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 <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>
This commit is contained in:
parent
f4cb1cc18f
commit
661c80192d
|
@ -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
|
||||
|
|
Loading…
Reference in a new issue