mfbt/MemoryChecking.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /*
   8  * Provides a common interface to the ASan (AddressSanitizer) and Valgrind
   9  * functions used to mark memory in certain ways. In detail, the following
  10  * three macros are provided:
  11  *
  12  *   MOZ_MAKE_MEM_NOACCESS  - Mark memory as unsafe to access (e.g. freed)
  13  *   MOZ_MAKE_MEM_UNDEFINED - Mark memory as accessible, with content undefined
  14  *   MOZ_MAKE_MEM_DEFINED - Mark memory as accessible, with content defined
  15  *
  16  * With Valgrind in use, these directly map to the three respective Valgrind
  17  * macros. With ASan in use, the NOACCESS macro maps to poisoning the memory,
  18  * while the UNDEFINED/DEFINED macros unpoison memory.
  19  *
  20  * With no memory checker available, all macros expand to the empty statement.
  21  */
  22
  23 #ifndef mozilla_MemoryChecking_h
  24 #define mozilla_MemoryChecking_h
  25
  26 #if defined(MOZ_VALGRIND)
  27 #include "valgrind/memcheck.h"
  28 #endif
  29
  30 #if defined(MOZ_ASAN) || defined(MOZ_VALGRIND)
  31 #define MOZ_HAVE_MEM_CHECKS 1
  32 #endif
  33
  34 #if defined(MOZ_ASAN)
  35 #include <stddef.h>
  36
  37 extern "C" {
  38   /* These definitions are usually provided through the
  39    * sanitizer/asan_interface.h header installed by ASan.
  40    */
  41   void __asan_poison_memory_region(void const volatile *addr, size_t size)
  42     __attribute__((visibility("default")));
  43   void __asan_unpoison_memory_region(void const volatile *addr, size_t size)
  44     __attribute__((visibility("default")));
  45
  46 #define MOZ_MAKE_MEM_NOACCESS(addr, size) \
  47   __asan_poison_memory_region((addr), (size))
  48
  49 #define MOZ_MAKE_MEM_UNDEFINED(addr, size) \
  50   __asan_unpoison_memory_region((addr), (size))
  51
  52 #define MOZ_MAKE_MEM_DEFINED(addr, size) \
  53   __asan_unpoison_memory_region((addr), (size))
  54 }
  55 #elif defined(MOZ_VALGRIND)
  56 #define MOZ_MAKE_MEM_NOACCESS(addr, size) \
  57   VALGRIND_MAKE_MEM_NOACCESS((addr), (size))
  58
  59 #define MOZ_MAKE_MEM_UNDEFINED(addr, size) \
  60   VALGRIND_MAKE_MEM_UNDEFINED((addr), (size))
  61
  62 #define MOZ_MAKE_MEM_DEFINED(addr, size) \
  63   VALGRIND_MAKE_MEM_DEFINED((addr), (size))
  64 #else
  65
  66 #define MOZ_MAKE_MEM_NOACCESS(addr, size) do {} while(0)
  67 #define MOZ_MAKE_MEM_UNDEFINED(addr, size) do {} while(0)
  68 #define MOZ_MAKE_MEM_DEFINED(addr, size) do {} while(0)
  69
  70 #endif
  71
  72 #endif /* mozilla_MemoryChecking_h */