From: Alexandre Belloni <alexandre.belloni@bootlin•com>
To: Yizhuo <yzhai003@ucr•edu>
Cc: csong@cs•ucr.edu, Daniel Lezcano <daniel.lezcano@linaro•org>,
zhiyunq@cs•ucr.edu, linux-kernel@vger•kernel.org,
Ludovic Desroches <ludovic.desroches@microchip•com>,
Thomas Gleixner <tglx@linutronix•de>,
linux-arm-kernel@lists•infradead.org
Subject: Re: [PATCH] clocksource: atmel-st: Variable sr in at91rm9200_timer_interrupt() could be uninitialized
Date: Tue, 3 Sep 2019 00:36:50 +0200 [thread overview]
Message-ID: <20190902223650.GJ21922@piout.net> (raw)
In-Reply-To: <20190902222946.20548-1-yzhai003@ucr.edu>
On 02/09/2019 15:29:46-0700, Yizhuo wrote:
> Inside function at91rm9200_timer_interrupt(), variable sr could
> be uninitialized if regmap_read() fails. However, sr is used
Could you elaborate on how this could fail?
> to decide the control flow later in the if statement, which is
> potentially unsafe. We could check the return value of
> regmap_read() and print an error here.
>
> Signed-off-by: Yizhuo <yzhai003@ucr•edu>
> ---
> drivers/clocksource/timer-atmel-st.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clocksource/timer-atmel-st.c b/drivers/clocksource/timer-atmel-st.c
> index ab0aabfae5f0..061a3f27847e 100644
> --- a/drivers/clocksource/timer-atmel-st.c
> +++ b/drivers/clocksource/timer-atmel-st.c
> @@ -48,8 +48,14 @@ static inline unsigned long read_CRTR(void)
> static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id)
> {
> u32 sr;
> + int ret;
> +
> + ret = regmap_read(regmap_st, AT91_ST_SR, &sr);
> + if (ret) {
> + pr_err("Fail to read AT91_ST_SR.\n");
> + return ret;
> + }
>
> - regmap_read(regmap_st, AT91_ST_SR, &sr);
> sr &= irqmask;
>
> /*
> --
> 2.17.1
>
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
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next prev parent reply other threads:[~2019-09-02 22:37 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-02 22:29 [PATCH] clocksource: atmel-st: Variable sr in at91rm9200_timer_interrupt() could be uninitialized Yizhuo
2019-09-02 22:36 ` Alexandre Belloni [this message]
2019-09-03 5:56 ` Yizhuo Zhai
2019-09-03 8:16 ` Alexandre Belloni
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