Re: [PATCH] seccomp: remove unused arg from secure_computing()

From: Kees Cook
Date: Mon Sep 23 2019 - 19:51:37 EST


On Mon, Sep 23, 2019 at 09:34:46PM +0200, Borislav Petkov wrote:
> On Mon, Sep 23, 2019 at 11:41:59AM -0700, Andy Lutomirski wrote:
> > On Mon, Sep 23, 2019 at 2:49 AM Borislav Petkov <bp@xxxxxxxxx> wrote:
> > >
> > > On Fri, Sep 20, 2019 at 03:19:09PM +0200, Christian Brauner wrote:
> > > > While touching seccomp code I realized that the struct seccomp_data
> > > > argument to secure_computing() seems to be unused by all current
> > > > callers. So let's remove it unless there is some subtlety I missed.
> > > > Note, I only tested this on x86.
> > >
> > > What was amluto thinking in
> > >
> > > 2f275de5d1ed ("seccomp: Add a seccomp_data parameter secure_computing()")
> >
> > IIRC there was a period of time in which x86 used secure_computing()
> > for normal syscalls, and it was a good deal faster to have the arch
> > code supply seccomp_data. x86 no longer works like this, and syscalls
> > aren't fast anymore ayway :(
>
> Uhuh, thanks Andy.
>
> Christian, pls add that piece of history to the commit message.

Yeah, this is just left-over from the "two phase" seccomp optimization
that was removed a while back. I'll take this clean up into the seccomp
tree. Thanks!

--
Kees Cook