[PATCH 2/6] efi_loader: Introduce helper functions for EFI

[Ilias Apalodimas <ilias.apalodimas@linaro.org>]

Hi Heinrich, 

> > +
> > +	/* make sure we have enough space for replacements */
> > +	if (u16_strsize(name) < sizeof(*name) * start + u16_strsize(L"####")) {
> > +		ret = EFI_INVALID_PARAMETER;
> > +		goto out;
> > +	}
> > +	boot_order_size = sizeof(boot_order);
> > +	ret = efi_get_variable_int(L"BootCurrent",
> > +				   &efi_global_variable_guid, NULL,
> > +				   &boot_order_size, &boot_order, NULL);
> > +	if (ret != EFI_SUCCESS)
> > +		goto out;
> > +
> > +	name_dup = u16_strdup(name);
> > +	if (!name_dup) {
> > +		ret = EFI_OUT_OF_RESOURCES;
> > +		goto out;
> > +	}
> > +	/* Match name variable to BootCurrent */
> > +	name_dup[start] = hexmap[(boot_order & 0xf000) >> 12];
> > +	name_dup[start + 1] = hexmap[(boot_order & 0x0f00) >> 8];
> > +	name_dup[start + 2] = hexmap[(boot_order & 0x00f0) >> 4];
> > +	name_dup[start + 3] = hexmap[(boot_order & 0x000f) >> 0];
> 
> Please, consider using  efi_create_indexed_name().

That one doesn't check any input variables and just asks for the user to
provide sufficient buffers for the output. 
I am explicitly checking the sizes here. I guess I can add similar checks to 
efi_create_indexed_name() and use it, instead of open coding again.
Just a note here, there's similar code to the efi bootmgr, so we should
probably start replacing all of the functions.

Regards
/Ilias
> 
> Best regards
> 
> Heinrich
> 
> > +
> > +	var_value = get_var(name_dup, &efi_global_variable_guid, &size);
> > +	if (!var_value) {
> > +		ret = EFI_NOT_FOUND;
> > +		goto out;
> > +	}
> > +
> > +	ret = string_to_load_args(var_value, info);
> > +	if (ret != EFI_SUCCESS)
> > +		goto out;
> > +
> > +	if (fs_set_blk_dev(info->dev, info->part, FS_TYPE_ANY)) {
> > +		ret = EFI_NO_MEDIA;
> > +		goto out;
> > +	}
> > +
> > +	if (!fs_exists(info->filename)) {
> > +		ret = EFI_NOT_FOUND;
> > +		goto out;
> > +	}
> > +
> > +out:
> > +	free(var_value);
> > +	free(name_dup);
> > +	return ret;
> > +}
> > 
>