1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_POWERPC_BOOK3S_32_KUP_H
3 #define _ASM_POWERPC_BOOK3S_32_KUP_H
5 #include <asm/book3s/32/mmu-hash.h>
9 .macro kuep_update_sr gpr1
, gpr2
/* NEVER use r0 as gpr2 due to addis */
10 101: mtsrin \gpr1
, \gpr2
11 addi \gpr1
, \gpr1
, 0x111 /* next VSID */
12 rlwinm \gpr1
, \gpr1
, 0, 0xf0ffffff /* clear VSID overflow */
13 addis \gpr2
, \gpr2
, 0x1000 /* address of next segment */
18 .macro kuep_lock gpr1
, gpr2
19 #ifdef CONFIG_PPC_KUEP
20 li \gpr1
, NUM_USER_SEGMENTS
24 oris \gpr1
, \gpr1
, SR_NX@h
/* set Nx */
25 kuep_update_sr \gpr1
, \gpr2
29 .macro kuep_unlock gpr1
, gpr2
30 #ifdef CONFIG_PPC_KUEP
31 li \gpr1
, NUM_USER_SEGMENTS
35 rlwinm \gpr1
, \gpr1
, 0, ~SR_NX
/* Clear Nx */
36 kuep_update_sr \gpr1
, \gpr2
40 #ifdef CONFIG_PPC_KUAP
42 .macro kuap_update_sr gpr1
, gpr2
, gpr3
/* NEVER use r0 as gpr2 due to addis */
43 101: mtsrin \gpr1
, \gpr2
44 addi \gpr1
, \gpr1
, 0x111 /* next VSID */
45 rlwinm \gpr1
, \gpr1
, 0, 0xf0ffffff /* clear VSID overflow */
46 addis \gpr2
, \gpr2
, 0x1000 /* address of next segment */
52 .macro kuap_save_and_lock sp
, thread
, gpr1
, gpr2
, gpr3
53 lwz \gpr2
, KUAP(\thread
)
54 rlwinm
. \gpr3
, \gpr2
, 28, 0xf0000000
55 stw \gpr2
, STACK_REGS_KUAP(\sp
)
58 stw \gpr1
, KUAP(\thread
)
60 oris \gpr1
, \gpr1
, SR_KS@h
/* set Ks */
61 kuap_update_sr \gpr1
, \gpr2
, \gpr3
65 .macro kuap_restore sp
, current
, gpr1
, gpr2
, gpr3
66 lwz \gpr2
, STACK_REGS_KUAP(\sp
)
67 rlwinm
. \gpr3
, \gpr2
, 28, 0xf0000000
68 stw \gpr2
, THREAD
+ KUAP(\current
)
71 rlwinm \gpr1
, \gpr1
, 0, ~SR_KS
/* Clear Ks */
72 kuap_update_sr \gpr1
, \gpr2
, \gpr3
76 .macro kuap_check current
, gpr
77 #ifdef CONFIG_PPC_KUAP_DEBUG
78 lwz \gpr2
, KUAP(thread
)
80 EMIT_BUG_ENTRY
999b
, __FILE__
, __LINE__
, (BUGFLAG_WARNING
| BUGFLAG_ONCE
)
84 #endif /* CONFIG_PPC_KUAP */
86 #else /* !__ASSEMBLY__ */
88 #ifdef CONFIG_PPC_KUAP
90 #include <linux/sched.h>
92 static inline void kuap_update_sr(u32 sr
, u32 addr
, u32 end
)
94 addr
&= 0xf0000000; /* align addr to start of segment */
95 barrier(); /* make sure thread.kuap is updated before playing with SRs */
98 sr
+= 0x111; /* next VSID */
99 sr
&= 0xf0ffffff; /* clear VSID overflow */
100 addr
+= 0x10000000; /* address of next segment */
102 isync(); /* Context sync required after mtsrin() */
105 static __always_inline
void allow_user_access(void __user
*to
, const void __user
*from
,
106 u32 size
, unsigned long dir
)
110 BUILD_BUG_ON(!__builtin_constant_p(dir
));
111 BUILD_BUG_ON(dir
== KUAP_CURRENT
);
113 if (!(dir
& KUAP_WRITE
))
116 addr
= (__force u32
)to
;
118 if (unlikely(addr
>= TASK_SIZE
|| !size
))
121 end
= min(addr
+ size
, TASK_SIZE
);
123 current
->thread
.kuap
= (addr
& 0xf0000000) | ((((end
- 1) >> 28) + 1) & 0xf);
124 kuap_update_sr(mfsrin(addr
) & ~SR_KS
, addr
, end
); /* Clear Ks */
127 static __always_inline
void prevent_user_access(void __user
*to
, const void __user
*from
,
128 u32 size
, unsigned long dir
)
132 BUILD_BUG_ON(!__builtin_constant_p(dir
));
134 if (dir
== KUAP_CURRENT
) {
135 u32 kuap
= current
->thread
.kuap
;
140 addr
= kuap
& 0xf0000000;
142 } else if (dir
& KUAP_WRITE
) {
143 addr
= (__force u32
)to
;
144 end
= min(addr
+ size
, TASK_SIZE
);
146 if (unlikely(addr
>= TASK_SIZE
|| !size
))
152 current
->thread
.kuap
= 0;
153 kuap_update_sr(mfsrin(addr
) | SR_KS
, addr
, end
); /* set Ks */
156 static inline unsigned long prevent_user_access_return(void)
158 unsigned long flags
= current
->thread
.kuap
;
159 unsigned long addr
= flags
& 0xf0000000;
160 unsigned long end
= flags
<< 28;
161 void __user
*to
= (__force
void __user
*)addr
;
164 prevent_user_access(to
, to
, end
- addr
, KUAP_READ_WRITE
);
169 static inline void restore_user_access(unsigned long flags
)
171 unsigned long addr
= flags
& 0xf0000000;
172 unsigned long end
= flags
<< 28;
173 void __user
*to
= (__force
void __user
*)addr
;
176 allow_user_access(to
, to
, end
- addr
, KUAP_READ_WRITE
);
180 bad_kuap_fault(struct pt_regs
*regs
, unsigned long address
, bool is_write
)
182 unsigned long begin
= regs
->kuap
& 0xf0000000;
183 unsigned long end
= regs
->kuap
<< 28;
188 return WARN(address
< begin
|| address
>= end
,
189 "Bug: write fault blocked by segment registers !");
192 #endif /* CONFIG_PPC_KUAP */
194 #endif /* __ASSEMBLY__ */
196 #endif /* _ASM_POWERPC_BOOK3S_32_KUP_H */