| 1 | /*␊ |
| 2 | * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.␊ |
| 3 | *␊ |
| 4 | * @APPLE_LICENSE_HEADER_START@␊ |
| 5 | * ␊ |
| 6 | * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.␊ |
| 7 | * ␊ |
| 8 | * This file contains Original Code and/or Modifications of Original Code␊ |
| 9 | * as defined in and that are subject to the Apple Public Source License␊ |
| 10 | * Version 2.0 (the 'License'). You may not use this file except in␊ |
| 11 | * compliance with the License. Please obtain a copy of the License at␊ |
| 12 | * http://www.opensource.apple.com/apsl/ and read it before using this␊ |
| 13 | * file.␊ |
| 14 | * ␊ |
| 15 | * The Original Code and all software distributed under the License are␊ |
| 16 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER␊ |
| 17 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,␊ |
| 18 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,␊ |
| 19 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.␊ |
| 20 | * Please see the License for the specific language governing rights and␊ |
| 21 | * limitations under the License.␊ |
| 22 | * ␊ |
| 23 | * @APPLE_LICENSE_HEADER_END@␊ |
| 24 | */␊ |
| 25 | /*␊ |
| 26 | *␉File:␉sbrk.c␊ |
| 27 | *␊ |
| 28 | *␉Unix compatibility for sbrk system call.␊ |
| 29 | *␊ |
| 30 | * HISTORY␊ |
| 31 | * 09-Mar-90 Gregg Kellogg (gk) at NeXT.␊ |
| 32 | *␉include <kern/mach_interface.h> instead of <kern/mach.h>␊ |
| 33 | *␊ |
| 34 | * 14-Feb-89 Avadis Tevanian (avie) at NeXT.␊ |
| 35 | *␉Total rewrite using a fixed area of VM from break region.␊ |
| 36 | */␊ |
| 37 | ␊ |
| 38 | #include "libsa.h"␊ |
| 39 | #include "memory.h"␊ |
| 40 | ␊ |
| 41 | /*␊ |
| 42 | * natural_t and integer_t are Mach's legacy types for machine-␊ |
| 43 | * independent integer types (unsigned, and signed, respectively).␊ |
| 44 | * Their original purpose was to define other types in a machine/␊ |
| 45 | * compiler independent way.␊ |
| 46 | *␊ |
| 47 | * They also had an implicit "same size as pointer" characteristic␊ |
| 48 | * to them (i.e. Mach's traditional types are very ILP32 or ILP64␊ |
| 49 | * centric). We support x86 ABIs that do not follow either of␊ |
| 50 | * these models (specifically LP64). Therefore, we had to make a␊ |
| 51 | * choice between making these types scale with pointers or stay␊ |
| 52 | * tied to integers. Because their use is predominantly tied to␊ |
| 53 | * to the size of an integer, we are keeping that association and␊ |
| 54 | * breaking free from pointer size guarantees.␊ |
| 55 | *␊ |
| 56 | * New use of these types is discouraged.␊ |
| 57 | */␊ |
| 58 | typedef __darwin_natural_t␉natural_t;␊ |
| 59 | ␊ |
| 60 | /*␊ |
| 61 | * A vm_offset_t is a type-neutral pointer,␊ |
| 62 | * e.g. an offset into a virtual memory space.␊ |
| 63 | */␊ |
| 64 | #ifdef __LP64__␊ |
| 65 | typedef uintptr_t␉␉vm_offset_t;␊ |
| 66 | #else␉/* __LP64__ */␊ |
| 67 | typedef␉natural_t␉␉vm_offset_t;␊ |
| 68 | #endif␉/* __LP64__ */␊ |
| 69 | ␊ |
| 70 | /*␊ |
| 71 | * A vm_size_t is the proper type for e.g.␊ |
| 72 | * expressing the difference between two␊ |
| 73 | * vm_offset_t entities.␊ |
| 74 | */␊ |
| 75 | #ifdef __LP64__␊ |
| 76 | typedef uintptr_t␉␉vm_size_t;␊ |
| 77 | #else␉/* __LP64__ */␊ |
| 78 | typedef␉natural_t␉␉vm_size_t;␊ |
| 79 | #endif␉/* __LP64__ */␊ |
| 80 | ␊ |
| 81 | typedef vm_offset_t ␉vm_address_t;␊ |
| 82 | ␊ |
| 83 | static vm_size_t sbrk_region_size = (vm_size_t)MALLOC_LEN; /* Well, what should it be? */␊ |
| 84 | static vm_address_t sbrk_curbrk = (vm_address_t)MALLOC_ADDR;␊ |
| 85 | ␊ |
| 86 | caddr_t sbrk(size)␊ |
| 87 | int␉size;␊ |
| 88 | {␉␉␊ |
| 89 | ␉if (size <= 0)␊ |
| 90 | ␉␉return((caddr_t)sbrk_curbrk);␊ |
| 91 | ␊ |
| 92 | if (size > sbrk_region_size)␊ |
| 93 | return((caddr_t)-1);␊ |
| 94 | ␊ |
| 95 | ␉sbrk_curbrk += size;␊ |
| 96 | ␉sbrk_region_size -= size;␊ |
| 97 | ␉␊ |
| 98 | ␉return((caddr_t)(sbrk_curbrk - size));␊ |
| 99 | }␊ |
| 100 | ␊ |
| 101 | caddr_t brk(x)␊ |
| 102 | caddr_t x;␊ |
| 103 | {␊ |
| 104 | ␉return((caddr_t)-1);␊ |
| 105 | }␊ |
| 106 | |
