mfbt/MemoryChecking.h@97036ab72558
mfbt/MemoryChecking.h
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
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/. */
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 */
23 #ifndef mozilla_MemoryChecking_h
24 #define mozilla_MemoryChecking_h
26 #if defined(MOZ_VALGRIND)
27 #include "valgrind/memcheck.h"
28 #endif
30 #if defined(MOZ_ASAN) || defined(MOZ_VALGRIND)
31 #define MOZ_HAVE_MEM_CHECKS 1
32 #endif
34 #if defined(MOZ_ASAN)
35 #include <stddef.h>
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")));
46 #define MOZ_MAKE_MEM_NOACCESS(addr, size) \
47 __asan_poison_memory_region((addr), (size))
49 #define MOZ_MAKE_MEM_UNDEFINED(addr, size) \
50 __asan_unpoison_memory_region((addr), (size))
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))
59 #define MOZ_MAKE_MEM_UNDEFINED(addr, size) \
60 VALGRIND_MAKE_MEM_UNDEFINED((addr), (size))
62 #define MOZ_MAKE_MEM_DEFINED(addr, size) \
63 VALGRIND_MAKE_MEM_DEFINED((addr), (size))
64 #else
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)
70 #endif
72 #endif /* mozilla_MemoryChecking_h */
