Re: [PATCH v4 1/4] tpm: migrate tpm2_shutdown() to use struct tpm_buf

[Nayna Jain <nayna@linux.vnet.ibm.com>]

On 03/26/2018 05:44 PM, Jarkko Sakkinen wrote:
> In order to make struct tpm_buf the first class object for constructing TPM
> commands, migrate tpm2_shutdown() to use it. In addition, removed the klog
> entry when tpm_transmit_cmd() fails because tpm_tansmit_cmd() already
> prints an error message.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Reviewed-by: Nayna Jain<nayna@linux.vnet.ibm.com>
Tested-by: Nayna Jain<nayna@linux.vnet.ibm.com>

> ---
>   drivers/char/tpm/tpm2-cmd.c | 44 ++++++++++++--------------------------------
>   1 file changed, 12 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> index 96c77c8e7f40..7665661d9230 100644
> --- a/drivers/char/tpm/tpm2-cmd.c
> +++ b/drivers/char/tpm/tpm2-cmd.c
> @@ -27,10 +27,6 @@ enum tpm2_session_attributes {
>   	TPM2_SA_CONTINUE_SESSION	= BIT(0),
>   };
>
> -struct tpm2_startup_in {
> -	__be16	startup_type;
> -} __packed;
> -
>   struct tpm2_get_tpm_pt_in {
>   	__be32	cap_id;
>   	__be32	property_id;
> @@ -55,7 +51,6 @@ struct tpm2_get_random_out {
>   } __packed;
>
>   union tpm2_cmd_params {
> -	struct	tpm2_startup_in		startup_in;
>   	struct	tpm2_get_tpm_pt_in	get_tpm_pt_in;
>   	struct	tpm2_get_tpm_pt_out	get_tpm_pt_out;
>   	struct	tpm2_get_random_in	getrandom_in;
> @@ -412,11 +407,8 @@ void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle,
>   	int rc;
>
>   	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
> -	if (rc) {
> -		dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
> -			 handle);
> +	if (rc)
>   		return;
> -	}
>
>   	tpm_buf_append_u32(&buf, handle);
>
> @@ -762,40 +754,28 @@ ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
>   }
>   EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
>
> -#define TPM2_SHUTDOWN_IN_SIZE \
> -	(sizeof(struct tpm_input_header) + \
> -	 sizeof(struct tpm2_startup_in))
> -
> -static const struct tpm_input_header tpm2_shutdown_header = {
> -	.tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
> -	.length = cpu_to_be32(TPM2_SHUTDOWN_IN_SIZE),
> -	.ordinal = cpu_to_be32(TPM2_CC_SHUTDOWN)
> -};
> -
>   /**
>    * tpm2_shutdown() - send shutdown command to the TPM chip
>    *
> + * In places where shutdown command is sent there's no much we can do except
> + * print the error code on a system failure.
> + *
>    * @chip:		TPM chip to use.
>    * @shutdown_type:	shutdown type. The value is either
>    *			TPM_SU_CLEAR or TPM_SU_STATE.
>    */
>   void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
>   {
> -	struct tpm2_cmd cmd;
> +	struct tpm_buf buf;
>   	int rc;
>
> -	cmd.header.in = tpm2_shutdown_header;
> -	cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type);
> -
> -	rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0, 0,
> -			      "stopping the TPM");
> -
> -	/* In places where shutdown command is sent there's no much we can do
> -	 * except print the error code on a system failure.
> -	 */
> -	if (rc < 0 && rc != -EPIPE)
> -		dev_warn(&chip->dev, "transmit returned %d while stopping the TPM",
> -			 rc);
> +	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
> +	if (rc)
> +		return;
> +	tpm_buf_append_u16(&buf, shutdown_type);
> +	tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
> +			 "stopping the TPM");
> +	tpm_buf_destroy(&buf);
>   }
>
>   /*