Messages in this thread | | | Date | Wed, 10 Nov 2004 14:39:18 -0800 | From | Keshavamurthy Anil S <> | Subject | Re: [PATCH] kobject: fix double kobject_put in kobject_unregister() |
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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/
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