1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/assembler/jit/ExecutableAllocatorPosix.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,113 @@
1.4 +/*
1.5 + * Copyright (C) 2008 Apple Inc. All rights reserved.
1.6 + *
1.7 + * Redistribution and use in source and binary forms, with or without
1.8 + * modification, are permitted provided that the following conditions
1.9 + * are met:
1.10 + * 1. Redistributions of source code must retain the above copyright
1.11 + * notice, this list of conditions and the following disclaimer.
1.12 + * 2. Redistributions in binary form must reproduce the above copyright
1.13 + * notice, this list of conditions and the following disclaimer in the
1.14 + * documentation and/or other materials provided with the distribution.
1.15 + *
1.16 + * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
1.17 + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1.18 + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
1.19 + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
1.20 + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
1.21 + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
1.22 + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
1.23 + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
1.24 + * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.25 + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1.26 + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.27 + */
1.28 +
1.29 +#include "assembler/jit/ExecutableAllocator.h"
1.30 +
1.31 +#if ENABLE_ASSEMBLER && WTF_OS_UNIX && !WTF_OS_SYMBIAN
1.32 +
1.33 +#include <sys/mman.h>
1.34 +#include <unistd.h>
1.35 +
1.36 +#include "assembler/wtf/Assertions.h"
1.37 +#include "assembler/wtf/VMTags.h"
1.38 +#include "js/Utility.h"
1.39 +
1.40 +namespace JSC {
1.41 +
1.42 +size_t ExecutableAllocator::determinePageSize()
1.43 +{
1.44 + return getpagesize();
1.45 +}
1.46 +
1.47 +ExecutablePool::Allocation ExecutableAllocator::systemAlloc(size_t n)
1.48 +{
1.49 + void *allocation = mmap(NULL, n, INITIAL_PROTECTION_FLAGS, MAP_PRIVATE | MAP_ANON, VM_TAG_FOR_EXECUTABLEALLOCATOR_MEMORY, 0);
1.50 + if (allocation == MAP_FAILED)
1.51 + allocation = NULL;
1.52 + ExecutablePool::Allocation alloc = { reinterpret_cast<char*>(allocation), n };
1.53 + return alloc;
1.54 +}
1.55 +
1.56 +void ExecutableAllocator::systemRelease(const ExecutablePool::Allocation& alloc)
1.57 +{
1.58 + int result = munmap(alloc.pages, alloc.size);
1.59 + ASSERT_UNUSED(result, !result);
1.60 +}
1.61 +
1.62 +#if WTF_ENABLE_ASSEMBLER_WX_EXCLUSIVE
1.63 +void ExecutableAllocator::reprotectRegion(void* start, size_t size, ProtectionSetting setting)
1.64 +{
1.65 + if (!pageSize)
1.66 + intializePageSize();
1.67 +
1.68 + // Calculate the start of the page containing this region,
1.69 + // and account for this extra memory within size.
1.70 + intptr_t startPtr = reinterpret_cast<intptr_t>(start);
1.71 + intptr_t pageStartPtr = startPtr & ~(pageSize - 1);
1.72 + void* pageStart = reinterpret_cast<void*>(pageStartPtr);
1.73 + size += (startPtr - pageStartPtr);
1.74 +
1.75 + // Round size up
1.76 + size += (pageSize - 1);
1.77 + size &= ~(pageSize - 1);
1.78 +
1.79 + mprotect(pageStart, size, (setting == Writable) ? PROTECTION_FLAGS_RW : PROTECTION_FLAGS_RX);
1.80 +}
1.81 +#endif
1.82 +
1.83 +#if WTF_CPU_ARM_TRADITIONAL && WTF_OS_LINUX && WTF_COMPILER_RVCT
1.84 +__asm void ExecutableAllocator::cacheFlush(void* code, size_t size)
1.85 +{
1.86 + ARM
1.87 + push {r7}
1.88 + add r1, r1, r0
1.89 + mov r7, #0xf0000
1.90 + add r7, r7, #0x2
1.91 + mov r2, #0x0
1.92 + svc #0x0
1.93 + pop {r7}
1.94 + bx lr
1.95 +}
1.96 +#endif
1.97 +
1.98 +void
1.99 +ExecutablePool::toggleAllCodeAsAccessible(bool accessible)
1.100 +{
1.101 + char* begin = m_allocation.pages;
1.102 + size_t size = m_freePtr - begin;
1.103 +
1.104 + if (size) {
1.105 + // N.B. Some systems, like 32bit Mac OS 10.6, implicitly add PROT_EXEC
1.106 + // when mprotect'ing memory with any flag other than PROT_NONE. Be
1.107 + // sure to use PROT_NONE when making inaccessible.
1.108 + int flags = accessible ? PROT_READ | PROT_WRITE | PROT_EXEC : PROT_NONE;
1.109 + if (mprotect(begin, size, flags))
1.110 + MOZ_CRASH();
1.111 + }
1.112 +}
1.113 +
1.114 +}
1.115 +
1.116 +#endif // HAVE(ASSEMBLER)
