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s390/uaccess: add HAVE_GET_KERNEL_NOFAULT support

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Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Heiko Carstens 2020-09-14 13:42:25 +02:00 committed by Vasily Gorbik
parent fc3f61e1bc
commit 110a6dbb2e
1 changed files with 111 additions and 0 deletions
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111
arch/s390/include/asm/uaccess.h
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@ -278,4 +278,115 @@ static inline unsigned long __must_check clear_user(void __user *to, unsigned lo
int copy_to_user_real(void __user *dest, void *src, unsigned long count);
void *s390_kernel_write(void *dst, const void *src, size_t size);
#define HAVE_GET_KERNEL_NOFAULT
int __noreturn __put_kernel_bad(void);
#define __put_kernel_asm(val, to, insn) \
({ \
int __rc; \
\
asm volatile( \
"0: " insn " %2,%1\n" \
"1: xr %0,%0\n" \
"2:\n" \
".pushsection .fixup, \"ax\"\n" \
"3: lhi %0,%3\n" \
" jg 2b\n" \
".popsection\n" \
EX_TABLE(0b,3b) EX_TABLE(1b,3b) \
: "=d" (__rc), "+Q" (*(to)) \
: "d" (val), "K" (-EFAULT) \
: "cc"); \
__rc; \
})
#define __put_kernel_nofault(dst, src, type, err_label) \
do { \
u64 __x = (u64)(*((type *)(src))); \
int __pk_err; \
\
switch (sizeof(type)) { \
case 1: \
__pk_err = __put_kernel_asm(__x, (type *)(dst), "stc"); \
break; \
case 2: \
__pk_err = __put_kernel_asm(__x, (type *)(dst), "sth"); \
break; \
case 4: \
__pk_err = __put_kernel_asm(__x, (type *)(dst), "st"); \
break; \
case 8: \
__pk_err = __put_kernel_asm(__x, (type *)(dst), "stg"); \
break; \
default: \
__pk_err = __put_kernel_bad(); \
break; \
} \
if (unlikely(__pk_err)) \
goto err_label; \
} while (0)
int __noreturn __get_kernel_bad(void);
#define __get_kernel_asm(val, from, insn) \
({ \
int __rc; \
\
asm volatile( \
"0: " insn " %1,%2\n" \
"1: xr %0,%0\n" \
"2:\n" \
".pushsection .fixup, \"ax\"\n" \
"3: lhi %0,%3\n" \
" jg 2b\n" \
".popsection\n" \
EX_TABLE(0b,3b) EX_TABLE(1b,3b) \
: "=d" (__rc), "+d" (val) \
: "Q" (*(from)), "K" (-EFAULT) \
: "cc"); \
__rc; \
})
#define __get_kernel_nofault(dst, src, type, err_label) \
do { \
int __gk_err; \
\
switch (sizeof(type)) { \
case 1: { \
u8 __x = 0; \
\
__gk_err = __get_kernel_asm(__x, (type *)(src), "ic"); \
*((type *)(dst)) = (type)__x; \
break; \
}; \
case 2: { \
u16 __x = 0; \
\
__gk_err = __get_kernel_asm(__x, (type *)(src), "lh"); \
*((type *)(dst)) = (type)__x; \
break; \
}; \
case 4: { \
u32 __x = 0; \
\
__gk_err = __get_kernel_asm(__x, (type *)(src), "l"); \
*((type *)(dst)) = (type)__x; \
break; \
}; \
case 8: { \
u64 __x = 0; \
\
__gk_err = __get_kernel_asm(__x, (type *)(src), "lg"); \
*((type *)(dst)) = (type)__x; \
break; \
}; \
default: \
__gk_err = __get_kernel_bad(); \
break; \
} \
if (unlikely(__gk_err)) \
goto err_label; \
} while (0)
#endif /* __S390_UACCESS_H */