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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44CDDC3527C for ; Wed, 9 Mar 2022 16:50:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237819AbiCIQtn (ORCPT ); Wed, 9 Mar 2022 11:49:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239350AbiCIQc3 (ORCPT ); Wed, 9 Mar 2022 11:32:29 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D66D75C67C; Wed, 9 Mar 2022 08:27:39 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BD178619CB; Wed, 9 Mar 2022 16:27:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CB24C340E8; Wed, 9 Mar 2022 16:27:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646843228; bh=QCLclt6Podyl2puOmDCwjqlOCtweKVJusbddgI3eqP4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tIAW+lo7vhusB6KoDLoW3jWYN/m3VtExOALBBDl19X06X4b+9EcntmAYgr2ZmPtEA J8JcApzk9eCFWMN2YprM+KjecSnc2ZzwiB0rB7ZjepCBa9Ed1GvcwVD4dau6xIPGFc rY7NTeHQ5yd9vgOkS8YFsP+f0kUMwSPsmvWZ64Znyx8Qnly5r2EMbpbIjb3JK5pK5r 2BlR6elHsxAniqXj535EvacB66QtH/cvnU/3as+F4rc2stPsG6v5LZ5JR9qp5St9zp PCQewoO40GgOD8v+8wE2aoHNC5tdR7TtYjSe/AKpxgMmgJOFiZWlLXuazJWwbvAJGL +xwVxBg3EDztQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Niels Dossche , Martin Habets , "David S . Miller" , Sasha Levin , ecree.xilinx@gmail.com, kuba@kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 10/12] sfc: extend the locking on mcdi->seqno Date: Wed, 9 Mar 2022 11:26:15 -0500 Message-Id: <20220309162618.137226-10-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220309162618.137226-1-sashal@kernel.org> References: <20220309162618.137226-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Niels Dossche [ Upstream commit f1fb205efb0ccca55626fd4ef38570dd16b44719 ] seqno could be read as a stale value outside of the lock. The lock is already acquired to protect the modification of seqno against a possible race condition. Place the reading of this value also inside this locking to protect it against a possible race condition. Signed-off-by: Niels Dossche Acked-by: Martin Habets Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/sfc/mcdi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c index 3df872f56289..040b52affe19 100644 --- a/drivers/net/ethernet/sfc/mcdi.c +++ b/drivers/net/ethernet/sfc/mcdi.c @@ -167,9 +167,9 @@ static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd, /* Serialise with efx_mcdi_ev_cpl() and efx_mcdi_ev_death() */ spin_lock_bh(&mcdi->iface_lock); ++mcdi->seqno; + seqno = mcdi->seqno & SEQ_MASK; spin_unlock_bh(&mcdi->iface_lock); - seqno = mcdi->seqno & SEQ_MASK; xflags = 0; if (mcdi->mode == MCDI_MODE_EVENTS) xflags |= MCDI_HEADER_XFLAGS_EVREQ; -- 2.34.1