Hi Greg,
While trying to boot 4.14 on a RPi3 I encountered the following log
lines which preceded a kernel panic:
> OF: ERROR: Bad of_node_put() on /soc/firmware
> CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.14.3 #1-NixOS
> Hardware name: Raspberry Pi 3 Model B (DT)
> Call trace:
> [] dump_backtrace+0x0/0x298
> [] show_stack+0x24/0x30
> [] dump_stack+0x98/0xbc
> [] of_node_release+0xa4/0xa8
> [] kobject_put+0x94/0x218
> [] of_node_put+0x24/0x30
> [] optee_driver_init+0x60/0x4c4
> [] do_one_initcall+0x5c/0x168
> [] kernel_init_freeable+0x18c/0x22c
> [] kernel_init+0x18/0x110
> [] ret_from_fork+0x10/0x18
The PI spits this out a couple of times, stumbles upon other things and
decides to panic. (The full output can be seen at [1])
The below patch was discovered on LKML [2], applied and
successfully tested. Boot succeeds and log looks normal again.
It would make sense to me to see that patch being included in the
(long term) stable release as well. Since optee was introduced with 4.11
there is no need to include this on 4.9.
I would appreciate if you could pull that commit into the stable queue.
commit f044113113dd95ba73916bde10e804d3cdfa2662
Author: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
Date: Mon Oct 9 11:11:49 2017 +0200
optee: fix invalid of_node_put() in optee_driver_init()
The first node supplied to of_find_matching_node() has its reference
counter decreased as part of call to that function. In optee_driver_init()
after calling of_find_matching_node() it's invalid to call of_node_put() on
the supplied node again.
So remove the invalid call to of_node_put().
Reported-by: Alex Shi <alex.shi@xxxxxxxxxx>
Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
Kind regards,
Andreas Rammhold
[1] https://gist.githubusercontent.com/andir/0de9163e9e31493658ff185f5fcf0616/raw/4f3235b8196c6831b2084669d2038b5f7a21e57c/loglevel8.txt
[2] https://lkml.org/lkml/2017/11/29/230