Stack protector build failure (was Re: 2.6.25-mm1: not looking good)

[Arjan van de Ven <arjan@infradead.org>]

On Fri, 18 Apr 2008 00:28:58 -0700
Andrew Morton <akpm@linux-foundation.org> wrote:


> 
> > No harm done on a 
> > perfectly bug-free system - but once a bug happens that SELinux
> > should have mitigated, the breakage becomes real. Having a
> > prominent warning is the _minimum_.
> > 
> > having a build failure would be nice too because this is a build 
> > environment problem. (not a build warning - warnings can easily be 
> > missed because on a typical kernel build there's so many false
> > positives that get emitted by various other warning mechanisms)
> > Arjan?
> > 
> 
> Yeah, #error would work too.

I'm totally fine with that, but I think I need Sam's help on making that happen
the right way; this is going to need makefile fu L(

Sam:
Basically what I need is that if the
scripts/gcc-x86_64-has-stack-protector.sh script fails, the build aborts with
a message/#error that says that the compiler is not capable of supporting this feature.

Right now the script is used like this:

	stackp := $(CONFIG_SHELL) $(srctree)/scripts/gcc-x86_64-has-stack-protector.sh
        stackp-$(CONFIG_CC_STACKPROTECTOR) := $(shell $(stackp) \
                "$(CC)" -fstack-protector )

It's obviously easy to make this script print a warning.. but how do we make it stop the build?

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