Messages in this thread | | | Date | Tue, 26 Jan 2021 12:07:16 +0100 | From | Sebastian Andrzej Siewior <> | Subject | Re: [PATCH] ARM: mm: harden branch predictor before opening interrupts during fault |
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On 2021-01-26 10:59:32 [+0000], Russell King - ARM Linux admin wrote: > On Tue, Jan 26, 2021 at 05:17:08PM +0800, Lecopzer Chen wrote: > > Hi all, > > > > I don't see any fix for this issue now(maybe I missed it..?), > > could we fix this if there is better solution? > > This issue exists almost two years. > > I don't think anyone provided an acceptable patch. > > The first patch moved the hardening out of the translation/section > fault handling. Since the kernel is mapped with sections, these > are above TASK_SIZE, and the whole point of the branch prediction > hardening is to prevent the prediction in the kernel being exploited, > missing the hardening effectively makes the mitigation useless. > > The discussion in February 2019 never concluded from what I can see.
My memory is that I never got a reply which I understood. Let me try again this week with the information above.
Sebastian
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