On Tue, Nov 13, 2018 at 02:34:39PM +0100, Roberto Sassu wrote:

On 11/8/2018 2:46 PM, Jarkko Sakkinen wrote:

quoted

Orrayn Tue, Nov 06, 2018 at 04:01:54PM +0100, Roberto Sassu wrote:

quoted

This patch removes the hard-coded limit of the active_banks array size.
It stores in the tpm_chip structure the number of active PCR banks,
determined in tpm2_get_pcr_allocation(), and replaces the static array
with a pointer to a dynamically allocated array.

As a consequence of the introduction of nr_active_banks, tpm_pcr_extend()
does not check anymore if the algorithm stored in tpm_chip is equal to
zero. The active_banks array always contains valid algorithms.

Fixes: 1db15344f874 ("tpm: implement TPM 2.0 capability to get active
PCR banks")

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
  drivers/char/tpm/tpm-chip.c      |  1 +
  drivers/char/tpm/tpm-interface.c | 19 ++++++++++++-------
  drivers/char/tpm/tpm.h           |  3 ++-
  drivers/char/tpm/tpm2-cmd.c      | 17 ++++++++---------
  4 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 46caadca916a..2a9e8b744436 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->active_banks);
  	kfree(chip);
  }

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 1a803b0cf980..ba7ca6b3e664 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c

@@ -1039,8 +1039,7 @@ static int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash,
  int tpm_pcr_extend(struct tpm_chip *chip, int 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);

@@ -1048,16 +1047,22 @@ int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
  		return -ENODEV;

Should take digest_list as input. Probably callers could re-use the
same digest_list array multiple times?

Move struct tpm_chip to include/linux/tpm.h so that the caller can query
nr_active_banks and active_banks and can create the digest array by
itself. Lets do this right at once now that this is being restructured.

I have to move also other structures and #define. Wouldn't be better to
introduce a new function to pass to the caller active_banks and
nr_active_banks?

Revisited. I think it is fine how it is for now and we reconsider
later. Only thing I want to remark is that use should use kcalloc()
instead of kalloc_array() + memset().

/Jarkko