On Mon, Mar 02, 2020 at 05:11:23PM +0100, Joerg Roedel wrote:
> On Mon, Mar 02, 2020 at 11:53:01AM +0000, Will Deacon wrote:
> > On Fri, Feb 28, 2020 at 02:18:55PM +0000, Robin Murphy wrote:
> > > Since we ony support the TTB1 quirk for AArch64 contexts, and
> > > consequently only for 64-bit builds, the sign-extension aspect of the
> > > "are all bits above IAS consistent?" check should implicitly only apply
> > > to 64-bit IOVAs. Change the type of the cast to ensure that 32-bit longs
> > > don't inadvertently get sign-extended, and thus considered invalid, if
> > > they happen to be above 2GB in the TTB0 region.
> > >
> > > Reported-by: Stephan Gerhold <step...@gerhold.net>
> > > Signed-off-by: Robin Murphy <robin.mur...@arm.com>
> > >
> > > ---
> > >
> > > Logically there may also have been a UBSAN "shift greater than size of
> > > type" warning too, but arch/arm doesn't support UBSAN_SANITIZE_ALL,
> > > and that's now my only easy "spin up a 32-bit VM" option to hand :)
> > >
> > > drivers/iommu/io-pgtable-arm.c | 4 ++--
> > > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > Acked-by: Will Deacon <w...@kernel.org>
> >
> > Joerg -- pleae can you take this as a fix for 5.6?
>
> Done, do you also have a fixes-tag for me?
Fixes: db6903010aa5 ("iommu/io-pgtable-arm: Prepare for TTBR1 usage")
Although it doesn't need to go to -stable, since this was only introduced
during the recent merge window.
Will
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