firmware: tee_bnxt: Release TEE shm, session, and context during kexec
Implement a .shutdown hook that will be called during a kexec operation so that the TEE shared memory, session, and context that were set up during .probe can be properly freed/closed. Additionally, don't use dma-buf backed shared memory for the fw_shm_pool. dma-buf backed shared memory cannot be reliably freed and unregistered during a kexec operation even when tee_shm_free() is called on the shm from a .shutdown hook. The problem occurs because dma_buf_put() calls fput() which then uses task_work_add(), with the TWA_RESUME parameter, to queue tee_shm_release() to be called before the current task returns to user mode. However, the current task never returns to user mode before the kexec completes so the memory is never freed nor unregistered. Use tee_shm_alloc_kernel_buf() to avoid dma-buf backed shared memory allocation so that tee_shm_free() can directly call tee_shm_release(). This will ensure that the shm can be freed and unregistered during a kexec operation. Fixes: 24688095 ("firmware: broadcom: add OP-TEE based BNXT f/w manager") Cc: stable@vger.kernel.org Signed-off-by:Allen Pais <apais@linux.microsoft.com> Co-developed-by:
Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by:
Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by:
Sumit Garg <sumit.garg@linaro.org> Acked-by:
Florian Fainelli <f.fainelli@gmail.com> Signed-off-by:
Jens Wiklander <jens.wiklander@linaro.org>
parent
dfb703ad
Please register or sign in to comment