From owner-svn-src-all@freebsd.org Wed Sep 11 04:55:11 2019 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 5E7F0EE97F; Wed, 11 Sep 2019 04:55:11 +0000 (UTC) (envelope-from kib@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 46SqMg1t0wz4Qq3; Wed, 11 Sep 2019 04:55:11 +0000 (UTC) (envelope-from kib@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 1FBB313D8; Wed, 11 Sep 2019 04:55:11 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x8B4tAga062845; Wed, 11 Sep 2019 04:55:10 GMT (envelope-from kib@FreeBSD.org) Received: (from kib@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x8B4tAn9062844; Wed, 11 Sep 2019 04:55:10 GMT (envelope-from kib@FreeBSD.org) Message-Id: <201909110455.x8B4tAn9062844@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kib set sender to kib@FreeBSD.org using -f From: Konstantin Belousov Date: Wed, 11 Sep 2019 04:55:10 +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: r352202 - stable/12/sys/vm X-SVN-Group: stable-12 X-SVN-Commit-Author: kib X-SVN-Commit-Paths: stable/12/sys/vm X-SVN-Commit-Revision: 352202 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: Wed, 11 Sep 2019 04:55:11 -0000 Author: kib Date: Wed Sep 11 04:55:10 2019 New Revision: 352202 URL: https://svnweb.freebsd.org/changeset/base/352202 Log: MFC r351830: madvise(MADV_FREE): Quick fix to time rewind. PR: 240061 Modified: stable/12/sys/vm/vm_map.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/vm/vm_map.c ============================================================================== --- stable/12/sys/vm/vm_map.c Wed Sep 11 03:25:30 2019 (r352201) +++ stable/12/sys/vm/vm_map.c Wed Sep 11 04:55:10 2019 (r352202) @@ -2735,6 +2735,18 @@ vm_map_madvise( if (current->eflags & MAP_ENTRY_IS_SUB_MAP) continue; + /* + * MADV_FREE would otherwise rewind time to + * the creation of the shadow object. Because + * we hold the VM map read-locked, neither the + * entry's object nor the presence of a + * backing object can change. + */ + if (behav == MADV_FREE && + current->object.vm_object != NULL && + current->object.vm_object->backing_object != NULL) + continue; + pstart = OFF_TO_IDX(current->offset); pend = pstart + atop(current->end - current->start); useStart = current->start;