compiler-rt/lib/hwasan/hwasan_globals.h

   1 //===-- hwasan_globals.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 HWAddressSanitizer.
  10 //
  11 // Private Hwasan header.
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef HWASAN_GLOBALS_H
  15 #define HWASAN_GLOBALS_H
  16
  17 #include <link.h>
  18
  19 #include "sanitizer_common/sanitizer_array_ref.h"
  20 #include "sanitizer_common/sanitizer_common.h"
  21 #include "sanitizer_common/sanitizer_internal_defs.h"
  22
  23 namespace __hwasan {
  24 // This object should only ever be casted over the global (i.e. not constructed)
  25 // in the ELF PT_NOTE in order for `addr()` to work correctly.
  26 struct hwasan_global {
  27   // The size of this global variable. Note that the size in the descriptor is
  28   // max 1 << 24. Larger globals have multiple descriptors.
  29   uptr size() const { return info & 0xffffff; }
  30   // The fully-relocated address of this global.
  31   uptr addr() const { return reinterpret_cast<uintptr_t>(this) + gv_relptr; }
  32   // The static tag of this global.
  33   u8 tag() const { return info >> 24; };
  34
  35   // The relative address between the start of the descriptor for the HWASan
  36   // global (in the PT_NOTE), and the fully relocated address of the global.
  37   s32 gv_relptr;
  38   u32 info;
  39 };
  40
  41 // Walk through the specific DSO (as specified by the base, phdr, and phnum),
  42 // and return the range of the [beginning, end) of the HWASan globals descriptor
  43 // array.
  44 ArrayRef<const hwasan_global> HwasanGlobalsFor(ElfW(Addr) base,
  45                                                const ElfW(Phdr) * phdr,
  46                                                ElfW(Half) phnum);
  47
  48 }  // namespace __hwasan
  49
  50 #endif  // HWASAN_GLOBALS_H