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 bool arch_validate_prot(unsigned long prot,
39 unsigned long addr __always_unused)
40 {
41 unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM;
42
43 if (system_supports_bti())
44 supported |= PROT_BTI;
45
46 if (system_supports_mte())
47 supported |= PROT_MTE;
48
49 return (prot & ~supported) == 0;
50 }
51 #define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr)
52
53 static inline bool arch_validate_flags(unsigned long vm_flags)
54 {
55 if (!system_supports_mte())
56 return true;
57
58 /* only allow VM_MTE if VM_MTE_ALLOWED has been set previously */
59 return !(vm_flags & VM_MTE) || (vm_flags & VM_MTE_ALLOWED);
60 }
61 #define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags)
62
63 #endif /* ! __ASM_MMAN_H__ */
64
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