On Mon, Dec 31, 2018 at 10:27:31AM -0800, James Bottomley wrote:
> Ever since 627448e85c766 "tpm: separate cmd_ready/go_idle from
> runtime_pm" we have been returning success from tpm_try_transmit()
> even if an error occurred. The reason is that the introduction of rc
> = tpm_go_idle() at the end of processing overwrites the value of rc if
> it contains an error code (mostly with success). Fix this by writing
> the return to a new variable rc1 instead.
>
> Fixes: 627448e85c766 "tpm: separate cmd_ready/go_idle from runtime_pm"
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
>
> ---
>
> Note: the goto out looks fishy as well. The only go_idle implementor
> is tpm_crb and that can return a timeout as -ETIME, so it looks like it
> would then loop forever
>
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index 129f640424b7..ac7ebab6140c 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -432,7 +432,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
> unsigned int flags)
> {
> struct tpm_output_header *header = (void *)buf;
> - int rc;
> + int rc, rc1;
> ssize_t len = 0;
> u32 count, ordinal;
> unsigned long stop;
> @@ -547,8 +547,8 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
> dev_err(&chip->dev, "tpm2_commit_space: error %d\n", rc);
>
> out:
> - rc = tpm_go_idle(chip, flags);
> - if (rc)
> + rc1 = tpm_go_idle(chip, flags);
> + if (rc1)
> goto out;
>
> if (need_locality)
Thanks James and sorry for latency (holiday season). Just a small
suggestion. I would just:
if (tpm_go_idle(chip, flags))
goto out;
What do you think?
/Jarkko
