Re: [patch 20/24] x86/speculation: Split out TIF update

From: Jiri Kosina
Date: Tue Nov 27 2018 - 02:30:14 EST


On Tue, 27 Nov 2018, Thomas Gleixner wrote:

> That's racy and does not prevent the situation because the TIF flags are
> updated befor the UPDATE bit is set.

> So __speculation_ctrl_update() might see the new bits, but not
> TIF_SPEC_UPDATE.

Hm, right, scratch that. We'd need to do that before updating TIF_SPEC_IB
in task_update_spec_tif(), but that has the opposite ordering issue.

Thanks,

--
Jiri Kosina
SUSE Labs