[PATCH 5/8] clocksource/drivers/vf_pit_timer: Prevent ftrace recursion

From: Daniel Lezcano
Date: Wed Oct 28 2015 - 09:12:14 EST


From: Jisheng Zhang <jszhang@xxxxxxxxxxx>

Having a traceable function in the sched_clock() path leads to a recursion
within ftrace and a kernel crash.

We should not trace the pit_read_sched_clock() function. Fix this by adding a
notrace attribute to this function.

Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx>
Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
---
drivers/clocksource/vf_pit_timer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/vf_pit_timer.c b/drivers/clocksource/vf_pit_timer.c
index f07ba99..a0e6c68 100644
--- a/drivers/clocksource/vf_pit_timer.c
+++ b/drivers/clocksource/vf_pit_timer.c
@@ -52,7 +52,7 @@ static inline void pit_irq_acknowledge(void)
__raw_writel(PITTFLG_TIF, clkevt_base + PITTFLG);
}

-static u64 pit_read_sched_clock(void)
+static u64 notrace pit_read_sched_clock(void)
{
return ~__raw_readl(clksrc_base + PITCVAL);
}
--
1.9.1

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