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

From: H. Peter Anvin
Date: Sat Jul 01 2006 - 19:25:43 EST


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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