-----Original Message-----
From: Jarkko Sakkinen [mailto:jarkko.sakkinen at linux.intel.com]
Sent: Friday, December 22, 2017 10:42 AM
To: Shaikh, Azhar <redacted>
Cc: jgg at ziepe.ca; javierm at redhat.com; peterhuewe at gmx.de; linux-security-
module at vger.kernel.org; linux-integrity at vger.kernel.org; linux-
kernel at vger.kernel.org
Subject: Re: [PATCH v2] tpm: Fix the driver cleanup code

On Thu, Dec 21, 2017 at 03:13:39PM -0800, Azhar Shaikh wrote:

quoted

Commit 3c1701339284353c41 ("tpm: Keep CLKRUN enabled throughout the
duration of transmit_cmd()") added code which accessed
chip->ops, even after it was set to NULL in tpm_del_char_device(),
called from tpm_chip_unregister() in error / driver exit paths.
So fix this code.

Fixes: 3c1701339284353c41 ("tpm: Keep CLKRUN enabled throughout the
duration of transmit_cmd()")

Suggested-by: Javier Martinez Canillas <javierm@redhat.com>
Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Azhar Shaikh <redacted>
---
Changes in v2:
- Remove TPM_CHIP_FLAG_DO_NOT_CLEAR_OPS flag, instead call
  tpm_tis_clkrun_enable() directly in tpm_tis_remove()
- Add comment to tpm_tis_clkrun_enable()

 drivers/char/tpm/tpm_tis.c      |  6 ------
 drivers/char/tpm/tpm_tis_core.c | 29 +++++++++++++++++------------
 2 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index d29add49b033..c847fc69a2fc 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c

@@ -275,9 +275,6 @@ static void tpm_tis_pnp_remove(struct pnp_dev

*dev)

 	tpm_chip_unregister(chip);
 	tpm_tis_remove(chip);
-	if (is_bsw())
-		iounmap(priv->ilb_base_addr);
-
 }

 static struct pnp_driver tis_pnp_driver = { @@ -329,9 +326,6 @@
static int tpm_tis_plat_remove(struct platform_device *pdev)
 	tpm_chip_unregister(chip);
 	tpm_tis_remove(chip);

-	if (is_bsw())
-		iounmap(priv->ilb_base_addr);
-
 	return 0;
 }

diff --git a/drivers/char/tpm/tpm_tis_core.c

b/drivers/char/tpm/tpm_tis_core.c index c2227983ed88..519e4a78c8f8
100644

--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c

@@ -37,6 +37,8 @@
  */
 #define TPM_POLL_SLEEP	1  /* msec */

+static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value);
+
 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 					bool check_cancel, bool *canceled)  {

@@ -716,8 +718,7 @@ void

quoted

tpm_tis_remove(struct tpm_chip *chip)
 	u32 interrupt;
 	int rc;

-	if (chip->ops->clk_enable != NULL)
-		chip->ops->clk_enable(chip, true);
+	tpm_tis_clkrun_enable(chip, true);

 	rc = tpm_tis_read32(priv, reg, &interrupt);
 	if (rc < 0)

@@ -725,8 +726,10 @@ void tpm_tis_remove(struct tpm_chip *chip)

 	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);

-	if (chip->ops->clk_enable != NULL)
-		chip->ops->clk_enable(chip, false);
+	tpm_tis_clkrun_enable(chip, false);
+
+	if (priv->ilb_base_addr)
+		iounmap(priv->ilb_base_addr);
 }
 EXPORT_SYMBOL_GPL(tpm_tis_remove);

@@ -736,6 +739,9 @@ void tpm_tis_remove(struct tpm_chip *chip)
  * @chip:	TPM chip to use
  * @value:	1 - Disable CLKRUN protocol, so that clocks are free running
  *		0 - Enable CLKRUN protocol
+ *
+ * Call this function directly in tpm_tis_remove() in error or driver
+ removal
+ * path, since the chip->ops is set to NULL in tpm_chip_unregister().
  */
 static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value)

{ @@ -922,21 +928,20 @@ int tpm_tis_core_init(struct device *dev,
struct tpm_tis_data *priv, int irq,
 	}

 	rc = tpm_chip_register(chip);
-	if (rc && is_bsw())
-		iounmap(priv->ilb_base_addr);
+	if (rc)
+		goto out_err;

 	if (chip->ops->clk_enable != NULL)
 		chip->ops->clk_enable(chip, false);

-	return rc;
-out_err:
-	tpm_tis_remove(chip);
-	if (is_bsw())
-		iounmap(priv->ilb_base_addr);
+	return 0;

-	if (chip->ops->clk_enable != NULL)
+out_err:
+	if ((chip->ops != NULL) && (chip->ops->clk_enable != NULL))
 		chip->ops->clk_enable(chip, false);

+	tpm_tis_remove(chip);
+
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_tis_core_init);
--
1.9.1

Since the original commit is not in the mainline yet, you should rather
send an updated version of that commit.