1 // Copyright 2024 The Chromium Authors
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/memory/protected_memory.h"
6
7 #include <windows.h>
8
9 #include <stdint.h>
10
11 #include "base/bits.h"
12 #include "base/memory/page_size.h"
13 #include "base/process/process_metrics.h"
14 #include "base/synchronization/lock.h"
15 #include "build/build_config.h"
16
17 namespace base {
18
19 #if BUILDFLAG(PROTECTED_MEMORY_ENABLED)
20 namespace {
21
SetMemory(void * start,void * end,DWORD prot)22 bool SetMemory(void* start, void* end, DWORD prot) {
23 CHECK(end > start);
24 const uintptr_t page_start =
25 bits::AlignDown(reinterpret_cast<uintptr_t>(start), GetPageSize());
26 DWORD old_prot;
27 return VirtualProtect(reinterpret_cast<void*>(page_start),
28 reinterpret_cast<uintptr_t>(end) - page_start, prot,
29 &old_prot) != 0;
30 }
31
32 } // namespace
33
34 namespace internal {
CheckMemoryReadOnly(const void * ptr)35 void CheckMemoryReadOnly(const void* ptr) {
36 const uintptr_t page_start =
37 bits::AlignDown(reinterpret_cast<uintptr_t>(ptr), GetPageSize());
38
39 MEMORY_BASIC_INFORMATION info;
40 SIZE_T result =
41 VirtualQuery(reinterpret_cast<LPCVOID>(page_start), &info, sizeof(info));
42
43 CHECK((result > 0U) && (info.Protect == PAGE_READONLY));
44 }
45 } // namespace internal
46
SetMemoryReadWrite(void * start,void * end)47 bool AutoWritableMemoryBase::SetMemoryReadWrite(void* start, void* end) {
48 return SetMemory(start, end, PAGE_READWRITE);
49 }
50
SetMemoryReadOnly(void * start,void * end)51 bool AutoWritableMemoryBase::SetMemoryReadOnly(void* start, void* end) {
52 return SetMemory(start, end, PAGE_READONLY);
53 }
54 #endif // BUILDFLAG(PROTECTED_MEMORY_ENABLED)
55
56 } // namespace base
57