On Thu, 2019-02-07 at 15:29 +1100, Michael Ellerman wrote:
> Russell Currey <rus...@russell.cc> writes:
> >
> > Fixes: 3b10d0095a1e ("powerpc/mm/radix: Prevent kernel execution of
> > user
> > space")
>
> Don't word wrap the fixes line please.
My bad, will teach my editor :)
> > Cc: <sta...@vger.kernel.org>
> > Signed-off-by: Russell Currey <rus...@russell.cc>
> > ---
> > arch/powerpc/include/asm/cpuidle.h | 1 +
> > arch/powerpc/kernel/asm-offsets.c | 1 +
> > arch/powerpc/kernel/idle_book3s.S | 20 ++++++++++++++++++++
> > 3 files changed, 22 insertions(+)
> >
> > diff --git a/arch/powerpc/include/asm/cpuidle.h
> > b/arch/powerpc/include/asm/cpuidle.h
> > index 43e5f31fe64d..ad67dbe59498 100644
> > --- a/arch/powerpc/include/asm/cpuidle.h
> > +++ b/arch/powerpc/include/asm/cpuidle.h
> > @@ -77,6 +77,7 @@ struct stop_sprs {
> > u64 mmcr1;
> > u64 mmcr2;
> > u64 mmcra;
> > + u64 iamr;
> > };
>
> We don't actually need to put this in the paca anymore.
>
> > diff --git a/arch/powerpc/kernel/idle_book3s.S
> > b/arch/powerpc/kernel/idle_book3s.S
> > index 7f5ac2e8581b..bb4f552f6c7e 100644
> > --- a/arch/powerpc/kernel/idle_book3s.S
> > +++ b/arch/powerpc/kernel/idle_book3s.S
> > @@ -200,6 +200,12 @@ pnv_powersave_common:
> > /* Continue saving state */
> > SAVE_GPR(2, r1)
> > SAVE_NVGPRS(r1)
> > +
> > +BEGIN_FTR_SECTION
> > + mfspr r5, SPRN_IAMR
> > + std r5, STOP_IAMR(r13)
> > +END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
>
> We have space for a full pt_regs on the stack, and we're not using it
> all.
>
> We don't have a specific slot for the IAMR (we may want to in
> future),
> but for now you could follow the time-honoured tradition of (ab)using
> the _DAR slot, with an appropriate comment.
I read this, then did it, and when writing the comment I thought I was
clever using "(ab)use". I then reread this and realised I just
subconsciously stole it.
Thanks for the review.
> cheers
