KVM: x86: Terminate early if task_switch_16/32 failed
[linux-2.6/libata-dev.git] / arch / s390 / mm / mmap.c
blob869efbaed3eadf76db6c90de2bd75550fb630bf6
1 /*
2 * linux/arch/s390/mm/mmap.c
4 * flexible mmap layout support
6 * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
7 * All Rights Reserved.
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.
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.
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
24 * Started by Ingo Molnar <mingo@elte.hu>
27 #include <linux/personality.h>
28 #include <linux/mm.h>
29 #include <linux/module.h>
30 #include <asm/pgalloc.h>
31 #include <asm/compat.h>
34 * Top of mmap area (just below the process stack).
36 * Leave an at least ~128 MB hole.
38 #define MIN_GAP (128*1024*1024)
39 #define MAX_GAP (STACK_TOP/6*5)
41 static inline unsigned long mmap_base(void)
43 unsigned long gap = rlimit(RLIMIT_STACK);
45 if (gap < MIN_GAP)
46 gap = MIN_GAP;
47 else if (gap > MAX_GAP)
48 gap = MAX_GAP;
50 return STACK_TOP - (gap & PAGE_MASK);
53 static inline int mmap_is_legacy(void)
55 #ifdef CONFIG_64BIT
57 * Force standard allocation for 64 bit programs.
59 if (!is_compat_task())
60 return 1;
61 #endif
62 return sysctl_legacy_va_layout ||
63 (current->personality & ADDR_COMPAT_LAYOUT) ||
64 rlimit(RLIMIT_STACK) == RLIM_INFINITY;
67 #ifndef CONFIG_64BIT
70 * This function, called very early during the creation of a new
71 * process VM image, sets up which VM layout function to use:
73 void arch_pick_mmap_layout(struct mm_struct *mm)
76 * Fall back to the standard layout if the personality
77 * bit is set, or if the expected stack growth is unlimited:
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;
89 EXPORT_SYMBOL_GPL(arch_pick_mmap_layout);
91 #else
93 int s390_mmap_check(unsigned long addr, unsigned long len)
95 if (!is_compat_task() &&
96 len >= TASK_SIZE && TASK_SIZE < (1UL << 53))
97 return crst_table_upgrade(current->mm, 1UL << 53);
98 return 0;
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)
105 struct mm_struct *mm = current->mm;
106 unsigned long area;
107 int rc;
109 area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
110 if (!(area & ~PAGE_MASK))
111 return area;
112 if (area == -ENOMEM && !is_compat_task() && TASK_SIZE < (1UL << 53)) {
113 /* Upgrade the page table to 4 levels and retry. */
114 rc = crst_table_upgrade(mm, 1UL << 53);
115 if (rc)
116 return (unsigned long) rc;
117 area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
119 return area;
122 static unsigned long
123 s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr,
124 const unsigned long len, const unsigned long pgoff,
125 const unsigned long flags)
127 struct mm_struct *mm = current->mm;
128 unsigned long area;
129 int rc;
131 area = arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
132 if (!(area & ~PAGE_MASK))
133 return area;
134 if (area == -ENOMEM && !is_compat_task() && TASK_SIZE < (1UL << 53)) {
135 /* Upgrade the page table to 4 levels and retry. */
136 rc = crst_table_upgrade(mm, 1UL << 53);
137 if (rc)
138 return (unsigned long) rc;
139 area = arch_get_unmapped_area_topdown(filp, addr, len,
140 pgoff, flags);
142 return area;
145 * This function, called very early during the creation of a new
146 * process VM image, sets up which VM layout function to use:
148 void arch_pick_mmap_layout(struct mm_struct *mm)
151 * Fall back to the standard layout if the personality
152 * bit is set, or if the expected stack growth is unlimited:
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;
164 EXPORT_SYMBOL_GPL(arch_pick_mmap_layout);
166 #endif