1 /*

     2  * Copyright (C) 2005, 2006, 2007, 2010 Apple Inc. All rights reserved.

     3  *           (C) 2007 Graham Dennis (graham.dennis@gmail.com)

     4  *           (C) 2007 Eric Seidel <eric@webkit.org>

     5  *

     6  * Redistribution and use in source and binary forms, with or without

     7  * modification, are permitted provided that the following conditions

     8  * are met:

     9  *

    10  * 1.  Redistributions of source code must retain the above copyright

    11  *     notice, this list of conditions and the following disclaimer. 

    12  * 2.  Redistributions in binary form must reproduce the above copyright

    13  *     notice, this list of conditions and the following disclaimer in the

    14  *     documentation and/or other materials provided with the distribution. 

    15  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of

    16  *     its contributors may be used to endorse or promote products derived

    17  *     from this software without specific prior written permission. 

    18  *

    19  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY

    20  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

    21  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

    22  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY

    23  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

    24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

    25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

    26  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

    27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

    28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    29  */

    30 

    31 #import "config.h" 

    32 #import "CheckedMalloc.h"

    33 

    34 #import <malloc/malloc.h>

    35 #import <sys/mman.h>

    36 

    37 static void* (*savedMalloc)(malloc_zone_t*, size_t);

    38 static void* (*savedRealloc)(malloc_zone_t*, void*, size_t);

    39 

    40 static void* checkedMalloc(malloc_zone_t* zone, size_t size)

    41 {

    42     if (size >= 0x10000000)

    43         return 0;

    44     return savedMalloc(zone, size);

    45 }

    46 

    47 static void* checkedRealloc(malloc_zone_t* zone, void* ptr, size_t size)

    48 {

    49     if (size >= 0x10000000)

    50         return 0;

    51     return savedRealloc(zone, ptr, size);

    52 }

    53 

    54 void makeLargeMallocFailSilently()

    55 {

    56     malloc_zone_t* zone = malloc_default_zone();

    57 

    58 #if !defined(BUILDING_ON_TIGER) && !defined(BUILDING_ON_LEOPARD) && !defined(BUILDING_ON_SNOW_LEOPARD)

    59     vm_address_t pageStart = reinterpret_cast<vm_address_t>(zone) & static_cast<vm_size_t>(~(getpagesize() - 1));

    60     vm_size_t len = reinterpret_cast<vm_address_t>(zone) - pageStart + sizeof(malloc_zone_t);

    61     mprotect(reinterpret_cast<void*>(pageStart), len, PROT_READ | PROT_WRITE);

    62 #endif

    63 

    64     savedMalloc = zone->malloc;

    65     savedRealloc = zone->realloc;

    66     zone->malloc = checkedMalloc;

    67     zone->realloc = checkedRealloc;

    68 

    69 #if !defined(BUILDING_ON_TIGER) && !defined(BUILDING_ON_LEOPARD) && !defined(BUILDING_ON_SNOW_LEOPARD)

    70     mprotect(reinterpret_cast<void*>(pageStart), len, PROT_READ);

    71 #endif

    72 }