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1da177e4 LT |
1 | /* |
2 | * linux/arch/s390/mm/mmap.c | |
3 | * | |
4 | * flexible mmap layout support | |
5 | * | |
6 | * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina. | |
7 | * All Rights Reserved. | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to the Free Software | |
21 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
22 | * | |
23 | * | |
24 | * Started by Ingo Molnar <mingo@elte.hu> | |
25 | */ | |
26 | ||
27 | #include <linux/personality.h> | |
28 | #include <linux/mm.h> | |
29 | #include <linux/module.h> | |
6252d702 | 30 | #include <asm/pgalloc.h> |
7757591a | 31 | #include <asm/compat.h> |
1da177e4 LT |
32 | |
33 | /* | |
34 | * Top of mmap area (just below the process stack). | |
35 | * | |
36 | * Leave an at least ~128 MB hole. | |
37 | */ | |
38 | #define MIN_GAP (128*1024*1024) | |
f481bfaf | 39 | #define MAX_GAP (STACK_TOP/6*5) |
1da177e4 LT |
40 | |
41 | static inline unsigned long mmap_base(void) | |
42 | { | |
a58c26bb | 43 | unsigned long gap = rlimit(RLIMIT_STACK); |
1da177e4 LT |
44 | |
45 | if (gap < MIN_GAP) | |
46 | gap = MIN_GAP; | |
47 | else if (gap > MAX_GAP) | |
48 | gap = MAX_GAP; | |
49 | ||
f481bfaf | 50 | return STACK_TOP - (gap & PAGE_MASK); |
1da177e4 LT |
51 | } |
52 | ||
53 | static inline int mmap_is_legacy(void) | |
54 | { | |
347a8dc3 | 55 | #ifdef CONFIG_64BIT |
1da177e4 LT |
56 | /* |
57 | * Force standard allocation for 64 bit programs. | |
58 | */ | |
7757591a | 59 | if (!is_compat_task()) |
1da177e4 LT |
60 | return 1; |
61 | #endif | |
62 | return sysctl_legacy_va_layout || | |
63 | (current->personality & ADDR_COMPAT_LAYOUT) || | |
a58c26bb | 64 | rlimit(RLIMIT_STACK) == RLIM_INFINITY; |
1da177e4 LT |
65 | } |
66 | ||
6252d702 MS |
67 | #ifndef CONFIG_64BIT |
68 | ||
1da177e4 LT |
69 | /* |
70 | * This function, called very early during the creation of a new | |
71 | * process VM image, sets up which VM layout function to use: | |
72 | */ | |
73 | void arch_pick_mmap_layout(struct mm_struct *mm) | |
74 | { | |
75 | /* | |
76 | * Fall back to the standard layout if the personality | |
77 | * bit is set, or if the expected stack growth is unlimited: | |
78 | */ | |
79 | if (mmap_is_legacy()) { | |
80 | mm->mmap_base = TASK_UNMAPPED_BASE; | |
81 | mm->get_unmapped_area = arch_get_unmapped_area; | |
82 | mm->unmap_area = arch_unmap_area; | |
83 | } else { | |
84 | mm->mmap_base = mmap_base(); | |
85 | mm->get_unmapped_area = arch_get_unmapped_area_topdown; | |
86 | mm->unmap_area = arch_unmap_area_topdown; | |
87 | } | |
88 | } | |
89 | EXPORT_SYMBOL_GPL(arch_pick_mmap_layout); | |
90 | ||
6252d702 MS |
91 | #else |
92 | ||
0fb1d9bc MS |
93 | int s390_mmap_check(unsigned long addr, unsigned long len) |
94 | { | |
7757591a | 95 | if (!is_compat_task() && |
0fb1d9bc MS |
96 | len >= TASK_SIZE && TASK_SIZE < (1UL << 53)) |
97 | return crst_table_upgrade(current->mm, 1UL << 53); | |
98 | return 0; | |
99 | } | |
100 | ||
6252d702 MS |
101 | static unsigned long |
102 | s390_get_unmapped_area(struct file *filp, unsigned long addr, | |
103 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
104 | { | |
105 | struct mm_struct *mm = current->mm; | |
0fb1d9bc | 106 | unsigned long area; |
6252d702 MS |
107 | int rc; |
108 | ||
0fb1d9bc MS |
109 | area = arch_get_unmapped_area(filp, addr, len, pgoff, flags); |
110 | if (!(area & ~PAGE_MASK)) | |
111 | return area; | |
7757591a | 112 | if (area == -ENOMEM && !is_compat_task() && TASK_SIZE < (1UL << 53)) { |
0fb1d9bc MS |
113 | /* Upgrade the page table to 4 levels and retry. */ |
114 | rc = crst_table_upgrade(mm, 1UL << 53); | |
6252d702 MS |
115 | if (rc) |
116 | return (unsigned long) rc; | |
0fb1d9bc | 117 | area = arch_get_unmapped_area(filp, addr, len, pgoff, flags); |
6252d702 | 118 | } |
0fb1d9bc | 119 | return area; |
6252d702 MS |
120 | } |
121 | ||
122 | static unsigned long | |
0fb1d9bc | 123 | s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr, |
6252d702 MS |
124 | const unsigned long len, const unsigned long pgoff, |
125 | const unsigned long flags) | |
126 | { | |
127 | struct mm_struct *mm = current->mm; | |
0fb1d9bc | 128 | unsigned long area; |
6252d702 MS |
129 | int rc; |
130 | ||
0fb1d9bc MS |
131 | area = arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags); |
132 | if (!(area & ~PAGE_MASK)) | |
133 | return area; | |
7757591a | 134 | if (area == -ENOMEM && !is_compat_task() && TASK_SIZE < (1UL << 53)) { |
0fb1d9bc MS |
135 | /* Upgrade the page table to 4 levels and retry. */ |
136 | rc = crst_table_upgrade(mm, 1UL << 53); | |
6252d702 MS |
137 | if (rc) |
138 | return (unsigned long) rc; | |
0fb1d9bc MS |
139 | area = arch_get_unmapped_area_topdown(filp, addr, len, |
140 | pgoff, flags); | |
6252d702 | 141 | } |
0fb1d9bc | 142 | return area; |
6252d702 MS |
143 | } |
144 | /* | |
145 | * This function, called very early during the creation of a new | |
146 | * process VM image, sets up which VM layout function to use: | |
147 | */ | |
148 | void arch_pick_mmap_layout(struct mm_struct *mm) | |
149 | { | |
150 | /* | |
151 | * Fall back to the standard layout if the personality | |
152 | * bit is set, or if the expected stack growth is unlimited: | |
153 | */ | |
154 | if (mmap_is_legacy()) { | |
155 | mm->mmap_base = TASK_UNMAPPED_BASE; | |
156 | mm->get_unmapped_area = s390_get_unmapped_area; | |
157 | mm->unmap_area = arch_unmap_area; | |
158 | } else { | |
159 | mm->mmap_base = mmap_base(); | |
160 | mm->get_unmapped_area = s390_get_unmapped_area_topdown; | |
161 | mm->unmap_area = arch_unmap_area_topdown; | |
162 | } | |
163 | } | |
164 | EXPORT_SYMBOL_GPL(arch_pick_mmap_layout); | |
165 | ||
166 | #endif |