[U-Boot] [RFC 1/8] efi_loader: boottime: don't add device path protocol to image handle

[Heinrich Schuchardt]

On 3/6/19 1:27 AM, AKASHI Takahiro wrote:
> On Tue, Mar 05, 2019 at 08:48:37PM +0100, Heinrich Schuchardt wrote:
>> On 3/5/19 6:53 AM, AKASHI Takahiro wrote:
>>> It is just wrong to add devcie path protocol to image handle.
>>>
>>> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
>>> ---
>>>  lib/efi_loader/efi_boottime.c | 11 +----------
>>>  1 file changed, 1 insertion(+), 10 deletions(-)
>>>
>>> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
>>> index bd8b8a17ae71..7bd9c0a952d4 100644
>>> --- a/lib/efi_loader/efi_boottime.c
>>> +++ b/lib/efi_loader/efi_boottime.c
>>> @@ -1540,17 +1540,8 @@ efi_status_t efi_setup_loaded_image(struct efi_device_path *device_path,
>>>  	info->file_path = file_path;
>>>  	info->system_table = &systab;
>>>  
>>> -	if (device_path) {
>>> +	if (device_path)
>>>  		info->device_handle = efi_dp_find_obj(device_path, NULL);
>>> -		/*
>>> -		 * When asking for the device path interface, return
>>> -		 * bootefi_device_path
>>> -		 */
>>> -		ret = efi_add_protocol(&obj->header,
>>> -				       &efi_guid_device_path, device_path);
>>
>> Installing the device path is not the problem. It is the GUID that is
>> wrong. Use EFI_LOADED_IMAGE_DEVICE_PATH_PROTOCOL_GUID here.
> 
> Okay, but I believe that we need duplicate device_path here
> before installing it as EFI_LOADED_IMAGE_DEVICE_PATH_PROTOCOL_GUID.
> 
> See this line:
> 
>>>  		info->device_handle = efi_dp_find_obj(device_path, NULL);
> 
> Normally, device_path is expected to be already associated with
> another handle. We should not allow two handles to share one protocol(data).
> That is also why I initially believed that add_protocol() should be removed.

The spec says we should use a copy of the unchanged DevicePath parameter
of LoadImage() which may be NULL.

So we have to rework all callers to get the device_path parameter of
efi_setup_loaded_image() right.

Best regards

Heinrich

> 
> Thanks,
> -Takahiro Akashi
> 
> 
>> UEFI Spec 2.7:
>>
>> "The Loaded Image Device Path Protocol must be installed onto the image
>> handle of a PE/COFF image loaded through the EFI Boot Service LoadImage()."
>>
>> Best regards
>>
>> Heinrich
>>
>>> -		if (ret != EFI_SUCCESS)
>>> -			goto failure;
>>> -	}
>>>  
>>>  	/*
>>>  	 * When asking for the loaded_image interface, just
>>>
>>
>