Re: [git patches] libata fixes

[Mark Lord]

Greg Freemyer wrote:
> On Sun, Nov 2, 2008 at 8:21 AM, Jeff Garzik <jeff@xxxxxxxxxx> wrote:
> > Greg Freemyer wrote:
> > > On Fri, Oct 31, 2008 at 1:49 AM, Jeff Garzik <jeff@xxxxxxxxxx> wrote:
> > > > Notes:
> > > >
> > > > 1) 1.5TB drive fix from Roland
> > > >
> > > > 2) Tejun's sata_via brings a non-working via configuration thanks to a
> > > >  new facility also being used in recent (ICH9/10) ata_piix.
> > > >
> > > >  Change is longer than one might like, but it accurately describes the
> > > >  hardware now, the previous stuff wasn't working, and the newly added
> > > >  support code shouldn't touch non-broken VIA controllers.
> > > >
> > > >
> > > >
> > > > Please pull from 'upstream-linus' branch of
> > > > master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev.git
> > > > upstream-linus
> > > >
> > > > to receive the following updates:
> > > >
> > > >  drivers/ata/ata_piix.c    |    1 -
> > > >  drivers/ata/libata-core.c |   11 +++-
> > > >  drivers/ata/sata_via.c    |  155
> > > > +++++++++++++++++++++++++++++++++++++++++----
> > > >  include/linux/libata.h    |    1 +
> > > >  4 files changed, 152 insertions(+), 16 deletions(-)
> > > >
> > > > Jens Axboe (1):
> > > >     libata: add whitelist for devices with known good pata-sata bridges
> > > >
> > > > Randy Dunlap (1):
> > > >     ATA: remove excess kernel-doc notation
> > > >
> > > > Roland Dreier (1):
> > > >     libata: Avoid overflow in ata_tf_to_lba48() when tf->hba_lbal > 127
> > > >
> > > > Tejun Heo (1):
> > > >     sata_via: fix support for 5287
> > > <snip>
> > >
> > > > diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> > > > index 2ff633c..82af701 100644
> > > > --- a/drivers/ata/libata-core.c
> > > > +++ b/drivers/ata/libata-core.c
> > > > @@ -1268,7 +1268,7 @@ u64 ata_tf_to_lba48(const struct ata_taskfile *tf)
> > > >
> > > >       sectors |= ((u64)(tf->hob_lbah & 0xff)) << 40;
> > > >       sectors |= ((u64)(tf->hob_lbam & 0xff)) << 32;
> > > > -       sectors |= (tf->hob_lbal & 0xff) << 24;
> > > > +       sectors |= ((u64)(tf->hob_lbal & 0xff)) << 24;
> > > >       sectors |= (tf->lbah & 0xff) << 16;
> > > >       sectors |= (tf->lbam & 0xff) << 8;
> > > >       sectors |= (tf->lbal & 0xff);
> > > <snip>
> > >
> > > That looks really serious.
> > >
> > > What happens with all previous / stable kernels when connecting up a
> > > 1.5TB drive and the user tries to use the last portion of the drive?
> > tf-to-lba48 is a far less common operation, generally used for error
> > reporting (and in Host-Protected Area code as well, it appears).
> >
> >        Jeff
>
> So are you saying it is not on any data read / write paths?
>
> Or that it is only on rarely used data read/write paths?
>
> Because if this is on a data read/write path at all, it looks like it
> could cause major data corruption with 1.5 TB drives (or larger).
..

It's on the initialization path for all lba48 devices which have
a configured HPA (Host Protected Area, mostly seen in brand-name
consumer-level systems).

The data it generates is then used on subsequent R/W commands.
I recommend the fix be backported for earlier kernels.

Cheers
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/