1 /*
2 * Copyright (C) 2008 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include "config.h"
27
28 #include "ExecutableAllocator.h"
29
30 #if ENABLE(ASSEMBLER)
31
32 namespace JSC {
33
34 size_t ExecutableAllocator::pageSize = 0;
35
36 #if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
37
intializePageSize()38 void ExecutableAllocator::intializePageSize()
39 {
40 #if OS(SYMBIAN) && CPU(ARMV5_OR_LOWER)
41 // The moving memory model (as used in ARMv5 and earlier platforms)
42 // on Symbian OS limits the number of chunks for each process to 16.
43 // To mitigate this limitation increase the pagesize to allocate
44 // fewer, larger chunks. Set the page size to 256 Kb to compensate
45 // for moving memory model limitation
46 ExecutableAllocator::pageSize = 256 * 1024;
47 #else
48 ExecutableAllocator::pageSize = WTF::pageSize();
49 #endif
50 }
51
systemAlloc(size_t size)52 ExecutablePool::Allocation ExecutablePool::systemAlloc(size_t size)
53 {
54 PageAllocation allocation = PageAllocation::allocate(size, OSAllocator::JSJITCodePages, EXECUTABLE_POOL_WRITABLE, true);
55 if (!allocation)
56 CRASH();
57 return allocation;
58 }
59
systemRelease(ExecutablePool::Allocation & allocation)60 void ExecutablePool::systemRelease(ExecutablePool::Allocation& allocation)
61 {
62 allocation.deallocate();
63 }
64
isValid() const65 bool ExecutableAllocator::isValid() const
66 {
67 return true;
68 }
69
underMemoryPressure()70 bool ExecutableAllocator::underMemoryPressure()
71 {
72 return false;
73 }
74
committedByteCount()75 size_t ExecutableAllocator::committedByteCount()
76 {
77 return 0;
78 }
79
80 #endif
81
82 #if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
83
84 #if OS(WINDOWS) || OS(SYMBIAN)
85 #error "ASSEMBLER_WX_EXCLUSIVE not yet suported on this platform."
86 #endif
87
reprotectRegion(void * start,size_t size,ProtectionSetting setting)88 void ExecutableAllocator::reprotectRegion(void* start, size_t size, ProtectionSetting setting)
89 {
90 if (!pageSize)
91 intializePageSize();
92
93 // Calculate the start of the page containing this region,
94 // and account for this extra memory within size.
95 intptr_t startPtr = reinterpret_cast<intptr_t>(start);
96 intptr_t pageStartPtr = startPtr & ~(pageSize - 1);
97 void* pageStart = reinterpret_cast<void*>(pageStartPtr);
98 size += (startPtr - pageStartPtr);
99
100 // Round size up
101 size += (pageSize - 1);
102 size &= ~(pageSize - 1);
103
104 mprotect(pageStart, size, (setting == Writable) ? PROTECTION_FLAGS_RW : PROTECTION_FLAGS_RX);
105 }
106
107 #endif
108
109 #if CPU(ARM_TRADITIONAL) && OS(LINUX) && COMPILER(RVCT)
110
cacheFlush(void * code,size_t size)111 __asm void ExecutableAllocator::cacheFlush(void* code, size_t size)
112 {
113 ARM
114 push {r7}
115 add r1, r1, r0
116 mov r7, #0xf0000
117 add r7, r7, #0x2
118 mov r2, #0x0
119 svc #0x0
120 pop {r7}
121 bx lr
122 }
123
124 #endif
125
126 }
127
128 #endif // HAVE(ASSEMBLER)
129