m32r: get rid of zeroing (8cd920f2) · Commits · 戴 / test

arch/m32r/include/asm/uaccess.h

+1 −65

Original line number	Diff line number	Diff line
		@@ -460,77 +460,13 @@ do { \
		: "r14", "memory"); \
		} while (0)

		#define __copy_user_zeroing(to, from, size) \
		do { \
		unsigned long __dst, __src, __c; \
		__asm__ __volatile__ ( \
		" mv r14, %0\n" \
		" or r14, %1\n" \
		" beq %0, %1, 9f\n" \
		" beqz %2, 9f\n" \
		" and3 r14, r14, #3\n" \
		" bnez r14, 2f\n" \
		" and3 %2, %2, #3\n" \
		" beqz %3, 2f\n" \
		" addi %0, #-4 ; word_copy \n" \
		" .fillinsn\n" \
		"0: ld r14, @%1+\n" \
		" addi %3, #-1\n" \
		" .fillinsn\n" \
		"1: st r14, @+%0\n" \
		" bnez %3, 0b\n" \
		" beqz %2, 9f\n" \
		" addi %0, #4\n" \
		" .fillinsn\n" \
		"2: ldb r14, @%1 ; byte_copy \n" \
		" .fillinsn\n" \
		"3: stb r14, @%0\n" \
		" addi %1, #1\n" \
		" addi %2, #-1\n" \
		" addi %0, #1\n" \
		" bnez %2, 2b\n" \
		" .fillinsn\n" \
		"9:\n" \
		".section .fixup,\"ax\"\n" \
		" .balign 4\n" \
		"5: addi %3, #1\n" \
		" addi %1, #-4\n" \
		" .fillinsn\n" \
		"6: slli %3, #2\n" \
		" add %2, %3\n" \
		" addi %0, #4\n" \
		" .fillinsn\n" \
		"7: ldi r14, #0 ; store zero \n" \
		" .fillinsn\n" \
		"8: addi %2, #-1\n" \
		" stb r14, @%0 ; ACE? \n" \
		" addi %0, #1\n" \
		" bnez %2, 8b\n" \
		" seth r14, #high(9b)\n" \
		" or3 r14, r14, #low(9b)\n" \
		" jmp r14\n" \
		".previous\n" \
		".section __ex_table,\"a\"\n" \
		" .balign 4\n" \
		" .long 0b,6b\n" \
		" .long 1b,5b\n" \
		" .long 2b,7b\n" \
		" .long 3b,7b\n" \
		".previous\n" \
		: "=&r" (__dst), "=&r" (__src), "=&r" (size), \
		"=&r" (__c) \
		: "0" (to), "1" (from), "2" (size), "3" (size / 4) \
		: "r14", "memory"); \
		} while (0)


		/* We let the __ versions of copy_from/to_user inline, because they're often
		* used in fast paths and have only a small space overhead.
		*/
		static inline unsigned long __generic_copy_from_user_nocheck(void *to,
		const void __user *from, unsigned long n)
		{
		__copy_user_zeroing(to, from, n);
		__copy_user(to, from, n);
		return n;
		}

arch/m32r/lib/usercopy.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -23,12 +23,13 @@ __generic_copy_to_user(void __user to, const void from, unsigned long n)
		unsigned long
		__generic_copy_from_user(void to, const void __user from, unsigned long n)
		{
		unsigned long ret = n;
		prefetchw(to);
		if (access_ok(VERIFY_READ, from, n))
		__copy_user_zeroing(to,from,n);
		else
		memset(to, 0, n);
		return n;
		ret = __copy_user(to,from,n);
		if (unlikely(ret))
		memset(to + n - ret, 0, ret);
		return ret;
		}

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