From owner-svn-src-head@freebsd.org Fri Jun 28 22:40:35 2019 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 A9B6015CDF13; Fri, 28 Jun 2019 22:40:35 +0000 (UTC) (envelope-from alc@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 4C7CA8BE79; Fri, 28 Jun 2019 22:40:35 +0000 (UTC) (envelope-from alc@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 274B7571F; Fri, 28 Jun 2019 22:40:35 +0000 (UTC) (envelope-from alc@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x5SMeZrZ065203; Fri, 28 Jun 2019 22:40:35 GMT (envelope-from alc@FreeBSD.org) Received: (from alc@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x5SMeY01065201; Fri, 28 Jun 2019 22:40:34 GMT (envelope-from alc@FreeBSD.org) Message-Id: <201906282240.x5SMeY01065201@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: alc set sender to alc@FreeBSD.org using -f From: Alan Cox Date: Fri, 28 Jun 2019 22:40:34 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r349526 - in head/sys: amd64/amd64 i386/i386 X-SVN-Group: head X-SVN-Commit-Author: alc X-SVN-Commit-Paths: in head/sys: amd64/amd64 i386/i386 X-SVN-Commit-Revision: 349526 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 4C7CA8BE79 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.96 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_SHORT(-0.96)[-0.965,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US]; NEURAL_HAM_LONG(-1.00)[-1.000,0] 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: Fri, 28 Jun 2019 22:40:35 -0000 Author: alc Date: Fri Jun 28 22:40:34 2019 New Revision: 349526 URL: https://svnweb.freebsd.org/changeset/base/349526 Log: When we protect PTEs (as opposed to PDEs), we only call vm_page_dirty() when, in fact, we are write protecting the page and the PTE has PG_M set. However, pmap_protect_pde() was always calling vm_page_dirty() when the PDE has PG_M set. So, adding PG_NX to a writeable PDE could result in unnecessary (but harmless) calls to vm_page_dirty(). Simplify the loop calling vm_page_dirty() in pmap_protect_pde(). Reviewed by: kib, markj MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20793 Modified: head/sys/amd64/amd64/pmap.c head/sys/i386/i386/pmap.c Modified: head/sys/amd64/amd64/pmap.c ============================================================================== --- head/sys/amd64/amd64/pmap.c Fri Jun 28 22:36:27 2019 (r349525) +++ head/sys/amd64/amd64/pmap.c Fri Jun 28 22:40:34 2019 (r349526) @@ -5202,8 +5202,7 @@ static boolean_t pmap_protect_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t sva, vm_prot_t prot) { pd_entry_t newpde, oldpde; - vm_offset_t eva, va; - vm_page_t m; + vm_page_t m, mt; boolean_t anychanged; pt_entry_t PG_G, PG_M, PG_RW; @@ -5217,15 +5216,15 @@ pmap_protect_pde(pmap_t pmap, pd_entry_t *pde, vm_offs anychanged = FALSE; retry: oldpde = newpde = *pde; - if ((oldpde & (PG_MANAGED | PG_M | PG_RW)) == - (PG_MANAGED | PG_M | PG_RW)) { - eva = sva + NBPDR; - for (va = sva, m = PHYS_TO_VM_PAGE(oldpde & PG_PS_FRAME); - va < eva; va += PAGE_SIZE, m++) - vm_page_dirty(m); - } - if ((prot & VM_PROT_WRITE) == 0) + if ((prot & VM_PROT_WRITE) == 0) { + if ((oldpde & (PG_MANAGED | PG_M | PG_RW)) == + (PG_MANAGED | PG_M | PG_RW)) { + m = PHYS_TO_VM_PAGE(oldpde & PG_PS_FRAME); + for (mt = m; mt < &m[NBPDR / PAGE_SIZE]; mt++) + vm_page_dirty(mt); + } newpde &= ~(PG_RW | PG_M); + } if ((prot & VM_PROT_EXECUTE) == 0) newpde |= pg_nx; if (newpde != oldpde) { Modified: head/sys/i386/i386/pmap.c ============================================================================== --- head/sys/i386/i386/pmap.c Fri Jun 28 22:36:27 2019 (r349525) +++ head/sys/i386/i386/pmap.c Fri Jun 28 22:40:34 2019 (r349526) @@ -3251,8 +3251,7 @@ static boolean_t pmap_protect_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t sva, vm_prot_t prot) { pd_entry_t newpde, oldpde; - vm_offset_t eva, va; - vm_page_t m; + vm_page_t m, mt; boolean_t anychanged; PMAP_LOCK_ASSERT(pmap, MA_OWNED); @@ -3261,15 +3260,15 @@ pmap_protect_pde(pmap_t pmap, pd_entry_t *pde, vm_offs anychanged = FALSE; retry: oldpde = newpde = *pde; - if ((oldpde & (PG_MANAGED | PG_M | PG_RW)) == - (PG_MANAGED | PG_M | PG_RW)) { - eva = sva + NBPDR; - for (va = sva, m = PHYS_TO_VM_PAGE(oldpde & PG_PS_FRAME); - va < eva; va += PAGE_SIZE, m++) - vm_page_dirty(m); - } - if ((prot & VM_PROT_WRITE) == 0) + if ((prot & VM_PROT_WRITE) == 0) { + if ((oldpde & (PG_MANAGED | PG_M | PG_RW)) == + (PG_MANAGED | PG_M | PG_RW)) { + m = PHYS_TO_VM_PAGE(oldpde & PG_PS_FRAME); + for (mt = m; mt < &m[NBPDR / PAGE_SIZE]; mt++) + vm_page_dirty(mt); + } newpde &= ~(PG_RW | PG_M); + } #ifdef PMAP_PAE_COMP if ((prot & VM_PROT_EXECUTE) == 0 && !i386_read_exec) newpde |= pg_nx;