Messages in this thread Patch in this message | | | Date | Wed, 20 Nov 2013 12:54:35 -0800 | From | "tip-bot for H. Peter Anvin" <> | Subject | [tip:x86/asm] x86-64, copy_user: Use leal to produce 32-bit results |
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Commit-ID: 372474e12a858807f03f73cb30e830a76fd1ae07 Gitweb: http://git.kernel.org/tip/372474e12a858807f03f73cb30e830a76fd1ae07 Author: H. Peter Anvin <hpa@linux.intel.com> AuthorDate: Wed, 20 Nov 2013 12:50:51 -0800 Committer: H. Peter Anvin <hpa@linux.intel.com> CommitDate: Wed, 20 Nov 2013 12:50:51 -0800
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.
Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1384634221-6006-1-git-send-email-fenghua.yu@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> --- 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 ffe4eb9..f00a87c 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: lea (%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: lea (%rdx,%rcx,8),%ecx 12: movl %ecx,%edx /* ecx is zerorest also */ jmp copy_user_handle_tail .previous
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