From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: [PATCH] ARM: sched_clock: Add more notrace to prevent recursion Date: Thu, 14 Mar 2013 17:08:06 -0700 Message-ID: <1363306086-23501-1-git-send-email-sboyd@codeaurora.org> Return-path: Received: from wolverine01.qualcomm.com ([199.106.114.254]:32946 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750820Ab3COAIJ (ORCPT ); Thu, 14 Mar 2013 20:08:09 -0400 Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Russell King Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org 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 --- 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; -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation From mboxrd@z Thu Jan 1 00:00:00 1970 From: sboyd@codeaurora.org (Stephen Boyd) Date: Thu, 14 Mar 2013 17:08:06 -0700 Subject: [PATCH] ARM: sched_clock: Add more notrace to prevent recursion Message-ID: <1363306086-23501-1-git-send-email-sboyd@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- 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; -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation