Messages in this thread | | | Subject | Re: [PATCH 3/7] x86/enter: Use IBRS on syscall and interrupts | From | Dave Hansen <> | Date | Thu, 4 Jan 2018 21:11:23 -0800 |
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On 01/04/2018 08:51 PM, Andy Lutomirski wrote: > Do we need an arch_prctl() to enable IBRS for user mode?
Eventually, once the dust settles. I think there's a spectrum of paranoia here, that is roughly (with increasing paranoia):
1. do nothing 2. do retpoline 3. do IBRS in kernel 4. do IBRS always
I think you're asking for ~3.5.
Patches for 1-3 are out there and 4 is pretty straightforward. Doing a arch_prctl() is still straightforward, but will be a much more niche thing than any of the other choices. Plus, with a user interface, we have to argue over the ABI for at least a month or two. ;)
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