xref: /linux/arch/arm64/include/asm/mman.h (revision 79d2e1919a2728ef49d938eb20ebd5903c14dfb0)
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__ */
99