| Message ID | 20210609132619.45017-1-jarkko@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] tpm: Replace WARN_ONCE() with dev_err_once() in tpm_tis_status() | expand |
On Wed, Jun 09, 2021 at 04:26:19PM +0300, Jarkko Sakkinen wrote: > Do not tear down the system when getting invalid status from a TPM chip. > This can happen when panic-on-warn is used. > > Instead, introduce TPM_TIS_INVALID_STATUS bitflag and use it to trigger > once the error reporting per chip. In addition, print out the value of > TPM_STS for improved forensics. > > Link: https://lore.kernel.org/keyrings/YKzlTR1AzUigShtZ@kroah.com/ > Fixes: 55707d531af6 ("tpm_tis: Add a check for invalid status") > Cc: stable@vger.kernel.org > Cc: Hans de Goede <hdegoede@redhat.com> > Cc: Greg KH <greg@kroah.com> > Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> > --- Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 55b9d3965ae1..69579efb247b 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -196,13 +196,24 @@ static u8 tpm_tis_status(struct tpm_chip *chip) return 0; if (unlikely((status & TPM_STS_READ_ZERO) != 0)) { - /* - * If this trips, the chances are the read is - * returning 0xff because the locality hasn't been - * acquired. Usually because tpm_try_get_ops() hasn't - * been called before doing a TPM operation. - */ - WARN_ONCE(1, "TPM returned invalid status\n"); + if (!test_and_set_bit(TPM_TIS_INVALID_STATUS, &priv->flags)) { + /* + * If this trips, the chances are the read is + * returning 0xff because the locality hasn't been + * acquired. Usually because tpm_try_get_ops() hasn't + * been called before doing a TPM operation. + */ + dev_err(&chip->dev, "invalid TPM_STS.x 0x%02x, dumping stack for forensics\n", + status); + + /* + * Dump stack for forensics, as invalid TPM_STS.x could be + * potentially triggered by impaired tpm_try_get_ops() or + * tpm_find_get_ops(). + */ + dump_stack(); + } + return 0; } diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index 9b2d32a59f67..b2a3c6c72882 100644 --- a/drivers/char/tpm/tpm_tis_core.h +++ b/drivers/char/tpm/tpm_tis_core.h @@ -83,6 +83,7 @@ enum tis_defaults { enum tpm_tis_flags { TPM_TIS_ITPM_WORKAROUND = BIT(0), + TPM_TIS_INVALID_STATUS = BIT(1), }; struct tpm_tis_data { @@ -90,7 +91,7 @@ struct tpm_tis_data { int locality; int irq; bool irq_tested; - unsigned int flags; + unsigned long flags; void __iomem *ilb_base_addr; u16 clkrun_enabled; wait_queue_head_t int_queue;
Do not tear down the system when getting invalid status from a TPM chip. This can happen when panic-on-warn is used. Instead, introduce TPM_TIS_INVALID_STATUS bitflag and use it to trigger once the error reporting per chip. In addition, print out the value of TPM_STS for improved forensics. Link: https://lore.kernel.org/keyrings/YKzlTR1AzUigShtZ@kroah.com/ Fixes: 55707d531af6 ("tpm_tis: Add a check for invalid status") Cc: stable@vger.kernel.org Cc: Hans de Goede <hdegoede@redhat.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> --- v3: * torn -> tear * A per chip flag TPM_TIS_INVALID_STATUS. v2: Dump also stack only once. drivers/char/tpm/tpm_tis_core.c | 25 ++++++++++++++++++------- drivers/char/tpm/tpm_tis_core.h | 3 ++- 2 files changed, 20 insertions(+), 8 deletions(-)