From: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
To: Peter Huewe <peterhuewe@gmx.de>,
Jarkko Sakkinen <jarkko@kernel.org>,
Jason Gunthorpe <jgg@ziepe.ca>,
linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
Jia Zhang <zhang.jia@linux.alibaba.com>
Cc: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Subject: [PATCH] tpm/tpm_tis: Fix variable reset during IRQ probing
Date: Wed, 13 Jan 2021 20:00:21 +0800 [thread overview]
Message-ID: <20210113120021.59045-1-tianjia.zhang@linux.alibaba.com> (raw)
In tpm_tis_core_init(), tpm2_probe() will be called first, this
function will eventually call tpm_tis_send(), and then
tpm_tis_probe_irq_single() will detect whether the interrupt is
normal, mainly the installation interrupted, set `priv->irq_tested`
to false. The logic will eventually be executed to tpm_tis_send()
to trigger an interrupt.
There is currently such a scenario, which will cause the IRQ probe
code to never be executed, so that the TPM device is in polling
mode: after setting irq_tested to false, an interrupt occurs
between entering the ttpm_tis_send() function, and the interrupt
will be first set irq_tested to true will cause the IRQ probe code
to never be executed.
It seems that this interrupt comes from tpm2_probe(). Although the
interrupt has not been installed when tpm2_probe() is called, the
interrupt of tpm2_probe() is only received after IRQ detection.
This patch solves this issue by introducing a new variable, which
is only used in interrupts, and irq_tested only marks whether the
interrupt test has been completed.
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
---
drivers/char/tpm/tpm_tis_core.c | 8 ++++----
drivers/char/tpm/tpm_tis_core.h | 1 +
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 92c51c6cfd1b..d7589b0b3e56 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -502,7 +502,7 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
int rc, irq;
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
- if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || priv->irq_tested)
+ if (priv->irq_tested)
return tpm_tis_send_main(chip, buf, len);
/* Verify receipt of the expected IRQ */
@@ -512,9 +512,9 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
rc = tpm_tis_send_main(chip, buf, len);
priv->irq = irq;
chip->flags |= TPM_CHIP_FLAG_IRQ;
- if (!priv->irq_tested)
+ if (!priv->int_count)
tpm_msleep(1);
- if (!priv->irq_tested)
+ if (!priv->int_count)
disable_interrupts(chip);
priv->irq_tested = true;
return rc;
@@ -725,7 +725,7 @@ static irqreturn_t tis_int_handler(int dummy, void *dev_id)
if (interrupt == 0)
return IRQ_NONE;
- priv->irq_tested = true;
+ priv->int_count += 1;
if (interrupt & TPM_INTF_DATA_AVAIL_INT)
wake_up_interruptible(&priv->read_queue);
if (interrupt & TPM_INTF_LOCALITY_CHANGE_INT)
diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h
index 9b2d32a59f67..c6845672f6f7 100644
--- a/drivers/char/tpm/tpm_tis_core.h
+++ b/drivers/char/tpm/tpm_tis_core.h
@@ -90,6 +90,7 @@ struct tpm_tis_data {
int locality;
int irq;
bool irq_tested;
+ unsigned int int_count;
unsigned int flags;
void __iomem *ilb_base_addr;
u16 clkrun_enabled;
--
2.19.1.3.ge56e4f7
next reply other threads:[~2021-01-13 12:01 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-13 12:00 Tianjia Zhang [this message]
2021-01-14 2:51 ` [PATCH] tpm/tpm_tis: Fix variable reset during IRQ probing Jarkko Sakkinen
2021-01-14 4:12 ` Tianjia Zhang
2021-01-15 9:23 ` Jarkko Sakkinen
2021-01-20 4:03 ` Tianjia Zhang
2021-01-28 5:20 ` [tpm/tpm_tis] cad8219df0: BUG:unable_to_handle_page_fault_for_address kernel test robot
2021-01-28 5:20 ` kernel test robot
2021-01-28 5:20 ` [LTP] " kernel test robot
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