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/fs.h>
7 #include <linux/shmem_fs.h>
8 #include <linux/types.h>
9 #include <uapi/asm/mman.h>
10
arch_calc_vm_prot_bits(unsigned long prot,unsigned long pkey __always_unused)11 static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
12 unsigned long pkey __always_unused)
13 {
14 unsigned long ret = 0;
15
16 if (system_supports_bti() && (prot & PROT_BTI))
17 ret |= VM_ARM64_BTI;
18
19 if (system_supports_mte() && (prot & PROT_MTE))
20 ret |= VM_MTE;
21
22 return ret;
23 }
24 #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
25
arch_calc_vm_flag_bits(struct file * file,unsigned long flags)26 static inline unsigned long arch_calc_vm_flag_bits(struct file *file,
27 unsigned long flags)
28 {
29 /*
30 * Only allow MTE on anonymous mappings as these are guaranteed to be
31 * backed by tags-capable memory. The vm_flags may be overridden by a
32 * filesystem supporting MTE (RAM-based).
33 */
34 if (system_supports_mte()) {
35 if ((flags & MAP_ANONYMOUS) && !(flags & MAP_HUGETLB))
36 return VM_MTE_ALLOWED;
37 if (shmem_file(file))
38 return VM_MTE_ALLOWED;
39 }
40
41 return 0;
42 }
43 #define arch_calc_vm_flag_bits(file, flags) arch_calc_vm_flag_bits(file, flags)
44
arch_validate_prot(unsigned long prot,unsigned long addr __always_unused)45 static inline bool arch_validate_prot(unsigned long prot,
46 unsigned long addr __always_unused)
47 {
48 unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM;
49
50 if (system_supports_bti())
51 supported |= PROT_BTI;
52
53 if (system_supports_mte())
54 supported |= PROT_MTE;
55
56 return (prot & ~supported) == 0;
57 }
58 #define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr)
59
arch_validate_flags(unsigned long vm_flags)60 static inline bool arch_validate_flags(unsigned long vm_flags)
61 {
62 if (!system_supports_mte())
63 return true;
64
65 /* only allow VM_MTE if VM_MTE_ALLOWED has been set previously */
66 return !(vm_flags & VM_MTE) || (vm_flags & VM_MTE_ALLOWED);
67 }
68 #define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags)
69
70 #endif /* ! __ASM_MMAN_H__ */
71