Yes, will do. Can you mark a Reviewed-by on this version of the patch as well? You marked v2 already, but this is probably the version that should be submitted. Josh
On Sat, May 20, 2017 at 6:20 AM, Jarkko Sakkinen <jarkko.sakki...@linux.intel.com> wrote: > Yes. Can you ping me once it is in? I can merge this after that. > > /Jarkko > > On Thu, May 18, 2017 at 08:21:32AM -0700, Josh Zimmerman wrote: >> Are there any other changes I should make to this patch, or is it good >> to go once the patch it depends on is in? >> >> Thanks! >> Josh >> >> >> On Mon, May 15, 2017 at 5:08 PM, Josh Zimmerman <jo...@google.com> wrote: >> > If a TPM2 loses power without a TPM2_Shutdown command being issued (a >> > "disorderly reboot"), it may lose some state that has yet to be >> > persisted to NVRam, and will increment the DA counter (eventually, this >> > will cause the TPM to lock the user out.) >> > >> > NOTE: This only changes behavior on TPM2 devices. Since TPM1 uses sysfs, >> > and sysfs relies on implicit locking on chip->ops, it is not safe to >> > allow this code to run in TPM1, or to add sysfs support to TPM2, until >> > that locking is made explicit. >> > >> > This patch is dependent on '[PATCH] Add "shutdown" to "struct class".' >> > http://marc.info/?l=linux-kernel&m=149463235025420&w=2 >> > >> > Signed-off-by: Josh Zimmerman <jo...@google.com> >> > >> > ---- >> > v2: >> > - Properly split changes between this and another commit >> > - Use proper locking primitive. >> > - Fix commenting style >> > v3: >> > - Re-fix commenting style >> > --- >> > drivers/char/tpm/tpm-chip.c | 20 ++++++++++++++++++++ >> > drivers/char/tpm/tpm-sysfs.c | 3 +++ >> > 2 files changed, 23 insertions(+) >> > >> > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c >> > index 9dec9f551b83..272a42e77574 100644 >> > --- a/drivers/char/tpm/tpm-chip.c >> > +++ b/drivers/char/tpm/tpm-chip.c >> > @@ -142,6 +142,25 @@ static void tpm_devs_release(struct device *dev) >> > put_device(&chip->dev); >> > } >> > >> > +static void tpm_shutdown(struct device *dev) >> > +{ >> > + struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev); >> > + /* TPM 2.0 requires that the TPM2_Shutdown() command be issued >> > prior to >> > + * loss of power. If it is not, the DA counter will be incremented >> > and, >> > + * eventually, the user will be locked out of their TPM. >> > + * XXX: This codepath relies on the fact that sysfs is not enabled >> > for >> > + * TPM2: sysfs uses an implicit lock on chip->ops, so this use >> > could >> > + * race if TPM2 has sysfs support enabled before TPM sysfs's >> > implicit >> > + * locking is fixed. >> > + */ >> > + if (chip->flags & TPM_CHIP_FLAG_TPM2) { >> > + down_write(&chip->ops_sem); >> > + tpm2_shutdown(chip, TPM_SU_CLEAR); >> > + chip->ops = NULL; >> > + up_write(&chip->ops_sem); >> > + } >> > +} >> > + >> > /** >> > * tpm_chip_alloc() - allocate a new struct tpm_chip instance >> > * @pdev: device to which the chip is associated >> > @@ -181,6 +200,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev, >> > device_initialize(&chip->devs); >> > >> > chip->dev.class = tpm_class; >> > + chip->dev.class.shutdown = tpm_shutdown; >> > chip->dev.release = tpm_dev_release; >> > chip->dev.parent = pdev; >> > chip->dev.groups = chip->groups; >> > diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c >> > index 55405dbe43fa..5e5ff7eb6f7e 100644 >> > --- a/drivers/char/tpm/tpm-sysfs.c >> > +++ b/drivers/char/tpm/tpm-sysfs.c >> > @@ -294,6 +294,9 @@ static const struct attribute_group tpm_dev_group = { >> > >> > void tpm_sysfs_add_device(struct tpm_chip *chip) >> > { >> > + /* XXX: Before this restriction is removed, tpm_sysfs must be >> > updated >> > + * to explicitly lock chip->ops. >> > + */ >> > if (chip->flags & TPM_CHIP_FLAG_TPM2) >> > return; >> > >> > -- >> > 2.13.0.303.g4ebf302169-goog >> > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ tpmdd-devel mailing list tpmdd-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tpmdd-devel
