Re: [PATCH] arm64: make secondary_start_kernel() notrace

From: Catalin Marinas
Date: Mon Jun 18 2018 - 13:12:40 EST


On Tue, Jun 12, 2018 at 05:07:37PM +0800, Zhizhou Zhang wrote:
> We can't call function trace hook before setup percpu offset.
> When entering secondary_start_kernel(), percpu offset has not
> been initialized. So this lead hotplug malfunction.
> Here is the flow to reproduce this bug:
>
> echo 0 > /sys/devices/system/cpu/cpu1/online
> echo function > /sys/kernel/debug/tracing/current_tracer
> echo 1 > /sys/kernel/debug/tracing/tracing_on
> echo 1 > /sys/devices/system/cpu/cpu1/online
>
> Signed-off-by: Zhizhou Zhang <zhizhouzhang@xxxxxxxxxxxx>

Queued for 4.18. Thanks.

--
Catalin