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 #  include "mozilla/Attributes.h"
  38 #  include "mozilla/Types.h"
  39
  40 #  ifdef _MSC_VER
  41 // In clang-cl based ASAN, we link against the memory poisoning functions
  42 // statically.
  43 #    define MOZ_ASAN_VISIBILITY
  44 #  else
  45 #    define MOZ_ASAN_VISIBILITY MOZ_EXPORT
  46 #  endif
  47
  48 extern "C" {
  49 /* These definitions are usually provided through the
  50  * sanitizer/asan_interface.h header installed by ASan.
  51  */
  52 void MOZ_ASAN_VISIBILITY __asan_poison_memory_region(void const volatile* addr,
  53                                                      size_t size);
  54 void MOZ_ASAN_VISIBILITY
  55 __asan_unpoison_memory_region(void const volatile* addr, size_t size);
  56
  57 #  define MOZ_MAKE_MEM_NOACCESS(addr, size) \
  58     __asan_poison_memory_region((addr), (size))
  59
  60 #  define MOZ_MAKE_MEM_UNDEFINED(addr, size) \
  61     __asan_unpoison_memory_region((addr), (size))
  62
  63 #  define MOZ_MAKE_MEM_DEFINED(addr, size) \
  64     __asan_unpoison_memory_region((addr), (size))
  65
  66 /*
  67  * These definitions are usually provided through the
  68  * sanitizer/lsan_interface.h header installed by LSan.
  69  */
  70 void MOZ_EXPORT __lsan_ignore_object(const void* p);
  71 }
  72 #elif defined(MOZ_MSAN)
  73 #  include <stddef.h>
  74
  75 #  include "mozilla/Types.h"
  76
  77 extern "C" {
  78 /* These definitions are usually provided through the
  79  * sanitizer/msan_interface.h header installed by MSan.
  80  */
  81 void MOZ_EXPORT __msan_poison(void const volatile* addr, size_t size);
  82 void MOZ_EXPORT __msan_unpoison(void const volatile* addr, size_t size);
  83
  84 #  define MOZ_MAKE_MEM_NOACCESS(addr, size) __msan_poison((addr), (size))
  85
  86 #  define MOZ_MAKE_MEM_UNDEFINED(addr, size) __msan_poison((addr), (size))
  87
  88 #  define MOZ_MAKE_MEM_DEFINED(addr, size) __msan_unpoison((addr), (size))
  89 }
  90 #elif defined(MOZ_VALGRIND)
  91 #  define MOZ_MAKE_MEM_NOACCESS(addr, size) \
  92     VALGRIND_MAKE_MEM_NOACCESS((addr), (size))
  93
  94 #  define MOZ_MAKE_MEM_UNDEFINED(addr, size) \
  95     VALGRIND_MAKE_MEM_UNDEFINED((addr), (size))
  96
  97 #  define MOZ_MAKE_MEM_DEFINED(addr, size) \
  98     VALGRIND_MAKE_MEM_DEFINED((addr), (size))
  99 #else
 100
 101 #  define MOZ_MAKE_MEM_NOACCESS(addr, size) \
 102     do {                                    \
 103     } while (0)
 104 #  define MOZ_MAKE_MEM_UNDEFINED(addr, size) \
 105     do {                                     \
 106     } while (0)
 107 #  define MOZ_MAKE_MEM_DEFINED(addr, size) \
 108     do {                                   \
 109     } while (0)
 110
 111 #endif
 112
 113 /*
 114  * MOZ_LSAN_INTENTIONAL_LEAK(X) is a macro to tell LeakSanitizer that X
 115  * points to a value that will intentionally never be deallocated during
 116  * the execution of the process.
 117  *
 118  * Additional uses of this macro should be reviewed by people
 119  * conversant in leak-checking and/or MFBT peers.
 120  */
 121 #if defined(MOZ_ASAN)
 122 #  define MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(X) __lsan_ignore_object(X)
 123 #else
 124 #  define MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(X) /* nothing */
 125 #endif                                          // defined(MOZ_ASAN)
 126
 127 #endif /* mozilla_MemoryChecking_h */