[PATCH 4/9] sandbox: tpm: Correct handling of get-capability

[Ilias Apalodimas]

Hi Simon, 

On Mon, Jul 05, 2021 at 09:48:44AM -0600, Simon Glass wrote:
> This function current handles the kernel case incorrectly. Fix it, and
> use the shorter TPM_HDR_LEN while we are here.
> 
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
> 
>  drivers/tpm/tpm_tis_sandbox.c | 14 ++++----------
>  1 file changed, 4 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/tpm/tpm_tis_sandbox.c b/drivers/tpm/tpm_tis_sandbox.c
> index 85b22afa4d9..efbeb00ab63 100644
> --- a/drivers/tpm/tpm_tis_sandbox.c
> +++ b/drivers/tpm/tpm_tis_sandbox.c
> @@ -140,16 +140,13 @@ static int sandbox_tpm_xfer(struct udevice *dev, const uint8_t *sendbuf,
>  			printf("Get flags index %#02x\n", index);
>  			*recv_len = 22;
>  			memset(recvbuf, '\0', *recv_len);
> -			data = recvbuf + TPM_RESPONSE_HEADER_LENGTH +
> -					sizeof(uint32_t);
> +			data = recvbuf + TPM_HDR_LEN + sizeof(uint32_t);
>  			switch (index) {
>  			case FIRMWARE_NV_INDEX:
>  				break;
>  			case KERNEL_NV_INDEX:
>  				handle_cap_flag_space(&data, index);
> -				*recv_len = data - recvbuf -
> -					TPM_RESPONSE_HEADER_LENGTH -
> -					sizeof(uint32_t);
> +				*recv_len = data - recvbuf;

This is the only actual fix right?
TPM_RESPONSE_HEADER_LENGTH and TPM_HDR_LEN are both defined to 10?
Is it worth updating the commit message with exactly the problem that was
fixed?

>  				break;
>  			case TPM_CAP_FLAG_PERMANENT: {
>  				struct tpm_permanent_flags *pflags;
> @@ -166,15 +163,12 @@ static int sandbox_tpm_xfer(struct udevice *dev, const uint8_t *sendbuf,
>  				printf("   ** Unknown flags index %x\n", index);
>  				return -ENOSYS;
>  			}
> -			put_unaligned_be32(*recv_len,
> -					   recvbuf +
> -					   TPM_RESPONSE_HEADER_LENGTH);
> +			put_unaligned_be32(*recv_len, recvbuf + TPM_HDR_LEN);
>  			break;
>  		case TPM_CAP_NV_INDEX:
>  			index = get_unaligned_be32(sendbuf + 18);
>  			printf("Get cap nv index %#02x\n", index);
> -			put_unaligned_be32(22, recvbuf +
> -					   TPM_RESPONSE_HEADER_LENGTH);
> +			put_unaligned_be32(22, recvbuf + TPM_HDR_LEN);
>  			break;
>  		default:
>  			printf("   ** Unknown 0x65 command type %#02x\n",
> -- 
> 2.32.0.93.g670b81a890-goog
>