From mboxrd@z Thu Jan  1 00:00:00 1970
From: Greg KH <greg@kroah.com>
Subject: Re: fbdev sysfs support.
Date: Fri, 6 Feb 2004 17:19:16 -0800
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References: <20040207005954.GB4492@kroah.com> <Pine.LNX.4.44.0402070100420.19559-100000@phoenix.infradead.org> <20040207011047.GR21151@parcelfarce.linux.theplanet.co.uk>
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To: viro@parcelfarce.linux.theplanet.co.uk
Cc: James Simmons <jsimmons@infradead.org>, Linus Torvalds <torvalds@transmeta.com>, Linux Fbdev development list <linux-fbdev-devel@lists.sourceforge.net>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>

On Sat, Feb 07, 2004 at 01:10:48AM +0000, viro@parcelfarce.linux.theplanet.co.uk wrote:
> On Sat, Feb 07, 2004 at 01:01:35AM +0000, James Simmons wrote:
> > +static void release_fb_info(struct class_device *class_dev)
> > +{
> > +	struct fb_info *info = to_fb_info(class_dev);
> > +
> > +	/* This doesn't harm */
> > +	fb_dealloc_cmap(&info->cmap);
> > +
> > +	kfree(info);
> > +}
> 
> So what has happens when we hit existing kfree() on fb_info while sysfs
> node is busy?

This function will not get called until the sysfs node stops being busy,
so it should all work properly.  But only if that fb_info structure was
allocated dynamically, unlike all of the current fb drivers (see my
other comment about this patch.)

So in that case, this will cause us to try to call kfree on a static
structure :(

thanks,

greg k-h