clocksource/drivers/ti-32k: Prevent ftrace recursion

Jisheng Zhang · KAGA-KOKO · commit 3aa601492bab · 2016-09-22T16:49:19.000+02:00
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() function. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Cc: daniel.lezcano@linaro.org Cc: linux-arm-kernel@lists.infradead.org Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20160922075621.3725-1-jszhang@marvell.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git 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);
 

Original file line number	Diff line number	Diff line change
`@@ -65,7 +65,7 @@ static inline struct ti_32k to_ti_32k(struct clocksource cs)`
`65`	`65`	`return container_of(cs, struct ti_32k, cs);`
`66`	`66`	`}`
`67`	`67`
`68`		`-static cycle_t ti_32k_read_cycles(struct clocksource *cs)`
	`68`	`+static cycle_t notrace ti_32k_read_cycles(struct clocksource *cs)`
`69`	`69`	`{`
`70`	`70`	`struct ti_32k *ti = to_ti_32k(cs);`
`71`	`71`