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 63 static inline void mm_compute_batch(int overcommit_policy) 64 { 65 } 66 #endif 67 68 unsigned long vm_memory_committed(void); 69 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 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 bits 82 */ 83 84 #ifndef arch_calc_vm_prot_bits 85 #define arch_calc_vm_prot_bits(prot, pkey) 0 86 #endif 87 88 #ifndef arch_vm_get_page_prot 89 #define arch_vm_get_page_prot(vm_flags) __pgprot(0) 90 #endif 91 92 #ifndef arch_validate_prot 93 /* 94 * This is called from mprotect(). PROT_GROWSDOWN and PROT_GROWSUP have 95 * already been masked out. 96 * 97 * Returns true if the prot flags are valid 98 */ 99 static inline bool arch_validate_prot(unsigned long prot, unsigned long addr) 100 { 101 return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0; 102 } 103 #define arch_validate_prot arch_validate_prot 104 #endif 105 106 /* 107 * Optimisation macro. It is equivalent to: 108 * (x & bit1) ? bit2 : 0 109 * but this version is faster. 110 * ("bit1" and "bit2" must be single bits) 111 */ 112 #define _calc_vm_trans(x, bit1, bit2) \ 113 ((!(bit1) || !(bit2)) ? 0 : \ 114 ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \ 115 : ((x) & (bit1)) / ((bit1) / (bit2)))) 116 117 /* 118 * Combine the mmap "prot" argument into "vm_flags" used internally. 119 */ 120 static inline unsigned long 121 calc_vm_prot_bits(unsigned long prot, unsigned long pkey) 122 { 123 return _calc_vm_trans(prot, PROT_READ, VM_READ ) | 124 _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) | 125 _calc_vm_trans(prot, PROT_EXEC, VM_EXEC) | 126 arch_calc_vm_prot_bits(prot, pkey); 127 } 128 129 /* 130 * Combine the mmap "flags" argument into "vm_flags" used internally. 131 */ 132 static inline unsigned long 133 calc_vm_flag_bits(unsigned long flags) 134 { 135 return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) | 136 _calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) | 137 _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) | 138 _calc_vm_trans(flags, MAP_SYNC, VM_SYNC ); 139 } 140 141 unsigned long vm_commit_limit(void); 142 #endif /* _LINUX_MMAN_H */ 143