On Thu, Jun 10, 2021 at 11:09 PM Tyler Hicks tyhicks@linux.microsoft.com wrote:
Fix a hung task issue, seen when booting the kdump kernel, that is caused by all of the secure world threads being in a permanent suspended state:
INFO: task swapper/0:1 blocked for more than 120 seconds. Not tainted 5.4.83 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. swapper/0 D 0 1 0 0x00000028 Call trace: __switch_to+0xc8/0x118 __schedule+0x2e0/0x700 schedule+0x38/0xb8 schedule_timeout+0x258/0x388 wait_for_completion+0x16c/0x4b8 optee_cq_wait_for_completion+0x28/0xa8 optee_disable_shm_cache+0xb8/0xf8 optee_probe+0x560/0x61c platform_drv_probe+0x58/0xa8 really_probe+0xe0/0x338 driver_probe_device+0x5c/0xf0 device_driver_attach+0x74/0x80 __driver_attach+0x64/0xe0 bus_for_each_dev+0x84/0xd8 driver_attach+0x30/0x40 bus_add_driver+0x188/0x1e8 driver_register+0x64/0x110 __platform_driver_register+0x54/0x60 optee_driver_init+0x20/0x28 do_one_initcall+0x54/0x24c kernel_init_freeable+0x1e8/0x2c0 kernel_init+0x18/0x118 ret_from_fork+0x10/0x18
The invoke_fn hook returned OPTEE_SMC_RETURN_ETHREAD_LIMIT, indicating that the secure world threads were all in a suspended state at the time of the kernel crash. This intermittently prevented the kdump kernel from booting, resulting in a failure to collect the kernel dump.
Make kernel dump collection more reliable on systems utilizing OP-TEE by refusing to load the driver under the kdump kernel.
Signed-off-by: Tyler Hicks tyhicks@linux.microsoft.com
drivers/tee/optee/core.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
Looks good Reviewed-by: Jens Wiklander jens.wiklander@linaro.org