From 661c80192d21269c7fc566f1d547510b0c867677 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Wed, 20 Nov 2013 12:50:51 -0800 Subject: [PATCH] x86-64, copy_user: Use leal to produce 32-bit results When we are using lea to produce a 32-bit result, we can use the leal form, rather than using leaq and worry about truncation elsewhere. Make the leal explicit, both to be more obvious and since that is what gcc generates and thus is less likely to trigger obscure gas bugs. Cc: Fenghua Yu Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1384634221-6006-1-git-send-email-fenghua.yu@intel.com Signed-off-by: H. Peter Anvin --- arch/x86/lib/copy_user_64.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index ffe4eb9f09eb..dee945d55594 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -186,7 +186,7 @@ ENTRY(copy_user_generic_unrolled) 30: shll $6,%ecx addl %ecx,%edx jmp 60f -40: lea (%rdx,%rcx,8),%rdx +40: leal (%rdx,%rcx,8),%edx jmp 60f 50: movl %ecx,%edx 60: jmp copy_user_handle_tail /* ecx is zerorest also */ @@ -252,7 +252,7 @@ ENTRY(copy_user_generic_string) ret .section .fixup,"ax" -11: lea (%rdx,%rcx,8),%rcx +11: leal (%rdx,%rcx,8),%ecx 12: movl %ecx,%edx /* ecx is zerorest also */ jmp copy_user_handle_tail .previous -- 2.39.5