Re: [PATCH v3 08/10] tpm-buf: Remove chip parameter from tpm_buf_append_handle

[Jonathan McDowell <noodles@earth.li>]

On Mon, Sep 29, 2025 at 10:48:30PM +0300, Jarkko Sakkinen wrote:
> From: Jarkko Sakkinen <jarkko.sakkinen@opinsys.com>
> 
> Remove chip parameter from tpm_buf_append_handle() in order to maintain
> decoupled state with tpm-buf. This is mandatory change in order to re-use
> the module in early boot code of Trenchboot, and the binding itself brings
> no benefit. Use WARN like in other functions, as the error condition can
> happen only as a net effect of a trivial programming mistake.
> 
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@opinsys.com>

Reviewed-by: Jonathan McDowell <noodles@meta.com>

> ---
> v3:
> - No changes.
> v2:
> - A new patch.
> ---
>  drivers/char/tpm/tpm-buf.c       | 5 ++---
>  drivers/char/tpm/tpm2-cmd.c      | 2 +-
>  drivers/char/tpm/tpm2-sessions.c | 2 +-
>  include/linux/tpm.h              | 2 +-
>  4 files changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
> index 69ee77400539..1b9dee0d0681 100644
> --- a/drivers/char/tpm/tpm-buf.c
> +++ b/drivers/char/tpm/tpm-buf.c
> @@ -147,20 +147,19 @@ EXPORT_SYMBOL_GPL(tpm_buf_append_u32);
>  
>  /**
>   * tpm_buf_append_handle() - Add a handle
> - * @chip:	&tpm_chip instance
>   * @buf:	&tpm_buf instance
>   * @handle:	a TPM object handle
>   *
>   * Add a handle to the buffer, and increase the count tracking the number of
>   * handles in the command buffer. Works only for command buffers.
>   */
> -void tpm_buf_append_handle(struct tpm_chip *chip, struct tpm_buf *buf, u32 handle)
> +void tpm_buf_append_handle(struct tpm_buf *buf, u32 handle)
>  {
>  	if (buf->flags & TPM_BUF_INVALID)
>  		return;
>  
>  	if (buf->flags & TPM_BUF_TPM2B) {
> -		dev_err(&chip->dev, "Invalid buffer type (TPM2B)\n");
> +		WARN(1, "tpm-buf: invalid type: TPM2B\n");
>  		buf->flags |= TPM_BUF_INVALID;
>  		return;
>  	}
> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> index c7bfa705ea8f..b69ff7266450 100644
> --- a/drivers/char/tpm/tpm2-cmd.c
> +++ b/drivers/char/tpm/tpm2-cmd.c
> @@ -190,7 +190,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
>  		tpm_buf_append_name(chip, &buf, pcr_idx, NULL);
>  		tpm_buf_append_hmac_session(chip, &buf, 0, NULL, 0);
>  	} else {
> -		tpm_buf_append_handle(chip, &buf, pcr_idx);
> +		tpm_buf_append_handle(&buf, pcr_idx);
>  		tpm_buf_append_auth(chip, &buf, NULL, 0);
>  	}
>  
> diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c
> index 13f019d1312a..bbc05f0997a8 100644
> --- a/drivers/char/tpm/tpm2-sessions.c
> +++ b/drivers/char/tpm/tpm2-sessions.c
> @@ -232,7 +232,7 @@ void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf,
>  #endif
>  
>  	if (!tpm2_chip_auth(chip)) {
> -		tpm_buf_append_handle(chip, buf, handle);
> +		tpm_buf_append_handle(buf, handle);
>  		return;
>  	}
>  
> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> index 5283f32781c4..b2d89df70c18 100644
> --- a/include/linux/tpm.h
> +++ b/include/linux/tpm.h
> @@ -423,7 +423,7 @@ void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value);
>  u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset);
>  u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset);
>  u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset);
> -void tpm_buf_append_handle(struct tpm_chip *chip, struct tpm_buf *buf, u32 handle);
> +void tpm_buf_append_handle(struct tpm_buf *buf, u32 handle);
>  
>  /*
>   * Check if TPM device is in the firmware upgrade mode.
> -- 
> 2.39.5
> 
> 

J.

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