Re: [PATCH v4 07/13] tpm: export the context save and load commands

[Stefan Berger <stefanb@xxxxxxxxxxxxx>]

On 4/3/23 17:39, James Bottomley wrote:
> The TPM2 session HMAC and encryption handling code needs to save and
> restore a single volatile context for the elliptic curve version of
> the NULL seed, so export the APIs which do this for internal use.
>
> Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>

Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>

> ---
>   drivers/char/tpm/tpm.h        | 4 ++++
>   drivers/char/tpm/tpm2-space.c | 8 ++++----
>   2 files changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index 830014a26609..00a06e3ba892 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -310,6 +310,10 @@ int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space, void *buf,
>   		      size_t *bufsiz);
>   int tpm_devs_add(struct tpm_chip *chip);
>   void tpm_devs_remove(struct tpm_chip *chip);
> +int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
> +		      unsigned int buf_size, unsigned int *offset);
> +int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
> +		      unsigned int *offset, u32 *handle);
>   
>   void tpm_bios_log_setup(struct tpm_chip *chip);
>   void tpm_bios_log_teardown(struct tpm_chip *chip);
> diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
> index ffb35f0154c1..d77ee4af9d65 100644
> --- a/drivers/char/tpm/tpm2-space.c
> +++ b/drivers/char/tpm/tpm2-space.c
> @@ -68,8 +68,8 @@ void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space)
>   	kfree(space->session_buf);
>   }
>   
> -static int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
> -			     unsigned int *offset, u32 *handle)
> +int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
> +		      unsigned int *offset, u32 *handle)
>   {
>   	struct tpm_buf tbuf;
>   	struct tpm2_context *ctx;
> @@ -119,8 +119,8 @@ static int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
>   	return 0;
>   }
>   
> -static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
> -			     unsigned int buf_size, unsigned int *offset)
> +int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
> +		      unsigned int buf_size, unsigned int *offset)
>   {
>   	struct tpm_buf tbuf;
>   	unsigned int body_size;