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

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

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@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.

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
> > 
>