lkml.org 
[lkml]   [2004]   [Nov]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] kobject: fix double kobject_put in kobject_unregister()
On Wed, Nov 10, 2004 at 10:30:16PM +0000, Russell King wrote:
> On Wed, Nov 10, 2004 at 02:19:23PM -0800, Keshavamurthy Anil S wrote:
> > Hi Greg,
> >
> > This patch fixes the problem where in kobject resources were getting
> > freed when those kobject were still in use due to double kobject_put()
> > getting called in the kobject_unregister() code path.
>
> Isn't it intended that, after an sysfs/kobject/device object is
> unregistered that the thread doing the unregistering must not
> dereference the memory associated with that object?
Yes, nobody is touching the resource once it is freed. But because of
double kobject_put() getting called in the kobject_unregister() code patch
I am seeing successive parent's kobject_unregister() causing panic as that kobject's
kobject_cleanup() gets called when childs kobject_unregiser() is getting called.
i.e patern's kobject_cleanup() gets called for some reason when clild's kobject_unregister()
is called. My patch fixes this issues.



>
> IOW, the sequence:
>
> allocate
> register (refcount >= 2 after this completes)
> unregister
>
> will automatically free the object once the last user has gone.
>
> --
> Russell King
> Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
> maintainer of: 2.6 PCMCIA - http://pcmcia.arm.linux.org.uk/
> 2.6 Serial core
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:07    [W:0.045 / U:10.192 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site