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? thanks, greg k-h
