Messages in this thread | | | Date | Wed, 20 Nov 2013 13:44:16 -0800 | Subject | Re: [tip:x86/asm] x86-64, copy_user: Remove zero byte check before copy user buffer. | From | Linus Torvalds <> |
| |
On Wed, Nov 20, 2013 at 12:36 PM, H. Peter Anvin <hpa@zytor.com> wrote: > > That being said, "lea (%rdx,%rcx,8),%ecx" (leal, as opposed to leaq) is > a perfectly legitimate instruction and actually one byte shorter. The > big question is if some broken version of gas will choke on it.
At least gcc-4.8.2 generates that instruction (try multiplying an integer value by 9), so I guess gas will be happy. Except gcc uses "leal", so to be safe..
Linus
| |