Re: 2.6.17-mm5 -- Busted toolchain? -- usr/klibc/exec_l.c:59: undefined reference to `__stack_chk_fail'

Ingo Molnar
2006-07-03T05:22:05Z

* Miles Lane <miles.lane@gmail.com> wrote:

> >If Ubuntu patched gcc rather than just putting it in the build
> >environment... then you should switch to a less braindead distribution
> >really ;)

> Well, from the web page referenced at the top of this message, you can
> see that they are already aware of these issues:
>
> Cons:
> * It breaks current upstream kernel builds and potentially
> other direct usages of gcc. Kernel is by far the most important use
> case. Upstream should change the default options to build with
> -fno-stack-protector by default.
> * It is not conformant to upstream gcc behaviour.

i think the only sane way for a generic distro to introduce an intrusive
security feature is a 3-phase process:

#1 - introduce the new security option
#2 - increase use of it gradually, map all the exceptions on the way
#3 - once exceptions are mapped widely enough, switch the option to
default-on

this makes the introduction of security seemless/gradual to
users/developers, without compromising on the end goal of having the
security feature on by default.

Ubuntu seems to have opted to go to phase #3 directly, which is no doubt
quite brutal but it's their choice. In any case, whichever methodology
is used the kernel got flagged as an "exception" and we should help this
security effort and change the kernel: i.e. lets apply the
-fno-stack-protector flag to the kernel build.

Ingo