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