Re: [PATCH] tpm: Fix the driver cleanup code
Jason Gunthorpe <[email protected]>
| Newsgroups | net.sourceforge.lists.tpmdd-devel,org.kernel.vger.linux-integrity,org.kernel.vger.linux-kernel,org.kernel.vger.linux-security-module |
|---|---|
| Message-ID | <[email protected]> |
On Thu, Dec 21, 2017 at 12:17:02PM -0800, Azhar Shaikh wrote:
> Commit 3c1701339284353c41 ("tpm: Keep CLKRUN enabled throughout
> the duration of transmit_cmd()") added code which accessed
> chip->ops, even after it was set to NULL in tpm_del_char_device(),
> called from tpm_chip_unregister() in error / driver exit paths.
> So fix this code.
>
> Fixes: 3c1701339284353c41 ("tpm: Keep CLKRUN enabled throughout
> the duration of transmit_cmd()")
>
> Suggested-by: Javier Martinez Canillas <[email protected]>
> Suggested-by: Jason Gunthorpe <[email protected]>
> Signed-off-by: Azhar Shaikh <[email protected]>
> drivers/char/tpm/tpm-chip.c | 5 +++++
> drivers/char/tpm/tpm.h | 1 +
> drivers/char/tpm/tpm_tis.c | 8 ++------
> drivers/char/tpm/tpm_tis_core.c | 23 +++++++++++++++--------
> drivers/char/tpm/tpm_tis_spi.c | 1 +
> 5 files changed, 24 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index 0a62c19937b6..c88ec9a32a7e 100644
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -346,6 +346,10 @@ static void tpm_del_char_device(struct tpm_chip *chip)
> down_write(&chip->ops_sem);
> if (chip->flags & TPM_CHIP_FLAG_TPM2)
> tpm2_shutdown(chip, TPM2_SU_CLEAR);
> + if (chip->flags & TPM_CHIP_FLAG_DO_NOT_CLEAR_OPS) {
> + up_write(&chip->ops_sem);
> + return;
> + }
Yikes, too ugly. Figure something else out.. ops->clk_enable is always
tpm_tis_clkrun_enable at this point, so maybe call it directly in
the removal path in tpm_tis_core?
Jason