Not able to Open Persistent Object

[sahilnxp]

Hi All,

I am new to TA programming and having some issue with the Persistent Objects creation/opening.
Below is the code snippet and output when i run the code.
In this program first created a Persistent Object then Opened it and then Closed it.
After this I tried creating already created Persistent Object, It gives the TEE_ERROR_ACCESS_CONFLICT, which i fine.

After this when I tried opening that Persistent Object it is again giving the TEE_ERROR_ACCESS_CONFLICT, which I am not able to understand.

I want to know that why Second TEE_OpenPersistentObject is failing ?
Is there any limitation that if you try creating an already created PersistentObject, access to that object is locked somehow ?

Any help on this is really appreciated.

Thanks
Sahil

[jbech-linaro]

Hi @sahilnxp ,

Please have a look at the not yet merged pull request here so see whether that helps understand how to work with persistent storage objects.
linaro-swg/optee_examples#5

// Joakim

[sahilnxp]

Hi @jbech-linaro

Thanks for reply.
I studied the code given in the pull request, but it is not having the case I am trying.

I am trying to create an already created Persistent object without TEE_DATA_FLAG_OVERWRITE which is giving me the TEEC_ERROR_ACCESS_CONFLICT, which is correct according to the specification.
After getting this error since I know that the object is already created, so I tried opening that Persistent Object but it is giving the TEEC_ERROR_ACCESS_CONFLICT.

So I want to understand that if we try creating an already created object without TEE_DATA_FLAG_OVERWRITE, then we will be not be able to open that object any further ?

Thanks,
Sahil

[etienne-lms]

This puzzle me and i tried to same from the ote_secure_storage. I think you spotted an issue in the core. The create_object without overwrite fails, but it still create an object instance and does not release it. See OP-TEE/optee_os#1903 (needs storage experts review).

[sahilnxp]

Thanks @etienne-lms for the fix.

When I was going through pull request linaro-swg/optee_examples#5, I think i found a typo in error message at 204 line of secure_storage/host/main.c file.
If I understood correctly, it should be "Failed to read object from secure storage" instead of "Failed to create an object in the secure storage".

[etienne-lms]

Thank you @sahilnxp. Could you add the comment straight in linaro-swg/optee_examples#5? It will be more handy to track and fix.

[sahilnxp]

@etienne-lms , added the comment in pull request.

Thanks
Sahil