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  
      22  namespace __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.
      25  struct 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.
      43  ArrayRef<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