| Message ID | 1513887422-123222-1-git-send-email-azhar.shaikh@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Dec 21, 2017 at 12:17:02PM -0800, Azhar Shaikh wrote: > 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 <azhar.shaikh@intel.com> > drivers/char/tpm/tpm-chip.c | 5 +++++ > drivers/char/tpm/tpm.h | 1 + > drivers/char/tpm/tpm_tis.c | 8 ++------ > drivers/char/tpm/tpm_tis_core.c | 23 +++++++++++++++-------- > drivers/char/tpm/tpm_tis_spi.c | 1 + > 5 files changed, 24 insertions(+), 14 deletions(-) > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > index 0a62c19937b6..c88ec9a32a7e 100644 > +++ b/drivers/char/tpm/tpm-chip.c > @@ -346,6 +346,10 @@ static void tpm_del_char_device(struct tpm_chip *chip) > down_write(&chip->ops_sem); > if (chip->flags & TPM_CHIP_FLAG_TPM2) > tpm2_shutdown(chip, TPM2_SU_CLEAR); > + if (chip->flags & TPM_CHIP_FLAG_DO_NOT_CLEAR_OPS) { > + up_write(&chip->ops_sem); > + return; > + } Yikes, too ugly. Figure something else out.. ops->clk_enable is always tpm_tis_clkrun_enable at this point, so maybe call it directly in the removal path in tpm_tis_core? Jason
>-----Original Message----- >From: Jason Gunthorpe [mailto:jgg@ziepe.ca] >Sent: Thursday, December 21, 2017 12:27 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 12:17:02PM -0800, Azhar Shaikh wrote: >> 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 <azhar.shaikh@intel.com> >> drivers/char/tpm/tpm-chip.c | 5 +++++ >> drivers/char/tpm/tpm.h | 1 + >> drivers/char/tpm/tpm_tis.c | 8 ++------ >> drivers/char/tpm/tpm_tis_core.c | 23 +++++++++++++++-------- >> drivers/char/tpm/tpm_tis_spi.c | 1 + >> 5 files changed, 24 insertions(+), 14 deletions(-) >> >> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c >> index 0a62c19937b6..c88ec9a32a7e 100644 >> +++ b/drivers/char/tpm/tpm-chip.c >> @@ -346,6 +346,10 @@ static void tpm_del_char_device(struct tpm_chip >*chip) >> down_write(&chip->ops_sem); >> if (chip->flags & TPM_CHIP_FLAG_TPM2) >> tpm2_shutdown(chip, TPM2_SU_CLEAR); >> + if (chip->flags & TPM_CHIP_FLAG_DO_NOT_CLEAR_OPS) { >> + up_write(&chip->ops_sem); >> + return; >> + } > >Yikes, too ugly. Figure something else out.. ops->clk_enable is always >tpm_tis_clkrun_enable at this point, so maybe call it directly in the removal >path in tpm_tis_core? > 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. I can use ops->clk_enable instead of introducing the new flag. >Jason Regards, Azhar Shaikh
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. Recommend a short comment in the ops clk_enale initializer and call direct? Jason
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 0a62c19937b6..c88ec9a32a7e 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -346,6 +346,10 @@ static void tpm_del_char_device(struct tpm_chip *chip) down_write(&chip->ops_sem); if (chip->flags & TPM_CHIP_FLAG_TPM2) tpm2_shutdown(chip, TPM2_SU_CLEAR); + if (chip->flags & TPM_CHIP_FLAG_DO_NOT_CLEAR_OPS) { + up_write(&chip->ops_sem); + return; + } chip->ops = NULL; up_write(&chip->ops_sem); } @@ -454,6 +458,7 @@ int tpm_chip_register(struct tpm_chip *chip) rc = tpm_add_legacy_sysfs(chip); if (rc) { + chip->flags |= TPM_CHIP_FLAG_DO_NOT_CLEAR_OPS; tpm_chip_unregister(chip); return rc; } diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index f895fba4e20d..dc2a532649e0 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -183,6 +183,7 @@ enum tpm_chip_flags { TPM_CHIP_FLAG_VIRTUAL = BIT(3), TPM_CHIP_FLAG_HAVE_TIMEOUTS = BIT(4), TPM_CHIP_FLAG_ALWAYS_POWERED = BIT(5), + TPM_CHIP_FLAG_DO_NOT_CLEAR_OPS = BIT(6), }; struct tpm_bios_log { diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index d29add49b033..a146ef4e499b 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -273,11 +273,9 @@ static void tpm_tis_pnp_remove(struct pnp_dev *dev) struct tpm_chip *chip = pnp_get_drvdata(dev); struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); + chip->flags |= TPM_CHIP_FLAG_DO_NOT_CLEAR_OPS; tpm_chip_unregister(chip); tpm_tis_remove(chip); - if (is_bsw()) - iounmap(priv->ilb_base_addr); - } static struct pnp_driver tis_pnp_driver = { @@ -326,12 +324,10 @@ static int tpm_tis_plat_remove(struct platform_device *pdev) struct tpm_chip *chip = dev_get_drvdata(&pdev->dev); struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); + chip->flags |= TPM_CHIP_FLAG_DO_NOT_CLEAR_OPS; 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..d9099281fc2e 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -727,6 +727,14 @@ void tpm_tis_remove(struct tpm_chip *chip) if (chip->ops->clk_enable != NULL) chip->ops->clk_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); } EXPORT_SYMBOL_GPL(tpm_tis_remove); @@ -922,21 +930,20 @@ 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); diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c index 424ff2fde1f2..79c18cfc6519 100644 --- a/drivers/char/tpm/tpm_tis_spi.c +++ b/drivers/char/tpm/tpm_tis_spi.c @@ -221,6 +221,7 @@ static int tpm_tis_spi_remove(struct spi_device *dev) { struct tpm_chip *chip = spi_get_drvdata(dev); + chip->flags |= TPM_CHIP_FLAG_DO_NOT_CLEAR_OPS; tpm_chip_unregister(chip); tpm_tis_remove(chip); return 0;
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 <azhar.shaikh@intel.com> --- drivers/char/tpm/tpm-chip.c | 5 +++++ drivers/char/tpm/tpm.h | 1 + drivers/char/tpm/tpm_tis.c | 8 ++------ drivers/char/tpm/tpm_tis_core.c | 23 +++++++++++++++-------- drivers/char/tpm/tpm_tis_spi.c | 1 + 5 files changed, 24 insertions(+), 14 deletions(-)