From owner-svn-src-all@freebsd.org Tue Jan 14 00:50:30 2020 Return-Path: Delivered-To: svn-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id F03ED1F2501; Tue, 14 Jan 2020 00:50:30 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 47xX1f65v5z4N4j; Tue, 14 Jan 2020 00:50:30 +0000 (UTC) (envelope-from mav@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 mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id CC271D539; Tue, 14 Jan 2020 00:50:30 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 00E0oUlr044380; Tue, 14 Jan 2020 00:50:30 GMT (envelope-from mav@FreeBSD.org) Received: (from mav@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 00E0oUkJ044379; Tue, 14 Jan 2020 00:50:30 GMT (envelope-from mav@FreeBSD.org) Message-Id: <202001140050.00E0oUkJ044379@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: mav set sender to mav@FreeBSD.org using -f From: Alexander Motin Date: Tue, 14 Jan 2020 00:50:30 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r356711 - stable/12/sys/netinet X-SVN-Group: stable-12 X-SVN-Commit-Author: mav X-SVN-Commit-Paths: stable/12/sys/netinet X-SVN-Commit-Revision: 356711 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Jan 2020 00:50:31 -0000 Author: mav Date: Tue Jan 14 00:50:30 2020 New Revision: 356711 URL: https://svnweb.freebsd.org/changeset/base/356711 Log: MFC r356240: Relax locking of carp_forus(). This fixes deadlock between CARP and bridge. Bridge calls this function taking CARP lock while holding bridge lock. Same time CARP tries to send its announcements via the bridge while holding CARP lock. Use of CARP_LOCK() here does not solve anything, since sc_addr is constant while race on sc_state is harmless and use of the lock does not close it. Modified: stable/12/sys/netinet/ip_carp.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/netinet/ip_carp.c ============================================================================== --- stable/12/sys/netinet/ip_carp.c Mon Jan 13 23:09:00 2020 (r356710) +++ stable/12/sys/netinet/ip_carp.c Tue Jan 14 00:50:30 2020 (r356711) @@ -1232,14 +1232,15 @@ carp_forus(struct ifnet *ifp, u_char *dhost) CIF_LOCK(ifp->if_carp); IFNET_FOREACH_CARP(ifp, sc) { - CARP_LOCK(sc); + /* + * CARP_LOCK() is not here, since would protect nothing, but + * cause deadlock with if_bridge, calling this under its lock. + */ if (sc->sc_state == MASTER && !bcmp(dhost, LLADDR(&sc->sc_addr), ETHER_ADDR_LEN)) { - CARP_UNLOCK(sc); CIF_UNLOCK(ifp->if_carp); return (1); } - CARP_UNLOCK(sc); } CIF_UNLOCK(ifp->if_carp);