From owner-svn-src-stable@freebsd.org Mon Apr 1 14:19:11 2019 Return-Path: Delivered-To: svn-src-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 227B11564608; Mon, 1 Apr 2019 14:19:11 +0000 (UTC) (envelope-from markj@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 BBDBE70C75; Mon, 1 Apr 2019 14:19:10 +0000 (UTC) (envelope-from markj@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 9783BF8DA; Mon, 1 Apr 2019 14:19:10 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x31EJAnA040792; Mon, 1 Apr 2019 14:19:10 GMT (envelope-from markj@FreeBSD.org) Received: (from markj@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x31EJAwd040790; Mon, 1 Apr 2019 14:19:10 GMT (envelope-from markj@FreeBSD.org) Message-Id: <201904011419.x31EJAwd040790@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: markj set sender to markj@FreeBSD.org using -f From: Mark Johnston Date: Mon, 1 Apr 2019 14:19:10 +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: r345764 - stable/12/sys/net X-SVN-Group: stable-12 X-SVN-Commit-Author: markj X-SVN-Commit-Paths: stable/12/sys/net X-SVN-Commit-Revision: 345764 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: BBDBE70C75 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.97 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.998,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.97)[-0.974,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Apr 2019 14:19:11 -0000 Author: markj Date: Mon Apr 1 14:19:09 2019 New Revision: 345764 URL: https://svnweb.freebsd.org/changeset/base/345764 Log: Fix if_(m)addr_rlock(). The use of a per-ifnet epoch context meant that these KPIs were not reentrant. This was fixed in head in r340413, but the change cannot be MFCed because it breaks the KBI by modifying struct thread. This is a direct commit to stable/12 which uses a per-CPU mutex to fix the problem without changing the KBI. PR: 236846 Submitted by: hselasky Reported and tested by: Viktor Dukhovni Reviewed by: hselasky (previous version) Differential Revision: https://reviews.freebsd.org/D19764 Modified: stable/12/sys/net/if.c stable/12/sys/net/if_var.h Modified: stable/12/sys/net/if.c ============================================================================== --- stable/12/sys/net/if.c Mon Apr 1 12:14:45 2019 (r345763) +++ stable/12/sys/net/if.c Mon Apr 1 14:19:09 2019 (r345764) @@ -62,6 +62,8 @@ #include #include #include +#include +#include #include #include @@ -1754,6 +1756,30 @@ if_data_copy(struct ifnet *ifp, struct if_data *ifd) ifd->ifi_noproto = ifp->if_get_counter(ifp, IFCOUNTER_NOPROTO); } +struct ifnet_read_lock { + struct mtx mtx; /* lock protecting tracker below */ + struct epoch_tracker et; +}; + +DPCPU_DEFINE_STATIC(struct ifnet_read_lock, ifnet_addr_read_lock); +DPCPU_DEFINE_STATIC(struct ifnet_read_lock, ifnet_maddr_read_lock); + +static void +ifnet_read_lock_init(void __unused *arg) +{ + struct ifnet_read_lock *pifrl; + int cpu; + + CPU_FOREACH(cpu) { + pifrl = DPCPU_ID_PTR(cpu, ifnet_addr_read_lock); + mtx_init(&pifrl->mtx, "ifnet_addr_read_lock", NULL, MTX_DEF); + + pifrl = DPCPU_ID_PTR(cpu, ifnet_maddr_read_lock); + mtx_init(&pifrl->mtx, "ifnet_maddr_read_lock", NULL, MTX_DEF); + } +} +SYSINIT(ifnet_read_lock_init, SI_SUB_CPU + 1, SI_ORDER_FIRST, &ifnet_read_lock_init, NULL); + /* * Wrapper functions for struct ifnet address list locking macros. These are * used by kernel modules to avoid encoding programming interface or binary @@ -1763,35 +1789,47 @@ if_data_copy(struct ifnet *ifp, struct if_data *ifd) void if_addr_rlock(struct ifnet *ifp) { - MPASS(*(uint64_t *)&ifp->if_addr_et == 0); - epoch_enter_preempt(net_epoch_preempt, &ifp->if_addr_et); + struct ifnet_read_lock *pifrl; + + sched_pin(); + pifrl = DPCPU_PTR(ifnet_addr_read_lock); + mtx_lock(&pifrl->mtx); + epoch_enter_preempt(net_epoch_preempt, &pifrl->et); } void if_addr_runlock(struct ifnet *ifp) { - epoch_exit_preempt(net_epoch_preempt, &ifp->if_addr_et); -#ifdef INVARIANTS - bzero(&ifp->if_addr_et, sizeof(struct epoch_tracker)); -#endif + struct ifnet_read_lock *pifrl; + + pifrl = DPCPU_PTR(ifnet_addr_read_lock); + + epoch_exit_preempt(net_epoch_preempt, &pifrl->et); + mtx_unlock(&pifrl->mtx); + sched_unpin(); } void if_maddr_rlock(if_t ifp) { + struct ifnet_read_lock *pifrl; - MPASS(*(uint64_t *)&ifp->if_maddr_et == 0); - epoch_enter_preempt(net_epoch_preempt, &ifp->if_maddr_et); + sched_pin(); + pifrl = DPCPU_PTR(ifnet_maddr_read_lock); + mtx_lock(&pifrl->mtx); + epoch_enter_preempt(net_epoch_preempt, &pifrl->et); } void if_maddr_runlock(if_t ifp) { + struct ifnet_read_lock *pifrl; - epoch_exit_preempt(net_epoch_preempt, &ifp->if_maddr_et); -#ifdef INVARIANTS - bzero(&ifp->if_maddr_et, sizeof(struct epoch_tracker)); -#endif + pifrl = DPCPU_PTR(ifnet_maddr_read_lock); + + epoch_exit_preempt(net_epoch_preempt, &pifrl->et); + mtx_unlock(&pifrl->mtx); + sched_unpin(); } /* Modified: stable/12/sys/net/if_var.h ============================================================================== --- stable/12/sys/net/if_var.h Mon Apr 1 12:14:45 2019 (r345763) +++ stable/12/sys/net/if_var.h Mon Apr 1 14:19:09 2019 (r345764) @@ -381,8 +381,7 @@ struct ifnet { */ struct netdump_methods *if_netdump_methods; struct epoch_context if_epoch_ctx; - struct epoch_tracker if_addr_et; - struct epoch_tracker if_maddr_et; + void *if_unused[4]; /* * Spare fields to be added before branching a stable branch, so