On 2021-06-11 11:11:33, Jens Wiklander wrote:
On Thu, Jun 10, 2021 at 11:09 PM Tyler Hicks tyhicks@linux.microsoft.com wrote:
From: Allen Pais apais@linux.microsoft.com
The following out of memory errors are seen on kexec reboot from the optee core.
[ 0.368428] tee_bnxt_fw optee-clnt0: tee_shm_alloc failed [ 0.368461] tee_bnxt_fw: probe of optee-clnt0 failed with error -22
tee_shm_release() is not invoked on dma shm buffer.
Implement .shutdown() method to handle the release of the buffers correctly.
More info: https://github.com/OP-TEE/optee_os/issues/3637
Signed-off-by: Allen Pais apais@linux.microsoft.com Reviewed-by: Tyler Hicks tyhicks@linux.microsoft.com
Do we really need this considering the patch "optee: Refuse to load the driver under the kdump kernel"?
Yes. That patch fixes boot hangs when all of the OP-TEE threads were in the suspended state at the time of a kernel panic. The kexec into the kdump kernel after a panic is an "emergency" kexec that doesn't even call .shutdown hooks. There's no way for the OP-TEE driver to clean up after itself.
This patch disables the shm cache (and unregisters the shm buffers) during a normal kexec from one perfectly working kernel into a new kernel. This is required because the new kernel will not be able to handle the virtual addresses that were cached under the old kernel. The new kernel has an entirely different memory layout and the old addresses point to unmapped memory or memory that's mapped but probably not a TEE shm.
Tyler
Jens