----------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of DataFlowSanitizer.
//
// Platform specific information for DFSan.
//===----------------------------------------------------------------------===//

#ifndef DFSAN_PLATFORM_H
#define DFSAN_PLATFORM_H

#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_platform.h"

namespace __dfsan {

uptr;

// TODO: The memory mapping code to setup a 1:1 shadow is based on msan.
// Consider refactoring these into a shared implementation.

struct MappingDesc { … };

// Note: MappingDesc::ALLOCATOR entries are only used to check for memory
// layout compatibility. The actual allocation settings are in
// dfsan_allocator.cpp, which need to be kept in sync.
#if SANITIZER_LINUX && SANITIZER_WORDSIZE == 64

#  if defined(__aarch64__)
// The mapping assumes 48-bit VMA. AArch64 maps:
// - 0x0000000000000-0x0100000000000: 39/42/48-bits program own segments
// - 0x0a00000000000-0x0b00000000000: 48-bits PIE program segments
//   Ideally, this would extend to 0x0c00000000000 (2^45 bytes - the
//   maximum ASLR region for 48-bit VMA) but it is too hard to fit in
//   the larger app/shadow/origin regions.
// - 0x0e00000000000-0x1000000000000: 48-bits libraries segments
const MappingDesc kMemoryLayout[] = {
    {0X0000000000000, 0X0100000000000, MappingDesc::APP, "app-10-13"},
    {0X0100000000000, 0X0200000000000, MappingDesc::SHADOW, "shadow-14"},
    {0X0200000000000, 0X0300000000000, MappingDesc::INVALID, "invalid"},
    {0X0300000000000, 0X0400000000000, MappingDesc::ORIGIN, "origin-14"},
    {0X0400000000000, 0X0600000000000, MappingDesc::SHADOW, "shadow-15"},
    {0X0600000000000, 0X0800000000000, MappingDesc::ORIGIN, "origin-15"},
    {0X0800000000000, 0X0A00000000000, MappingDesc::INVALID, "invalid"},
    {0X0A00000000000, 0X0B00000000000, MappingDesc::APP, "app-14"},
    {0X0B00000000000, 0X0C00000000000, MappingDesc::SHADOW, "shadow-10-13"},
    {0X0C00000000000, 0X0D00000000000, MappingDesc::INVALID, "invalid"},
    {0X0D00000000000, 0X0E00000000000, MappingDesc::ORIGIN, "origin-10-13"},
    {0X0E00000000000, 0X0E40000000000, MappingDesc::ALLOCATOR, "allocator"},
    {0X0E40000000000, 0X1000000000000, MappingDesc::APP, "app-15"},
};
#define MEM_TO_SHADOW …
#define SHADOW_TO_ORIGIN …

#  else
// All of the following configurations are supported.
// ASLR disabled: main executable and DSOs at 0x555550000000
// PIE and ASLR: main executable and DSOs at 0x7f0000000000
// non-PIE: main executable below 0x100000000, DSOs at 0x7f0000000000
// Heap at 0x700000000000.
const MappingDesc kMemoryLayout[] = …;
#define MEM_TO_SHADOW(mem) …
#define SHADOW_TO_ORIGIN(mem) …
#  endif

#else
#  error "Unsupported platform"
#endif

const uptr kMemoryLayoutSize = …;

#define MEM_TO_ORIGIN(mem) …

#ifndef __clang__
__attribute__((optimize("unroll-loops")))
#endif
inline bool
addr_is_type(uptr addr, int mapping_types) { … }

#define MEM_IS_APP(mem) …
#define MEM_IS_SHADOW(mem) …
#define MEM_IS_ORIGIN(mem) …

}  // namespace __dfsan

#endif