arch/arm64/include/asm/mman.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ASM_MMAN_H__
   3 #define __ASM_MMAN_H__
   4
   5 #include <uapi/asm/mman.h>
   6
   7 #ifndef BUILD_VDSO
   8 #include <linux/compiler.h>
   9 #include <linux/fs.h>
  10 #include <linux/hugetlb.h>
  11 #include <linux/shmem_fs.h>
  12 #include <linux/types.h>
  13
  14 static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
  15         unsigned long pkey)
  16 {
  17         unsigned long ret = 0;
  18
  19         if (system_supports_bti() && (prot & PROT_BTI))
  20                 ret |= VM_ARM64_BTI;
  21
  22         if (system_supports_mte() && (prot & PROT_MTE))
  23                 ret |= VM_MTE;
  24
  25 #ifdef CONFIG_ARCH_HAS_PKEYS
  26         if (system_supports_poe()) {
  27                 ret |= pkey & BIT(0) ? VM_PKEY_BIT0 : 0;
  28                 ret |= pkey & BIT(1) ? VM_PKEY_BIT1 : 0;
  29                 ret |= pkey & BIT(2) ? VM_PKEY_BIT2 : 0;
  30         }
  31 #endif
  32
  33         return ret;
  34 }
  35 #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
  36
  37 static inline unsigned long arch_calc_vm_flag_bits(struct file *file,
  38                                                    unsigned long flags)
  39 {
  40         /*
  41          * Only allow MTE on anonymous mappings as these are guaranteed to be
  42          * backed by tags-capable memory. The vm_flags may be overridden by a
  43          * filesystem supporting MTE (RAM-based).
  44          */
  45         if (system_supports_mte()) {
  46                 if (flags & (MAP_ANONYMOUS | MAP_HUGETLB))
  47                         return VM_MTE_ALLOWED;
  48                 if (shmem_file(file) || is_file_hugepages(file))
  49                         return VM_MTE_ALLOWED;
  50         }
  51
  52         return 0;
  53 }
  54 #define arch_calc_vm_flag_bits(file, flags) arch_calc_vm_flag_bits(file, flags)
  55
  56 static inline bool arch_validate_prot(unsigned long prot,
  57         unsigned long addr __always_unused)
  58 {
  59         unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM;
  60
  61         if (system_supports_bti())
  62                 supported |= PROT_BTI;
  63
  64         if (system_supports_mte())
  65                 supported |= PROT_MTE;
  66
  67         return (prot & ~supported) == 0;
  68 }
  69 #define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr)
  70
  71 static inline bool arch_validate_flags(unsigned long vm_flags)
  72 {
  73         if (system_supports_mte()) {
  74                 /*
  75                  * only allow VM_MTE if VM_MTE_ALLOWED has been set
  76                  * previously
  77                  */
  78                 if ((vm_flags & VM_MTE) && !(vm_flags & VM_MTE_ALLOWED))
  79                         return false;
  80         }
  81
  82         if (system_supports_gcs() && (vm_flags & VM_SHADOW_STACK)) {
  83                 /* An executable GCS isn't a good idea. */
  84                 if (vm_flags & VM_EXEC)
  85                         return false;
  86
  87                 /* The memory management core should prevent this */
  88                 VM_WARN_ON(vm_flags & VM_SHARED);
  89         }
  90
  91         return true;
  92
  93 }
  94 #define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags)
  95
  96 #endif /* !BUILD_VDSO */
  97
  98 #endif /* ! __ASM_MMAN_H__ */