1 /* SPDX-License-Identifier: GPL-2.0 */ 1
2 /*
3 * Copyright (C) 2023 Arm Ltd.
4 *
5 * Based on arch/x86/include/asm/pkeys.h
6 */
7
8 #ifndef _ASM_ARM64_PKEYS_H
9 #define _ASM_ARM64_PKEYS_H
10
11 #define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_
12
13 #define arch_max_pkey() 8
14
15 int arch_set_user_pkey_access(struct task_stru
16 unsigned long init_val);
17
18 static inline bool arch_pkeys_enabled(void)
19 {
20 return system_supports_poe();
21 }
22
23 static inline int vma_pkey(struct vm_area_stru
24 {
25 return (vma->vm_flags & ARCH_VM_PKEY_F
26 }
27
28 static inline int arch_override_mprotect_pkey(
29 int prot, int pkey)
30 {
31 if (pkey != -1)
32 return pkey;
33
34 return vma_pkey(vma);
35 }
36
37 static inline int execute_only_pkey(struct mm_
38 {
39 // Execute-only mappings are handled b
40 return -1;
41 }
42
43 #define mm_pkey_allocation_map(mm) (mm)->
44 #define mm_set_pkey_allocated(mm, pkey) do {
45 mm_pkey_allocation_map(mm) |= (1U << p
46 } while (0)
47 #define mm_set_pkey_free(mm, pkey) do {
48 mm_pkey_allocation_map(mm) &= ~(1U <<
49 } while (0)
50
51 static inline bool mm_pkey_is_allocated(struct
52 {
53 /*
54 * "Allocated" pkeys are those that ha
55 * from pkey_alloc() or pkey 0 which i
56 * implicitly when the mm is created.
57 */
58 if (pkey < 0 || pkey >= arch_max_pkey(
59 return false;
60
61 return mm_pkey_allocation_map(mm) & (1
62 }
63
64 /*
65 * Returns a positive, 3-bit key on success, o
66 */
67 static inline int mm_pkey_alloc(struct mm_stru
68 {
69 /*
70 * Note: this is the one and only plac
71 * that the pkey is valid as far as th
72 * concerned. The rest of the kernel
73 * only good, valid pkeys come out of
74 */
75 u8 all_pkeys_mask = GENMASK(arch_max_p
76 int ret;
77
78 if (!arch_pkeys_enabled())
79 return -1;
80
81 /*
82 * Are we out of pkeys? We must handl
83 * because ffz() behavior is undefined
84 * zeros.
85 */
86 if (mm_pkey_allocation_map(mm) == all_
87 return -1;
88
89 ret = ffz(mm_pkey_allocation_map(mm));
90
91 mm_set_pkey_allocated(mm, ret);
92
93 return ret;
94 }
95
96 static inline int mm_pkey_free(struct mm_struc
97 {
98 if (!mm_pkey_is_allocated(mm, pkey))
99 return -EINVAL;
100
101 mm_set_pkey_free(mm, pkey);
102
103 return 0;
104 }
105
106 #endif /* _ASM_ARM64_PKEYS_H */
107
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