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