Messages in this thread | | | Subject | Re: [PATCH 00/45] arm Spectre fix backport review for LTS 4.9 | From | Ivaylo Dimitrov <> | Date | Thu, 8 Mar 2018 15:33:58 +0200 |
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Hi,
On 8.03.2018 15:21, Pali Rohár wrote: > On Thursday 08 March 2018 13:27:15 Pavel Machek wrote: >> Hi! >> >>> Resent without non-upstream patches. >>> >>> This backport patchset fixed the spectre issue, it's original branch: >>> https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/log/?h=kpti >>> A few dependency or fixingpatches are also picked up, if they are necessary >>> and no functional changes. >>> >>> No bug found from kernelci.org and lkft testing. It also could be gotten from: >>> >>> git://git.linaro.org/kernel/linux-linaro-stable.git v4.9-spectre-upstream-only >>> >>> Comments are appreciated! >> >> Not entirely related to this patched, but... I have few older ARM >> boards here, and Nokia N9000 I really care about. >> >> AFAICT Meltdown is arm64 only? > > IIRC ARMv7 is not affected by meltdown. > >> Spectre affects the older boards, too, right? Was there any work done >> on that? cpuinfo says "ARMv7" for N900. > > I remember that I saw some spectre patches for ARMv7 on LKML. > > In general for ARMv7 it is problematic as mitigation needs to change IBE > bit which is not possible on OMAP HS devices. But for Nokia N900 there > is special code which do it via smc instruction (function > rx51_secure_update_aux_cr(), see also nokia_n900_legacy_init()). >
I *think* N900 should be safe from spectre attack as a side effect of thumb2 errata (430973) workaround (BTB is flushed on every context switch), but don't quote me on that one, lets more knowledgeable than me to confirm first.
Ivo
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