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1 // Copyright 2014 The Chromium Authors. All rights reserved. | 1 // Copyright 2014 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "wtf/allocator/AddressSpaceRandomization.h" | 5 #include "base/allocator/partition_allocator/address_space_randomization.h" |
6 | 6 |
7 #include "wtf/SpinLock.h" | 7 #include "base/allocator/partition_allocator/page_allocator.h" |
8 #include "wtf/allocator/PageAllocator.h" | 8 #include "base/synchronization/spin_lock.h" |
| 9 #include "build/build_config.h" |
9 | 10 |
10 #if OS(WIN) | 11 #if defined(OS_WIN) |
11 #include <windows.h> | 12 #include <windows.h> |
12 #else | 13 #else |
13 #include <sys/time.h> | 14 #include <sys/time.h> |
14 #include <unistd.h> | 15 #include <unistd.h> |
15 #endif | 16 #endif |
16 | 17 |
17 namespace WTF { | 18 namespace base { |
18 | 19 |
19 namespace { | 20 namespace { |
20 | 21 |
21 // This is the same PRNG as used by tcmalloc for mapping address randomness; | 22 // This is the same PRNG as used by tcmalloc for mapping address randomness; |
22 // see http://burtleburtle.net/bob/rand/smallprng.html | 23 // see http://burtleburtle.net/bob/rand/smallprng.html |
23 struct ranctx { | 24 struct ranctx { |
24 SpinLock lock; | 25 subtle::SpinLock lock; |
25 bool initialized; | 26 bool initialized; |
26 uint32_t a; | 27 uint32_t a; |
27 uint32_t b; | 28 uint32_t b; |
28 uint32_t c; | 29 uint32_t c; |
29 uint32_t d; | 30 uint32_t d; |
30 }; | 31 }; |
31 | 32 |
32 #define rot(x, k) (((x) << (k)) | ((x) >> (32 - (k)))) | 33 #define rot(x, k) (((x) << (k)) | ((x) >> (32 - (k)))) |
33 | 34 |
34 uint32_t ranvalInternal(ranctx* x) { | 35 uint32_t ranvalInternal(ranctx* x) { |
35 uint32_t e = x->a - rot(x->b, 27); | 36 uint32_t e = x->a - rot(x->b, 27); |
36 x->a = x->b ^ rot(x->c, 17); | 37 x->a = x->b ^ rot(x->c, 17); |
37 x->b = x->c + x->d; | 38 x->b = x->c + x->d; |
38 x->c = x->d + e; | 39 x->c = x->d + e; |
39 x->d = e + x->a; | 40 x->d = e + x->a; |
40 return x->d; | 41 return x->d; |
41 } | 42 } |
42 | 43 |
43 #undef rot | 44 #undef rot |
44 | 45 |
45 uint32_t ranval(ranctx* x) { | 46 uint32_t ranval(ranctx* x) { |
46 SpinLock::Guard guard(x->lock); | 47 subtle::SpinLock::Guard guard(x->lock); |
47 if (UNLIKELY(!x->initialized)) { | 48 if (UNLIKELY(!x->initialized)) { |
48 x->initialized = true; | 49 x->initialized = true; |
49 char c; | 50 char c; |
50 uint32_t seed = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(&c)); | 51 uint32_t seed = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(&c)); |
51 uint32_t pid; | 52 uint32_t pid; |
52 uint32_t usec; | 53 uint32_t usec; |
53 #if OS(WIN) | 54 #if defined(OS_WIN) |
54 pid = GetCurrentProcessId(); | 55 pid = GetCurrentProcessId(); |
55 SYSTEMTIME st; | 56 SYSTEMTIME st; |
56 GetSystemTime(&st); | 57 GetSystemTime(&st); |
57 usec = static_cast<uint32_t>(st.wMilliseconds * 1000); | 58 usec = static_cast<uint32_t>(st.wMilliseconds * 1000); |
58 #else | 59 #else |
59 pid = static_cast<uint32_t>(getpid()); | 60 pid = static_cast<uint32_t>(getpid()); |
60 struct timeval tv; | 61 struct timeval tv; |
61 gettimeofday(&tv, 0); | 62 gettimeofday(&tv, 0); |
62 usec = static_cast<uint32_t>(tv.tv_usec); | 63 usec = static_cast<uint32_t>(tv.tv_usec); |
63 #endif | 64 #endif |
(...skipping 12 matching lines...) Expand all Loading... |
76 static struct ranctx s_ranctx; | 77 static struct ranctx s_ranctx; |
77 | 78 |
78 } // namespace | 79 } // namespace |
79 | 80 |
80 // Calculates a random preferred mapping address. In calculating an | 81 // Calculates a random preferred mapping address. In calculating an |
81 // address, we balance good ASLR against not fragmenting the address | 82 // address, we balance good ASLR against not fragmenting the address |
82 // space too badly. | 83 // space too badly. |
83 void* getRandomPageBase() { | 84 void* getRandomPageBase() { |
84 uintptr_t random; | 85 uintptr_t random; |
85 random = static_cast<uintptr_t>(ranval(&s_ranctx)); | 86 random = static_cast<uintptr_t>(ranval(&s_ranctx)); |
86 #if CPU(X86_64) | 87 #if defined(ARCH_CPU_X86_64) |
87 random <<= 32UL; | 88 random <<= 32UL; |
88 random |= static_cast<uintptr_t>(ranval(&s_ranctx)); | 89 random |= static_cast<uintptr_t>(ranval(&s_ranctx)); |
89 // This address mask gives a low liklihood of address space collisions. | 90 // This address mask gives a low liklihood of address space collisions. |
90 // We handle the situation gracefully if there is a collision. | 91 // We handle the situation gracefully if there is a collision. |
91 #if OS(WIN) | 92 #if defined(OS_WIN) |
92 // 64-bit Windows has a bizarrely small 8TB user address space. | 93 // 64-bit Windows has a bizarrely small 8TB user address space. |
93 // Allocates in the 1-5TB region. | 94 // Allocates in the 1-5TB region. |
94 // TODO(cevans): I think Win 8.1 has 47-bits like Linux. | 95 // TODO(cevans): I think Win 8.1 has 47-bits like Linux. |
95 random &= 0x3ffffffffffUL; | 96 random &= 0x3ffffffffffUL; |
96 random += 0x10000000000UL; | 97 random += 0x10000000000UL; |
97 #elif defined(MEMORY_TOOL_REPLACES_ALLOCATOR) | 98 #elif defined(MEMORY_TOOL_REPLACES_ALLOCATOR) |
98 // This range is copied from the TSan source, but works for all tools. | 99 // This range is copied from the TSan source, but works for all tools. |
99 random &= 0x007fffffffffUL; | 100 random &= 0x007fffffffffUL; |
100 random += 0x7e8000000000UL; | 101 random += 0x7e8000000000UL; |
101 #else | 102 #else |
102 // Linux and OS X support the full 47-bit user space of x64 processors. | 103 // Linux and OS X support the full 47-bit user space of x64 processors. |
103 random &= 0x3fffffffffffUL; | 104 random &= 0x3fffffffffffUL; |
104 #endif | 105 #endif |
105 #elif CPU(ARM64) | 106 #elif defined(ARCH_CPU_ARM64) |
106 // ARM64 on Linux has 39-bit user space. | 107 // ARM64 on Linux has 39-bit user space. |
107 random &= 0x3fffffffffUL; | 108 random &= 0x3fffffffffUL; |
108 random += 0x1000000000UL; | 109 random += 0x1000000000UL; |
109 #else // !CPU(X86_64) && !CPU(ARM64) | 110 #else // !defined(ARCH_CPU_X86_64) && !defined(ARCH_CPU_ARM64) |
110 #if OS(WIN) | 111 #if defined(OS_WIN) |
111 // On win32 host systems the randomization plus huge alignment causes | 112 // On win32 host systems the randomization plus huge alignment causes |
112 // excessive fragmentation. Plus most of these systems lack ASLR, so the | 113 // excessive fragmentation. Plus most of these systems lack ASLR, so the |
113 // randomization isn't buying anything. In that case we just skip it. | 114 // randomization isn't buying anything. In that case we just skip it. |
114 // TODO(jschuh): Just dump the randomization when HE-ASLR is present. | 115 // TODO(jschuh): Just dump the randomization when HE-ASLR is present. |
115 static BOOL isWow64 = -1; | 116 static BOOL isWow64 = -1; |
116 if (isWow64 == -1 && !IsWow64Process(GetCurrentProcess(), &isWow64)) | 117 if (isWow64 == -1 && !IsWow64Process(GetCurrentProcess(), &isWow64)) |
117 isWow64 = FALSE; | 118 isWow64 = FALSE; |
118 if (!isWow64) | 119 if (!isWow64) |
119 return nullptr; | 120 return nullptr; |
120 #endif // OS(WIN) | 121 #endif // defined(OS_WIN) |
121 // This is a good range on Windows, Linux and Mac. | 122 // This is a good range on Windows, Linux and Mac. |
122 // Allocates in the 0.5-1.5GB region. | 123 // Allocates in the 0.5-1.5GB region. |
123 random &= 0x3fffffff; | 124 random &= 0x3fffffff; |
124 random += 0x20000000; | 125 random += 0x20000000; |
125 #endif // CPU(X86_64) | 126 #endif // defined(ARCH_CPU_X86_64) |
126 random &= kPageAllocationGranularityBaseMask; | 127 random &= kPageAllocationGranularityBaseMask; |
127 return reinterpret_cast<void*>(random); | 128 return reinterpret_cast<void*>(random); |
128 } | 129 } |
129 | 130 |
130 } // namespace WTF | 131 } // namespace base |
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