Re: [PATCH ] cpufreq: ti-cpufreq: kfree opp_data when failure

From: Viresh Kumar <viresh.kumar@linaro.org>
To: Zumeng Chen <zumeng.chen@windriver.com>
Cc: linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-omap@vger.kernel.org, rjw@rjwysocki.net, d-gerlach@ti.com,
	tony@atomide.com
Subject: Re: [PATCH ] cpufreq: ti-cpufreq: kfree opp_data when failure
Date: Wed, 27 Sep 2017 21:19:33 -0700	[thread overview]
Message-ID: <20170928041933.GG12211@ubuntu> (raw)
In-Reply-To: <7b7315f0-c2e4-a09e-8769-2d15a167fa73@windriver.com>

On 28-09-17, 07:49, Zumeng Chen wrote:
> On 09/28/2017 01:40 AM, Viresh Kumar wrote:
> >On 27-09-17, 15:08, Zumeng Chen wrote:
> >>From: Zumeng Chen <zumeng.chen@gmail.com>
> >>
> >>memory leakage was found by kmemleak. opp_data needs to be freed
> >>when failure, including fail_put_node.
> >>
> >>unreferenced object 0xccdd4c40 (size 64):
> >>   comm "swapper", pid 1, jiffies 4294938465 (age 888.520s)
> >>   hex dump (first 32 bytes):
> >>     00 7c 00 c1 98 69 d8 ce 00 24 03 ce 00 24 03 ce  .|...i...$...$..
> >>     20 35 23 c1 00 00 00 00 00 00 00 00 00 00 00 00   5#.............
> >>   backtrace:
> >>     [<c028fb64>] kmem_cache_alloc_trace+0x2c4/0x3cc
> >>     [<c076d5f0>] ti_cpufreq_probe+0x6c/0x334
> >>     [<c068d6e4>] platform_drv_probe+0x60/0xc0
> >>     [<c068b384>] driver_probe_device+0x218/0x2c4
> >>     [<c068b5a4>] __device_attach_driver+0xa8/0xdc
> >>     [<c0689340>] bus_for_each_drv+0x70/0xa4
> >>     [<c068b020>] __device_attach+0xc0/0x124
> >>     [<c068b634>] device_initial_probe+0x1c/0x20
> >>     [<c068a3b8>] bus_probe_device+0x94/0x9c
> >>     [<c0688300>] device_add+0x404/0x590
> >>     [<c068d408>] platform_device_add+0x11c/0x230
> >>     [<c068df40>] platform_device_register_full+0x10c/0x128
> >>     [<c076d578>] ti_cpufreq_init+0x44/0x50
> >>     [<c01017c4>] do_one_initcall+0x54/0x180
> >>     [<c0e00fe0>] kernel_init_freeable+0x270/0x33c
> >>     [<c093f2bc>] kernel_init+0x18/0x124
> >>
> >>Signed-off-by: Zumeng Chen <zumeng.chen@gmail.com>
> >>---
> >>  drivers/cpufreq/ti-cpufreq.c | 5 ++++-
> >>  1 file changed, 4 insertions(+), 1 deletion(-)
> >>
> >>diff --git a/drivers/cpufreq/ti-cpufreq.c b/drivers/cpufreq/ti-cpufreq.c
> >>index 4bf47de..ffcddcd 100644
> >>--- a/drivers/cpufreq/ti-cpufreq.c
> >>+++ b/drivers/cpufreq/ti-cpufreq.c
> >>@@ -217,7 +217,8 @@ static int ti_cpufreq_init(void)
> >>  	opp_data->cpu_dev = get_cpu_device(0);
> >>  	if (!opp_data->cpu_dev) {
> >>  		pr_err("%s: Failed to get device for CPU0\n", __func__);
> >>-		return -ENODEV;
> >>+		ret = ENODEV;
> >>+		goto free_opp_data;
> >>  	}
> >>  	opp_data->opp_node = dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev);
> >>@@ -262,6 +263,8 @@ static int ti_cpufreq_init(void)
> >>  fail_put_node:
> >>  	of_node_put(opp_data->opp_node);
> >>+free_opp_data:
> >>+	kfree(opp_data);
> >>  	return ret;
> >>  }
> >Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
> >
> >I also see that you are missing an of_node_put(np) in the driver. Maybe you
> >want to fix that as well (in a separate patch) ?
> 
> Ha, thanks, I'm not sure if I follow your meanings.
> 
> opp_data->opp_node will be set after goto free_opp_data, so are we safe
> here?
> 
>         opp_data->cpu_dev = get_cpu_device(0);
>         if (!opp_data->cpu_dev) {
>                 pr_err("%s: Failed to get device for CPU0\n", __func__);
>                 ret = ENODEV;
>                 goto free_opp_data;
>         }
> 
>         opp_data->opp_node =
> dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev);

I was talking about this one.

        np = of_find_node_by_path("/");

There is no counterpart of this one.

-- 
viresh