From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C20DC432C0 for ; Thu, 21 Nov 2019 20:21:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5150120643 for ; Thu, 21 Nov 2019 20:21:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727171AbfKUUVn (ORCPT ); Thu, 21 Nov 2019 15:21:43 -0500 Received: from jabberwock.ucw.cz ([46.255.230.98]:46426 "EHLO jabberwock.ucw.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726658AbfKUUVn (ORCPT ); Thu, 21 Nov 2019 15:21:43 -0500 Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 5DF181C1BCF; Thu, 21 Nov 2019 21:21:41 +0100 (CET) Date: Thu, 21 Nov 2019 21:21:40 +0100 From: Pavel Machek To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Jia-Ju Bai , "David S. Miller" , Sasha Levin Subject: Re: [PATCH 4.19 241/422] net: socionext: Fix two sleep-in-atomic-context bugs in ave_rxfifo_reset() Message-ID: <20191121202140.GA7573@duo.ucw.cz> References: <20191119051400.261610025@linuxfoundation.org> <20191119051414.641566074@linuxfoundation.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="CE+1k2dSO48ffgeK" Content-Disposition: inline In-Reply-To: <20191119051414.641566074@linuxfoundation.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --CE+1k2dSO48ffgeK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > [ Upstream commit 0020f5c807ef67954d9210eea0ba17a6134cdf7d ] >=20 > The driver may sleep with holding a spinlock. > The function call paths (from bottom to top) in Linux-4.17 are: >=20 > [FUNC] usleep_range > drivers/net/ethernet/socionext/sni_ave.c, 892: > usleep_range in ave_rxfifo_reset > drivers/net/ethernet/socionext/sni_ave.c, 932: > ave_rxfifo_reset in ave_irq_handler >=20 > [FUNC] usleep_range > drivers/net/ethernet/socionext/sni_ave.c, 888: > usleep_range in ave_rxfifo_reset > drivers/net/ethernet/socionext/sni_ave.c, 932: > ave_rxfifo_reset in ave_irq_handler >=20 > To fix these bugs, usleep_range() is replaced with udelay(). I don't believe this is serious enough for -stable, but more importantly: > +++ b/drivers/net/ethernet/socionext/sni_ave.c > @@ -906,11 +906,11 @@ static void ave_rxfifo_reset(struct net_device *nde= v) > =20 > /* assert reset */ > writel(AVE_GRR_RXFFR, priv->base + AVE_GRR); > - usleep_range(40, 50); > + udelay(50); > =20 > /* negate reset */ > writel(0, priv->base + AVE_GRR); > - usleep_range(10, 20); > + udelay(20); > udelay(40) / udelay(10) should be enough here. Best regards, Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --CE+1k2dSO48ffgeK Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCXdbx1AAKCRAw5/Bqldv6 8lsUAJ0Y8goOEYKzk+t/j8TzwhKtk/nf5wCeJX3E5CvCZSNLVxyHha0EDUnewew= =d7wy -----END PGP SIGNATURE----- --CE+1k2dSO48ffgeK--