Re: Unnecessary overhead with stack protector.

Chuck Ebbert
2009-10-26T16:31:59Z

On Wed, 21 Oct 2009 18:26:36 -0700
Andrew Morton <akpm@linux-foundation.org> wrote:

> On Thu, 15 Oct 2009 14:35:41 -0400 Dave Jones <davej@redhat.com> wrote:
>
> > 113c5413cf9051cc50b88befdc42e3402bb92115 introduced a change that
> > made CC_STACKPROTECTOR_ALL not-selectable if someone enables CC_STACKPROTECTOR.
> >
> > We've noticed in Fedora that this has introduced noticable overhead on
> > some functions, including those which don't even have any on-stack variables.
> >
> > According to the gcc manpage, -fstack-protector will protect functions with
> > as little as 8 bytes of stack usage. So we're introducing a huge amount
> > of overhead, to close a small amount of vulnerability (the >0 && <8 case).
> >
> > The overhead as it stands right now means this whole option is unusable for
> > a distro kernel without reverting the above commit.
> >
>
> This looks like a fairly serious problem to me, but I'm confused by the
> commit ID. February 2008 - is this correct?
>

That date is pure fiction AFAICT. And the Mercurial kernel repo says May 2008...
Is there some way to get the date a change was merged into the official tree as
opposed to the date it was created in some other tree?