m68k: get rid of zeroing (7cefa5a0) · Commits · 戴 / test

arch/m68k/include/asm/uaccess_mm.h

+40 −17

Original line number	Diff line number	Diff line
		@@ -179,39 +179,55 @@ asm volatile ("\n" \
		unsigned long __generic_copy_from_user(void to, const void __user from, unsigned long n);
		unsigned long __generic_copy_to_user(void __user to, const void from, unsigned long n);

		#define __constant_copy_from_user_asm(res, to, from, tmp, n, s1, s2, s3)\
		#define __suffix0
		#define __suffix1 b
		#define __suffix2 w
		#define __suffix4 l

		#define ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
		asm volatile ("\n" \
		"1: "MOVES"."#s1" (%2)+,%3\n" \
		" move."#s1" %3,(%1)+\n" \
		" .ifnc \""#s2"\",\"\"\n" \
		"2: "MOVES"."#s2" (%2)+,%3\n" \
		" move."#s2" %3,(%1)+\n" \
		" .ifnc \""#s3"\",\"\"\n" \
		"3: "MOVES"."#s3" (%2)+,%3\n" \
		" move."#s3" %3,(%1)+\n" \
		" .endif\n" \
		" .endif\n" \
		"4:\n" \
		" .section __ex_table,\"a\"\n" \
		" .align 4\n" \
		" .long 1b,10f\n" \
		" .ifnc \""#s2"\",\"\"\n" \
		" .long 2b,20f\n" \
		" .ifnc \""#s3"\",\"\"\n" \
		" .long 3b,30f\n" \
		" .endif\n" \
		" .endif\n" \
		" .previous\n" \
		"\n" \
		" .section .fixup,\"ax\"\n" \
		" .even\n" \
		"10: clr."#s1" (%1)+\n" \
		"20: clr."#s2" (%1)+\n" \
		"10: addq.l #"#n1",%0\n" \
		" .ifnc \""#s2"\",\"\"\n" \
		"20: addq.l #"#n2",%0\n" \
		" .ifnc \""#s3"\",\"\"\n" \
		"30: clr."#s3" (%1)+\n" \
		"30: addq.l #"#n3",%0\n" \
		" .endif\n" \
		" .endif\n" \
		" moveq.l #"#n",%0\n" \
		" jra 4b\n" \
		" .previous\n" \
		: "+d" (res), "+&a" (to), "+a" (from), "=&d" (tmp) \
		: : "memory")

		#define ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
		____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)
		#define __constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3) \
		___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, \
		__suffix##n1, __suffix##n2, __suffix##n3)

		static __always_inline unsigned long
		__constant_copy_from_user(void to, const void __user from, unsigned long n)
		{
		@@ -219,37 +235,37 @@ __constant_copy_from_user(void to, const void __user from, unsigned long n)

		switch (n) {
		case 1:
		__get_user_asm(res, (u8 )to, (u8 __user *)from, u8, b, d, 1);
		__constant_copy_from_user_asm(res, to, from, tmp, 1, 0, 0);
		break;
		case 2:
		__get_user_asm(res, (u16 )to, (u16 __user *)from, u16, w, r, 2);
		__constant_copy_from_user_asm(res, to, from, tmp, 2, 0, 0);
		break;
		case 3:
		__constant_copy_from_user_asm(res, to, from, tmp, 3, w, b,);
		__constant_copy_from_user_asm(res, to, from, tmp, 2, 1, 0);
		break;
		case 4:
		__get_user_asm(res, (u32 )to, (u32 __user *)from, u32, l, r, 4);
		__constant_copy_from_user_asm(res, to, from, tmp, 4, 0, 0);
		break;
		case 5:
		__constant_copy_from_user_asm(res, to, from, tmp, 5, l, b,);
		__constant_copy_from_user_asm(res, to, from, tmp, 4, 1, 0);
		break;
		case 6:
		__constant_copy_from_user_asm(res, to, from, tmp, 6, l, w,);
		__constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 0);
		break;
		case 7:
		__constant_copy_from_user_asm(res, to, from, tmp, 7, l, w, b);
		__constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 1);
		break;
		case 8:
		__constant_copy_from_user_asm(res, to, from, tmp, 8, l, l,);
		__constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 0);
		break;
		case 9:
		__constant_copy_from_user_asm(res, to, from, tmp, 9, l, l, b);
		__constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 1);
		break;
		case 10:
		__constant_copy_from_user_asm(res, to, from, tmp, 10, l, l, w);
		__constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 2);
		break;
		case 12:
		__constant_copy_from_user_asm(res, to, from, tmp, 12, l, l, l);
		__constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 4);
		break;
		default:
		/* we limit the inlined version to 3 moves */
		@@ -353,7 +369,14 @@ __constant_copy_to_user(void __user to, const void from, unsigned long n)
		#define __copy_to_user_inatomic __copy_to_user
		#define __copy_from_user_inatomic __copy_from_user

		#define copy_from_user(to, from, n) __copy_from_user(to, from, n)
		static inline unsigned long
		copy_from_user(void to, const void __user from, unsigned long n)
		{
		unsigned long res = __copy_from_user_inatomic(to, from, n);
		if (unlikely(res))
		memset(to + (n - res), 0, res);
		return res;
		}
		#define copy_to_user(to, from, n) __copy_to_user(to, from, n)

		#define user_addr_max() \

arch/m68k/lib/uaccess.c

+3 −9

Original line number	Diff line number	Diff line
		@@ -30,19 +30,13 @@ unsigned long __generic_copy_from_user(void to, const void __user from,
		"6:\n"
		" .section .fixup,\"ax\"\n"
		" .even\n"
		"10: move.l %0,%3\n"
		"7: clr.l (%2)+\n"
		" subq.l #1,%3\n"
		" jne 7b\n"
		" lsl.l #2,%0\n"
		"10: lsl.l #2,%0\n"
		" btst #1,%5\n"
		" jeq 8f\n"
		"30: clr.w (%2)+\n"
		" addq.l #2,%0\n"
		"30: addq.l #2,%0\n"
		"8: btst #0,%5\n"
		" jeq 6b\n"
		"50: clr.b (%2)+\n"
		" addq.l #1,%0\n"
		"50: addq.l #1,%0\n"
		" jra 6b\n"
		" .previous\n"
		"\n"

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