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[78.210.255.2]) by smtp.gmail.com with ESMTPSA id lv4sm49967344wjb.43.2015.10.28.06.11.59 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 28 Oct 2015 06:11:59 -0700 (PDT) From: Daniel Lezcano To: tglx@linutronix.de Cc: Jisheng Zhang , linux-kernel@vger.kernel.org (open list:CLOCKSOURCE, CLOC...) Subject: [PATCH 3/8] clocksource/drivers/samsung_pwm_timer: Prevent ftrace recursion Date: Wed, 28 Oct 2015 14:11:28 +0100 Message-Id: <1446037894-22601-3-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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jisheng Zhang Currently samsung_pwm_timer can be used as a scheduler clock. We properly marked samsung_read_sched_clock() as notrace but we then call another function samsung_clocksource_read() 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 samsung_clocksource_read() function. Signed-off-by: Jisheng Zhang Signed-off-by: Daniel Lezcano --- drivers/clocksource/samsung_pwm_timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 1.9.1 -- 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/ diff --git a/drivers/clocksource/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c index bc90e13..9502bc4 100644 --- a/drivers/clocksource/samsung_pwm_timer.c +++ b/drivers/clocksource/samsung_pwm_timer.c @@ -307,7 +307,7 @@ static void samsung_clocksource_resume(struct clocksource *cs) samsung_time_start(pwm.source_id, true); } -static cycle_t samsung_clocksource_read(struct clocksource *c) +static cycle_t notrace samsung_clocksource_read(struct clocksource *c) { return ~readl_relaxed(pwm.source_reg); }