Messages in this thread | | | Date | Mon, 27 Apr 2015 11:47:30 -0700 | Subject | Re: [PATCH] x86_64, asm: Work around AMD SYSRET SS descriptor attribute issue | From | Linus Torvalds <> |
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On Mon, Apr 27, 2015 at 11:38 AM, Borislav Petkov <bp@alien8.de> wrote: > > So our current NOP-infrastructure does ASM_NOP_MAX NOPs of 8 bytes so > without more invasive changes, our longest NOPs are 8 byte long and then > we have to repeat.
Btw (and I'm too lazy to check) do we take alignment into account?
Because if you have to split, and use multiple nops, it is *probably* a good idea to try to avoid 16-byte boundaries, since that's can be the I$ fetch granularity from L1 (although I guess 32B is getting more common).
So the exact split might depend on the alignment of the nop replacement..
> You can recognize the p6_nops being the same as in-the-manual-suggested > F16h ones.
Can we perhaps get rid of the distinction entirely, and just use one set of 64-bit nops for both Intel/AMD?
Linus
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