projects/linux·blob v5.8 · refs

138 lines · 3.3 KiB

1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_MMAN_H
3#define _LINUX_MMAN_H
4
5#include <linux/mm.h>
6#include <linux/percpu_counter.h>
7
8#include <linux/atomic.h>
9#include <uapi/linux/mman.h>
10
11/*
12 * Arrange for legacy / undefined architecture specific flags to be
13 * ignored by mmap handling code.
14 */
15#ifndef MAP_32BIT
16#define MAP_32BIT 0
17#endif
18#ifndef MAP_HUGE_2MB
19#define MAP_HUGE_2MB 0
20#endif
21#ifndef MAP_HUGE_1GB
22#define MAP_HUGE_1GB 0
23#endif
24#ifndef MAP_UNINITIALIZED
25#define MAP_UNINITIALIZED 0
26#endif
27#ifndef MAP_SYNC
28#define MAP_SYNC 0
29#endif
30
31/*
32 * The historical set of flags that all mmap implementations implicitly
33 * support when a ->mmap_validate() op is not provided in file_operations.
34 */
35#define LEGACY_MAP_MASK (MAP_SHARED \
36 | MAP_PRIVATE \
37 | MAP_FIXED \
38 | MAP_ANONYMOUS \
39 | MAP_DENYWRITE \
40 | MAP_EXECUTABLE \
41 | MAP_UNINITIALIZED \
42 | MAP_GROWSDOWN \
43 | MAP_LOCKED \
44 | MAP_NORESERVE \
45 | MAP_POPULATE \
46 | MAP_NONBLOCK \
47 | MAP_STACK \
48 | MAP_HUGETLB \
49 | MAP_32BIT \
50 | MAP_HUGE_2MB \
51 | MAP_HUGE_1GB)
52
53extern int sysctl_overcommit_memory;
54extern int sysctl_overcommit_ratio;
55extern unsigned long sysctl_overcommit_kbytes;
56extern struct percpu_counter vm_committed_as;
57
58#ifdef CONFIG_SMP
59extern s32 vm_committed_as_batch;
60#else
61#define vm_committed_as_batch 0
62#endif
63
64unsigned long vm_memory_committed(void);
65
66static inline void vm_acct_memory(long pages)
67{
68 percpu_counter_add_batch(&vm_committed_as, pages, vm_committed_as_batch);
69}
70
71static inline void vm_unacct_memory(long pages)
72{
73 vm_acct_memory(-pages);
74}
75
76/*
77 * Allow architectures to handle additional protection bits
78 */
79
80#ifndef arch_calc_vm_prot_bits
81#define arch_calc_vm_prot_bits(prot, pkey) 0
82#endif
83
84#ifndef arch_vm_get_page_prot
85#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
86#endif
87
88#ifndef arch_validate_prot
89/*
90 * This is called from mprotect(). PROT_GROWSDOWN and PROT_GROWSUP have
91 * already been masked out.
92 *
93 * Returns true if the prot flags are valid
94 */
95static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
96{
97 return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0;
98}
99#define arch_validate_prot arch_validate_prot
100#endif
101
102/*
103 * Optimisation macro. It is equivalent to:
104 * (x & bit1) ? bit2 : 0
105 * but this version is faster.
106 * ("bit1" and "bit2" must be single bits)
107 */
108#define _calc_vm_trans(x, bit1, bit2) \
109 ((!(bit1) || !(bit2)) ? 0 : \
110 ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \
111 : ((x) & (bit1)) / ((bit1) / (bit2))))
112
113/*
114 * Combine the mmap "prot" argument into "vm_flags" used internally.
115 */
116static inline unsigned long
117calc_vm_prot_bits(unsigned long prot, unsigned long pkey)
118{
119 return _calc_vm_trans(prot, PROT_READ, VM_READ ) |
120 _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) |
121 _calc_vm_trans(prot, PROT_EXEC, VM_EXEC) |
122 arch_calc_vm_prot_bits(prot, pkey);
123}
124
125/*
126 * Combine the mmap "flags" argument into "vm_flags" used internally.
127 */
128static inline unsigned long
129calc_vm_flag_bits(unsigned long flags)
130{
131 return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) |
132 _calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) |
133 _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) |
134 _calc_vm_trans(flags, MAP_SYNC, VM_SYNC );
135}
136
137unsigned long vm_commit_limit(void);
138#endif /* _LINUX_MMAN_H */