[U-Boot] efi_loader: execute image's unload function

[Heinrich Schuchardt]

On 09/28/2018 06:24 AM, AKASHI Takahiro wrote:
> Heinrich,
> 
> On Fri, Sep 28, 2018 at 04:35:57AM +0200, Heinrich Schuchardt wrote:
>> On 08/09/2018 08:50 AM, AKASHI Takahiro wrote:
>>> Currently, unload function in EFI_LOADED_IMAGE_PROTOCOL is never called
>>> at UnloadImage Boot Service. This is not compliant to UEFI specification.
>>> See chapter "9.1 EFI Loaded Image Protocol."
>>
>> With all the patches we got into U-Boot (+HII protocols, +HOB and DXE
>> tables) we now can start the EFI shell. But I do not succeed to run the
>> SCT. Could you, please, provide an overview what is needed.
>>
>> I use the sct-prepare target in
>> https://github.com/xypron/u-boot-build/blob/qemu-arm64/Makefile to set
>> up my disk image with the SCT.
>>
>> Are we missing further patches or is there something wrong with the
>> image I generate?
> 
> I have the same problem since I rebased my own branch to Alex's
> efi-next this week. I'm trying to understand what's happening now.
> 
> I will address your comments below later.
> 
> Thanks,
> -Takahiro Akashi
> 
> 
>>>
>>> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
>>> ---
>>>  include/efi_api.h             | 4 +++-
>>>  lib/efi_loader/efi_boottime.c | 9 +++++++++
>>>  2 files changed, 12 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/include/efi_api.h b/include/efi_api.h
>>> index a4343ae98e2..b2806fba3b8 100644
>>> --- a/include/efi_api.h
>>> +++ b/include/efi_api.h
>>> @@ -326,6 +326,8 @@ struct efi_system_table {
>>>  
>>>  #define EFI_LOADED_IMAGE_PROTOCOL_REVISION 0x1000
>>>  
>>> +typedef efi_status_t (EFIAPI *efi_image_unload_t)(efi_handle_t *image_handle);
>>
>> In the rest of efi_api.h we never used typedefs for function prototypes.
>> I would prefer to use the explicit type.
>>
>> In scripts/checkpatch.pl this will create a warning.
>>
>>> +
>>>  struct efi_loaded_image {
>>>  	u32 revision;
>>>  	void *parent_handle;
>>> @@ -339,7 +341,7 @@ struct efi_loaded_image {
>>>  	aligned_u64 image_size;
>>>  	unsigned int image_code_type;
>>>  	unsigned int image_data_type;
>>> -	unsigned long unload;
>>> +	efi_image_unload_t unload;
>>>  
>>>  	/* Below are efi loader private fields */
>>>  #ifdef CONFIG_EFI_LOADER
>>> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
>>> index 80061e10ebc..d6fcf7e0049 100644
>>> --- a/lib/efi_loader/efi_boottime.c
>>> +++ b/lib/efi_loader/efi_boottime.c
>>> @@ -1843,9 +1843,18 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
>>>   */
>>>  static efi_status_t EFIAPI efi_unload_image(efi_handle_t image_handle)
>>>  {
>>> +	struct efi_loaded_image *info = image_handle;
>>
>> Please, do not assume the the image_handle points to the
>> EFI_LOADED_IMAGE_PROTOCOL. Anyway this is not valid anymore after
>> http://git.denx.de/?p=u-boot.git;a=commitdiff;h=c982874e930d5d673501cd94df07bcbd215d5883
>>
>> Best regards
>>
>> Heinrich
>>
>>>  	struct efi_object *efiobj;
>>> +	efi_status_t ret;
>>>  
>>>  	EFI_ENTRY("%p", image_handle);
>>> +
>>> +	if (info->unload) {
>>> +		ret = info->unload(image_handle);
>>> +		if (ret != EFI_SUCCESS)
>>> +			return EFI_EXIT(ret);
>>> +	}

We have to check that image_handle is valid and refers to a loaded image
before trying to call the unload function.

The unload function shall only be called for a loaded image.

When unloading we have to close all protocol interfaces opened by
image_handle as agent.

Best regards

Heinrich

>>> +
>>>  	efiobj = efi_search_obj(image_handle);
>>>  	if (efiobj)
>>>  		list_del(&efiobj->link);
>>>
>>
>