clocksource/drivers/arm_arch_timer: Don't trace count reader functions
authorJulien Thierry <julien.thierry@arm.com>
Fri, 24 May 2019 09:10:25 +0000 (10:10 +0100)
committerDaniel Lezcano <daniel.lezcano@linaro.org>
Wed, 12 Jun 2019 13:38:54 +0000 (15:38 +0200)
commit5d6168fc61b7f13baf27ae5567be7ea1fccb463e
treef23288db2b1273774467432550d4d12c406c3101
parentcda03a9a7be6b94c637cffae5be1d269c538661b
clocksource/drivers/arm_arch_timer: Don't trace count reader functions

With v5.2-rc1, The ftrace functions_graph tracer locks up whenever it is
enabled on arm64.

Since commit 0ea415390cd3 ("clocksource/arm_arch_timer: Use
arch_timer_read_counter to access stable counters") a function pointer
is consistently used to read the counter instead of potentially
referencing an inlinable function.

The graph tracers relies on accessing the timer counters to compute the
time spent in functions which causes the lockup when attempting to trace
these code paths.

Annotate the arm arch timer counter accessors as notrace.

Fixes: 0ea415390cd3 ("clocksource/arm_arch_timer: Use
       arch_timer_read_counter to access stable counters")
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
drivers/clocksource/arm_arch_timer.c