From mboxrd@z Thu Jan 1 00:00:00 1970 From: sboyd@codeaurora.org (Stephen Boyd) Date: Tue, 26 Mar 2013 10:35:49 -0700 Subject: [PATCH] ARM: sched_clock: Add more notrace to prevent recursion In-Reply-To: <514B483F.7000304@codeaurora.org> References: <1363306086-23501-1-git-send-email-sboyd@codeaurora.org> <514B483F.7000304@codeaurora.org> Message-ID: <5151DC75.7030606@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 03/21/13 10:49, Stephen Boyd wrote: > On 03/14/13 17:08, Stephen Boyd wrote: >> 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. > Anyone else seeing this problem? Russell, should I put this into the patch tracker? >> Signed-off-by: Stephen Boyd >> --- >> 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; -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation