[PATCH v5] Input: i8042 add i8042_is_mr_coffee() helper to avoid refconut leak

[PATCH v5] Input: i8042 add i8042_is_mr_coffee() helper to avoid refconut leak

[Yangtao Li]

of_find_node_by_path() acquires a reference to the node returned by
it and that reference needs to be dropped by its caller. Add
i8042_is_mr_coffee() helper to avoid refconut leak.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
---
changes in v5:
-fix typo

changes in v4:
-fix typo

changes in v3:
-add i8042_is_mr_coffee
---
 drivers/input/serio/i8042-sparcio.h | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/input/serio/i8042-sparcio.h b/drivers/input/serio/i8042-sparcio.h
index 796289846204..9e9e512bc432 100644
--- a/drivers/input/serio/i8042-sparcio.h
+++ b/drivers/input/serio/i8042-sparcio.h
@@ -106,11 +106,23 @@ static struct platform_driver sparc_i8042_driver = {
 	.remove		= sparc_i8042_remove,
 };
 
+static inline bool i8042_is_mr_coffee(void)
+{
+	struct device_node *root;
+	bool is_mr_coffee;
+
+	root = of_find_node_by_path("/");
+	is_mr_coffee = !strcmp(root->name, "SUNW,JavaStation-1");
+	of_node_put(root);
+
+	return is_mr_coffee;
+}
+
 static int __init i8042_platform_init(void)
 {
-	struct device_node *root = of_find_node_by_path("/");
+	bool match = i8042_is_mr_coffee();
 
-	if (!strcmp(root->name, "SUNW,JavaStation-1")) {
+	if (match) {
 		/* Hardcoded values for MrCoffee.  */
 		i8042_kbd_irq = i8042_aux_irq = 13 | 0x20;
 		kbd_iobase = ioremap(0x71300060, 8);
@@ -138,9 +150,9 @@ static int __init i8042_platform_init(void)
 
 static inline void i8042_platform_exit(void)
 {
-	struct device_node *root = of_find_node_by_path("/");
+	bool match = i8042_is_mr_coffee();
 
-	if (strcmp(root->name, "SUNW,JavaStation-1"))
+	if (!match)
 		platform_driver_unregister(&sparc_i8042_driver);
 }
 
-- 
2.17.0

Re: [PATCH v5] Input: i8042 add i8042_is_mr_coffee() helper to avoid refconut leak

[Dmitry Torokhov]

On Sat, Dec 15, 2018 at 04:08:46AM -0500, Yangtao Li wrote:
> of_find_node_by_path() acquires a reference to the node returned by
> it and that reference needs to be dropped by its caller. Add
> i8042_is_mr_coffee() helper to avoid refconut leak.
> 
> Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
> ---
> changes in v5:
> -fix typo

Has this at least been actually compiled by you?

> 
> changes in v4:
> -fix typo
> 
> changes in v3:
> -add i8042_is_mr_coffee
> ---
>  drivers/input/serio/i8042-sparcio.h | 20 ++++++++++++++++----
>  1 file changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/input/serio/i8042-sparcio.h b/drivers/input/serio/i8042-sparcio.h
> index 796289846204..9e9e512bc432 100644
> --- a/drivers/input/serio/i8042-sparcio.h
> +++ b/drivers/input/serio/i8042-sparcio.h
> @@ -106,11 +106,23 @@ static struct platform_driver sparc_i8042_driver = {
>  	.remove		= sparc_i8042_remove,
>  };
>  
> +static inline bool i8042_is_mr_coffee(void)
> +{
> +	struct device_node *root;
> +	bool is_mr_coffee;
> +
> +	root = of_find_node_by_path("/");
> +	is_mr_coffee = !strcmp(root->name, "SUNW,JavaStation-1");
> +	of_node_put(root);
> +
> +	return is_mr_coffee;
> +}
> +
>  static int __init i8042_platform_init(void)
>  {
> -	struct device_node *root = of_find_node_by_path("/");
> +	bool match = i8042_is_mr_coffee();
>  
> -	if (!strcmp(root->name, "SUNW,JavaStation-1")) {
> +	if (match) {
>  		/* Hardcoded values for MrCoffee.  */
>  		i8042_kbd_irq = i8042_aux_irq = 13 | 0x20;
>  		kbd_iobase = ioremap(0x71300060, 8);
> @@ -138,9 +150,9 @@ static int __init i8042_platform_init(void)
>  
>  static inline void i8042_platform_exit(void)
>  {
> -	struct device_node *root = of_find_node_by_path("/");
> +	bool match = i8042_is_mr_coffee();
>  
> -	if (strcmp(root->name, "SUNW,JavaStation-1"))
> +	if (!match)
>  		platform_driver_unregister(&sparc_i8042_driver);
>  }
>  
> -- 
> 2.17.0
> 

-- 
Dmitry

Re: [PATCH v5] Input: i8042 add i8042_is_mr_coffee() helper to avoid refconut leak

[Frank Lee]

On Fri, Dec 21, 2018 at 4:42 PM Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
>
> On Sat, Dec 15, 2018 at 04:08:46AM -0500, Yangtao Li wrote:
> > of_find_node_by_path() acquires a reference to the node returned by
> > it and that reference needs to be dropped by its caller. Add
> > i8042_is_mr_coffee() helper to avoid refconut leak.
> >
> > Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
> > ---
> > changes in v5:
> > -fix typo
>
> Has this at least been actually compiled by you?
Sure!!!
On ubuntu 18 machine.

MBR,
Yangtao

Re: [PATCH v5] Input: i8042 add i8042_is_mr_coffee() helper to avoid refconut leak

[Pavel Machek]

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On Sat 2018-12-15 04:08:46, Yangtao Li wrote:
> of_find_node_by_path() acquires a reference to the node returned by
> it and that reference needs to be dropped by its caller. Add
> i8042_is_mr_coffee() helper to avoid refconut leak.

refconut->refcount, here and in subject.
									Pavel
									
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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