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tpm: Replace WARN_ONCE() with dev_err_once() in tpm_tis_status()

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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
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jarkko Sakkinen 2021-06-09 16:26:19 +03:00
parent 5a118a39ec
commit 0178f9d0f6
2 changed files with 20 additions and 8 deletions
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25
drivers/char/tpm/tpm_tis_core.c
View File

@ -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;
}

3
drivers/char/tpm/tpm_tis_core.h
View File

@ -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;