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
  53 __asan_poison_memory_region(void const volatile *addr, 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
  71 __lsan_ignore_object(const void *p);
  72
  73 }
  74 #elif defined(MOZ_MSAN)
  75 #include <stddef.h>
  76
  77 #include "mozilla/Types.h"
  78
  79 extern "C" {
  80 /* These definitions are usually provided through the
  81  * sanitizer/msan_interface.h header installed by MSan.
  82  */
  83 void MOZ_EXPORT
  84 __msan_poison(void const volatile *addr, size_t size);
  85 void MOZ_EXPORT
  86 __msan_unpoison(void const volatile *addr, size_t size);
  87
  88 #define MOZ_MAKE_MEM_NOACCESS(addr, size) \
  89   __msan_poison((addr), (size))
  90
  91 #define MOZ_MAKE_MEM_UNDEFINED(addr, size) \
  92   __msan_poison((addr), (size))
  93
  94 #define MOZ_MAKE_MEM_DEFINED(addr, size) \
  95   __msan_unpoison((addr), (size))
  96 }
  97 #elif defined(MOZ_VALGRIND)
  98 #define MOZ_MAKE_MEM_NOACCESS(addr, size) \
  99   VALGRIND_MAKE_MEM_NOACCESS((addr), (size))
 100
 101 #define MOZ_MAKE_MEM_UNDEFINED(addr, size) \
 102   VALGRIND_MAKE_MEM_UNDEFINED((addr), (size))
 103
 104 #define MOZ_MAKE_MEM_DEFINED(addr, size) \
 105   VALGRIND_MAKE_MEM_DEFINED((addr), (size))
 106 #else
 107
 108 #define MOZ_MAKE_MEM_NOACCESS(addr, size) do {} while (0)
 109 #define MOZ_MAKE_MEM_UNDEFINED(addr, size) do {} while (0)
 110 #define MOZ_MAKE_MEM_DEFINED(addr, size) do {} while (0)
 111
 112 #endif
 113
 114 /*
 115  * MOZ_LSAN_INTENTIONAL_LEAK(X) is a macro to tell LeakSanitizer that X
 116  * points to a value that will intentionally never be deallocated during
 117  * the execution of the process.
 118  *
 119  * Additional uses of this macro should be reviewed by people
 120  * conversant in leak-checking and/or MFBT peers.
 121  */
 122 #if defined(MOZ_ASAN)
 123 #  define MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(X) __lsan_ignore_object(X)
 124 #else
 125 #  define MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(X) /* nothing */
 126 #endif // defined(MOZ_ASAN)
 127
 128
 129 #endif /* mozilla_MemoryChecking_h */