Re: [PATCH 2/4] tpm2-sessions: Remove unused parameter from tpm_buf_append_auth

[Jarkko Sakkinen <jarkko@kernel.org>]

On Wed, Sep 24, 2025 at 09:47:59AM +0100, Jonathan McDowell wrote:
> On Mon, Sep 22, 2025 at 07:43:15PM +0300, Jarkko Sakkinen wrote:
> > From: Jarkko Sakkinen <jarkko.sakkinen@opinsys.com>
> > 
> > In earlier bug fix, an extra parameter was by mistake to the function.
> > 
> > Fixes: 27184f8905ba ("tpm: Opt-in in disable PCR integrity protection")
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@opinsys.com>
> > ---
> > drivers/char/tpm/tpm2-cmd.c      |  2 +-
> > drivers/char/tpm/tpm2-sessions.c |  5 ++---
> > include/linux/tpm.h              | 25 +------------------------
> > 3 files changed, 4 insertions(+), 28 deletions(-)
> > 
> > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> > index 7d77f6fbc152..61a4daaef292 100644
> > --- a/drivers/char/tpm/tpm2-cmd.c
> > +++ b/drivers/char/tpm/tpm2-cmd.c
> > @@ -191,7 +191,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
> > 		tpm_buf_append_hmac_session(chip, &buf, 0, NULL, 0);
> > 	} else {
> > 		tpm_buf_append_handle(chip, &buf, pcr_idx);
> > -		tpm_buf_append_auth(chip, &buf, 0, NULL, 0);
> > +		tpm_buf_append_auth(chip, &buf, NULL, 0);
> > 	}
> > 
> > 	tpm_buf_append_u32(&buf, chip->nr_allocated_banks);
> > diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c
> > index 6d03c224e6b2..13f019d1312a 100644
> > --- a/drivers/char/tpm/tpm2-sessions.c
> > +++ b/drivers/char/tpm/tpm2-sessions.c
> > @@ -266,7 +266,7 @@ void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf,
> > EXPORT_SYMBOL_GPL(tpm_buf_append_name);
> > 
> > void tpm_buf_append_auth(struct tpm_chip *chip, struct tpm_buf *buf,
> > -			 u8 attributes, u8 *passphrase, int passphrase_len)
> > +			 u8 *passphrase, int passphrase_len)
> > {
> > 	/* offset tells us where the sessions area begins */
> > 	int offset = buf->handles * 4 + TPM_HEADER_SIZE;
> > @@ -327,8 +327,7 @@ void tpm_buf_append_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf,
> > #endif
> > 
> > 	if (!tpm2_chip_auth(chip)) {
> > -		tpm_buf_append_auth(chip, buf, attributes, passphrase,
> > -				    passphrase_len);
> > +		tpm_buf_append_auth(chip, buf, passphrase, passphrase_len);
> > 		return;
> > 	}
> 
> This chunk below should be in patch 3/4 where you open code
> tpm_buf_append_hmac_session_opt, rather than here:

True, thanks for catching this.

> 
> > diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> > index 667d290789ca..a8984d273c28 100644
> > --- a/include/linux/tpm.h
> > +++ b/include/linux/tpm.h
> > @@ -533,30 +533,7 @@ void tpm_buf_append_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf,
> > 				 u8 attributes, u8 *passphrase,
> > 				 int passphraselen);
> > void tpm_buf_append_auth(struct tpm_chip *chip, struct tpm_buf *buf,
> > -			 u8 attributes, u8 *passphrase, int passphraselen);
> > -static inline void tpm_buf_append_hmac_session_opt(struct tpm_chip *chip,
> > -						   struct tpm_buf *buf,
> > -						   u8 attributes,
> > -						   u8 *passphrase,
> > -						   int passphraselen)
> > -{
> > -	struct tpm_header *head;
> > -	int offset;
> > -
> > -	if (tpm2_chip_auth(chip)) {
> > -		tpm_buf_append_hmac_session(chip, buf, attributes, passphrase, passphraselen);
> > -	} else  {
> > -		offset = buf->handles * 4 + TPM_HEADER_SIZE;
> > -		head = (struct tpm_header *)buf->data;
> > -
> > -		/*
> > -		 * If the only sessions are optional, the command tag must change to
> > -		 * TPM2_ST_NO_SESSIONS.
> > -		 */
> > -		if (tpm_buf_length(buf) == offset)
> > -			head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
> > -	}
> > -}
> > +			 u8 *passphrase, int passphraselen);
> > 
> > #ifdef CONFIG_TCG_TPM2_HMAC
> > 
> > -- 
> > 2.39.5
> > 
> > 
> 
> J.
> 
> -- 
> 101 things you can't have too much of : 19 - A Good Thing.
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BR, Jarkko