| Message ID | 1423864643-7318-1-git-send-email-chris.j.arges@canonical.com |
|---|---|
| State | New |
| Headers | show |
Looks safe.
Applied to Vivid master-next and unstable branches. Thanks, Leann On Fri, 2015-02-13 at 15:57 -0600, Chris J Arges wrote: > From: "Hon Ching (Vicky) Lo" <honclo@linux.vnet.ibm.com> > > There was an oops in tpm_ibmvtpm_get_desired_dma, which caused > kernel panic during boot when vTPM is enabled in Power partition > configured in AMS mode. > > vio_bus_probe calls vio_cmo_bus_probe which calls > tpm_ibmvtpm_get_desired_dma to get the size needed for DMA allocation. > The problem is, vio_cmo_bus_probe is called before calling probe, which > for vtpm is tpm_ibmvtpm_probe and it's this function that initializes > and sets up vtpm's CRQ and gets required data values. Therefore, > since this has not yet been done, NULL is returned in attempt to get > the size for DMA allocation. > > We added a NULL check. In addition, a default buffer size will > be set when NULL is returned. > > Cc: <stable@vger.kernel.org> > Signed-off-by: Hon Ching (Vicky) Lo <honclo@linux.vnet.ibm.com> > Signed-off-by: Peter Huewe <peterhuewe@gmx.de> > (cherry picked from commit 84eb186bc37c0900b53077ca21cf6dd15823a232) > Signed-off-by: Chris J Arges <chris.j.arges@canonical.com> > --- > drivers/char/tpm/tpm_ibmvtpm.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c > index af74c57..4109222 100644 > --- a/drivers/char/tpm/tpm_ibmvtpm.c > +++ b/drivers/char/tpm/tpm_ibmvtpm.c > @@ -307,6 +307,14 @@ static int tpm_ibmvtpm_remove(struct vio_dev *vdev) > static unsigned long tpm_ibmvtpm_get_desired_dma(struct vio_dev *vdev) > { > struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(&vdev->dev); > + > + /* ibmvtpm initializes at probe time, so the data we are > + * asking for may not be set yet. Estimate that 4K required > + * for TCE-mapped buffer in addition to CRQ. > + */ > + if (!ibmvtpm) > + return CRQ_RES_BUF_SIZE + PAGE_SIZE; > + > return CRQ_RES_BUF_SIZE + ibmvtpm->rtce_size; > } > > -- > 1.9.1 > >
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c index af74c57..4109222 100644 --- a/drivers/char/tpm/tpm_ibmvtpm.c +++ b/drivers/char/tpm/tpm_ibmvtpm.c @@ -307,6 +307,14 @@ static int tpm_ibmvtpm_remove(struct vio_dev *vdev) static unsigned long tpm_ibmvtpm_get_desired_dma(struct vio_dev *vdev) { struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(&vdev->dev); + + /* ibmvtpm initializes at probe time, so the data we are + * asking for may not be set yet. Estimate that 4K required + * for TCE-mapped buffer in addition to CRQ. + */ + if (!ibmvtpm) + return CRQ_RES_BUF_SIZE + PAGE_SIZE; + return CRQ_RES_BUF_SIZE + ibmvtpm->rtce_size; }