On Thu, Aug 18, 2011 at 09:23:41AM -0700, David Daney wrote:
> On 08/17/2011 07:32 PM, Yong Zhang wrote:
> >On Wed, Aug 17, 2011 at 10:17:52AM -0700, David Daney wrote:
> >>>diff --git a/arch/mips/kernel/scall64-o32.S
> >>>index 46c4763..f48b18e 100644
> >>>--- a/arch/mips/kernel/scall64-o32.S
> >>>+++ b/arch/mips/kernel/scall64-o32.S
> >>>@@ -441,7 +441,7 @@ sys_call_table:
> >>> PTR sys_fremovexattr /* 4235 */
> >>> PTR sys_tkill
> >>> PTR sys_sendfile64
> >>>- PTR compat_sys_futex
> >>>+ PTR sys_32_futex
> >>This change is redundant, scall64-o32.S already does the right thing
> >My first virsion(not sent out) doesn't include scall64-o32.S either.
> >>so additional zero extending is not needed and is just extra
> >>instructions to execute for no reason.
> >Why I'm adding it here is for:
> >1)code consistent, otherwise we must move SYSCALL_DEFINE6(32_futex,...)
> > under CONFIG_MIPS32_N32;
> No, you don't have to move it. Just don't call it.
> >2)I'm afraid there may be some other way to touch the high 32-bit of a
> > register, so touching scall64-o32.S is also for safety(due to unknown
> > reason, fix me if I'm wrong).
> OK: You are mistaken. You claim you don't understand what the code
> does. That is really a poor justification for modifying it.
If you don't like it and you are sure there is no potential security problem,
just make a patch to remove it. Go ahead.