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 #if CPU(ARM_TRADITIONAL) && OS(LINUX) && COMPILER(RVCT)

    58 __asm void ExecutableAllocator::cacheFlush(void* code, size_t size)

    59 {

    60     ARM

    61     push {r7}

    62     add r1, r1, r0

    63     mov r7, #0xf0000

    64     add r7, r7, #0x2

    65     mov r2, #0x0

    66     svc #0x0

    67     pop {r7}

    68     bx lr

    69 }

    70 #endif

    71 

    72 }

    73 

    74 #endif // HAVE(ASSEMBLER)