[Linaro-mm-sig] [PATCH v3 0/2] RFC: Secure Memory Allocation Framework

Tue Jul 28 00:56:59 PDT 2015

There is an API to do the same operation on kernel side than on userland.
You can get an dmabuf handle, select the allocator if required, and
secure it on kernel side.

Your question makes me realize that I have forget to add an
EXPORT_SYMBOL for smaf_create_handle function, I will fix that.

Benjamin

2015-07-28 4:22 GMT+02:00 Xiaoquan Li <xiaoquan.li at vivantecorp.com>:
> Hi Benjamin,
>
> It looks like this framework only allows user space client to talk with trust application, it there a plan to provide kernel side APIs for kernel space client?
>
> Please correct me if my understanding is wrong.
>
> Thanks
>
> Xiaoquan
>
> -----Original Message-----
> From: Linaro-mm-sig [mailto:linaro-mm-sig-bounces at lists.linaro.org] On Behalf Of Benjamin Gaignard
> Sent: Monday, July 27, 2015 6:12 PM
> To: linux-media at vger.kernel.org; Linux Kernel Mailing List; dri-devel at lists.freedesktop.org; Hans Verkuil; Laurent Pinchart; Daniel Vetter; Rob Clark; Thierry Reding; Sumit Semwal; Tom Cooksey; Daniel Stone
> Cc: Linaro MM SIG Mailman List
> Subject: Re: [Linaro-mm-sig] [PATCH v3 0/2] RFC: Secure Memory Allocation Framework
>
> Hi all,
>
> This thread doesn't get any feedback...
>
> What would be great is to know if this framework proposal fir with
> your platform needs.
>
> Maybe I haven't copy the good mailing lists so if you think there is
> better ones do not hesitate to forward.
>
> Regards,
> Benjamin
>
>
> 2015-07-10 14:28 GMT+02:00 Benjamin Gaignard <benjamin.gaignard at linaro.org>:
>> version 3 changes:
>>  - Remove ioctl for allocator selection instead provide the name of
>>    the targeted allocator with allocation request.
>>    Selecting allocator from userland isn't the prefered way of working
>>    but is needed when the first user of the buffer is a software component.
>>  - Fix issues in case of error while creating smaf handle.
>>  - Fix module license.
>>  - Update libsmaf and tests to care of the SMAF API evolution
>>    https://git.linaro.org/people/benjamin.gaignard/libsmaf.git
>>
>> version 2 changes:
>>  - Add one ioctl to allow allocator selection from userspace.
>>    This is required for the uses case where the first user of
>>    the buffer is a software IP which can't perform dma_buf attachement.
>>  - Add name and ranking to allocator structure to be able to sort them.
>>  - Create a tiny library to test SMAF:
>>    https://git.linaro.org/people/benjamin.gaignard/libsmaf.git
>>  - Fix one issue when try to secure buffer without secure module registered
>>
>> The outcome of the previous RFC about how do secure data path was the need
>> of a secure memory allocator (https://lkml.org/lkml/2015/5/5/551)
>>
>> SMAF goal is to provide a framework that allow allocating and securing
>> memory by using dma_buf. Each platform have it own way to perform those two
>> features so SMAF design allow to register helper modules to perform them.
>>
>> To be sure to select the best allocation method for devices SMAF implement
>> deferred allocation mechanism: memory allocation is only done when the first
>> device effectively required it.
>> Allocator modules have to implement a match() to let SMAF know if they are
>> compatibles with devices needs.
>> This patch set provide an example of allocator module which use
>> dma_{alloc/free/mmap}_attrs() and check if at least one device have
>> coherent_dma_mask set to DMA_BIT_MASK(32) in match function.
>> I have named smaf-cma.c like it is done for drm_gem_cma_helper.c even if
>> a better name could be found for this file.
>>
>> Secure modules are responsibles of granting and revoking devices access rights
>> on the memory. Secure module is also called to check if CPU map memory into
>> kernel and user address spaces.
>> An example of secure module implementation can be found here:
>> http://git.linaro.org/people/benjamin.gaignard/optee-sdp.git
>> This code isn't yet part of the patch set because it depends on generic TEE
>> which is still under discussion (https://lwn.net/Articles/644646/)
>>
>> For allocation part of SMAF code I get inspirated by Sumit Semwal work about
>> constraint aware allocator.
>>
>> Benjamin Gaignard (2):
>>   create SMAF module
>>   SMAF: add CMA allocator
>>
>>  drivers/Kconfig                |   2 +
>>  drivers/Makefile               |   1 +
>>  drivers/smaf/Kconfig           |  11 +
>>  drivers/smaf/Makefile          |   2 +
>>  drivers/smaf/smaf-cma.c        | 200 +++++++++++
>>  drivers/smaf/smaf-core.c       | 735 +++++++++++++++++++++++++++++++++++++++++
>>  include/linux/smaf-allocator.h |  54 +++
>>  include/linux/smaf-secure.h    |  62 ++++
>>  include/uapi/linux/smaf.h      |  52 +++
>>  9 files changed, 1119 insertions(+)
>>  create mode 100644 drivers/smaf/Kconfig
>>  create mode 100644 drivers/smaf/Makefile
>>  create mode 100644 drivers/smaf/smaf-cma.c
>>  create mode 100644 drivers/smaf/smaf-core.c
>>  create mode 100644 include/linux/smaf-allocator.h
>>  create mode 100644 include/linux/smaf-secure.h
>>  create mode 100644 include/uapi/linux/smaf.h
>>
>> --
>> 1.9.1
>>
>
>
>
> --
> Benjamin Gaignard
>
> Graphic Working Group
>
> Linaro.org │ Open source software for ARM SoCs
>
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-- 
Benjamin Gaignard

Graphic Working Group

Linaro.org │ Open source software for ARM SoCs

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