[PATCH] clocksource/drivers/ti-32k: Prevent ftrace recursion

From: Jisheng Zhang
Date: Thu Sep 22 2016 - 04:01:25 EST

Currently ti-32k can be used as a scheduler clock. We properly marked
omap_32k_read_sched_clock() as notrace but we then call another
function ti_32k_read_cycles() 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 ti_32k_read_cycles()

Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx>
drivers/clocksource/timer-ti-32k.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/timer-ti-32k.c b/drivers/clocksource/timer-ti-32k.c
index 92b7e39..cf5b14e 100644
--- a/drivers/clocksource/timer-ti-32k.c
+++ b/drivers/clocksource/timer-ti-32k.c
@@ -65,7 +65,7 @@ static inline struct ti_32k *to_ti_32k(struct clocksource *cs)
return container_of(cs, struct ti_32k, cs);

-static cycle_t ti_32k_read_cycles(struct clocksource *cs)
+static cycle_t notrace ti_32k_read_cycles(struct clocksource *cs)
struct ti_32k *ti = to_ti_32k(cs);