Messages in this thread | | | Date | Thu, 25 Jan 2018 19:41:03 +0100 (CET) | From | Jiri Kosina <> | Subject | Re: [tip:x86/pti] x86/retpoline: Fill return stack buffer on vmexit |
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On Thu, 25 Jan 2018, Andy Lutomirski wrote:
> Distros that use retpolines need their driver vendors to recompile no > matter what.
Absolutely. Tainting a kernel, issuing a warning, or even voluntarily deciding to not load modules loaded without retpolines, that all sounds like reasonable aproaches.
Artificially introducing kernel ABI breakage which is not there (as retpolines are fully compatible when it comes to ABI between modules and kernel ... the fact that it potentially brings non-retpolined indirect jump into the kernel is a security concent, but not ABI issue) sounds like a bad idea.
Those two things (ABI and security concerns) are independent.
> Distros that use IBRS and refuse to use retpolines should get put on a > list of "didn't actually adequately mitigate spectre".
Oh absolutely, especially on archs where there is no IBRS. But how is this relevant to ABI?
Thanks,
-- Jiri Kosina SUSE Labs
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