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From: Stephen Boyd <swboyd@chromium.org>
To: Peter Huewe <peterhuewe@gmx.de>,
	Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Andrey Pronin <apronin@chromium.org>,
	linux-kernel@vger.kernel.org, Jason Gunthorpe <jgg@ziepe.ca>,
	Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-integrity@vger.kernel.org, devicetree@vger.kernel.org,
	Duncan Laurie <dlaurie@chromium.org>,
	Guenter Roeck <groeck@chromium.org>
Subject: [PATCH 1/8] tpm: block messages while suspended
Date: Thu, 13 Jun 2019 11:09:24 -0700
Message-ID: <20190613180931.65445-2-swboyd@chromium.org> (raw)
In-Reply-To: <20190613180931.65445-1-swboyd@chromium.org>

From: Andrey Pronin <apronin@chromium.org>

Other drivers or userspace may initiate sending a message to the tpm
while the device itself and the controller of the bus it is on are
suspended. That may break the bus driver logic.
Block sending messages while the device is suspended.

Signed-off-by: Andrey Pronin <apronin@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---

I don't think this was ever posted before.

 drivers/char/tpm/tpm-interface.c | 16 ++++++++++++++--
 include/linux/tpm.h              |  2 ++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index ae1030c9b086..7232527652e8 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -86,6 +86,11 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
 		return -E2BIG;
 	}
 
+	if (test_bit(0, &chip->is_suspended)) {
+		dev_warn(&chip->dev, "blocking transmit while suspended\n");
+		return -EAGAIN;
+	}
+
 	rc = chip->ops->send(chip, buf, count);
 	if (rc < 0) {
 		if (rc != -EPIPE)
@@ -403,14 +408,19 @@ int tpm_pm_suspend(struct device *dev)
 		return 0;
 
 	if (!tpm_chip_start(chip)) {
-		if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 			tpm2_shutdown(chip, TPM2_SU_STATE);
-		else
+			set_bit(0, &chip->is_suspended);
+		} else {
 			rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
+		}
 
 		tpm_chip_stop(chip);
 	}
 
+	if (!rc)
+		set_bit(0, &chip->is_suspended);
+
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
@@ -426,6 +436,8 @@ int tpm_pm_resume(struct device *dev)
 	if (chip == NULL)
 		return -ENODEV;
 
+	clear_bit(0, &chip->is_suspended);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(tpm_pm_resume);
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 1b5436b213a2..48df005228d0 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -132,6 +132,8 @@ struct tpm_chip {
 	int dev_num;		/* /dev/tpm# */
 	unsigned long is_open;	/* only one allowed */
 
+	unsigned long is_suspended;
+
 	char hwrng_name[64];
 	struct hwrng hwrng;
 
-- 
Sent by a computer through tubes


  reply index

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-13 18:09 [PATCH 0/8] tpm: Add driver for cr50 Stephen Boyd
2019-06-13 18:09 ` Stephen Boyd [this message]
2019-06-13 23:26   ` [PATCH 1/8] tpm: block messages while suspended Jason Gunthorpe
2019-06-14 18:12     ` Stephen Boyd
2019-06-17 22:51       ` Jason Gunthorpe
2019-06-21  1:03         ` Stephen Boyd
2019-06-24 14:26           ` Herbert Xu
2019-07-16 18:28             ` Stephen Boyd
2019-06-14 15:27   ` Jarkko Sakkinen
2019-06-14 18:13     ` Stephen Boyd
2019-06-17 16:38       ` Jarkko Sakkinen
2019-06-13 18:09 ` [PATCH 2/8] tpm_tis_core: add optional max xfer size check Stephen Boyd
2019-06-14 15:24   ` Jarkko Sakkinen
2019-06-13 18:09 ` [PATCH 3/8] tpm_tis_spi: add max xfer size Stephen Boyd
2019-06-14 15:25   ` Jarkko Sakkinen
2019-06-13 18:09 ` [PATCH 4/8] dt-bindings: tpm: document properties for cr50 Stephen Boyd
2019-07-09 14:41   ` Rob Herring
2019-06-13 18:09 ` [PATCH 5/8] tpm: add driver for cr50 on SPI Stephen Boyd
2019-06-13 18:09 ` [PATCH 6/8] tpm: Add driver for cr50 on I2C Stephen Boyd
2019-06-13 18:09 ` [PATCH 7/8] tpm: add sysfs attributes for tpm2 Stephen Boyd
2019-06-13 23:30   ` Jason Gunthorpe
2019-06-14 15:31   ` Jarkko Sakkinen
2019-06-13 18:09 ` [PATCH 8/8] tpm: add legacy " Stephen Boyd
2019-06-13 23:44   ` Jason Gunthorpe

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