Messages in this thread | | | Date | Wed, 3 Nov 2021 09:35:59 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] static_call,x86: Robustify trampoline patching |
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On Tue, Nov 02, 2021 at 05:20:05PM -0700, Andy Lutomirski wrote: > I think that's a big mistake -- any sane ENDBR-using scheme would > really prefer that ENDBR to be right next to the actual function body, > and really any scheme would benefit due to better cache locality.
Agreed, IBT/BTI want the landing pad in front of the actual function.
> But, more importantly, IMO any sane ENDBR-using scheme wants to > generate the indirect stub as part of code gen for the actual > function.
Sorta, I really want to be able to not have a landing pad for functions whose address is never taken. At that point it doesn't matter if it gets generated along with the function and then stripped/poisoned later, or generated later.
As such, the landing pad should not be part of the function proper, direct calls should never observe it.
Less landing pads is more better.
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