linux/drivers/char/tpm/tpm_ibmvtpm.h
Stefan Berger 047d4226b0 tpm: ibmvtpm: Avoid error message when process gets signal while waiting
When rngd is run as root then lots of these types of message will appear
in the kernel log if the TPM has been configured to provide random bytes:

[ 7406.275163] tpm tpm0: tpm_transmit: tpm_recv: error -4

The issue is caused by the following call that is interrupted while
waiting for the TPM's response.

sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);

Rather than waiting for the response in the low level driver, have it use
the polling loop in tpm_try_transmit() that uses a command's duration to
poll until a result has been returned by the TPM, thus ending when the
timeout has occurred but not responding to signals and ctrl-c anymore. To
stay in this polling loop extend tpm_ibmvtpm_status() to return
'true' for as long as the vTPM is indicated as being busy in
tpm_processing_cmd. Since the loop requires the TPM's timeouts, get them
now using tpm_get_timeouts() after setting the TPM2 version flag on the
chip.

To recreat the resolved issue start rngd like this:

sudo rngd -r /dev/hwrng -t
sudo rngd -r /dev/tpm0 -t

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1981473
Fixes: 6674ff145e ("tpm_ibmvtpm: properly handle interrupted packet receptions")
Cc: Nayna Jain <nayna@linux.ibm.com>
Cc: George Wilson <gcwilson@linux.ibm.com>
Reported-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
2021-08-23 19:55:42 +03:00

74 lines
1.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012 IBM Corporation
*
* Author: Ashley Lai <ashleydlai@gmail.com>
*
* Maintained by: <tpmdd-devel@lists.sourceforge.net>
*
* Device driver for TCG/TCPA TPM (trusted platform module).
* Specifications at www.trustedcomputinggroup.org
*/
#ifndef __TPM_IBMVTPM_H__
#define __TPM_IBMVTPM_H__
/* vTPM Message Format 1 */
struct ibmvtpm_crq {
u8 valid;
u8 msg;
__be16 len;
__be32 data;
__be64 reserved;
} __attribute__((packed, aligned(8)));
struct ibmvtpm_crq_queue {
struct ibmvtpm_crq *crq_addr;
u32 index;
u32 num_entry;
wait_queue_head_t wq;
};
struct ibmvtpm_dev {
struct device *dev;
struct vio_dev *vdev;
struct ibmvtpm_crq_queue crq_queue;
dma_addr_t crq_dma_handle;
u32 rtce_size;
void __iomem *rtce_buf;
dma_addr_t rtce_dma_handle;
spinlock_t rtce_lock;
wait_queue_head_t wq;
u16 res_len;
u32 vtpm_version;
u8 tpm_processing_cmd;
};
#define CRQ_RES_BUF_SIZE PAGE_SIZE
/* Initialize CRQ */
#define INIT_CRQ_CMD 0xC001000000000000LL /* Init cmd */
#define INIT_CRQ_COMP_CMD 0xC002000000000000LL /* Init complete cmd */
#define INIT_CRQ_RES 0x01 /* Init respond */
#define INIT_CRQ_COMP_RES 0x02 /* Init complete respond */
#define VALID_INIT_CRQ 0xC0 /* Valid command for init crq */
/* vTPM CRQ response is the message type | 0x80 */
#define VTPM_MSG_RES 0x80
#define IBMVTPM_VALID_CMD 0x80
/* vTPM CRQ message types */
#define VTPM_GET_VERSION 0x01
#define VTPM_GET_VERSION_RES (0x01 | VTPM_MSG_RES)
#define VTPM_TPM_COMMAND 0x02
#define VTPM_TPM_COMMAND_RES (0x02 | VTPM_MSG_RES)
#define VTPM_GET_RTCE_BUFFER_SIZE 0x03
#define VTPM_GET_RTCE_BUFFER_SIZE_RES (0x03 | VTPM_MSG_RES)
#define VTPM_PREPARE_TO_SUSPEND 0x04
#define VTPM_PREPARE_TO_SUSPEND_RES (0x04 | VTPM_MSG_RES)
#endif