| 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(ASSEMBLER_WX_EXCLUSIVE) | 
| 37 | void ExecutableAllocator::reprotectRegion(void* start, size_t size, ProtectionSeting setting) | 
| 38 | { | 
| 39 |     if (!pageSize) | 
| 40 |         intializePageSize(); | 
| 41 |  | 
| 42 |     // Calculate the start of the page containing this region, | 
| 43 |     // and account for this extra memory within size. | 
| 44 |     intptr_t startPtr = reinterpret_cast<intptr_t>(start); | 
| 45 |     intptr_t pageStartPtr = startPtr & ~(pageSize - 1); | 
| 46 |     void* pageStart = reinterpret_cast<void*>(pageStartPtr); | 
| 47 |     size += (startPtr - pageStartPtr); | 
| 48 |  | 
| 49 |     // Round size up | 
| 50 |     size += (pageSize - 1); | 
| 51 |     size &= ~(pageSize - 1); | 
| 52 |  | 
| 53 |     mprotect(pageStart, size, (setting == Writable) ? PROTECTION_FLAGS_RW : PROTECTION_FLAGS_RX); | 
| 54 | } | 
| 55 | #endif | 
| 56 |  | 
| 57 | } | 
| 58 |  | 
| 59 | #endif // HAVE(ASSEMBLER) | 
| 60 |  |