From 481c2d14627de8ecbb54dd125466e4b4a5069b47 Mon Sep 17 00:00:00 2001 From: Lino Sanfilippo Date: Thu, 13 Jul 2023 21:01:08 +0200 Subject: tpm,tpm_tis: Disable interrupts after 1000 unhandled IRQs 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: e644b2f498d2 ("tpm, tpm_tis: Enable interrupt test") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202305041325.ae8b0c43-yujie.liu@intel.com/ Suggested-by: Lukas Wunner Signed-off-by: Lino Sanfilippo Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_tis_core.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/char/tpm/tpm_tis_core.h') diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index 610bfadb6acf..b1a169d7d1ca 100644 --- a/drivers/char/tpm/tpm_tis_core.h +++ b/drivers/char/tpm/tpm_tis_core.h @@ -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; -- cgit v1.2.3