From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bmailout2.hostsharing.net (bmailout2.hostsharing.net [83.223.78.240]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 422F1134AC; Fri, 5 Apr 2024 17:48:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.223.78.240 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712339299; cv=none; b=uyMhdBa6/iPvI4orH4W40vxrlf3L9ip1ekPwS7aKRI0huhHQIykBjRiPNGSYnp2C/0ffFg5e1UDifY2kVuzzEiAIhG05NHBo9RHhb+3un4bjQkNJjAjEXmD/j/SvZ/glvP4Tq6hXrGoPqbA4L7PAphCxFVhm0yfNKg3dLDC2iww= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712339299; c=relaxed/simple; bh=WvRsBVBjYEza67dv61GNHhs7Cd+qc3xljT52Ok2UXD8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MZLPoOvoeunHujmHfXIKJYjbHYDdFHO86ymTeueChbIX/eg6gjqjbwKR04H6nyLe5XMptBWrT3km2SM+UHmK2Nex8v1OgecD01rx/pvlMhdFjVKQdDCQtgQ4jcgKq/csRckLoRYDndfiDNmEtQlrWPHwZ4P3BW82gI02HZnitG0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de; spf=none smtp.mailfrom=h08.hostsharing.net; arc=none smtp.client-ip=83.223.78.240 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=h08.hostsharing.net Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS RSA CA G1" (verified OK)) by bmailout2.hostsharing.net (Postfix) with ESMTPS id 1D43B2800BB90; Fri, 5 Apr 2024 19:48:08 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 082829926D8; Fri, 5 Apr 2024 19:48:08 +0200 (CEST) Date: Fri, 5 Apr 2024 19:48:08 +0200 From: Lukas Wunner To: Heiner Kallweit Cc: Roman Lozko , linux-pci@vger.kernel.org, Bjorn Helgaas , Dave Hansen , Sean Christopherson , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, Christian Marangi , Kurt Kanzenbach , Jesse Brandeburg , Tony Nguyen , intel-wired-lan@lists.osuosl.org Subject: Re: Deadlock in pciehp on dock disconnect Message-ID: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Apr 05, 2024 at 03:31:34PM +0200, Heiner Kallweit wrote: > On 05.04.2024 12:02, Lukas Wunner wrote: > > On Fri, Apr 05, 2024 at 11:14:01AM +0200, Roman Lozko wrote: > > > Hi, I'm using HP G4 Thunderbolt docking station, and recently (?) > > > kernel started to "partially" deadlock after disconnecting the dock > > > station. This results in inability to turn network interfaces on or > > > off, system can't reboot, `sudo` does not work (guess because it uses > > > DNS). > > > > unregister_netdev() acquires rtnl_lock(), indirectly invokes > > netdev_trig_deactivate() upon unregistering some LED, thereby > > calling unregister_netdevice_notifier(), which tries to > > acquire rtnl_lock() again. > > > > From a quick look at the source files involved, this doesn't look > > like something new, though I note LED support for igc was added > > only recently with ea578703b03d ("igc: Add support for LEDs on > > i225/i226"), which went into v6.9-rc1. > > It's unfortunate that the device-managed LED is bound to the netdev device. > Wouldn't binding it to the parent (&pdev->dev) solve the issue? I'm guessing igc commit ea578703b03d copy-pasted from r8169 commit be51ed104ba9 ("r8169: add LED support for RTL8125/RTL8126") because that driver has exactly the same problem. :) Roman, does the below patch fix the issue? Note that just changing the devm_led_classdev_register() call isn't sufficient: I'm changing the devm_kcalloc() in igc_led_setup() as well to avoid a use-after-free (memory would already get freed on netdev unregister but led a little later on pdev unbind). -- >8 -- diff --git a/drivers/net/ethernet/intel/igc/igc_leds.c b/drivers/net/ethernet/intel/igc/igc_leds.c index bf240c5..0b78c30 100644 --- a/drivers/net/ethernet/intel/igc/igc_leds.c +++ b/drivers/net/ethernet/intel/igc/igc_leds.c @@ -257,13 +257,13 @@ static void igc_setup_ldev(struct igc_led_classdev *ldev, led_cdev->hw_control_get = igc_led_hw_control_get; led_cdev->hw_control_get_device = igc_led_hw_control_get_device; - devm_led_classdev_register(&netdev->dev, led_cdev); + devm_led_classdev_register(&adapter->pdev->dev, led_cdev); } int igc_led_setup(struct igc_adapter *adapter) { struct net_device *netdev = adapter->netdev; - struct device *dev = &netdev->dev; + struct device *dev = &adapter->pdev->dev; struct igc_led_classdev *leds; int i;