lkml.org 
[lkml]   [2017]   [Dec]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRE: [PATCH] tpm: Fix the driver cleanup code
Date


>-----Original Message-----
>From: linux-integrity-owner@vger.kernel.org [mailto:linux-integrity-
>owner@vger.kernel.org] On Behalf Of Jason Gunthorpe
>Sent: Thursday, December 21, 2017 12:39 PM
>To: Shaikh, Azhar <azhar.shaikh@intel.com>
>Cc: jarkko.sakkinen@linux.intel.com; javierm@redhat.com;
>peterhuewe@gmx.de; linux-security-module@vger.kernel.org; linux-
>integrity@vger.kernel.org; linux-kernel@vger.kernel.org; tpmdd-
>devel@lists.sourceforge.net
>Subject: Re: [PATCH] tpm: Fix the driver cleanup code
>
>On Thu, Dec 21, 2017 at 08:31:14PM +0000, Shaikh, Azhar wrote:
>
>> Yes I thought about it too. But if some other chip->ops function in
>> future, which *might* be in this same case, hence for that introduced
>> this flag.
>
>It can't be - the ops struct is constant, can't be modified, and tpm_tis_core
>controls what is set. If someone future person meddles in this then they can
>fix here to.
>
Yes, I checked this part. What I was referring to is any other callback function similar to clk_enable if gets added in future and then needs to
Access ops even after it is set to NULL...

>Recommend a short comment in the ops clk_enale initializer and call direct?
>

But yes I get your point now.

So do you mean something like this?

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index d9099281fc2e..1187e72483f2 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -716,8 +716,7 @@ void 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)
@@ -725,14 +724,8 @@ 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 (chip->flags & TPM_CHIP_FLAG_DO_NOT_CLEAR_OPS) {
- down_write(&chip->ops_sem);
- chip->ops = NULL;
- up_write(&chip->ops_sem);
- }
if (priv->ilb_base_addr)
iounmap(priv->ilb_base_addr);
}
>Jason

Regards,
Azhar Shaikh

\
 
 \ /
  Last update: 2017-12-21 22:55    [W:0.059 / U:2.596 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site