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Jens Wiklander authored
This commit fixes a case overlooked in [1]. There are two kinds of shared memory buffers used by OP-TEE: 1. Normal payload buffer 2. Internal command structure buffers The internal command structure buffers are represented with a shadow copy internally in Xen since this buffer can contain physical addresses that may need to be translated between real physical address and guest physical address without leaking information to the guest. [1] fixes the problem when releasing the normal payload buffers. The internal command structure buffers must be released in the same way. Failure to follow this order opens a window where the guest has freed the shared memory but Xen is still tracking the buffer. During this window the guest may happen to recycle this particular shared memory in some other thread and try to use it. Xen will block this which will lead to spurious failures to register a new shared memory block. Fix this by freeing the internal command structure buffers first before informing the guest that the buffer can be freed. [1] 5b13eb1d ("optee: immediately free buffers that are released by OP-TEE") Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org> Reviewed-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com> [stefano: minor code style fix] Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
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