• Julien Thierry's avatar
    clocksource/drivers/arm_arch_timer: Don't trace count reader functions · 5d6168fc
    Julien Thierry authored
    With v5.2-rc1, The ftrace functions_graph tracer locks up whenever it is
    enabled on arm64.
    
    Since commit 0ea41539 ("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: 0ea41539 ("clocksource/arm_arch_timer: Use
           arch_timer_read_counter to access stable counters")
    Signed-off-by: default avatarJulien 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: default avatarMarc Zyngier <marc.zyngier@arm.com>
    Signed-off-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
    5d6168fc
arm_arch_timer.c 42.2 KB