Messages in this thread | | | Date | Tue, 11 Dec 2018 00:58:09 +0100 | From | Pavel Machek <> | Subject | Re: [PATCH v2 4/4] x86/static_call: Add inline static call implementation for x86-64 |
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On Thu 2018-11-29 11:11:50, Linus Torvalds wrote: > On Thu, Nov 29, 2018 at 11:08 AM Linus Torvalds > <torvalds@linux-foundation.org> wrote: > > > > What you can do then is basically add a single-byte prefix to the > > "call" instruction that does nothing (say, cs override), and then > > replace *that* with a 'int3' instruction. > > Hmm. the segment prefixes are documented as being "reserved" for > branch instructions. I *think* that means just conditional branches > (Intel at one point used the prefixes for static prediction > information), not "call", but who knows.. > > It might be better to use an empty REX prefix on x86-64 or something like that.
It might be easiest to use plain old NOP, no? :-). Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html [unhandled content-type:application/pgp-signature] | |