From 7cefa5a05dbda1f0bbbd98e9d2861b09a35cc6ea Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 20 Mar 2017 00:55:24 -0400 Subject: [PATCH] m68k: get rid of zeroing Signed-off-by: Al Viro --- arch/m68k/include/asm/uaccess_mm.h | 57 +++++++++++++++++++++--------- arch/m68k/lib/uaccess.c | 12 ++----- 2 files changed, 43 insertions(+), 26 deletions(-) diff --git a/arch/m68k/include/asm/uaccess_mm.h b/arch/m68k/include/asm/uaccess_mm.h index 23be968a53fd..931bbba449e2 100644 --- a/arch/m68k/include/asm/uaccess_mm.h +++ b/arch/m68k/include/asm/uaccess_mm.h @@ -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() \ diff --git a/arch/m68k/lib/uaccess.c b/arch/m68k/lib/uaccess.c index a76b73abaf64..7646e461aa62 100644 --- a/arch/m68k/lib/uaccess.c +++ b/arch/m68k/lib/uaccess.c @@ -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" -- 2.20.1