| Message ID | 20200312155332.671464-3-stefanb@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Enable vTPM 2.0 for the IBM vTPM driver | expand |
On Thu, Mar 12, 2020 at 11:53:31AM -0400, Stefan Berger wrote: > From: Stefan Berger <stefanb@linux.ibm.com> > > Synchronize with the results from the CRQs before continuing with > the initialization. This avoids trying to send TPM commands while > the rtce buffer has not been allocated, yet. > > This patch fixes an existing race condition that may occurr if the > hypervisor does not quickly respond to the VTPM_GET_RTCE_BUFFER_SIZE > request sent during initialization and therefore the ibmvtpm->rtce_buf > has not been allocated at the time the first TPM command is sent. > > Fixes: 132f76294744 ("Add new device driver to support IBM vTPM") > Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> > Acked-by: Nayna Jain <nayna@linux.ibm.com> > Tested-by: Nayna Jain <nayna@linux.ibm.com> > --- > drivers/char/tpm/tpm_ibmvtpm.c | 9 +++++++++ > drivers/char/tpm/tpm_ibmvtpm.h | 1 + > 2 files changed, 10 insertions(+) > > diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c > index 78cc52690177..cfe40e7b1ba4 100644 > --- a/drivers/char/tpm/tpm_ibmvtpm.c > +++ b/drivers/char/tpm/tpm_ibmvtpm.c > @@ -571,6 +571,7 @@ static irqreturn_t ibmvtpm_interrupt(int irq, void *vtpm_instance) > */ > while ((crq = ibmvtpm_crq_get_next(ibmvtpm)) != NULL) { > ibmvtpm_crq_process(crq, ibmvtpm); > + wake_up_interruptible(&ibmvtpm->crq_queue.wq); > crq->valid = 0; > smp_wmb(); > } > @@ -618,6 +619,7 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, > } > > crq_q->num_entry = CRQ_RES_BUF_SIZE / sizeof(*crq_q->crq_addr); > + init_waitqueue_head(&crq_q->wq); > ibmvtpm->crq_dma_handle = dma_map_single(dev, crq_q->crq_addr, > CRQ_RES_BUF_SIZE, > DMA_BIDIRECTIONAL); > @@ -670,6 +672,13 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, > if (rc) > goto init_irq_cleanup; > > + if (!wait_event_timeout(ibmvtpm->crq_queue.wq, > + ibmvtpm->rtce_buf != NULL, > + HZ)) { > + dev_err(dev, "CRQ response timed out\n"); > + goto init_irq_cleanup; > + } > + > return tpm_chip_register(chip); > init_irq_cleanup: > do { > diff --git a/drivers/char/tpm/tpm_ibmvtpm.h b/drivers/char/tpm/tpm_ibmvtpm.h > index 7983f1a33267..b92aa7d3e93e 100644 > --- a/drivers/char/tpm/tpm_ibmvtpm.h > +++ b/drivers/char/tpm/tpm_ibmvtpm.h > @@ -26,6 +26,7 @@ struct ibmvtpm_crq_queue { > struct ibmvtpm_crq *crq_addr; > u32 index; > u32 num_entry; > + wait_queue_head_t wq; > }; > > struct ibmvtpm_dev { > -- > 2.23.0 > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> /Jarkko
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c index 78cc52690177..cfe40e7b1ba4 100644 --- a/drivers/char/tpm/tpm_ibmvtpm.c +++ b/drivers/char/tpm/tpm_ibmvtpm.c @@ -571,6 +571,7 @@ static irqreturn_t ibmvtpm_interrupt(int irq, void *vtpm_instance) */ while ((crq = ibmvtpm_crq_get_next(ibmvtpm)) != NULL) { ibmvtpm_crq_process(crq, ibmvtpm); + wake_up_interruptible(&ibmvtpm->crq_queue.wq); crq->valid = 0; smp_wmb(); } @@ -618,6 +619,7 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, } crq_q->num_entry = CRQ_RES_BUF_SIZE / sizeof(*crq_q->crq_addr); + init_waitqueue_head(&crq_q->wq); ibmvtpm->crq_dma_handle = dma_map_single(dev, crq_q->crq_addr, CRQ_RES_BUF_SIZE, DMA_BIDIRECTIONAL); @@ -670,6 +672,13 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, if (rc) goto init_irq_cleanup; + if (!wait_event_timeout(ibmvtpm->crq_queue.wq, + ibmvtpm->rtce_buf != NULL, + HZ)) { + dev_err(dev, "CRQ response timed out\n"); + goto init_irq_cleanup; + } + return tpm_chip_register(chip); init_irq_cleanup: do { diff --git a/drivers/char/tpm/tpm_ibmvtpm.h b/drivers/char/tpm/tpm_ibmvtpm.h index 7983f1a33267..b92aa7d3e93e 100644 --- a/drivers/char/tpm/tpm_ibmvtpm.h +++ b/drivers/char/tpm/tpm_ibmvtpm.h @@ -26,6 +26,7 @@ struct ibmvtpm_crq_queue { struct ibmvtpm_crq *crq_addr; u32 index; u32 num_entry; + wait_queue_head_t wq; }; struct ibmvtpm_dev {