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Side by Side Diff: base/allocator/partition_allocator/address_space_randomization.cc

Issue 2518253002: Move Partition Allocator into Chromium base. (Closed)
Patch Set: Respond to more of Primiano's comments; move PartitionAllocator.* back to wtf; some build fixes Created 4 years ago
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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
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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