[PATCH 1/2] eficonfig: curve out efi_get_next_variable_name_int calls

[Heinrich Schuchardt]

%s/curve/carve/

On 12/8/22 05:40, Masahisa Kojima wrote:
> To retrieve the EFI variable name by efi_get_next_variable_name_int(),
> the sequence of alloc -> efi_get_next_variable_name_int ->
> realloc -> efi_get_next_variable_name_int is required.
> In current code, this sequence repeatedly appears in
> the several functions. It should be curved out a common function.
>
> This commit also fixes the missing free() of var_name16
> in eficonfig_delete_invalid_boot_option().
>
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> ---
>   cmd/eficonfig.c             | 62 +++++++++----------------------------
>   include/efi_loader.h        |  2 ++
>   lib/efi_loader/efi_helper.c | 34 ++++++++++++++++++++
>   3 files changed, 51 insertions(+), 47 deletions(-)
>
> diff --git a/cmd/eficonfig.c b/cmd/eficonfig.c
> index 394ae67cce..cd7a51cc7e 100644
> --- a/cmd/eficonfig.c
> +++ b/cmd/eficonfig.c
> @@ -1683,7 +1683,7 @@ static efi_status_t eficonfig_show_boot_selection(unsigned int *selected)
>   	u32 i;
>   	u16 *bootorder;
>   	efi_status_t ret;
> -	u16 *var_name16 = NULL, *p;
> +	u16 *var_name16 = NULL;
>   	efi_uintn_t num, size, buf_size;

buf_size = 0;
see below

>   	struct efimenu *efi_menu;
>   	struct list_head *pos, *n;
> @@ -1718,24 +1718,12 @@ static efi_status_t eficonfig_show_boot_selection(unsigned int *selected)
>   		int index;
>   		efi_guid_t guid;
>
> -		size = buf_size;
> -		ret = efi_get_next_variable_name_int(&size, var_name16, &guid);
> +		ret = efi_get_variable_name(&buf_size, &var_name16, &guid);
>   		if (ret == EFI_NOT_FOUND)
>   			break;
> -		if (ret == EFI_BUFFER_TOO_SMALL) {
> -			buf_size = size;
> -			p = realloc(var_name16, buf_size);
> -			if (!p) {
> -				free(var_name16);
> -				return EFI_OUT_OF_RESOURCES;
> -			}
> -			var_name16 = p;
> -			ret = efi_get_next_variable_name_int(&size, var_name16, &guid);
> -		}
> -		if (ret != EFI_SUCCESS) {
> -			free(var_name16);
> -			return ret;
> -		}
> +		if (ret != EFI_SUCCESS)
> +			goto out;
> +
>   		if (efi_varname_is_load_option(var_name16, &index)) {
>   			/* If the index is included in the BootOrder, skip it */
>   			if (search_bootorder(bootorder, num, index, NULL))
> @@ -2026,7 +2014,7 @@ static efi_status_t eficonfig_create_change_boot_order_entry(struct efimenu *efi
>   	u32 i;
>   	char *title;
>   	efi_status_t ret;
> -	u16 *var_name16 = NULL, *p;
> +	u16 *var_name16 = NULL;
>   	efi_uintn_t size, buf_size;
>
>   	/* list the load option in the order of BootOrder variable */
> @@ -2054,19 +2042,9 @@ static efi_status_t eficonfig_create_change_boot_order_entry(struct efimenu *efi
>   			break;
>
>   		size = buf_size;
> -		ret = efi_get_next_variable_name_int(&size, var_name16, &guid);
> +		ret = efi_get_variable_name(&buf_size, &var_name16, &guid);
>   		if (ret == EFI_NOT_FOUND)
>   			break;
> -		if (ret == EFI_BUFFER_TOO_SMALL) {
> -			buf_size = size;
> -			p = realloc(var_name16, buf_size);
> -			if (!p) {
> -				ret = EFI_OUT_OF_RESOURCES;
> -				goto out;
> -			}
> -			var_name16 = p;
> -			ret = efi_get_next_variable_name_int(&size, var_name16, &guid);
> -		}
>   		if (ret != EFI_SUCCESS)
>   			goto out;
>
> @@ -2336,10 +2314,10 @@ efi_status_t eficonfig_delete_invalid_boot_option(struct eficonfig_media_boot_op
>   	efi_uintn_t size;
>   	void *load_option;
>   	struct efi_load_option lo;
> -	u16 *var_name16 = NULL, *p;
> +	u16 *var_name16 = NULL;
>   	u16 varname[] = u"Boot####";
>   	efi_status_t ret = EFI_SUCCESS;
> -	efi_uintn_t varname_size, buf_size;
> +	efi_uintn_t buf_size;
>
>   	buf_size = 128;
>   	var_name16 = malloc(buf_size);

Why allocate anything here? We already have a realloc() in
efi_get_variable_name() which will do the job. Just start with
var_name16 = NULL, buf_size = 0.

> @@ -2352,24 +2330,12 @@ efi_status_t eficonfig_delete_invalid_boot_option(struct eficonfig_media_boot_op
>   		efi_guid_t guid;
>   		efi_uintn_t tmp;
>
> -		varname_size = buf_size;
> -		ret = efi_get_next_variable_name_int(&varname_size, var_name16, &guid);
> +		ret = efi_get_variable_name(&buf_size, &var_name16, &guid);
>   		if (ret == EFI_NOT_FOUND)
>   			break;
> -		if (ret == EFI_BUFFER_TOO_SMALL) {
> -			buf_size = varname_size;
> -			p = realloc(var_name16, buf_size);
> -			if (!p) {
> -				free(var_name16);
> -				return EFI_OUT_OF_RESOURCES;
> -			}
> -			var_name16 = p;
> -			ret = efi_get_next_variable_name_int(&varname_size, var_name16, &guid);
> -		}
> -		if (ret != EFI_SUCCESS) {
> -			free(var_name16);
> -			return ret;
> -		}
> +		if (ret != EFI_SUCCESS)
> +			goto out;
> +
>   		if (!efi_varname_is_load_option(var_name16, &index))
>   			continue;
>
> @@ -2407,6 +2373,8 @@ next:
>   	}
>
>   out:
> +	free(var_name16);
> +
>   	return ret;
>   }
>
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 0899e293e5..f80a16108a 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -708,6 +708,8 @@ int algo_to_len(const char *algo);
>   int efi_link_dev(efi_handle_t handle, struct udevice *dev);
>   int efi_unlink_dev(efi_handle_t handle);
>   bool efi_varname_is_load_option(u16 *var_name16, int *index);
> +efi_status_t efi_get_variable_name(efi_uintn_t *size, u16 **buf,
> +				   efi_guid_t *guid);
>
>   /**
>    * efi_size_in_pages() - convert size in bytes to size in pages
> diff --git a/lib/efi_loader/efi_helper.c b/lib/efi_loader/efi_helper.c
> index 788cb9faec..ca9854ec79 100644
> --- a/lib/efi_loader/efi_helper.c
> +++ b/lib/efi_loader/efi_helper.c
> @@ -223,3 +223,37 @@ bool efi_varname_is_load_option(u16 *var_name16, int *index)
>
>   	return false;
>   }
> +
> +/**
> + * efi_get_variable_name_() - get variable name
> + *
> + * This function is a wrapper of efi_get_next_variable_name_int().
> + * If efi_get_next_variable_name_int() returns EFI_BUFFER_TOO_SMALL,
> + * @size and @buf are updated by new buffer size and realloced buffer.
> + *
> + * @size:	pointer to the buffer size
> + * @buf:	pointer to the buffer
> + * @guid:	pointer to the guid
> + * Return:	status code
> + */
> +efi_status_t efi_get_variable_name(efi_uintn_t *size, u16 **buf, efi_guid_t *guid)

We should have next in the function name, e.g. "efi_next_variable_name".

> +{
> +	u16 *p;
> +	efi_status_t ret;
> +	efi_uintn_t buf_size = *size;
> +
> +	ret = efi_get_next_variable_name_int(&buf_size, *buf, guid);
> +	if (ret == EFI_NOT_FOUND)
> +		return ret;
> +	if (ret == EFI_BUFFER_TOO_SMALL) {
> +		p = realloc(*buf, buf_size);
> +		if (!p)

*buf should be freed here and set to NULL.

Best regards

Heinrich

> +			return EFI_OUT_OF_RESOURCES;
> +
> +		*buf = p;
> +		*size = buf_size;
> +		ret = efi_get_next_variable_name_int(&buf_size, *buf, guid);
> +	}
> +
> +	return ret;
> +}