Commit 110a6dbb authored by Heiko Carstens's avatar Heiko Carstens Committed by Vasily Gorbik
Browse files

s390/uaccess: add HAVE_GET_KERNEL_NOFAULT support 



Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent fc3f61e1

arch/s390/include/asm/uaccess.h

+111 −0
Original line number Diff line number Diff line
@@ -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 */