From: Viresh Kumar <viresh.kumar@linaro.org>
To: Jisheng Zhang <jszhang@marvell.com>
Cc: vireshk@kernel.org, nm@ti.com, sboyd@codeaurora.org,
rjw@rjwysocki.net, gregkh@linuxfoundation.org,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] PM / OPP: optimize dev_pm_opp_set_rate() a bit
Date: Fri, 22 Jul 2016 09:21:51 -0700 [thread overview]
Message-ID: <20160722162151.GT3122@ubuntu> (raw)
In-Reply-To: <1469191370-1285-1-git-send-email-jszhang@marvell.com>
On 22-07-16, 20:42, Jisheng Zhang wrote:
> static int _set_opp_voltage(struct device *dev, struct regulator *reg,
> unsigned long u_volt, unsigned long u_volt_min,
> unsigned long u_volt_max)
> @@ -586,9 +565,24 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
> return -EINVAL;
> }
>
> - clk = _get_opp_clk(dev);
> - if (IS_ERR(clk))
> + rcu_read_lock();
> +
> + opp_table = _find_opp_table(dev);
> + if (IS_ERR(opp_table)) {
> + dev_err(dev, "%s: device opp doesn't exist\n", __func__);
> + rcu_read_unlock();
> + return PTR_ERR(opp_table);
> + }
> +
> + clk = opp_table->clk;
> + if (IS_ERR(clk)) {
> + dev_err(dev, "%s: No clock available for the device\n",
> + __func__);
> + rcu_read_unlock();
> return PTR_ERR(clk);
> + }
> +
> + rcu_read_unlock();
It is not _safe_ to use opp_table pointer after the rcu_read_unlock()
here.
--
viresh
WARNING: multiple messages have this Message-ID (diff)
From: viresh.kumar@linaro.org (Viresh Kumar)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] PM / OPP: optimize dev_pm_opp_set_rate() a bit
Date: Fri, 22 Jul 2016 09:21:51 -0700 [thread overview]
Message-ID: <20160722162151.GT3122@ubuntu> (raw)
In-Reply-To: <1469191370-1285-1-git-send-email-jszhang@marvell.com>
On 22-07-16, 20:42, Jisheng Zhang wrote:
> static int _set_opp_voltage(struct device *dev, struct regulator *reg,
> unsigned long u_volt, unsigned long u_volt_min,
> unsigned long u_volt_max)
> @@ -586,9 +565,24 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
> return -EINVAL;
> }
>
> - clk = _get_opp_clk(dev);
> - if (IS_ERR(clk))
> + rcu_read_lock();
> +
> + opp_table = _find_opp_table(dev);
> + if (IS_ERR(opp_table)) {
> + dev_err(dev, "%s: device opp doesn't exist\n", __func__);
> + rcu_read_unlock();
> + return PTR_ERR(opp_table);
> + }
> +
> + clk = opp_table->clk;
> + if (IS_ERR(clk)) {
> + dev_err(dev, "%s: No clock available for the device\n",
> + __func__);
> + rcu_read_unlock();
> return PTR_ERR(clk);
> + }
> +
> + rcu_read_unlock();
It is not _safe_ to use opp_table pointer after the rcu_read_unlock()
here.
--
viresh
next prev parent reply other threads:[~2016-07-22 16:21 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-22 12:42 [PATCH] PM / OPP: optimize dev_pm_opp_set_rate() a bit Jisheng Zhang
2016-07-22 12:42 ` Jisheng Zhang
2016-07-22 12:42 ` Jisheng Zhang
2016-07-22 14:30 ` kbuild test robot
2016-07-22 14:30 ` kbuild test robot
2016-07-22 14:30 ` kbuild test robot
2016-07-25 5:19 ` Jisheng Zhang
2016-07-25 5:19 ` Jisheng Zhang
2016-07-25 5:19 ` Jisheng Zhang
2016-07-25 6:05 ` Jisheng Zhang
2016-07-25 6:05 ` Jisheng Zhang
2016-07-25 6:05 ` Jisheng Zhang
2016-07-22 16:21 ` Viresh Kumar [this message]
2016-07-22 16:21 ` Viresh Kumar
2016-07-25 5:12 ` Jisheng Zhang
2016-07-25 5:12 ` Jisheng Zhang
2016-07-25 5:12 ` Jisheng Zhang
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