From: Kent Overstreet <koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH 04/11] cgroup: use kzalloc() and list_del_init()
Date: Wed, 12 Jun 2013 19:43:10 -0700
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To: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Cgroups <cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, lkml <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Christoph Lameter <cl-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>

On Wed, Jun 12, 2013 at 07:41:15PM -0700, Tejun Heo wrote:
> Hello,
> 
> On Wed, Jun 12, 2013 at 7:38 PM, Kent Overstreet <koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> wrote:
> > IMO, list_del() is preferred when the object shouldn't be reused (i.e.
> > it gets taken off a list and then it's freed). list_del_init() could
> > hide bugs.
> 
> Nah... use-after-frees are detected much more reliably by poisoning
> anyway. Using list_del() instead of list_del_init() to hunt down
> use-after-free isn't a good idea because you're likely to corrupt the
> memory of unrelated area. I really don't see much point in using
> list_del().

list_del() does do poisoning - and list debugging is cheaper to enable
than full slab debugging.