Re: [PATCH v3 1/5] tpm: change the end marker of the active_banks array to zero

[Roberto Sassu]

On 11/1/2018 3:42 PM, Mimi Zohar wrote:
> On Wed, 2018-10-31 at 10:43 -0400, Mimi Zohar wrote:
> > On Tue, 2018-10-30 at 16:47 +0100, Roberto Sassu wrote:
> > > This patch changes the end marker of the active_banks array from
> > > TPM2_ALG_ERROR to zero.
> >
> > The patch description is a bit off.
> >
> > TPM2_ALG_ERROR is defined as zero. ÂSince tpm_chip_alloc() calls
> > kzalloc to allocate the structure, there is no need to explicitly set
> > the active_banks end marker to TPM2_ALG_ERROR, nor is there a need to
> > explicitly test for the end marker.
> >
> > This patch removes explicitly setting the end marker and changes the
> > coding style.
> >
> > > Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> > > ---
> > >   drivers/char/tpm/tpm-interface.c | 2 +-
> > >   drivers/char/tpm/tpm2-cmd.c      | 3 ---
> > >   2 files changed, 1 insertion(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> > > index 1a803b0cf980..f7fc4b5ee239 100644
> > > --- a/drivers/char/tpm/tpm-interface.c
> > > +++ b/drivers/char/tpm/tpm-interface.c
> > > @@ -1051,7 +1051,7 @@ int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
> > >   		memset(digest_list, 0, sizeof(digest_list));
> > >   
> > >   		for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
> > > -			    chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
> > > +			    chip->active_banks[i]; i++) {
> > >   			digest_list[i].alg_id = chip->active_banks[i];
> > >   			memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
> > >   			count++;
>
> The fourth patch further updates this code. ÂPlease move those changes
> to this first patch. ÂNo need to touch the same code in both places.

alg_id is introduced in patch 4/5. It cannot be moved here.

Roberto


>                  for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
> -                           chip->active_banks[i]; i++) {
> -                       digest_list[i].alg_id = chip->active_banks[i];
> +                           chip->active_banks[i].alg_id; i++) {
> +                       digest_list[i].alg_id = chip->active_banks[i].alg_id;
>                          memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
>                          count++;
>                  }
> Mimi
>
> > > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> > > index c31b490bd41d..046c9d8f3c1e 100644
> > > --- a/drivers/char/tpm/tpm2-cmd.c
> > > +++ b/drivers/char/tpm/tpm2-cmd.c
> > > @@ -908,9 +908,6 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
> > >   	}
> > >   
> > >   out:
> > > -	if (i < ARRAY_SIZE(chip->active_banks))
> > > -		chip->active_banks[i] = TPM2_ALG_ERROR;
> > > -
> > >   	tpm_buf_destroy(&buf);
> > >   
> > >   	return rc;

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