Linux kernel mirror (for testing)
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linux
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;
60extern void mm_compute_batch(int overcommit_policy);
61#else
62#define vm_committed_as_batch 0
63static inline void mm_compute_batch(int overcommit_policy)
64{
65}
66#endif
67
68unsigned long vm_memory_committed(void);
69
70static inline void vm_acct_memory(long pages)
71{
72 percpu_counter_add_batch(&vm_committed_as, pages, vm_committed_as_batch);
73}
74
75static inline void vm_unacct_memory(long pages)
76{
77 vm_acct_memory(-pages);
78}
79
80/*
81 * Allow architectures to handle additional protection and flag bits. The
82 * overriding macros must be defined in the arch-specific asm/mman.h file.
83 */
84
85#ifndef arch_calc_vm_prot_bits
86#define arch_calc_vm_prot_bits(prot, pkey) 0
87#endif
88
89#ifndef arch_calc_vm_flag_bits
90#define arch_calc_vm_flag_bits(flags) 0
91#endif
92
93#ifndef arch_vm_get_page_prot
94#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
95#endif
96
97#ifndef arch_validate_prot
98/*
99 * This is called from mprotect(). PROT_GROWSDOWN and PROT_GROWSUP have
100 * already been masked out.
101 *
102 * Returns true if the prot flags are valid
103 */
104static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
105{
106 return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0;
107}
108#define arch_validate_prot arch_validate_prot
109#endif
110
111#ifndef arch_validate_flags
112/*
113 * This is called from mmap() and mprotect() with the updated vma->vm_flags.
114 *
115 * Returns true if the VM_* flags are valid.
116 */
117static inline bool arch_validate_flags(unsigned long flags)
118{
119 return true;
120}
121#define arch_validate_flags arch_validate_flags
122#endif
123
124/*
125 * Optimisation macro. It is equivalent to:
126 * (x & bit1) ? bit2 : 0
127 * but this version is faster.
128 * ("bit1" and "bit2" must be single bits)
129 */
130#define _calc_vm_trans(x, bit1, bit2) \
131 ((!(bit1) || !(bit2)) ? 0 : \
132 ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \
133 : ((x) & (bit1)) / ((bit1) / (bit2))))
134
135/*
136 * Combine the mmap "prot" argument into "vm_flags" used internally.
137 */
138static inline unsigned long
139calc_vm_prot_bits(unsigned long prot, unsigned long pkey)
140{
141 return _calc_vm_trans(prot, PROT_READ, VM_READ ) |
142 _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) |
143 _calc_vm_trans(prot, PROT_EXEC, VM_EXEC) |
144 arch_calc_vm_prot_bits(prot, pkey);
145}
146
147/*
148 * Combine the mmap "flags" argument into "vm_flags" used internally.
149 */
150static inline unsigned long
151calc_vm_flag_bits(unsigned long flags)
152{
153 return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) |
154 _calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) |
155 _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) |
156 _calc_vm_trans(flags, MAP_SYNC, VM_SYNC ) |
157 arch_calc_vm_flag_bits(flags);
158}
159
160unsigned long vm_commit_limit(void);
161#endif /* _LINUX_MMAN_H */