On Tue, Nov 13, 2018 at 04:29:06PM +0100, Alexander Graf wrote: > I've already stumbled over 2 cases where people got confused about how to > disable kpti on AArch64. In both cases, they used existing x86_64 options > and just applied that to an AArch64 system, expecting it to work. > > I think it makes a lot of sense to have compatible kernel command line > parameters whenever we can have them be compatible. > > So this patch adds the pti= and no_pti kernel command line options, mapping > them into the existing kpti= command line framework. It preserves the old > syntax to maintain compatibility with older command lines. > > While at it, the patch also marks the respective options as dual-arch. > > Reported-by: Richard Brown <rbrown@xxxxxxx> > Signed-off-by: Alexander Graf <agraf@xxxxxxx> > > --- > > v1 -> v2: > > - Actually make it compile. Sorry for the sloppy v1. > --- > Documentation/admin-guide/kernel-parameters.txt | 6 +++--- > arch/arm64/kernel/cpufeature.c | 20 +++++++++++++++++++- > 2 files changed, 22 insertions(+), 4 deletions(-) This patch doesn't help though, right, because kpti= has already been included with backports etc so the ship has sailed? Yeah, it's not ideal, but we went over this before: http://lists.infradead.org/pipermail/linux-arm-kernel/2018-August/598395.html The thing we really need is the sysfs interface hooking up so you can easily check the state of the mitigation. Still waiting for a follow-up on that ;) http://lists.infradead.org/pipermail/linux-arm-kernel/2018-September/603412.html Will
