From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stephen Boyd , Russell King , Jonghwan Choi Subject: [ 41/42] ARM: 7699/1: sched_clock: Add more notrace to prevent recursion Date: Mon, 29 Apr 2013 12:02:23 -0700 Message-Id: <20130429184757.010994053@linuxfoundation.org> In-Reply-To: <20130429184752.435249613@linuxfoundation.org> References: <20130429184752.435249613@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stephen Boyd 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 Signed-off-by: Russell King Signed-off-by: Jonghwan Choi Signed-off-by: Greg Kroah-Hartman --- arch/arm/kernel/sched_clock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/arm/kernel/sched_clock.c +++ b/arch/arm/kernel/sched_clock.c @@ -45,12 +45,12 @@ static u32 notrace jiffy_sched_clock_rea 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;