Linux kernel mirror (for testing)
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linux
1#ifndef _LINUX_MMAN_H
2#define _LINUX_MMAN_H
3
4#include <asm/mman.h>
5
6#define MREMAP_MAYMOVE 1
7#define MREMAP_FIXED 2
8
9#define OVERCOMMIT_GUESS 0
10#define OVERCOMMIT_ALWAYS 1
11#define OVERCOMMIT_NEVER 2
12
13#ifdef __KERNEL__
14#include <linux/mm.h>
15
16#include <asm/atomic.h>
17
18extern int sysctl_overcommit_memory;
19extern int sysctl_overcommit_ratio;
20extern atomic_long_t vm_committed_space;
21
22#ifdef CONFIG_SMP
23extern void vm_acct_memory(long pages);
24#else
25static inline void vm_acct_memory(long pages)
26{
27 atomic_long_add(pages, &vm_committed_space);
28}
29#endif
30
31static inline void vm_unacct_memory(long pages)
32{
33 vm_acct_memory(-pages);
34}
35
36/*
37 * Allow architectures to handle additional protection bits
38 */
39
40#ifndef arch_calc_vm_prot_bits
41#define arch_calc_vm_prot_bits(prot) 0
42#endif
43
44#ifndef arch_vm_get_page_prot
45#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
46#endif
47
48#ifndef arch_validate_prot
49/*
50 * This is called from mprotect(). PROT_GROWSDOWN and PROT_GROWSUP have
51 * already been masked out.
52 *
53 * Returns true if the prot flags are valid
54 */
55static inline int arch_validate_prot(unsigned long prot)
56{
57 return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0;
58}
59#define arch_validate_prot arch_validate_prot
60#endif
61
62/*
63 * Optimisation macro. It is equivalent to:
64 * (x & bit1) ? bit2 : 0
65 * but this version is faster.
66 * ("bit1" and "bit2" must be single bits)
67 */
68#define _calc_vm_trans(x, bit1, bit2) \
69 ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \
70 : ((x) & (bit1)) / ((bit1) / (bit2)))
71
72/*
73 * Combine the mmap "prot" argument into "vm_flags" used internally.
74 */
75static inline unsigned long
76calc_vm_prot_bits(unsigned long prot)
77{
78 return _calc_vm_trans(prot, PROT_READ, VM_READ ) |
79 _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) |
80 _calc_vm_trans(prot, PROT_EXEC, VM_EXEC) |
81 arch_calc_vm_prot_bits(prot);
82}
83
84/*
85 * Combine the mmap "flags" argument into "vm_flags" used internally.
86 */
87static inline unsigned long
88calc_vm_flag_bits(unsigned long flags)
89{
90 return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) |
91 _calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) |
92 _calc_vm_trans(flags, MAP_EXECUTABLE, VM_EXECUTABLE) |
93 _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED );
94}
95#endif /* __KERNEL__ */
96#endif /* _LINUX_MMAN_H */