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 * MAP_EXECUTABLE and MAP_DENYWRITE are completely ignored throughout the 36 * kernel. 37 */ 38 #define LEGACY_MAP_MASK (MAP_SHARED \ 39 | MAP_PRIVATE \ 40 | MAP_FIXED \ 41 | MAP_ANONYMOUS \ 42 | MAP_DENYWRITE \ 43 | MAP_EXECUTABLE \ 44 | MAP_UNINITIALIZED \ 45 | MAP_GROWSDOWN \ 46 | MAP_LOCKED \ 47 | MAP_NORESERVE \ 48 | MAP_POPULATE \ 49 | MAP_NONBLOCK \ 50 | MAP_STACK \ 51 | MAP_HUGETLB \ 52 | MAP_32BIT \ 53 | MAP_HUGE_2MB \ 54 | MAP_HUGE_1GB) 55 56 extern int sysctl_overcommit_memory; 57 extern int sysctl_overcommit_ratio; 58 extern unsigned long sysctl_overcommit_kbytes; 59 extern struct percpu_counter vm_committed_as; 60 61 #ifdef CONFIG_SMP 62 extern s32 vm_committed_as_batch; 63 extern void mm_compute_batch(int overcommit_policy); 64 #else 65 #define vm_committed_as_batch 0 66 static inline void mm_compute_batch(int overcommit_policy) 67 { 68 } 69 #endif 70 71 unsigned long vm_memory_committed(void); 72 73 static inline void vm_acct_memory(long pages) 74 { 75 percpu_counter_add_batch(&vm_committed_as, pages, vm_committed_as_batch); 76 } 77 78 static inline void vm_unacct_memory(long pages) 79 { 80 vm_acct_memory(-pages); 81 } 82 83 /* 84 * Allow architectures to handle additional protection and flag bits. The 85 * overriding macros must be defined in the arch-specific asm/mman.h file. 86 */ 87 88 #ifndef arch_calc_vm_prot_bits 89 #define arch_calc_vm_prot_bits(prot, pkey) 0 90 #endif 91 92 #ifndef arch_calc_vm_flag_bits 93 #define arch_calc_vm_flag_bits(flags) 0 94 #endif 95 96 #ifndef arch_vm_get_page_prot 97 #define arch_vm_get_page_prot(vm_flags) __pgprot(0) 98 #endif 99 100 #ifndef arch_validate_prot 101 /* 102 * This is called from mprotect(). PROT_GROWSDOWN and PROT_GROWSUP have 103 * already been masked out. 104 * 105 * Returns true if the prot flags are valid 106 */ 107 static inline bool arch_validate_prot(unsigned long prot, unsigned long addr) 108 { 109 return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0; 110 } 111 #define arch_validate_prot arch_validate_prot 112 #endif 113 114 #ifndef arch_validate_flags 115 /* 116 * This is called from mmap() and mprotect() with the updated vma->vm_flags. 117 * 118 * Returns true if the VM_* flags are valid. 119 */ 120 static inline bool arch_validate_flags(unsigned long flags) 121 { 122 return true; 123 } 124 #define arch_validate_flags arch_validate_flags 125 #endif 126 127 /* 128 * Optimisation macro. It is equivalent to: 129 * (x & bit1) ? bit2 : 0 130 * but this version is faster. 131 * ("bit1" and "bit2" must be single bits) 132 */ 133 #define _calc_vm_trans(x, bit1, bit2) \ 134 ((!(bit1) || !(bit2)) ? 0 : \ 135 ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \ 136 : ((x) & (bit1)) / ((bit1) / (bit2)))) 137 138 /* 139 * Combine the mmap "prot" argument into "vm_flags" used internally. 140 */ 141 static inline unsigned long 142 calc_vm_prot_bits(unsigned long prot, unsigned long pkey) 143 { 144 return _calc_vm_trans(prot, PROT_READ, VM_READ ) | 145 _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) | 146 _calc_vm_trans(prot, PROT_EXEC, VM_EXEC) | 147 arch_calc_vm_prot_bits(prot, pkey); 148 } 149 150 /* 151 * Combine the mmap "flags" argument into "vm_flags" used internally. 152 */ 153 static inline unsigned long 154 calc_vm_flag_bits(unsigned long flags) 155 { 156 return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) | 157 _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) | 158 _calc_vm_trans(flags, MAP_SYNC, VM_SYNC ) | 159 arch_calc_vm_flag_bits(flags); 160 } 161 162 unsigned long vm_commit_limit(void); 163 #endif /* _LINUX_MMAN_H */ 164