Re: [git patches] libata fixes

[Greg Freemyer]

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).

Greg
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