From owner-svn-src-head@freebsd.org Tue Nov 13 22:58:40 2018 Return-Path: Delivered-To: svn-src-head@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 52C601135BE3; Tue, 13 Nov 2018 22:58:40 +0000 (UTC) (envelope-from glebius@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 8E0867D2DF; Tue, 13 Nov 2018 22:58:39 +0000 (UTC) (envelope-from glebius@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 6C4B416BB5; Tue, 13 Nov 2018 22:58:39 +0000 (UTC) (envelope-from glebius@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id wADMwd1B063538; Tue, 13 Nov 2018 22:58:39 GMT (envelope-from glebius@FreeBSD.org) Received: (from glebius@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id wADMwctL063533; Tue, 13 Nov 2018 22:58:38 GMT (envelope-from glebius@FreeBSD.org) Message-Id: <201811132258.wADMwctL063533@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: glebius set sender to glebius@FreeBSD.org using -f From: Gleb Smirnoff Date: Tue, 13 Nov 2018 22:58:38 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r340413 - in head/sys: kern net sys X-SVN-Group: head X-SVN-Commit-Author: glebius X-SVN-Commit-Paths: in head/sys: kern net sys X-SVN-Commit-Revision: 340413 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 8E0867D2DF X-Spamd-Result: default: False [-106.88 / 200.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; ALLOW_DOMAIN_WHITELIST(-100.00)[FreeBSD.org]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; TO_DN_NONE(0.00)[]; HAS_XAW(0.00)[]; R_SPF_SOFTFAIL(0.00)[~all]; DMARC_NA(0.00)[FreeBSD.org]; RCVD_COUNT_THREE(0.00)[4]; MX_GOOD(-0.01)[cached: mx1.FreeBSD.org]; NEURAL_HAM_SHORT(-1.00)[-0.998,0]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; RCVD_TLS_LAST(0.00)[]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US]; IP_SCORE(-3.77)[ip: (-9.91), ipnet: 2610:1c1:1::/48(-4.93), asn: 11403(-3.91), country: US(-0.09)] X-Rspamd-Server: mx1.freebsd.org X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Nov 2018 22:58:40 -0000 Author: glebius Date: Tue Nov 13 22:58:38 2018 New Revision: 340413 URL: https://svnweb.freebsd.org/changeset/base/340413 Log: For compatibility KPI functions like if_addr_rlock() that used to have mutexes but now are converted to epoch(9) use thread-private epoch_tracker. Embedding tracker into ifnet(9) or ifnet derived structures creates a non reentrable function, that will fail miserably if called simultaneously from two different contexts. A thread private tracker will provide a single tracker that would allow to call these functions safely. It doesn't allow nested call, but this is not expected from compatibility KPIs. Reviewed by: markj Modified: head/sys/kern/kern_thread.c head/sys/kern/subr_epoch.c head/sys/net/if.c head/sys/net/if_var.h head/sys/sys/epoch.h head/sys/sys/proc.h Modified: head/sys/kern/kern_thread.c ============================================================================== --- head/sys/kern/kern_thread.c Tue Nov 13 22:41:20 2018 (r340412) +++ head/sys/kern/kern_thread.c Tue Nov 13 22:58:38 2018 (r340413) @@ -272,6 +272,7 @@ thread_init(void *mem, int size, int flags) td->td_rlqe = NULL; EVENTHANDLER_DIRECT_INVOKE(thread_init, td); umtx_thread_init(td); + epoch_thread_init(td); td->td_kstack = 0; td->td_sel = NULL; return (0); @@ -291,6 +292,7 @@ thread_fini(void *mem, int size) turnstile_free(td->td_turnstile); sleepq_free(td->td_sleepqueue); umtx_thread_fini(td); + epoch_thread_fini(td); seltdfini(td); } Modified: head/sys/kern/subr_epoch.c ============================================================================== --- head/sys/kern/subr_epoch.c Tue Nov 13 22:41:20 2018 (r340412) +++ head/sys/kern/subr_epoch.c Tue Nov 13 22:58:38 2018 (r340413) @@ -667,3 +667,17 @@ in_epoch(epoch_t epoch) { return (in_epoch_verbose(epoch, 0)); } + +void +epoch_thread_init(struct thread *td) +{ + + td->td_et = malloc(sizeof(struct epoch_tracker), M_EPOCH, M_WAITOK); +} + +void +epoch_thread_fini(struct thread *td) +{ + + free(td->td_et, M_EPOCH); +} Modified: head/sys/net/if.c ============================================================================== --- head/sys/net/if.c Tue Nov 13 22:41:20 2018 (r340412) +++ head/sys/net/if.c Tue Nov 13 22:58:38 2018 (r340413) @@ -1767,35 +1767,29 @@ 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); + + epoch_enter_preempt(net_epoch_preempt, curthread->td_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 + + epoch_exit_preempt(net_epoch_preempt, curthread->td_et); } void if_maddr_rlock(if_t ifp) { - MPASS(*(uint64_t *)&ifp->if_maddr_et == 0); - epoch_enter_preempt(net_epoch_preempt, &ifp->if_maddr_et); + epoch_enter_preempt(net_epoch_preempt, curthread->td_et); } void if_maddr_runlock(if_t ifp) { - epoch_exit_preempt(net_epoch_preempt, &ifp->if_maddr_et); -#ifdef INVARIANTS - bzero(&ifp->if_maddr_et, sizeof(struct epoch_tracker)); -#endif + epoch_exit_preempt(net_epoch_preempt, curthread->td_et); } /* Modified: head/sys/net/if_var.h ============================================================================== --- head/sys/net/if_var.h Tue Nov 13 22:41:20 2018 (r340412) +++ head/sys/net/if_var.h Tue Nov 13 22:58:38 2018 (r340413) @@ -381,8 +381,6 @@ 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; /* * Spare fields to be added before branching a stable branch, so Modified: head/sys/sys/epoch.h ============================================================================== --- head/sys/sys/epoch.h Tue Nov 13 22:41:20 2018 (r340412) +++ head/sys/sys/epoch.h Tue Nov 13 22:58:38 2018 (r340413) @@ -82,5 +82,8 @@ void epoch_exit_preempt(epoch_t epoch, epoch_tracker_t void epoch_enter(epoch_t epoch); void epoch_exit(epoch_t epoch); +void epoch_thread_init(struct thread *); +void epoch_thread_fini(struct thread *); + #endif /* _KERNEL */ #endif /* _SYS_EPOCH_H_ */ Modified: head/sys/sys/proc.h ============================================================================== --- head/sys/sys/proc.h Tue Nov 13 22:41:20 2018 (r340412) +++ head/sys/sys/proc.h Tue Nov 13 22:58:38 2018 (r340413) @@ -193,6 +193,7 @@ struct trapframe; struct turnstile; struct vm_map; struct vm_map_entry; +struct epoch_tracker; /* * XXX: Does this belong in resource.h or resourcevar.h instead? @@ -360,6 +361,7 @@ struct thread { int td_lastcpu; /* (t) Last cpu we were on. */ int td_oncpu; /* (t) Which cpu we are on. */ void *td_lkpi_task; /* LinuxKPI task struct pointer */ + struct epoch_tracker *td_et; /* (k) compat KPI spare tracker */ int td_pmcpend; };