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tpm,tpm_tis: Disable interrupts after 1000 unhandled IRQs

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After activation of interrupts for TPM TIS drivers 0-day reports an
interrupt storm on an Inspur NF5180M6 server.

Fix this by detecting the storm and falling back to polling:
Count the number of unhandled interrupts within a 10 ms time interval. In
case that more than 1000 were unhandled deactivate interrupts entirely,
deregister the handler and use polling instead.

Also print a note to point to the tpm_tis_dmi_table.

Since the interrupt deregistration function devm_free_irq() waits for all
interrupt handlers to finish, only trigger a worker in the interrupt
handler and do the unregistration in the worker to avoid a deadlock.

Note: the storm detection logic equals the implementation in
note_interrupt() which uses timestamps and counters stored in struct
irq_desc. Since this structure is private to the generic interrupt core
the TPM TIS core uses its own timestamps and counters. Furthermore the TPM
interrupt handler always returns IRQ_HANDLED to prevent the generic
interrupt core from processing the interrupt storm.

Cc: stable@vger.kernel.org # v6.4+
Fixes: e644b2f498 ("tpm, tpm_tis: Enable interrupt test")
Reported-by: kernel test robot <yujie.liu@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202305041325.ae8b0c43-yujie.liu@intel.com/
Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
This commit is contained in:
Lino Sanfilippo 2023-07-13 21:01:08 +02:00 committed by Jarkko Sakkinen
parent 393f362389
commit 481c2d1462
2 changed files with 92 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

103
drivers/char/tpm/tpm_tis_core.c
View File

@ -24,9 +24,12 @@
#include <linux/wait.h>
#include <linux/acpi.h>
#include <linux/freezer.h>
#include <linux/dmi.h>
#include "tpm.h"
#include "tpm_tis_core.h"
#define TPM_TIS_MAX_UNHANDLED_IRQS 1000
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,
@ -468,25 +471,29 @@ out_err:
return rc;
}
static void disable_interrupts(struct tpm_chip *chip)
static void __tpm_tis_disable_interrupts(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
u32 int_mask = 0;
tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &int_mask);
int_mask &= ~TPM_GLOBAL_INT_ENABLE;
tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), int_mask);
chip->flags &= ~TPM_CHIP_FLAG_IRQ;
}
static void tpm_tis_disable_interrupts(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
u32 intmask;
int rc;
if (priv->irq == 0)
return;
rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
if (rc < 0)
intmask = 0;
intmask &= ~TPM_GLOBAL_INT_ENABLE;
rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
__tpm_tis_disable_interrupts(chip);
devm_free_irq(chip->dev.parent, priv->irq, chip);
priv->irq = 0;
chip->flags &= ~TPM_CHIP_FLAG_IRQ;
}
/*
@ -552,7 +559,7 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
if (!test_bit(TPM_TIS_IRQ_TESTED, &priv->flags))
tpm_msleep(1);
if (!test_bit(TPM_TIS_IRQ_TESTED, &priv->flags))
disable_interrupts(chip);
tpm_tis_disable_interrupts(chip);
set_bit(TPM_TIS_IRQ_TESTED, &priv->flags);
return rc;
}
@ -752,6 +759,57 @@ static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
return status == TPM_STS_COMMAND_READY;
}
static irqreturn_t tpm_tis_revert_interrupts(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
const char *product;
const char *vendor;
dev_warn(&chip->dev, FW_BUG
"TPM interrupt storm detected, polling instead\n");
vendor = dmi_get_system_info(DMI_SYS_VENDOR);
product = dmi_get_system_info(DMI_PRODUCT_VERSION);
if (vendor && product) {
dev_info(&chip->dev,
"Consider adding the following entry to tpm_tis_dmi_table:\n");
dev_info(&chip->dev, "\tDMI_SYS_VENDOR: %s\n", vendor);
dev_info(&chip->dev, "\tDMI_PRODUCT_VERSION: %s\n", product);
}
if (tpm_tis_request_locality(chip, 0) != 0)
return IRQ_NONE;
__tpm_tis_disable_interrupts(chip);
tpm_tis_relinquish_locality(chip, 0);
schedule_work(&priv->free_irq_work);
return IRQ_HANDLED;
}
static irqreturn_t tpm_tis_update_unhandled_irqs(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
irqreturn_t irqret = IRQ_HANDLED;
if (!(chip->flags & TPM_CHIP_FLAG_IRQ))
return IRQ_HANDLED;
if (time_after(jiffies, priv->last_unhandled_irq + HZ/10))
priv->unhandled_irqs = 1;
else
priv->unhandled_irqs++;
priv->last_unhandled_irq = jiffies;
if (priv->unhandled_irqs > TPM_TIS_MAX_UNHANDLED_IRQS)
irqret = tpm_tis_revert_interrupts(chip);
return irqret;
}
static irqreturn_t tis_int_handler(int dummy, void *dev_id)
{
struct tpm_chip *chip = dev_id;
@ -761,10 +819,10 @@ static irqreturn_t tis_int_handler(int dummy, void *dev_id)
rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
if (rc < 0)
return IRQ_NONE;
goto err;
if (interrupt == 0)
return IRQ_NONE;
goto err;
set_bit(TPM_TIS_IRQ_TESTED, &priv->flags);
if (interrupt & TPM_INTF_DATA_AVAIL_INT)
@ -780,10 +838,13 @@ static irqreturn_t tis_int_handler(int dummy, void *dev_id)
rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), interrupt);
tpm_tis_relinquish_locality(chip, 0);
if (rc < 0)
return IRQ_NONE;
goto err;
tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
return IRQ_HANDLED;
err:
return tpm_tis_update_unhandled_irqs(chip);
}
static void tpm_tis_gen_interrupt(struct tpm_chip *chip)
@ -804,6 +865,15 @@ static void tpm_tis_gen_interrupt(struct tpm_chip *chip)
chip->flags &= ~TPM_CHIP_FLAG_IRQ;
}
static void tpm_tis_free_irq_func(struct work_struct *work)
{
struct tpm_tis_data *priv = container_of(work, typeof(*priv), free_irq_work);
struct tpm_chip *chip = priv->chip;
devm_free_irq(chip->dev.parent, priv->irq, chip);
priv->irq = 0;
}
/* Register the IRQ and issue a command that will cause an interrupt. If an
* irq is seen then leave the chip setup for IRQ operation, otherwise reverse
* everything and leave in polling mode. Returns 0 on success.
@ -816,6 +886,7 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
int rc;
u32 int_status;
INIT_WORK(&priv->free_irq_work, tpm_tis_free_irq_func);
rc = devm_request_threaded_irq(chip->dev.parent, irq, NULL,
tis_int_handler, IRQF_ONESHOT | flags,
@ -918,6 +989,7 @@ void tpm_tis_remove(struct tpm_chip *chip)
interrupt = 0;
tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
flush_work(&priv->free_irq_work);
tpm_tis_clkrun_enable(chip, false);
@ -1021,6 +1093,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
chip->timeout_b = msecs_to_jiffies(TIS_TIMEOUT_B_MAX);
chip->timeout_c = msecs_to_jiffies(TIS_TIMEOUT_C_MAX);
chip->timeout_d = msecs_to_jiffies(TIS_TIMEOUT_D_MAX);
priv->chip = chip;
priv->timeout_min = TPM_TIMEOUT_USECS_MIN;
priv->timeout_max = TPM_TIMEOUT_USECS_MAX;
priv->phy_ops = phy_ops;
@ -1179,7 +1252,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
rc = tpm_tis_request_locality(chip, 0);
if (rc < 0)
goto out_err;
disable_interrupts(chip);
tpm_tis_disable_interrupts(chip);
tpm_tis_relinquish_locality(chip, 0);
}
}

4
drivers/char/tpm/tpm_tis_core.h
View File

@ -91,11 +91,15 @@ enum tpm_tis_flags {
};
struct tpm_tis_data {
struct tpm_chip *chip;
u16 manufacturer_id;
struct mutex locality_count_mutex;
unsigned int locality_count;
int locality;
int irq;
struct work_struct free_irq_work;
unsigned long last_unhandled_irq;
unsigned int unhandled_irqs;
unsigned int int_mask;
unsigned long flags;
void __iomem *ilb_base_addr;