mfbt/MemoryChecking.h

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