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

["H. Peter Anvin" <hpa@zytor.com>]

H. Peter Anvin wrote:
> Sam Ravnborg wrote:
> > For klibc you need to patch scripts/Kbuild.klibc
> >
> > Appending it to KLIBCWARNFLAGS seems the right place.
>
> KLIBCREQFLAGS, rather.
>
> > Do you know from what gcc version we can start using 
> > -fno-stack-protector?
>
> Isn't there a macro to test if gcc supports a specific option already?
>
> Either way, I can also add __stack_chk_fail() as an alias for abort(), 
> for people who actually want the feature.

I looked at it again, and it looks like gcc depends on the TLS ABI in 
order to pick the value of the cookie.  That makes it a potentially lot 
more cantankerous option; I would like to be able to support stack-smash 
checking in klibc, but if it means implementing TLS on all 
architectures, then that would really defeat the purpose (and we should 
add -fno-stack-protector to KLIBCREQFLAGS.)

Arjan: I see a few stack-protector-related have your name on it, do you 
have any details on implementation constraints for this across 
architectures?

	-hpa
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