On Wed, Jun 15, 2016 at 9:34 AM, machiry aravind <machiry_msidc@hotmail.com> wrote:





From: Jerome Forissier <jerome.forissier@linaro.org>
Sent: Wednesday, June 15, 2016 12:30 AM
To: machiry aravind
Cc: Jens Wiklander; tee-dev@lists.linaro.org; Eric Gustafson
Subject: Re: [Tee-dev] OP-TEE OS: Param Mapping in TA
 
Hi guys,

On Wed, Jun 15, 2016 at 9:10 AM, machiry aravind <machiry_msidc@hotmail.com> wrote:

Thanks a lot Jens.


I just want to make sure that, there was nothing fundamental problem for this.


My idea is to change op-tee kernel driver to pin the corresponding user-pages (i.e memref.buffer)  which ensures that these will not be unmapped, before making smc and unpinning them on return.


Would that be triggered by TEEC_RegisterSharedMemory() in libteec?

[Aravind] Nope, The plan is to be transparent. non-secure user space can pass any user-space pointer as buffer argument. op-tee kernel driver verifies the address, pins corresponding pages.

While it sounds quite convenient, I'm afraid it can encourage the development of non-GP-compliant applications.

 -- 
Jerome