1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __ASM_MMAN_H__ 3 #define __ASM_MMAN_H__ 4 5 #include <linux/compiler.h> 6 #include <linux/types.h> 7 #include <uapi/asm/mman.h> 8 9 static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot, 10 unsigned long pkey __always_unused) 11 { 12 unsigned long ret = 0; 13 14 if (system_supports_bti() && (prot & PROT_BTI)) 15 ret |= VM_ARM64_BTI; 16 17 if (system_supports_mte() && (prot & PROT_MTE)) 18 ret |= VM_MTE; 19 20 return ret; 21 } 22 #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey) 23 24 static inline unsigned long arch_calc_vm_flag_bits(unsigned long flags) 25 { 26 /* 27 * Only allow MTE on anonymous mappings as these are guaranteed to be 28 * backed by tags-capable memory. The vm_flags may be overridden by a 29 * filesystem supporting MTE (RAM-based). 30 */ 31 if (system_supports_mte() && (flags & MAP_ANONYMOUS)) 32 return VM_MTE_ALLOWED; 33 34 return 0; 35 } 36 #define arch_calc_vm_flag_bits(flags) arch_calc_vm_flag_bits(flags) 37 38 static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags) 39 { 40 pteval_t prot = 0; 41 42 if (vm_flags & VM_ARM64_BTI) 43 prot |= PTE_GP; 44 45 /* 46 * There are two conditions required for returning a Normal Tagged 47 * memory type: (1) the user requested it via PROT_MTE passed to 48 * mmap() or mprotect() and (2) the corresponding vma supports MTE. We 49 * register (1) as VM_MTE in the vma->vm_flags and (2) as 50 * VM_MTE_ALLOWED. Note that the latter can only be set during the 51 * mmap() call since mprotect() does not accept MAP_* flags. 52 * Checking for VM_MTE only is sufficient since arch_validate_flags() 53 * does not permit (VM_MTE & !VM_MTE_ALLOWED). 54 */ 55 if (vm_flags & VM_MTE) 56 prot |= PTE_ATTRINDX(MT_NORMAL_TAGGED); 57 58 return __pgprot(prot); 59 } 60 #define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags) 61 62 static inline bool arch_validate_prot(unsigned long prot, 63 unsigned long addr __always_unused) 64 { 65 unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM; 66 67 if (system_supports_bti()) 68 supported |= PROT_BTI; 69 70 if (system_supports_mte()) 71 supported |= PROT_MTE; 72 73 return (prot & ~supported) == 0; 74 } 75 #define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr) 76 77 static inline bool arch_validate_flags(unsigned long vm_flags) 78 { 79 if (!system_supports_mte()) 80 return true; 81 82 /* only allow VM_MTE if VM_MTE_ALLOWED has been set previously */ 83 return !(vm_flags & VM_MTE) || (vm_flags & VM_MTE_ALLOWED); 84 } 85 #define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags) 86 87 #endif /* ! __ASM_MMAN_H__ */ 88