del_timer_sync() can cause a deadlock when called in interrupt context.
It is used with on_each_cpu() in some parts for sysfs files like bank*,
check_interval, cmci_disabled and ignore_ce.
However, use of on_each_cpu() results in calling the function passed
as the argument in interrupt context. This causes a flood of nested
warnings from del_timer_sync() (it runs on each CPU) caused even by a
simple file access like:
$ echo 300 > /sys/devices/system/machinecheck/machinecheck0/check_interval
Fortunately, these MCE-specific files are rarely used and AFAIK only few
MCE geeks experience this warning.
To remove the warning, move timer deletion outside of the interrupt
context.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
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