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Commit abc5b427 authored by Stefan Berger's avatar Stefan Berger Committed by Greg Kroah-Hartman
Browse files

tpm: ibmvtpm: Wait for buffer to be set before proceeding 



[ Upstream commit d8d74ea3c00214aee1e1826ca18e77944812b9b4 ]

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: 132f7629 ("drivers/char/tpm: Add new device driver to support IBM vTPM")
Signed-off-by: default avatarStefan Berger <stefanb@linux.ibm.com>
Acked-by: default avatarNayna Jain <nayna@linux.ibm.com>
Tested-by: default avatarNayna Jain <nayna@linux.ibm.com>
Reviewed-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent ff331054

drivers/char/tpm/tpm_ibmvtpm.c

+9 −0
Original line number Diff line number Diff line
@@ -588,6 +588,7 @@ 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();

	}
@@ -635,6 +636,7 @@ 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);
@@ -687,6 +689,13 @@ 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 {

drivers/char/tpm/tpm_ibmvtpm.h

+1 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ struct ibmvtpm_crq_queue { 
	struct ibmvtpm_crq *crq_addr;

	u32 index;

	u32 num_entry;

	wait_queue_head_t wq;

};



struct ibmvtpm_dev {