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 extern void mm_compute_batch(int overcommit_policy);
61 #else
62 #define vm_committed_as_batch 0
mm_compute_batch(int overcommit_policy)63 static inline void mm_compute_batch(int overcommit_policy)
64 {
65 }
66 #endif
67
68 unsigned long vm_memory_committed(void);
69
vm_acct_memory(long pages)70 static inline void vm_acct_memory(long pages)
71 {
72 percpu_counter_add_batch(&vm_committed_as, pages, vm_committed_as_batch);
73 }
74
vm_unacct_memory(long pages)75 static 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 */
arch_validate_prot(unsigned long prot,unsigned long addr)104 static 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 */
arch_validate_flags(unsigned long flags)117 static 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 */
138 static inline unsigned long
calc_vm_prot_bits(unsigned long prot,unsigned long pkey)139 calc_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 */
150 static inline unsigned long
calc_vm_flag_bits(unsigned long flags)151 calc_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
160 unsigned long vm_commit_limit(void);
161 #endif /* _LINUX_MMAN_H */
162