Messages in this thread | | | Date | Mon, 19 Oct 2015 13:25:26 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86: Add an explicit barrier() to clflushopt() |
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On Mon, Oct 19, 2015 at 12:05:29PM +0100, Chris Wilson wrote: > In order to add the clobbers, I had to adjust the macro slightly: > > +#define alternative_output(oldinstr, newinstr, feature, output) \ > + asm volatile (ALTERNATIVE(oldinstr, newinstr, feature) \ > + : output : "i" (0) : "memory") > > and that also works. The concern I have here is that the asm does use > "+m" as its output already, and the clflush() asm doesn't require the > manual clobber.
Yeah, you could make the above
#define alternative_output(oldinstr, newinstr, feature, output, clobber...)
and use it to define clflushopt(). hpa might have a better idea, though...
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply.
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