On Mon, Jan 07, 2019 at 11:06:33AM +0100, Roberto Sassu wrote: > On 12/22/2018 1:03 AM, Jarkko Sakkinen wrote: > > On Fri, Dec 21, 2018 at 10:40:09AM +0100, Roberto Sassu wrote: > > > On 12/20/2018 3:55 PM, Jarkko Sakkinen wrote: > > > > On Thu, Dec 13, 2018 at 11:29:41AM +0100, Roberto Sassu wrote: > > > > > This patch renames active_banks (member of tpm_chip) to allocated_banks, > > > > > stores the number of allocated PCR banks in nr_allocated_banks (new member > > > > > of tpm_chip), and replaces the static array with a pointer to a dynamically > > > > > allocated array. > > > > > > > > > > tpm2_get_pcr_allocation() determines if a PCR bank is allocated by checking > > > > > the mask in the TPML_PCR_SELECTION structure returned by the TPM for > > > > > TPM2_Get_Capability(). If a bank is not allocated, the TPM returns that > > > > > bank in TPML_PCR_SELECTION, with all bits in the mask set to zero. In this > > > > > case, the bank is not included in chip->allocated_banks, to avoid that TPM > > > > > driver users unnecessarily calculate a digest for that bank. > > > > > > > > > > One PCR bank with algorithm set to SHA1 is always allocated for TPM 1.x. > > > > > > > > > > As a consequence of the introduction of nr_allocated_banks, > > > > > tpm_pcr_extend() does not check anymore if the algorithm stored in tpm_chip > > > > > is equal to zero. > > > > > > > > > > Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx> > > > > > Tested-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> > > > > > --- > > > > > drivers/char/tpm/tpm-chip.c | 1 + > > > > > drivers/char/tpm/tpm-interface.c | 18 +++++++++-------- > > > > > drivers/char/tpm/tpm.h | 3 ++- > > > > > drivers/char/tpm/tpm1-cmd.c | 10 ++++++++++ > > > > > drivers/char/tpm/tpm2-cmd.c | 34 ++++++++++++++++++++++---------- > > > > > 5 files changed, 47 insertions(+), 19 deletions(-) > > > > > > > > > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > > > > > index 32db84683c40..ce851c62bb68 100644 > > > > > --- a/drivers/char/tpm/tpm-chip.c > > > > > +++ b/drivers/char/tpm/tpm-chip.c > > > > > @@ -160,6 +160,7 @@ static void tpm_dev_release(struct device *dev) > > > > > kfree(chip->log.bios_event_log); > > > > > kfree(chip->work_space.context_buf); > > > > > kfree(chip->work_space.session_buf); > > > > > + kfree(chip->allocated_banks); > > > > > kfree(chip); > > > > > } > > > > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > > > > > index d9439f9abe78..7b80919228be 100644 > > > > > --- a/drivers/char/tpm/tpm-interface.c > > > > > +++ b/drivers/char/tpm/tpm-interface.c > > > > > @@ -488,8 +488,7 @@ EXPORT_SYMBOL_GPL(tpm_pcr_read); > > > > > int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash) > > > > > { > > > > > int rc; > > > > > - struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)]; > > > > > - u32 count = 0; > > > > > + struct tpm2_digest *digest_list; > > > > > int i; > > > > > chip = tpm_find_get_ops(chip); > > > > > @@ -497,16 +496,19 @@ int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash) > > > > > return -ENODEV; > > > > > if (chip->flags & TPM_CHIP_FLAG_TPM2) { > > > > > - memset(digest_list, 0, sizeof(digest_list)); > > > > > + digest_list = kcalloc(chip->nr_allocated_banks, > > > > > + sizeof(*digest_list), GFP_KERNEL); > > > > > + if (!digest_list) > > > > > + return -ENOMEM; > > > > > > > > You could preallocate digest list and place it to struct tpm_chip > > > > instead of doing it everytime tpm_pcr_extend() called. > > > > > > This part will be removed with patch 5/5. > > > > Even if it did, it does not make this patch unbroken. > > Can two calls to tpm_pcr_extend() be executed at the same time? > > If yes, the digest list should be protected by a mutex. Good question: the answer is no. Mutex locking is done inside the transmit flow ATM. /Jarkko