tpm: vtpm_proxy: Avoid reading host log when using a virtual device

commit 9716ac65efc8f780549b03bddf41e60c445d4709 upstream.

Avoid allocating memory and reading the host log when a virtual device
is used since this log is of no use to that driver. A virtual
device can be identified through the flag TPM_CHIP_FLAG_VIRTUAL, which
is only set for the tpm_vtpm_proxy driver.

Cc: stable@vger.kernel.org
Fixes: 6f99612e2500 ("tpm: Proxy driver for supporting multiple emulated TPMs")
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/char/tpm/eventlog/common.c b/drivers/char/tpm/eventlog/common.c
index 7d70b654df04d44c974ee069407a0294a4b9da78..462476467bffe00d62e22b4399d8ac9a93d83a03 100644 (file)
--- a/drivers/char/tpm/eventlog/common.c
+++ b/drivers/char/tpm/eventlog/common.c
@@ -112,6 +112,9 @@ void tpm_bios_log_setup(struct tpm_chip *chip)
        int log_version;
        int rc = 0;
 
+       if (chip->flags & TPM_CHIP_FLAG_VIRTUAL)
+               return;
+
        rc = tpm_read_log(chip);
        if (rc < 0)
                return;