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comparison: js/src/assembler/jit/ExecutableAllocatorPosix.cpp
js/src/assembler/jit/ExecutableAllocatorPosix.cpp
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| 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 "assembler/jit/ExecutableAllocator.h" | |
| 27 | |
| 28 #if ENABLE_ASSEMBLER && WTF_OS_UNIX && !WTF_OS_SYMBIAN | |
| 29 | |
| 30 #include <sys/mman.h> | |
| 31 #include <unistd.h> | |
| 32 | |
| 33 #include "assembler/wtf/Assertions.h" | |
| 34 #include "assembler/wtf/VMTags.h" | |
| 35 #include "js/Utility.h" | |
| 36 | |
| 37 namespace JSC { | |
| 38 | |
| 39 size_t ExecutableAllocator::determinePageSize() | |
| 40 { | |
| 41 return getpagesize(); | |
| 42 } | |
| 43 | |
| 44 ExecutablePool::Allocation ExecutableAllocator::systemAlloc(size_t n) | |
| 45 { | |
| 46 void *allocation = mmap(NULL, n, INITIAL_PROTECTION_FLAGS, MAP_PRIVATE | MAP_ANON, VM_TAG_FOR_EXECUTABLEALLOCATOR_MEMORY, 0); | |
| 47 if (allocation == MAP_FAILED) | |
| 48 allocation = NULL; | |
| 49 ExecutablePool::Allocation alloc = { reinterpret_cast<char*>(allocation), n }; | |
| 50 return alloc; | |
| 51 } | |
| 52 | |
| 53 void ExecutableAllocator::systemRelease(const ExecutablePool::Allocation& alloc) | |
| 54 { | |
| 55 int result = munmap(alloc.pages, alloc.size); | |
| 56 ASSERT_UNUSED(result, !result); | |
| 57 } | |
| 58 | |
| 59 #if WTF_ENABLE_ASSEMBLER_WX_EXCLUSIVE | |
| 60 void ExecutableAllocator::reprotectRegion(void* start, size_t size, ProtectionSetting setting) | |
| 61 { | |
| 62 if (!pageSize) | |
| 63 intializePageSize(); | |
| 64 | |
| 65 // Calculate the start of the page containing this region, | |
| 66 // and account for this extra memory within size. | |
| 67 intptr_t startPtr = reinterpret_cast<intptr_t>(start); | |
| 68 intptr_t pageStartPtr = startPtr & ~(pageSize - 1); | |
| 69 void* pageStart = reinterpret_cast<void*>(pageStartPtr); | |
| 70 size += (startPtr - pageStartPtr); | |
| 71 | |
| 72 // Round size up | |
| 73 size += (pageSize - 1); | |
| 74 size &= ~(pageSize - 1); | |
| 75 | |
| 76 mprotect(pageStart, size, (setting == Writable) ? PROTECTION_FLAGS_RW : PROTECTION_FLAGS_RX); | |
| 77 } | |
| 78 #endif | |
| 79 | |
| 80 #if WTF_CPU_ARM_TRADITIONAL && WTF_OS_LINUX && WTF_COMPILER_RVCT | |
| 81 __asm void ExecutableAllocator::cacheFlush(void* code, size_t size) | |
| 82 { | |
| 83 ARM | |
| 84 push {r7} | |
| 85 add r1, r1, r0 | |
| 86 mov r7, #0xf0000 | |
| 87 add r7, r7, #0x2 | |
| 88 mov r2, #0x0 | |
| 89 svc #0x0 | |
| 90 pop {r7} | |
| 91 bx lr | |
| 92 } | |
| 93 #endif | |
| 94 | |
| 95 void | |
| 96 ExecutablePool::toggleAllCodeAsAccessible(bool accessible) | |
| 97 { | |
| 98 char* begin = m_allocation.pages; | |
| 99 size_t size = m_freePtr - begin; | |
| 100 | |
| 101 if (size) { | |
| 102 // N.B. Some systems, like 32bit Mac OS 10.6, implicitly add PROT_EXEC | |
| 103 // when mprotect'ing memory with any flag other than PROT_NONE. Be | |
| 104 // sure to use PROT_NONE when making inaccessible. | |
| 105 int flags = accessible ? PROT_READ | PROT_WRITE | PROT_EXEC : PROT_NONE; | |
| 106 if (mprotect(begin, size, flags)) | |
| 107 MOZ_CRASH(); | |
| 108 } | |
| 109 } | |
| 110 | |
| 111 } | |
| 112 | |
| 113 #endif // HAVE(ASSEMBLER) |
