2021-04-15 07:35:28

by Dinghao Liu

[permalink] [raw]
Subject: [PATCH] [v3] clk: renesas: rcar-usb2-clock-sel: Fix error handling in rcar_usb2_clock_sel_probe

The error handling paths after pm_runtime_get_sync() has no
refcount decrement, which leads to refcount leak.

Signed-off-by: Dinghao Liu <[email protected]>
---

Changelog:

v2: - Move the position of pm_runtime_enable,_get_sync().
Use devm_clk_register() to simplify error handling.

v2: - Use devm_clk_hw_register() instead of devm_clk_register().
---
drivers/clk/renesas/rcar-usb2-clock-sel.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/clk/renesas/rcar-usb2-clock-sel.c b/drivers/clk/renesas/rcar-usb2-clock-sel.c
index 3abafd78f7c8..a6f82a5a6335 100644
--- a/drivers/clk/renesas/rcar-usb2-clock-sel.c
+++ b/drivers/clk/renesas/rcar-usb2-clock-sel.c
@@ -131,7 +131,6 @@ static int rcar_usb2_clock_sel_remove(struct platform_device *pdev)
struct usb2_clock_sel_priv *priv = platform_get_drvdata(pdev);

of_clk_del_provider(dev->of_node);
- clk_hw_unregister(&priv->hw);
pm_runtime_put(dev);
pm_runtime_disable(dev);

@@ -164,9 +163,6 @@ static int rcar_usb2_clock_sel_probe(struct platform_device *pdev)
if (IS_ERR(priv->rsts))
return PTR_ERR(priv->rsts);

- pm_runtime_enable(dev);
- pm_runtime_get_sync(dev);
-
clk = devm_clk_get(dev, "usb_extal");
if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
priv->extal = !!clk_get_rate(clk);
@@ -183,6 +179,8 @@ static int rcar_usb2_clock_sel_probe(struct platform_device *pdev)
return -ENOENT;
}

+ pm_runtime_enable(dev);
+ pm_runtime_get_sync(dev);
platform_set_drvdata(pdev, priv);
dev_set_drvdata(dev, priv);

@@ -193,11 +191,20 @@ static int rcar_usb2_clock_sel_probe(struct platform_device *pdev)
init.num_parents = 0;
priv->hw.init = &init;

- clk = clk_register(NULL, &priv->hw);
- if (IS_ERR(clk))
- return PTR_ERR(clk);
+ ret = devm_clk_hw_register(NULL, &priv->hw);
+ if (ret)
+ goto pm_put;
+
+ ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw);
+ if (ret)
+ goto pm_put;
+
+ return 0;

- return of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw);
+pm_put:
+ pm_runtime_put(dev);
+ pm_runtime_disable(dev);
+ return ret;
}

static const struct dev_pm_ops rcar_usb2_clock_sel_pm_ops = {
--
2.17.1


2021-04-23 07:48:03

by Geert Uytterhoeven

[permalink] [raw]
Subject: Re: [PATCH] [v3] clk: renesas: rcar-usb2-clock-sel: Fix error handling in rcar_usb2_clock_sel_probe

Hi Dinghao,

On Thu, Apr 15, 2021 at 9:33 AM Dinghao Liu <[email protected]> wrote:
> The error handling paths after pm_runtime_get_sync() has no
> refcount decrement, which leads to refcount leak.
>
> Signed-off-by: Dinghao Liu <[email protected]>
> ---
>
> Changelog:
>
> v2: - Move the position of pm_runtime_enable,_get_sync().
> Use devm_clk_register() to simplify error handling.

Thanks for the update!

> --- a/drivers/clk/renesas/rcar-usb2-clock-sel.c
> +++ b/drivers/clk/renesas/rcar-usb2-clock-sel.c
> @@ -131,7 +131,6 @@ static int rcar_usb2_clock_sel_remove(struct platform_device *pdev)
> struct usb2_clock_sel_priv *priv = platform_get_drvdata(pdev);

warning: unused variable ‘priv’ [-Wunused-variable]

Have you compiled this?

>
> of_clk_del_provider(dev->of_node);
> - clk_hw_unregister(&priv->hw);
> pm_runtime_put(dev);
> pm_runtime_disable(dev);
>

Reviewed-by: Geert Uytterhoeven <[email protected]>
i.e. will queue in renesas-clk-for-v5.14, with the above fixed.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

2021-04-23 08:10:03

by Dinghao Liu

[permalink] [raw]
Subject: Re: Re: [PATCH] [v3] clk: renesas: rcar-usb2-clock-sel: Fix error handling in rcar_usb2_clock_sel_probe

> Hi Dinghao,
>
> On Thu, Apr 15, 2021 at 9:33 AM Dinghao Liu <[email protected]> wrote:
> > The error handling paths after pm_runtime_get_sync() has no
> > refcount decrement, which leads to refcount leak.
> >
> > Signed-off-by: Dinghao Liu <[email protected]>
> > ---
> >
> > Changelog:
> >
> > v2: - Move the position of pm_runtime_enable,_get_sync().
> > Use devm_clk_register() to simplify error handling.
>
> Thanks for the update!
>
> > --- a/drivers/clk/renesas/rcar-usb2-clock-sel.c
> > +++ b/drivers/clk/renesas/rcar-usb2-clock-sel.c
> > @@ -131,7 +131,6 @@ static int rcar_usb2_clock_sel_remove(struct platform_device *pdev)
> > struct usb2_clock_sel_priv *priv = platform_get_drvdata(pdev);
>
> warning: unused variable ‘priv’ [-Wunused-variable]
>
> Have you compiled this?
>

This is my carelessness, thanks for pointing out this. When we use
devm_clk_hw_register(), we will not need to unregister priv->hw in
rcar_usb2_clock_sel_remove(). So I think it's okay to remove
platform_get_drvdata() in it to eliminate this warning.

Do you need a new version of patch to fix this warning?

Regards,
Dinghao

2021-04-23 08:17:02

by Geert Uytterhoeven

[permalink] [raw]
Subject: Re: Re: [PATCH] [v3] clk: renesas: rcar-usb2-clock-sel: Fix error handling in rcar_usb2_clock_sel_probe

Hi Dinghao,

On Fri, Apr 23, 2021 at 10:08 AM <[email protected]> wrote:
> > On Thu, Apr 15, 2021 at 9:33 AM Dinghao Liu <[email protected]> wrote:
> > > The error handling paths after pm_runtime_get_sync() has no
> > > refcount decrement, which leads to refcount leak.
> > >
> > > Signed-off-by: Dinghao Liu <[email protected]>
> > > ---
> > >
> > > Changelog:
> > >
> > > v2: - Move the position of pm_runtime_enable,_get_sync().
> > > Use devm_clk_register() to simplify error handling.
> >
> > Thanks for the update!
> >
> > > --- a/drivers/clk/renesas/rcar-usb2-clock-sel.c
> > > +++ b/drivers/clk/renesas/rcar-usb2-clock-sel.c
> > > @@ -131,7 +131,6 @@ static int rcar_usb2_clock_sel_remove(struct platform_device *pdev)
> > > struct usb2_clock_sel_priv *priv = platform_get_drvdata(pdev);
> >
> > warning: unused variable ‘priv’ [-Wunused-variable]
> >
> > Have you compiled this?
> >
>
> This is my carelessness, thanks for pointing out this. When we use
> devm_clk_hw_register(), we will not need to unregister priv->hw in
> rcar_usb2_clock_sel_remove(). So I think it's okay to remove
> platform_get_drvdata() in it to eliminate this warning.
>
> Do you need a new version of patch to fix this warning?

I'll remove that line while applying, so no need to fix and resend.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds