Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757535AbaGORYw (ORCPT ); Tue, 15 Jul 2014 13:24:52 -0400 Received: from mail-we0-f170.google.com ([74.125.82.170]:48104 "EHLO mail-we0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754898AbaGORCJ (ORCPT ); Tue, 15 Jul 2014 13:02:09 -0400 From: Sam Asadi To: gregkh@linuxfoundation.org Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Doug Anderson , Kukjin Kim , sam-the-6 Subject: [PATCH 23/94] clocksource: exynos_mct: Fix ftrace Date: Tue, 15 Jul 2014 20:00:38 +0300 Message-Id: <1405443709-15288-23-git-send-email-asadi.samuel@gmail.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1405443709-15288-1-git-send-email-asadi.samuel@gmail.com> References: <1405443709-15288-1-git-send-email-asadi.samuel@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Doug Anderson In (93bfb76 clocksource: exynos_mct: register sched_clock callback) we supported using the MCT as a scheduler clock. We properly marked exynos4_read_sched_clock() as notrace. However, we then went and called another function that _wasn't_ notrace. That means if you do: cd /sys/kernel/debug/tracing/ echo function_graph > current_tracer You'll get a crash. Fix this (but still let other readers of the MCT be trace-enabled) by adding an extra function. It's important to keep other users of MCT traceable because the MCT is actually quite slow to access and we want exynos4_frc_read() to show up in ftrace profiles if it's the bottleneck. Signed-off-by: Doug Anderson Signed-off-by: Kukjin Kim Signed-off-by: sam-the-6 --- drivers/clocksource/exynos_mct.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c index f71d55f..5ce99c0 100644 --- a/drivers/clocksource/exynos_mct.c +++ b/drivers/clocksource/exynos_mct.c @@ -162,7 +162,7 @@ static void exynos4_mct_frc_start(void) exynos4_mct_write(reg, EXYNOS4_MCT_G_TCON); } -static cycle_t exynos4_frc_read(struct clocksource *cs) +static cycle_t notrace _exynos4_frc_read(void) { unsigned int lo, hi; u32 hi2 = __raw_readl(reg_base + EXYNOS4_MCT_G_CNT_U); @@ -176,6 +176,11 @@ static cycle_t exynos4_frc_read(struct clocksource *cs) return ((cycle_t)hi << 32) | lo; } +static cycle_t exynos4_frc_read(struct clocksource *cs) +{ + return _exynos4_frc_read(); +} + static void exynos4_frc_resume(struct clocksource *cs) { exynos4_mct_frc_start(); @@ -192,7 +197,7 @@ struct clocksource mct_frc = { static u64 notrace exynos4_read_sched_clock(void) { - return exynos4_frc_read(&mct_frc); + return _exynos4_frc_read(); } static void __init exynos4_clocksource_init(void) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/