xref: /openbmc/linux/arch/powerpc/include/asm/kup.h (revision 59b4412f)
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  * For prevent_user_access() only.
10  * Use the current saved situation instead of the to/from/size params.
11  * Used on book3s/32
12  */
13 #define KUAP_CURRENT_READ	4
14 #define KUAP_CURRENT_WRITE	8
15 #define KUAP_CURRENT		(KUAP_CURRENT_READ | KUAP_CURRENT_WRITE)
16 
17 #ifdef CONFIG_PPC64
18 #include <asm/book3s/64/kup-radix.h>
19 #endif
20 #ifdef CONFIG_PPC_8xx
21 #include <asm/nohash/32/kup-8xx.h>
22 #endif
23 #ifdef CONFIG_PPC_BOOK3S_32
24 #include <asm/book3s/32/kup.h>
25 #endif
26 
27 #ifdef __ASSEMBLY__
28 #ifndef CONFIG_PPC_KUAP
29 .macro kuap_save_and_lock	sp, thread, gpr1, gpr2, gpr3
30 .endm
31 
32 .macro kuap_restore	sp, current, gpr1, gpr2, gpr3
33 .endm
34 
35 .macro kuap_check	current, gpr
36 .endm
37 
38 #endif
39 
40 #else /* !__ASSEMBLY__ */
41 
42 #include <linux/pgtable.h>
43 
44 void setup_kup(void);
45 
46 #ifdef CONFIG_PPC_KUEP
47 void setup_kuep(bool disabled);
48 #else
49 static inline void setup_kuep(bool disabled) { }
50 #endif /* CONFIG_PPC_KUEP */
51 
52 #ifdef CONFIG_PPC_KUAP
53 void setup_kuap(bool disabled);
54 #else
55 static inline void setup_kuap(bool disabled) { }
56 static inline void allow_user_access(void __user *to, const void __user *from,
57 				     unsigned long size, unsigned long dir) { }
58 static inline void prevent_user_access(void __user *to, const void __user *from,
59 				       unsigned long size, unsigned long dir) { }
60 static inline unsigned long prevent_user_access_return(void) { return 0UL; }
61 static inline void restore_user_access(unsigned long flags) { }
62 static inline bool
63 bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
64 {
65 	return false;
66 }
67 #endif /* CONFIG_PPC_KUAP */
68 
69 static inline void allow_read_from_user(const void __user *from, unsigned long size)
70 {
71 	allow_user_access(NULL, from, size, KUAP_READ);
72 }
73 
74 static inline void allow_write_to_user(void __user *to, unsigned long size)
75 {
76 	allow_user_access(to, NULL, size, KUAP_WRITE);
77 }
78 
79 static inline void allow_read_write_user(void __user *to, const void __user *from,
80 					 unsigned long size)
81 {
82 	allow_user_access(to, from, size, KUAP_READ_WRITE);
83 }
84 
85 static inline void prevent_read_from_user(const void __user *from, unsigned long size)
86 {
87 	prevent_user_access(NULL, from, size, KUAP_READ);
88 }
89 
90 static inline void prevent_write_to_user(void __user *to, unsigned long size)
91 {
92 	prevent_user_access(to, NULL, size, KUAP_WRITE);
93 }
94 
95 static inline void prevent_read_write_user(void __user *to, const void __user *from,
96 					   unsigned long size)
97 {
98 	prevent_user_access(to, from, size, KUAP_READ_WRITE);
99 }
100 
101 static inline void prevent_current_access_user(void)
102 {
103 	prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT);
104 }
105 
106 static inline void prevent_current_read_from_user(void)
107 {
108 	prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_READ);
109 }
110 
111 static inline void prevent_current_write_to_user(void)
112 {
113 	prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_WRITE);
114 }
115 
116 #endif /* !__ASSEMBLY__ */
117 
118 #endif /* _ASM_POWERPC_KUAP_H_ */
119