From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965766AbbJ1NR5 (ORCPT ); Wed, 28 Oct 2015 09:17:57 -0400 Received: from mail-wm0-f44.google.com ([74.125.82.44]:35058 "EHLO mail-wm0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965608AbbJ1NRl (ORCPT ); Wed, 28 Oct 2015 09:17:41 -0400 X-Greylist: delayed 342 seconds by postgrey-1.27 at vger.kernel.org; Wed, 28 Oct 2015 09:17:41 EDT From: Daniel Lezcano To: tglx@linutronix.de Cc: Jisheng Zhang , linux-kernel@vger.kernel.org (open list:CLOCKSOURCE, CLOC...) Subject: [PATCH 2/8] clocksource/drivers/pistachio: Prevent ftrace recursion Date: Wed, 28 Oct 2015 14:11:27 +0100 Message-Id: <1446037894-22601-2-git-send-email-daniel.lezcano@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1446037894-22601-1-git-send-email-daniel.lezcano@linaro.org> References: <5630C947.4020706@linaro.org> <1446037894-22601-1-git-send-email-daniel.lezcano@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jisheng Zhang Currently pistachio can be used as a scheduler clock. We properly marked pistachio_read_sched_clock() as notrace but we then call another function pistachio_clocksource_read_cycles() that _wasn't_ notrace. Having a traceable function in the sched_clock() path leads to a recursion within ftrace and a kernel crash. Fix this by adding notrace attribute to the pistachio_clocksource_read_cycles() function. Signed-off-by: Jisheng Zhang Signed-off-by: Daniel Lezcano --- drivers/clocksource/time-pistachio.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/clocksource/time-pistachio.c b/drivers/clocksource/time-pistachio.c index 18d4266..bba6799 100644 --- a/drivers/clocksource/time-pistachio.c +++ b/drivers/clocksource/time-pistachio.c @@ -67,7 +67,8 @@ static inline void gpt_writel(void __iomem *base, u32 value, u32 offset, writel(value, base + 0x20 * gpt_id + offset); } -static cycle_t pistachio_clocksource_read_cycles(struct clocksource *cs) +static cycle_t notrace +pistachio_clocksource_read_cycles(struct clocksource *cs) { struct pistachio_clocksource *pcs = to_pistachio_clocksource(cs); u32 counter, overflw; -- 1.9.1