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/shmem_fs.h>
11 #include <linux/types.h>
12 
arch_calc_vm_prot_bits(unsigned long prot,unsigned long pkey)13 static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
14 	unsigned long pkey)
15 {
16 	unsigned long ret = 0;
17 
18 	if (system_supports_bti() && (prot & PROT_BTI))
19 		ret |= VM_ARM64_BTI;
20 
21 	if (system_supports_mte() && (prot & PROT_MTE))
22 		ret |= VM_MTE;
23 
24 #ifdef CONFIG_ARCH_HAS_PKEYS
25 	if (system_supports_poe()) {
26 		ret |= pkey & BIT(0) ? VM_PKEY_BIT0 : 0;
27 		ret |= pkey & BIT(1) ? VM_PKEY_BIT1 : 0;
28 		ret |= pkey & BIT(2) ? VM_PKEY_BIT2 : 0;
29 	}
30 #endif
31 
32 	return ret;
33 }
34 #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
35 
arch_calc_vm_flag_bits(struct file * file,unsigned long flags)36 static inline unsigned long arch_calc_vm_flag_bits(struct file *file,
37 						   unsigned long flags)
38 {
39 	/*
40 	 * Only allow MTE on anonymous mappings as these are guaranteed to be
41 	 * backed by tags-capable memory. The vm_flags may be overridden by a
42 	 * filesystem supporting MTE (RAM-based).
43 	 */
44 	if (system_supports_mte() &&
45 	    ((flags & MAP_ANONYMOUS) || shmem_file(file)))
46 		return VM_MTE_ALLOWED;
47 
48 	return 0;
49 }
50 #define arch_calc_vm_flag_bits(file, flags) arch_calc_vm_flag_bits(file, flags)
51 
arch_validate_prot(unsigned long prot,unsigned long addr __always_unused)52 static inline bool arch_validate_prot(unsigned long prot,
53 	unsigned long addr __always_unused)
54 {
55 	unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM;
56 
57 	if (system_supports_bti())
58 		supported |= PROT_BTI;
59 
60 	if (system_supports_mte())
61 		supported |= PROT_MTE;
62 
63 	return (prot & ~supported) == 0;
64 }
65 #define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr)
66 
arch_validate_flags(unsigned long vm_flags)67 static inline bool arch_validate_flags(unsigned long vm_flags)
68 {
69 	if (!system_supports_mte())
70 		return true;
71 
72 	/* only allow VM_MTE if VM_MTE_ALLOWED has been set previously */
73 	return !(vm_flags & VM_MTE) || (vm_flags & VM_MTE_ALLOWED);
74 }
75 #define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags)
76 
77 #endif /* !BUILD_VDSO */
78 
79 #endif /* ! __ASM_MMAN_H__ */
80