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 | |