ad80c25987
commit adf752af454e91e123e85e3784972d166837af73 upstream.
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.
Cc: stable@vger.kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.