Messages in this thread |  | | Date | Tue, 23 Jan 2018 18:07:19 +0100 | From | Dominik Brodowski <> | Subject | Re: [PATCH 1/5] prctl: add PR_ISOLATE_BP process control |
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On Tue, Jan 23, 2018 at 02:07:01PM +0100, Martin Schwidefsky wrote: > Add the PR_ISOLATE_BP operation to prctl. The effect of the process > control is to make all branch prediction entries created by the execution > of the user space code of this task not applicable to kernel code or the > code of any other task.
What is the rationale for requiring a per-process *opt-in* for this added protection?
For KPTI on x86, the exact opposite approach is being discussed (see, e.g. http://lkml.kernel.org/r/1515612500-14505-1-git-send-email-w@1wt.eu ): By default, play it safe, with KPTI enabled. But for "trusted" processes, one may opt out using prctrl.
Thanks, Dominik
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