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Subject: Re: BUG: scheduling while atomic: ifconfig/0x00000002/4170
From: Johannes Berg <johannes@sipsolutions.net>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Satyam Sharma <satyam@infradead.org>, Florian Lohoff <flo@rfc822.org>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
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Date: Thu, 06 Sep 2007 14:09:35 +0200
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On Thu, 2007-09-06 at 16:23 +0800, Herbert Xu wrote:
> On Thu, Sep 06, 2007 at 10:32:33AM +0530, Satyam Sharma wrote:
> >=20
> > > > [  382.529041]  [<c02c8abc>] dev_close+0x24/0x67
> > > > [  382.529052]  [<e01f402b>] ieee80211_master_stop+0x4a/0x6d [mac80=
211]
>=20
> This is where the bug is.  You cannot call dev_close from an
> atomic context as i33380211_master_stop does it within spin
> locks.

Hah, I suspected as much but didn't have a chance to look yet. I had
plans to replace that sub_if_list with an RCU list and not require the
lock there, but that's far off. Any ideas how to fix this? We can't
reject the master stop so we have to walk the list, I guess we'll have
to audit the other list manipulation places, I think they're all under
RTNL.

johannes

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