Messages in this thread | | | Date | Thu, 11 Jan 2018 10:32:31 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] x86/retpoline: Fill return stack buffer on vmexit |
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On Thu, Jan 11, 2018 at 09:07:09AM +0000, Woodhouse, David wrote: > On Thu, 2018-01-11 at 09:49 +0100, Boris Petkov wrote: > > On January 11, 2018 9:42:38 AM GMT+01:00, Peter Zijlstra wrote: > > >Or we teach the alternative thing to patch in a jmp to end instead of > > >NOP padding the entire thing as soon as the jmp (3 bytes) fits ? > > > > Or, even better: use alternative_call() to call functions instead of patching gazillion bytes. > > For this one I kind of wanted to keep it as a macro so we can select > which register it uses.
can't you do lovely things like:
volatile asm ("call __fill_rsb_thunk_%1" : : "r" (dummy))
which would still let gcc select the register ?
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