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 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 */ 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 /* 112 * Optimisation macro. It is equivalent to: 113 * (x & bit1) ? bit2 : 0 114 * but this version is faster. 115 * ("bit1" and "bit2" must be single bits) 116 */ 117 #define _calc_vm_trans(x, bit1, bit2) \ 118 ((!(bit1) || !(bit2)) ? 0 : \ 119 ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \ 120 : ((x) & (bit1)) / ((bit1) / (bit2)))) 121 122 /* 123 * Combine the mmap "prot" argument into "vm_flags" used internally. 124 */ 125 static inline unsigned long 126 calc_vm_prot_bits(unsigned long prot, unsigned long pkey) 127 { 128 return _calc_vm_trans(prot, PROT_READ, VM_READ ) | 129 _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) | 130 _calc_vm_trans(prot, PROT_EXEC, VM_EXEC) | 131 arch_calc_vm_prot_bits(prot, pkey); 132 } 133 134 /* 135 * Combine the mmap "flags" argument into "vm_flags" used internally. 136 */ 137 static inline unsigned long 138 calc_vm_flag_bits(unsigned long flags) 139 { 140 return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) | 141 _calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) | 142 _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) | 143 _calc_vm_trans(flags, MAP_SYNC, VM_SYNC ) | 144 arch_calc_vm_flag_bits(flags); 145 } 146 147 unsigned long vm_commit_limit(void); 148 #endif /* _LINUX_MMAN_H */ 149