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

Jarkko Sakkinen
2025-09-24T17:18:42Z

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