On 8/7/2020 6:14 AM, Greg KH wrote: > On Thu, Aug 06, 2020 at 01:00:54PM -0700, Florian Fainelli wrote: >> >> >> On 7/20/2020 11:26 AM, Florian Fainelli wrote: >>> On 7/20/20 6:04 AM, Greg KH wrote: >>>> On Thu, Jul 09, 2020 at 12:50:23PM -0700, Florian Fainelli wrote: >>>>> From: Will Deacon <will.deacon@xxxxxxx> >>>>> >>>>> commit 679db70801da9fda91d26caf13bf5b5ccc74e8e8 upstream >>>>> >>>>> Some CPUs can speculate past an ERET instruction and potentially perform >>>>> speculative accesses to memory before processing the exception return. >>>>> Since the register state is often controlled by a lower privilege level >>>>> at the point of an ERET, this could potentially be used as part of a >>>>> side-channel attack. >>>>> >>>>> This patch emits an SB sequence after each ERET so that speculation is >>>>> held up on exception return. >>>>> >>>>> Signed-off-by: Will Deacon <will.deacon@xxxxxxx> >>>>> [florian: Adjust hyp-entry.S to account for the label >>>>> added change to hyp/entry.S] >>>>> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx> >>>>> --- >>>>> Changes in v2: >>>>> >>>>> - added missing hunk in hyp/entry.S per Will's feedback >>>> >>>> What about 4.19.y and 4.14.y trees? I can't take something for 4.9.y >>>> and then have a regression if someone moves to a newer release, right? >>> >>> Sure, send you candidates for 4.14 and 4.19. >> >> Greg, did you have a chance to queue those changes for 4.9, 4.14 and 4.19? >> >> https://lore.kernel.org/linux-arm-kernel/20200720182538.13304-1-f.fainelli@xxxxxxxxx/ >> https://lore.kernel.org/linux-arm-kernel/20200720182937.14099-1-f.fainelli@xxxxxxxxx/ >> https://lore.kernel.org/linux-arm-kernel/20200709195034.15185-1-f.fainelli@xxxxxxxxx/ > > Nope, I was waiting for Will's "ack" for these. OK, Will, can you review those? Thanks -- Florian