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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
53 extern int sysctl_overcommit_memory;
54 extern int sysctl_overcommit_ratio;
55 extern unsigned long sysctl_overcommit_kbytes;
56 extern struct percpu_counter vm_committed_as;
57
58 #ifdef CONFIG_SMP
59 extern s32 vm_committed_as_batch;
60 #else
61 #define vm_committed_as_batch 0
62 #endif
63
64 unsigned long vm_memory_committed(void);
65
66 static inline void vm_acct_memory(long pages)
67 {
68 percpu_counter_add_batch(&vm_committed_as, pages, vm_committed_as_batch);
69 }
70
71 static 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 */
95 static inline bool arch_validate_prot(unsigned long prot)
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 */
116 static inline unsigned long
117 calc_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 */
128 static inline unsigned long
129 calc_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
137 unsigned long vm_commit_limit(void);
138 #endif /* _LINUX_MMAN_H */