From b8725dab66f0b2d57affb33a7f6ca094d9f1f8dd Mon Sep 17 00:00:00 2001 From: Jisheng Zhang <jszhang@marvell.com> Date: Tue, 20 Oct 2015 16:02:35 +0800 Subject: [PATCH] clocksource/drivers/samsung_pwm_timer: Prevent ftrace recursion Currently samsung_pwm_timer can be used as a scheduler clock. We properly marked samsung_read_sched_clock() as notrace but we then call another function samsung_clocksource_read() that _wasn't_ notrace. Having a traceable function in the sched_clock() path leads to a recursion within ftrace and a kernel crash. Fix this by adding notrace attribute to the samsung_clocksource_read() function. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> --- drivers/clocksource/samsung_pwm_timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/clocksource/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c index bc90e13338cc..9502bc4c3f6d 100644 --- a/drivers/clocksource/samsung_pwm_timer.c +++ b/drivers/clocksource/samsung_pwm_timer.c @@ -307,7 +307,7 @@ static void samsung_clocksource_resume(struct clocksource *cs) samsung_time_start(pwm.source_id, true); } -static cycle_t samsung_clocksource_read(struct clocksource *c) +static cycle_t notrace samsung_clocksource_read(struct clocksource *c) { return ~readl_relaxed(pwm.source_reg); }