On Wed, Feb 21, 2024 at 04:47:11PM -0800, Deepak Gupta wrote: > On Tue, Feb 06, 2024 at 04:01:28PM +0000, Mark Brown wrote: > > > +#define SHADOW_STACK_SET_TOKEN (1ULL << 0) /* Set up a restore token in the shadow stack */ > > For arm64 I also added a SHADOW_STACK_SET_MARKER for adding a top of > > stack marker, did you have any thoughts on that for RISC-V? I think x86 > > were considering adding it too, it'd be good if we could get things > > consistent. > Please correct me on this. A token at the top which can't be consumed to restore > but *just* purely as marker, right? Yes, for arm64 we just leave a zero word (which can't be a valid token) above the stack switch token, that does mean you can't exactly tell that the top of stack marker is there unless there's also a stack switch token below it. > It's a good design basic with not a lot of cost. > I think risc-v should be able to converge on that. Great.
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