[PATCH v2 2/2] efi_loader: support fmp versioning for multi bank update

[Ilias Apalodimas]

Kojima-san

On Thu, Dec 21, 2023 at 06:52:58PM +0900, Masahisa Kojima wrote:
> This commit stores the firmware version into the array
> of fmp_state structure to support the fmp versioning
> for multi bank update. The index of the array is identified
> by the bank index.

Why do we all of them? Can't we just always store/use the version of the active
bank?

>
> This modification keeps the backward compatibility with
> the existing versioning feature.
>

Thanks
/Ilias
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> ---
>  lib/efi_loader/efi_firmware.c | 69 +++++++++++++++++++++++++++--------
>  1 file changed, 54 insertions(+), 15 deletions(-)
>
> diff --git a/lib/efi_loader/efi_firmware.c b/lib/efi_loader/efi_firmware.c
> index 9b8630625f..5459f3d38d 100644
> --- a/lib/efi_loader/efi_firmware.c
> +++ b/lib/efi_loader/efi_firmware.c
> @@ -207,18 +207,10 @@ void efi_firmware_fill_version_info(struct efi_firmware_image_descriptor *image_
>  {
>  	u16 varname[13]; /* u"FmpStateXXXX" */
>  	efi_status_t ret;
> -	efi_uintn_t size;
> -	struct fmp_state var_state = { 0 };
> -
> -	efi_create_indexed_name(varname, sizeof(varname), "FmpState",
> -				fw_array->image_index);
> -	size = sizeof(var_state);
> -	ret = efi_get_variable_int(varname, &fw_array->image_type_id,
> -				   NULL, &size, &var_state, NULL);
> -	if (ret == EFI_SUCCESS)
> -		image_info->version = var_state.fw_version;
> -	else
> -		image_info->version = 0;
> +	efi_uintn_t size, expected_size;
> +	uint num_banks = 1;
> +	uint active_index = 0;
> +	struct fmp_state *var_state;
>
>  	efi_firmware_get_lsv_from_dtb(fw_array->image_index,
>  				      &fw_array->image_type_id,
> @@ -227,6 +219,31 @@ void efi_firmware_fill_version_info(struct efi_firmware_image_descriptor *image_
>  	image_info->version_name = NULL; /* not supported */
>  	image_info->last_attempt_version = 0;
>  	image_info->last_attempt_status = LAST_ATTEMPT_STATUS_SUCCESS;
> +	image_info->version = 0;
> +
> +	/* get the fw_version */
> +	efi_create_indexed_name(varname, sizeof(varname), "FmpState",
> +				fw_array->image_index);
> +	if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> +		ret = fwu_get_active_index(&active_index);
> +		if (ret)
> +			return;
> +
> +		num_banks = CONFIG_FWU_NUM_BANKS;
> +	}
> +
> +	size = num_banks * sizeof(*var_state);
> +	expected_size = size;
> +	var_state = calloc(1, size);
> +	if (!var_state)
> +		return;
> +
> +	ret = efi_get_variable_int(varname, &fw_array->image_type_id,
> +				   NULL, &size, var_state, NULL);
> +	if (ret == EFI_SUCCESS && expected_size == size)
> +		image_info->version = var_state[active_index].fw_version;
> +
> +	free(var_state);
>  }
>
>  /**
> @@ -362,8 +379,11 @@ efi_status_t efi_firmware_set_fmp_state_var(struct fmp_state *state, u8 image_in
>  {
>  	u16 varname[13]; /* u"FmpStateXXXX" */
>  	efi_status_t ret;
> +	uint num_banks = 1;
> +	uint update_bank = 0;
> +	efi_uintn_t size;
>  	efi_guid_t *image_type_id;
> -	struct fmp_state var_state = { 0 };
> +	struct fmp_state *var_state;
>
>  	image_type_id = efi_firmware_get_image_type_id(image_index);
>  	if (!image_type_id)
> @@ -372,19 +392,38 @@ efi_status_t efi_firmware_set_fmp_state_var(struct fmp_state *state, u8 image_in
>  	efi_create_indexed_name(varname, sizeof(varname), "FmpState",
>  				image_index);
>
> +	if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> +		ret = fwu_plat_get_update_index(&update_bank);
> +		if (ret)
> +			return EFI_INVALID_PARAMETER;
> +
> +		num_banks = CONFIG_FWU_NUM_BANKS;
> +	}
> +
> +	size = num_banks * sizeof(*var_state);
> +	var_state = calloc(1, size);
> +	if (!var_state)
> +		return EFI_OUT_OF_RESOURCES;
> +
> +	ret = efi_get_variable_int(varname, image_type_id, NULL, &size,
> +				   var_state, NULL);
> +
>  	/*
>  	 * Only the fw_version is set here.
>  	 * lowest_supported_version in FmpState variable is ignored since
>  	 * it can be tampered if the file based EFI variable storage is used.
>  	 */
> -	var_state.fw_version = state->fw_version;
> +	var_state[update_bank].fw_version = state->fw_version;
>
> +	size = num_banks * sizeof(*var_state);
>  	ret = efi_set_variable_int(varname, image_type_id,
>  				   EFI_VARIABLE_READ_ONLY |
>  				   EFI_VARIABLE_NON_VOLATILE |
>  				   EFI_VARIABLE_BOOTSERVICE_ACCESS |
>  				   EFI_VARIABLE_RUNTIME_ACCESS,
> -				   sizeof(var_state), &var_state, false);
> +				   size, var_state, false);
> +
> +	free(var_state);
>
>  	return ret;
>  }
> --
> 2.34.1
>