Thanks for the excellent review comments. I'll do another spin an try to
incorporate most them.
/Jarkko
On Wed, Oct 22, 2014 at 11:26:46AM -0600, Jason Gunthorpe wrote:
> On Wed, Oct 22, 2014 at 07:23:56PM +0300, Jarkko Sakkinen wrote:
> > Traversal of the ACPI device tree was not done right. It should lookup
> > PPI only under the ACPI device that it is associated. Otherwise, it could
> > match to a wrong PPI interface if there are two TPM devices in the device
> > tree.
> >
> > Removed global ACPI handle and version string from tpm_ppi.c as this
> > is racy. Instead they should be associated with the chip.
> >
> > Moved code just a tiny bit towards two-phase allocation to implement
> > fix for the PPI race conditions.
>
> Not this version..
>
> > Added missing copyright platter to tpm_ppi.c.
> >
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
>
> Reviewed-by: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
>
> I like this one the most of the three I've seen :)
>
> Did you also look in tpm_acpi.c to see if it needs to use
> acpi_dev_handle somehow too?
>
> > + union acpi_object *obj;
> > + struct kobject *parent = &chip->dev->kobj;
>
> Nit, this variable is only used once, it would be clearer to inline
>
> > + /* Cache PPI version string. */
> > + obj = acpi_evaluate_dsm_typed(chip->acpi_dev_handle, tpm_ppi_uuid,
> > + TPM_PPI_REVISION_ID, TPM_PPI_FN_VERSION,
> > + NULL, ACPI_TYPE_STRING);
> > + if (obj) {
> > + strlcpy(chip->ppi_version, obj->string.pointer,
> > + PPI_VERSION_LEN + 1);
> > + ACPI_FREE(obj);
> > + } else
> > + return -ENOMEM;
> > +
> > + return chip->acpi_dev_handle ?
> > + sysfs_create_group(parent, &ppi_attr_grp) : 0;
>
> The above sequence can just be:
>
> if (!obj)
> return -ENOMEM;
>
> strlcpy(chip->ppi_version, obj->string.pointer, sizeof(chip->ppi_version));
> ACPI_FREE(obj);
>
> return sysfs_create_group(&chip->dev->kobj, &ppi_attr_grp);
>
> Which is more idiomatic. Also remove TPM_PPI_VERSION_LEN, sizeof is better.
>
> I know nothing about acpi, but is ENOMEM the right code? I would think
> acpi_evalute_dsm_typed would also fail if tpm_ppi_uuid is not found??
>
> > + return chip->acpi_dev_handle ?
> > + sysfs_create_group(parent, &ppi_attr_grp) : 0;
>
> dev_handle is already checked to be non 0
>
> > +void tpm_remove_ppi(struct tpm_chip *chip)
> > + struct kobject *parent = &chip->dev->kobj;
>
> Also used only once
>
> Jason
--
To unsubscribe from this list: send the line "unsubscribe linux-api" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
