FAILED: patch "[PATCH] tpm: vtpm_proxy: Avoid reading host log when using a virtual" failed to apply to 4.9-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 9716ac65efc8f780549b03bddf41e60c445d4709 Mon Sep 17 00:00:00 2001
From: Stefan Berger <stefanb@linux.ibm.com>
Date: Wed, 10 Mar 2021 17:19:16 -0500
Subject: [PATCH] tpm: vtpm_proxy: Avoid reading host log when using a virtual
 device

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>

diff --git a/drivers/char/tpm/eventlog/common.c b/drivers/char/tpm/eventlog/common.c
index 7460f230bae4..8512ec76d526 100644
--- a/drivers/char/tpm/eventlog/common.c
+++ b/drivers/char/tpm/eventlog/common.c
@@ -107,6 +107,9 @@ 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;