Messages in this thread | | | Date | Sun, 21 Jan 2018 20:53:03 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v2 5/8] x86/speculation: Add basic support for IBPB |
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On Sun, Jan 21, 2018 at 07:31:00PM +0000, David Woodhouse wrote: > Congratulations, you've just turned a potential GCC missed optimisation > into a kernel bug. We don't *care* that it's unlikely that GCC will > miss that optimisation. The point is that it doesn't *have* to do it, > and we don't *check*.
Err, I guess I'm missing something:
gcc doesn't add any code here - we do. We turn the JMP into a NOP and the three instructions of the wrmsr are from an asm volatile().
So please elaborate.
Thx.
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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