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