1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "base/process/memory.h"
6
7 #include <psapi.h>
8
9 #include "base/logging.h"
10 #include "base/memory/scoped_ptr.h"
11
12 namespace base {
13
14 namespace {
15
OnNoMemory()16 void OnNoMemory() {
17 // Kill the process. This is important for security, since WebKit doesn't
18 // NULL-check many memory allocations. If a malloc fails, returns NULL, and
19 // the buffer is then used, it provides a handy mapping of memory starting at
20 // address 0 for an attacker to utilize.
21 __debugbreak();
22 _exit(1);
23 }
24
25 // HeapSetInformation function pointer.
26 typedef BOOL (WINAPI* HeapSetFn)(HANDLE, HEAP_INFORMATION_CLASS, PVOID, SIZE_T);
27
28 } // namespace
29
EnableLowFragmentationHeap()30 bool EnableLowFragmentationHeap() {
31 HMODULE kernel32 = GetModuleHandle(L"kernel32.dll");
32 HeapSetFn heap_set = reinterpret_cast<HeapSetFn>(GetProcAddress(
33 kernel32,
34 "HeapSetInformation"));
35
36 // On Windows 2000, the function is not exported. This is not a reason to
37 // fail.
38 if (!heap_set)
39 return true;
40
41 unsigned number_heaps = GetProcessHeaps(0, NULL);
42 if (!number_heaps)
43 return false;
44
45 // Gives us some extra space in the array in case a thread is creating heaps
46 // at the same time we're querying them.
47 static const int MARGIN = 8;
48 scoped_ptr<HANDLE[]> heaps(new HANDLE[number_heaps + MARGIN]);
49 number_heaps = GetProcessHeaps(number_heaps + MARGIN, heaps.get());
50 if (!number_heaps)
51 return false;
52
53 for (unsigned i = 0; i < number_heaps; ++i) {
54 ULONG lfh_flag = 2;
55 // Don't bother with the result code. It may fails on heaps that have the
56 // HEAP_NO_SERIALIZE flag. This is expected and not a problem at all.
57 heap_set(heaps[i],
58 HeapCompatibilityInformation,
59 &lfh_flag,
60 sizeof(lfh_flag));
61 }
62 return true;
63 }
64
EnableTerminationOnHeapCorruption()65 void EnableTerminationOnHeapCorruption() {
66 // Ignore the result code. Supported on XP SP3 and Vista.
67 HeapSetInformation(NULL, HeapEnableTerminationOnCorruption, NULL, 0);
68 }
69
EnableTerminationOnOutOfMemory()70 void EnableTerminationOnOutOfMemory() {
71 std::set_new_handler(&OnNoMemory);
72 }
73
GetModuleFromAddress(void * address)74 HMODULE GetModuleFromAddress(void* address) {
75 HMODULE instance = NULL;
76 if (!::GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
77 GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
78 static_cast<char*>(address),
79 &instance)) {
80 NOTREACHED();
81 }
82 return instance;
83 }
84
85 // TODO(b.kelemen): implement it with the required semantics. On Linux this is
86 // implemented with a weak symbol that is overridden by tcmalloc. This is
87 // neccessary because base cannot have a direct dependency on tcmalloc. Since
88 // weak symbols are not supported on Windows this will involve some build time
89 // magic, much like what is done for libcrt in order to override the allocation
90 // functions.
UncheckedMalloc(size_t size,void ** result)91 bool UncheckedMalloc(size_t size, void** result) {
92 *result = malloc(size);
93 return *result != NULL;
94 }
95
96 } // namespace base
97