[PATCH] Input: evdev - get rid of old workaround for EVIOCGBIT

[PATCH] Input: evdev - get rid of old workaround for EVIOCGBIT

[Dmitry Torokhov]

We put this workaround in 2008 and the offending userspace has been fixed
up long time ago; the link in the message is no longer valid either, so it
is time to retire it.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/evdev.c | 18 ------------------
 1 file changed, 18 deletions(-)

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index ce953d8..fd325ec 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -629,12 +629,10 @@ static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 	return copy_to_user(p, str, len) ? -EFAULT : len;
 }
 
-#define OLD_KEY_MAX	0x1ff
 static int handle_eviocgbit(struct input_dev *dev,
 			    unsigned int type, unsigned int size,
 			    void __user *p, int compat_mode)
 {
-	static unsigned long keymax_warn_time;
 	unsigned long *bits;
 	int len;
 
@@ -652,24 +650,8 @@ static int handle_eviocgbit(struct input_dev *dev,
 	default: return -EINVAL;
 	}
 
-	/*
-	 * Work around bugs in userspace programs that like to do
-	 * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
-	 * should be in bytes, not in bits.
-	 */
-	if (type == EV_KEY && size == OLD_KEY_MAX) {
-		len = OLD_KEY_MAX;
-		if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
-			pr_warning("(EVIOCGBIT): Suspicious buffer size %u, "
-				   "limiting output to %zu bytes. See "
-				   "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
-				   OLD_KEY_MAX,
-				   BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
-	}
-
 	return bits_to_user(bits, len, size, p, compat_mode);
 }
-#undef OLD_KEY_MAX
 
 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
 {
-- 
1.9.0


-- 
Dmitry

Re: [PATCH] Input: evdev - get rid of old workaround for EVIOCGBIT

[Peter Hutterer]

On Wed, Apr 23, 2014 at 10:27:20PM -0700, Dmitry Torokhov wrote:
> We put this workaround in 2008 and the offending userspace has been fixed
> up long time ago; the link in the message is no longer valid either, so it
> is time to retire it.
> 
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

works for me, Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>

Cheers,
   Peter

> ---
>  drivers/input/evdev.c | 18 ------------------
>  1 file changed, 18 deletions(-)
> 
> diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
> index ce953d8..fd325ec 100644
> --- a/drivers/input/evdev.c
> +++ b/drivers/input/evdev.c
> @@ -629,12 +629,10 @@ static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
>  	return copy_to_user(p, str, len) ? -EFAULT : len;
>  }
>  
> -#define OLD_KEY_MAX	0x1ff
>  static int handle_eviocgbit(struct input_dev *dev,
>  			    unsigned int type, unsigned int size,
>  			    void __user *p, int compat_mode)
>  {
> -	static unsigned long keymax_warn_time;
>  	unsigned long *bits;
>  	int len;
>  
> @@ -652,24 +650,8 @@ static int handle_eviocgbit(struct input_dev *dev,
>  	default: return -EINVAL;
>  	}
>  
> -	/*
> -	 * Work around bugs in userspace programs that like to do
> -	 * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
> -	 * should be in bytes, not in bits.
> -	 */
> -	if (type == EV_KEY && size == OLD_KEY_MAX) {
> -		len = OLD_KEY_MAX;
> -		if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
> -			pr_warning("(EVIOCGBIT): Suspicious buffer size %u, "
> -				   "limiting output to %zu bytes. See "
> -				   "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
> -				   OLD_KEY_MAX,
> -				   BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
> -	}
> -
>  	return bits_to_user(bits, len, size, p, compat_mode);
>  }
> -#undef OLD_KEY_MAX
>  
>  static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
>  {
> -- 
> 1.9.0
> 
> 
> -- 
> Dmitry

Re: [PATCH] Input: evdev - get rid of old workaround for EVIOCGBIT

[David Herrmann]

Hi

On Thu, Apr 24, 2014 at 7:27 AM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
> We put this workaround in 2008 and the offending userspace has been fixed
> up long time ago; the link in the message is no longer valid either, so it
> is time to retire it.
>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Yes, pleeeease!

Reviewed-by: David Herrmann <dh.herrmann@gmail.com>

Thanks
David