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 b/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. Thanks, Yong
