From patchwork Thu May 19 00:42:13 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 623770 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3r9C2P2bBBz9vK7 for ; Thu, 19 May 2016 10:42:21 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751775AbcESAmT (ORCPT ); Wed, 18 May 2016 20:42:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60130 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750736AbcESAmS (ORCPT ); Wed, 18 May 2016 20:42:18 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C9E9364064; Thu, 19 May 2016 00:42:17 +0000 (UTC) Received: from localhost (ovpn-112-21.ams2.redhat.com [10.36.112.21]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u4J0gFB1014431; Wed, 18 May 2016 20:42:16 -0400 From: Stefan Hajnoczi To: netdev@vger.kernel.org Cc: "David S. Miller" , Stefan Hajnoczi Subject: [PATCH] net/atm: sk_err_soft must be positive Date: Wed, 18 May 2016 17:42:13 -0700 Message-Id: <1463618533-7098-1-git-send-email-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 19 May 2016 00:42:17 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The sk_err and sk_err_soft fields are positive errno values and userspace applications rely on this when using getsockopt(SO_ERROR). ATM code places an -errno into sk_err_soft in sigd_send() and returns it from svc_addparty()/svc_dropparty(). Although I am not familiar with ATM code I came to this conclusion because: 1. sigd_send() msg->type cases as_okay and as_error both have: sk->sk_err = -msg->reply; while the as_addparty and as_dropparty cases have: sk->sk_err_soft = msg->reply; This is the source of the inconsistency. 2. svc_addparty() returns an -errno and assumes sk_err_soft is also an -errno: if (flags & O_NONBLOCK) { error = -EINPROGRESS; goto out; } ... error = xchg(&sk->sk_err_soft, 0); out: release_sock(sk); return error; This shows that sk_err_soft is indeed being treated as an -errno. This patch ensures that sk_err_soft is always a positive errno. Signed-off-by: Stefan Hajnoczi --- This patch is untested and potentially affects the getsockopt(SO_ERROR) ABI for a specific case in ATM. I leave it to the maintainer to decide whether this inconsistency should be fixed or not. net/atm/signaling.c | 2 +- net/atm/svc.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/net/atm/signaling.c b/net/atm/signaling.c index 4fd6af4..adb6e3d 100644 --- a/net/atm/signaling.c +++ b/net/atm/signaling.c @@ -124,7 +124,7 @@ as_indicate_complete: break; case as_addparty: case as_dropparty: - sk->sk_err_soft = msg->reply; + sk->sk_err_soft = -msg->reply; /* < 0 failure, otherwise ep_ref */ clear_bit(ATM_VF_WAITING, &vcc->flags); break; diff --git a/net/atm/svc.c b/net/atm/svc.c index 3fa0a9e..878563a 100644 --- a/net/atm/svc.c +++ b/net/atm/svc.c @@ -546,7 +546,7 @@ static int svc_addparty(struct socket *sock, struct sockaddr *sockaddr, schedule(); } finish_wait(sk_sleep(sk), &wait); - error = xchg(&sk->sk_err_soft, 0); + error = -xchg(&sk->sk_err_soft, 0); out: release_sock(sk); return error; @@ -573,7 +573,7 @@ static int svc_dropparty(struct socket *sock, int ep_ref) error = -EUNATCH; goto out; } - error = xchg(&sk->sk_err_soft, 0); + error = -xchg(&sk->sk_err_soft, 0); out: release_sock(sk); return error;