Messages in this thread | | | Date | Tue, 1 Aug 2023 16:09:58 +0100 | From | Mark Brown <> | Subject | Re: [PATCH v3 00/36] arm64/gcs: Provide support for GCS in userspace |
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On Tue, Aug 01, 2023 at 03:13:20PM +0100, Will Deacon wrote: > On Mon, Jul 31, 2023 at 02:43:09PM +0100, Mark Brown wrote:
> > The arm64 Guarded Control Stack (GCS) feature provides support for > > hardware protected stacks of return addresses, intended to provide > > hardening against return oriented programming (ROP) attacks and to make > > it easier to gather call stacks for applications such as profiling.
> Why is this better than Clang's software shadow stack implementation? It > would be nice to see some justification behind adding all this, rather > than it being an architectural tick-box exercise.
Mainly that it's hardware enforced (as the quoted paragraph says). This makes it harder to attack, and hopefully it's also a bit faster (how measurable that might be will be an open question, but even NOPs in function entry/exit tend to get noticed). [unhandled content-type:application/pgp-signature] | |