| Message ID | 1612303743-29017-4-git-send-email-LinoSanfilippo@gmx.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | TPM fixes | expand |
On Tue, Feb 02, 2021 at 11:09:03PM +0100, Lino Sanfilippo wrote: > From: Lino Sanfilippo <l.sanfilippo@kunbus.com> > > In tpm2_del_space() the sessions are flushed by means of the tpm_chip > operations. However the concerning operations pointer my already be NULL at ~~ may What is "concerniog operations"? Unfamiliar term. Maybe just consistently se chip->ops? Now you have also "tpm_chip operations" and chip->ops, in addition to "concerning operations" in one paragraph commit message. > this time in case that the chip has been unregistered (see > tpm_chip_unregister() which calls tpm_del_char_device() which sets > chip->ops to NULL). > Before accessing chip->ops check if it is still valid. Skip flushing > the sessions in this case. > > Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Instead of cross referencing please describe the scenario (i.e. the sequence of operations) of failure. Fixes tag is also missing. > --- > drivers/char/tpm/tpm2-space.c | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c > index 784b8b3..9a29a40 100644 > --- a/drivers/char/tpm/tpm2-space.c > +++ b/drivers/char/tpm/tpm2-space.c > @@ -58,12 +58,17 @@ int tpm2_init_space(struct tpm_space *space, unsigned int buf_size) > > void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space) > { > - mutex_lock(&chip->tpm_mutex); > - if (!tpm_chip_start(chip)) { > - tpm2_flush_sessions(chip, space); > - tpm_chip_stop(chip); > + down_read(&chip->ops_sem); > + if (chip->ops) { > + mutex_lock(&chip->tpm_mutex); > + if (!tpm_chip_start(chip)) { > + tpm2_flush_sessions(chip, space); > + tpm_chip_stop(chip); > + } > + mutex_unlock(&chip->tpm_mutex); > } > - mutex_unlock(&chip->tpm_mutex); > + up_read(&chip->ops_sem); > + > kfree(space->context_buf); > kfree(space->session_buf); > } > -- > 2.7.4 > /Jarkko
Hi, On 03.02.21 02:17, Jarkko Sakkinen wrote: > On Tue, Feb 02, 2021 at 11:09:03PM +0100, Lino Sanfilippo wrote: >> From: Lino Sanfilippo <l.sanfilippo@kunbus.com> >> >> In tpm2_del_space() the sessions are flushed by means of the tpm_chip >> operations. However the concerning operations pointer my already be NULL at > ~~ > may > > What is "concerniog operations"? Unfamiliar term. Maybe just consistently > se chip->ops? Now you have also "tpm_chip operations" and chip->ops, in > addition to "concerning operations" in one paragraph commit message. 'concerning' referred to 'operations pointer'. But yes, using multiple times a different term for the same thing is quite confusing. I will fix this. >> this time in case that the chip has been unregistered (see >> tpm_chip_unregister() which calls tpm_del_char_device() which sets >> chip->ops to NULL). >> Before accessing chip->ops check if it is still valid. Skip flushing >> the sessions in this case. >> >> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> > > Instead of cross referencing please describe the scenario (i.e. > the sequence of operations) of failure. > > Fixes tag is also missing. > Right, will add it. Thanks, Lino
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c index 784b8b3..9a29a40 100644 --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -58,12 +58,17 @@ int tpm2_init_space(struct tpm_space *space, unsigned int buf_size) void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space) { - mutex_lock(&chip->tpm_mutex); - if (!tpm_chip_start(chip)) { - tpm2_flush_sessions(chip, space); - tpm_chip_stop(chip); + down_read(&chip->ops_sem); + if (chip->ops) { + mutex_lock(&chip->tpm_mutex); + if (!tpm_chip_start(chip)) { + tpm2_flush_sessions(chip, space); + tpm_chip_stop(chip); + } + mutex_unlock(&chip->tpm_mutex); } - mutex_unlock(&chip->tpm_mutex); + up_read(&chip->ops_sem); + kfree(space->context_buf); kfree(space->session_buf); }