From: Jonghwan Choi <jhbird.choi@samsung.com>
To: "'Jonghwan Choi'" <jhbird.choi@samsung.com>, linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org, "'Russell King'" <linux@arm.linux.org.uk>,
        "'Stephen Boyd'" <sboyd@codeaurora.org>
References: <004801ce33e4$0a2ffc00$1e8ff400$%choi@samsung.com>
In-reply-to: <004801ce33e4$0a2ffc00$1e8ff400$%choi@samsung.com>
Subject: [PATCH 3.8-stable] ARM: 7699/1: sched_clock: Add more notrace to
 prevent
Date: Thu, 25 Apr 2013 09:16:07 +0900
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This patch looks like it should be in the 3.8-stable tree, should we apply
it?

------------------

From: "Stephen Boyd <sboyd@codeaurora.org>"

commit cea15092f098b7018e89f64a5a14bb71955965d5 upstream

cyc_to_sched_clock() is called by sched_clock() and cyc_to_ns()
is called by cyc_to_sched_clock(). I suspect that some compilers
inline both of these functions into sched_clock() and so we've
been getting away without having a notrace marking. It seems that
my compiler isn't inlining cyc_to_sched_clock() though, so I'm
hitting a recursion bug when I enable the function graph tracer,
causing my system to crash. Marking these functions notrace fixes
it. Technically cyc_to_ns() doesn't need the notrace because it's
already marked inline, but let's just add it so that if we ever
remove inline from that function it doesn't blow up.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
---
 arch/arm/kernel/sched_clock.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c
index bd6f56b..59d2adb 100644
--- a/arch/arm/kernel/sched_clock.c
+++ b/arch/arm/kernel/sched_clock.c
@@ -45,12 +45,12 @@ static u32 notrace jiffy_sched_clock_read(void)
 
 static u32 __read_mostly (*read_sched_clock)(void) =
jiffy_sched_clock_read;
 
-static inline u64 cyc_to_ns(u64 cyc, u32 mult, u32 shift)
+static inline u64 notrace cyc_to_ns(u64 cyc, u32 mult, u32 shift)
 {
 	return (cyc * mult) >> shift;
 }
 
-static unsigned long long cyc_to_sched_clock(u32 cyc, u32 mask)
+static unsigned long long notrace cyc_to_sched_clock(u32 cyc, u32 mask)
 {
 	u64 epoch_ns;
 	u32 epoch_cyc;
-- 
1.7.9.5ml

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