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