Messages in this thread |  | | Date | Sun, 31 Oct 2021 21:09:46 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] static_call,x86: Robustify trampoline patching |
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On Sun, Oct 31, 2021 at 05:44:04PM +0100, Ard Biesheuvel wrote:
> > Is is also a terriblly gross hack. I really want the clang-cfi stuff to > > improve, not add layers of hacks on top of it. > > I'm just as annoyed as you are about the apparent need for this. > However, emitting an alias at build time is far better IMHO than > adding a magic byte sequence and having to check it at runtime.
Oh, I'm keeping that magic sequence :-) That's hardening in general, and I don't want to ever want to debug a wrong poke like that again.
Adding an extra label fixes this thing, but there's still the other cases where we need/want/desire a *real* function pointer.
I'm very close to saying that anything that mucks up function pointers like this is a complete non-starter. Let's start re-start this whole CFI endeavour from the start.
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