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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_POWERPC_KUP_H_
3#define _ASM_POWERPC_KUP_H_
4
5#define KUAP_READ 1
6#define KUAP_WRITE 2
7#define KUAP_READ_WRITE (KUAP_READ | KUAP_WRITE)
8
9#ifdef CONFIG_PPC_BOOK3S_64
10#include <asm/book3s/64/kup.h>
11#endif
12
13#ifdef CONFIG_PPC_8xx
14#include <asm/nohash/32/kup-8xx.h>
15#endif
16
17#ifdef CONFIG_BOOKE_OR_40x
18#include <asm/nohash/kup-booke.h>
19#endif
20
21#ifdef CONFIG_PPC_BOOK3S_32
22#include <asm/book3s/32/kup.h>
23#endif
24
25#ifdef __ASSEMBLY__
26#ifndef CONFIG_PPC_KUAP
27.macro kuap_check_amr gpr1, gpr2
28.endm
29
30#endif
31
32#else /* !__ASSEMBLY__ */
33
34extern bool disable_kuep;
35extern bool disable_kuap;
36
37#include <linux/pgtable.h>
38
39void setup_kup(void);
40void setup_kuep(bool disabled);
41
42#ifdef CONFIG_PPC_KUAP
43void setup_kuap(bool disabled);
44#else
45static inline void setup_kuap(bool disabled) { }
46
47static __always_inline bool kuap_is_disabled(void) { return true; }
48
49static inline bool
50__bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
51{
52 return false;
53}
54
55static inline void __kuap_lock(void) { }
56static inline void __kuap_save_and_lock(struct pt_regs *regs) { }
57static inline void kuap_user_restore(struct pt_regs *regs) { }
58static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }
59
60static inline unsigned long __kuap_get_and_assert_locked(void)
61{
62 return 0;
63}
64
65/*
66 * book3s/64/kup-radix.h defines these functions for the !KUAP case to flush
67 * the L1D cache after user accesses. Only include the empty stubs for other
68 * platforms.
69 */
70#ifndef CONFIG_PPC_BOOK3S_64
71static inline void __allow_user_access(void __user *to, const void __user *from,
72 unsigned long size, unsigned long dir) { }
73static inline void __prevent_user_access(unsigned long dir) { }
74static inline unsigned long __prevent_user_access_return(void) { return 0UL; }
75static inline void __restore_user_access(unsigned long flags) { }
76#endif /* CONFIG_PPC_BOOK3S_64 */
77#endif /* CONFIG_PPC_KUAP */
78
79static __always_inline bool
80bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
81{
82 if (kuap_is_disabled())
83 return false;
84
85 return __bad_kuap_fault(regs, address, is_write);
86}
87
88static __always_inline void kuap_assert_locked(void)
89{
90 if (kuap_is_disabled())
91 return;
92
93 if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
94 __kuap_get_and_assert_locked();
95}
96
97static __always_inline void kuap_lock(void)
98{
99 if (kuap_is_disabled())
100 return;
101
102 __kuap_lock();
103}
104
105static __always_inline void kuap_save_and_lock(struct pt_regs *regs)
106{
107 if (kuap_is_disabled())
108 return;
109
110 __kuap_save_and_lock(regs);
111}
112
113static __always_inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
114{
115 if (kuap_is_disabled())
116 return;
117
118 __kuap_kernel_restore(regs, amr);
119}
120
121static __always_inline unsigned long kuap_get_and_assert_locked(void)
122{
123 if (kuap_is_disabled())
124 return 0;
125
126 return __kuap_get_and_assert_locked();
127}
128
129#ifndef CONFIG_PPC_BOOK3S_64
130static __always_inline void allow_user_access(void __user *to, const void __user *from,
131 unsigned long size, unsigned long dir)
132{
133 if (kuap_is_disabled())
134 return;
135
136 __allow_user_access(to, from, size, dir);
137}
138
139static __always_inline void prevent_user_access(unsigned long dir)
140{
141 if (kuap_is_disabled())
142 return;
143
144 __prevent_user_access(dir);
145}
146
147static __always_inline unsigned long prevent_user_access_return(void)
148{
149 if (kuap_is_disabled())
150 return 0;
151
152 return __prevent_user_access_return();
153}
154
155static __always_inline void restore_user_access(unsigned long flags)
156{
157 if (kuap_is_disabled())
158 return;
159
160 __restore_user_access(flags);
161}
162#endif /* CONFIG_PPC_BOOK3S_64 */
163
164static __always_inline void allow_read_from_user(const void __user *from, unsigned long size)
165{
166 barrier_nospec();
167 allow_user_access(NULL, from, size, KUAP_READ);
168}
169
170static __always_inline void allow_write_to_user(void __user *to, unsigned long size)
171{
172 allow_user_access(to, NULL, size, KUAP_WRITE);
173}
174
175static __always_inline void allow_read_write_user(void __user *to, const void __user *from,
176 unsigned long size)
177{
178 barrier_nospec();
179 allow_user_access(to, from, size, KUAP_READ_WRITE);
180}
181
182static __always_inline void prevent_read_from_user(const void __user *from, unsigned long size)
183{
184 prevent_user_access(KUAP_READ);
185}
186
187static __always_inline void prevent_write_to_user(void __user *to, unsigned long size)
188{
189 prevent_user_access(KUAP_WRITE);
190}
191
192static __always_inline void prevent_read_write_user(void __user *to, const void __user *from,
193 unsigned long size)
194{
195 prevent_user_access(KUAP_READ_WRITE);
196}
197
198static __always_inline void prevent_current_access_user(void)
199{
200 prevent_user_access(KUAP_READ_WRITE);
201}
202
203static __always_inline void prevent_current_read_from_user(void)
204{
205 prevent_user_access(KUAP_READ);
206}
207
208static __always_inline void prevent_current_write_to_user(void)
209{
210 prevent_user_access(KUAP_WRITE);
211}
212
213#endif /* !__ASSEMBLY__ */
214
215#endif /* _ASM_POWERPC_KUAP_H_ */