From owner-svn-src-stable-11@freebsd.org Sat Sep 3 01:09:24 2016 Return-Path: Delivered-To: svn-src-stable-11@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 26227BCEA3B; Sat, 3 Sep 2016 01:09:24 +0000 (UTC) (envelope-from ache@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id D1107E29; Sat, 3 Sep 2016 01:09:23 +0000 (UTC) (envelope-from ache@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id u8319NiI093676; Sat, 3 Sep 2016 01:09:23 GMT (envelope-from ache@FreeBSD.org) Received: (from ache@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id u8319Nxn093675; Sat, 3 Sep 2016 01:09:23 GMT (envelope-from ache@FreeBSD.org) Message-Id: <201609030109.u8319Nxn093675@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: ache set sender to ache@FreeBSD.org using -f From: "Andrey A. Chernov" Date: Sat, 3 Sep 2016 01:09:23 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r305317 - stable/11/lib/libc/net X-SVN-Group: stable-11 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-stable-11@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: SVN commit messages for only the 11-stable src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 03 Sep 2016 01:09:24 -0000 Author: ache Date: Sat Sep 3 01:09:22 2016 New Revision: 305317 URL: https://svnweb.freebsd.org/changeset/base/305317 Log: MFC r305133 Apply the same qsort() usage fix as in r304911 getaddrinfo.c qsort() can't be stabilized with just return(-1) alone. Modified: stable/11/lib/libc/net/name6.c Directory Properties: stable/11/ (props changed) Modified: stable/11/lib/libc/net/name6.c ============================================================================== --- stable/11/lib/libc/net/name6.c Sat Sep 3 01:08:52 2016 (r305316) +++ stable/11/lib/libc/net/name6.c Sat Sep 3 01:09:22 2016 (r305317) @@ -185,6 +185,7 @@ struct hp_order { #define aio_sa aio_un.aiou_sa int aio_matchlen; char *aio_h_addr; + int aio_initial_sequence; }; static struct hostent *_hpcopy(struct hostent *, int *); @@ -711,6 +712,7 @@ _hpreorder(struct hostent *hp) aio[i].aio_dstscope = gai_addr2scopetype(sa); aio[i].aio_dstpolicy = match_addrselectpolicy(sa, &policyhead); set_source(&aio[i], &policyhead); + aio[i].aio_initial_sequence = i; } /* perform sorting. */ @@ -1045,6 +1047,23 @@ comp_dst(const void *arg1, const void *a } /* Rule 10: Otherwise, leave the order unchanged. */ + + /* + * Note that qsort is unstable; so, we can't return zero and + * expect the order to be unchanged. + * That also means we can't depend on the current position of + * dst2 being after dst1. We must enforce the initial order + * with an explicit compare on the original position. + * The qsort specification requires that "When the same objects + * (consisting of width bytes, irrespective of their current + * positions in the array) are passed more than once to the + * comparison function, the results shall be consistent with one + * another." + * In other words, If A < B, then we must also return B > A. + */ + if (dst2->aio_initial_sequence < dst1->aio_initial_sequence) + return(1); + return(-1); }