From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <johannes@sipsolutions.net>
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on gnuweeb.org
X-Spam-Level: 
X-Spam-Status: No, score=-0.2 required=5.0 tests=DKIM_SIGNED,DKIM_VALID,
	DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_PASS,SPF_PASS,URIBL_BLOCKED
	autolearn=ham autolearn_force=no version=3.4.6
Received: from sipsolutions.net (s3.sipsolutions.net [144.76.43.62])
	by gnuweeb.org (Postfix) with ESMTPS id 6BD967E35B
	for <gwml@vger.gnuweeb.org>; Mon, 11 Apr 2022 14:46:55 +0000 (UTC)
Authentication-Results: gnuweeb.org;
	dkim=pass (2048-bit key; secure) header.d=sipsolutions.net header.i=@sipsolutions.net header.a=rsa-sha256 header.s=mail header.b=QABvo6Oh;
	dkim-atps=neutral
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;
	d=sipsolutions.net; s=mail; h=Content-Transfer-Encoding:MIME-Version:
	Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender
	:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To:
	Resent-Cc:Resent-Message-ID; bh=0PQqok4VtRI+EwdhTAimsSjz59ctIfWRywOAu+VFE1Y=;
	t=1649688415; x=1650898015; b=QABvo6OhWOO7nXDh3LiKZ1Pl7gNCeRq5Q29FbeYmCe2EYND
	djQ7iL4kKTYxPkzjudQ5MNQLN6Vr+9Chko8lA3CyQWZOvkuGXQlansEUz89hZMZ9EOtd+zZzF9NFX
	pT08Ot7e9++iUBoNHSFaqXvz3P2JRtrDK5ET+oQ+HXvLoHy6VrnhP6KBDVcoSZrOqc7fSICJ/I9RM
	zrhGjIxArTjtx8xnu9seWiB+rMsligbeOM2PUS/A9BwmFMTzdR2e7HpR3lP+QEu2aNmOsY6cUCqr3
	Dhn3qMX2RuI/PC1r5krzOUdmAfBXh36jKufZlpicppjE/rHQL1ZwcpwtmNpD3ZVw==;
Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256)
	(Exim 4.95)
	(envelope-from <johannes@sipsolutions.net>)
	id 1ndvJY-008KQx-UY;
	Mon, 11 Apr 2022 16:46:49 +0200
Message-ID: <446ea9872d46fe0ad594cfa6d3df224cfcb5223f.camel@sipsolutions.net>
Subject: Re: [Linux 5.18-rc1] WARNING: possible circular locking dependency
 detected at (rtw_ops_config, ieee80211_mgd_probe_ap)
From: Johannes Berg <johannes@sipsolutions.net>
To: Ammar Faizi <ammarfaizi2@gnuweeb.org>, Linux Kernel Mailing List
	 <linux-kernel@vger.kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>, GNU/Weeb Mailing List
 <gwml@vger.gnuweeb.org>, Jakub Kicinski <kuba@kernel.org>, Kalle Valo
 <kvalo@kernel.org>, Linux Wireless Mailing List
 <linux-wireless@vger.kernel.org>,  netdev Mailing List
 <netdev@vger.kernel.org>, Paolo Abeni <pabeni@redhat.com>, Yan-Hsuan Chuang
 <tony0620emma@gmail.com>
Date: Mon, 11 Apr 2022 16:46:47 +0200
In-Reply-To: <875af62c-363e-3fc3-9c38-dcf8b3071c99@gnuweeb.org>
References: <2565e500-0e2f-c688-19e0-d241e4e7e031@gnuweeb.org>
	 <875af62c-363e-3fc3-9c38-dcf8b3071c99@gnuweeb.org>
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.42.4 (3.42.4-2.fc35) 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
X-malware-bazaar: not-scanned
List-Id: <gwml.vger.gnuweeb.org>

On Thu, 2022-04-07 at 08:26 +0700, Ammar Faizi wrote:
> 
> [21860.955836]  Possible unsafe locking scenario:
> 
> [21860.955837]        CPU0                    CPU1
> [21860.955837]        ----                    ----
> [21860.955838]   lock(&local->iflist_mtx);
> [21860.955839]                                lock(&rtwdev->mutex);
> [21860.955840]                                lock(&local->iflist_mtx);
> [21860.955841]   lock(&rtwdev->mutex);
> [21860.955842]
>                   *** DEADLOCK ***
> 

The driver needs to fix this, cannot call ieee80211_iterate_interfaces()
inside a section locked this way. I _think_ this deadlock used to be
documented by it looks like that documentation got moved around or
something.

johannes