Re: [PATCH v9 14/17] tpm: remove TPM_TRANSMIT_UNLOCKED flag
From: Jason Gunthorpe <jgg@ziepe.ca>
Date: 2018-11-18 19:51:09
Also in:
linux-integrity, lkml
On Sun, Nov 18, 2018 at 02:47:47PM +0200, Jarkko Sakkinen wrote:
Added locking as part of tpm_try_get_ops() and tpm_put_ops() as they are anyway used in most of the call sites except in tpmrm_release() where we take the locks manually. Signed-off-by: Jarkko Sakkinen <redacted> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> --- drivers/char/tpm/tpm-chip.c | 2 ++ drivers/char/tpm/tpm-dev-common.c | 4 +--- drivers/char/tpm/tpm-interface.c | 8 -------- drivers/char/tpm/tpm.h | 8 ++------ drivers/char/tpm/tpm2-cmd.c | 13 ++++--------- drivers/char/tpm/tpm2-space.c | 15 ++++++--------- 6 files changed, 15 insertions(+), 35 deletions(-)
quoted hunk ↗ jump to hunk
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 32db84683c40..157505b0f755 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c@@ -58,6 +58,7 @@ int tpm_try_get_ops(struct tpm_chip *chip) if (!chip->ops) goto out_lock; + mutex_lock(&chip->tpm_mutex); return 0;
It really isn't appropriate for something called 'get' to be exclusive like this.. Call it tpm_try_lock_ops() ?
quoted hunk ↗ jump to hunk
diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c index c7dc54930576..582caefcf19b 100644 --- a/drivers/char/tpm/tpm-dev-common.c +++ b/drivers/char/tpm/tpm-dev-common.c@@ -33,7 +33,6 @@ static ssize_t tpm_dev_transmit(struct tpm_chip *chip, struct tpm_space *space, struct tpm_header *header = (void *)buf; ssize_t ret, len; - mutex_lock(&chip->tpm_mutex);
The now implicit locking should be tested for using lockdep calls in all places that assume the lock is held by the caller. Jason