From owner-dev-commits-src-branches@freebsd.org Sun Feb 28 20:52:06 2021 Return-Path: Delivered-To: dev-commits-src-branches@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 A8EF354A30F; Sun, 28 Feb 2021 20:52:06 +0000 (UTC) (envelope-from git@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) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4DpbDQ4M8Zz4td4; Sun, 28 Feb 2021 20:52:06 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 88B62176C4; Sun, 28 Feb 2021 20:52:06 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 11SKq6q1081338; Sun, 28 Feb 2021 20:52:06 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 11SKq6rp081337; Sun, 28 Feb 2021 20:52:06 GMT (envelope-from git) Date: Sun, 28 Feb 2021 20:52:06 GMT Message-Id: <202102282052.11SKq6rp081337@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mark Johnston Subject: git: 5966aae9c7c2 - stable/13 - pmap: Fix largemap restart checks in the kernel_maps sysctl handler MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: 5966aae9c7c25707c785ec056cb8462a037a480e Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-branches@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commits to the stable branches of the FreeBSD src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 28 Feb 2021 20:52:06 -0000 The branch stable/13 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=5966aae9c7c25707c785ec056cb8462a037a480e commit 5966aae9c7c25707c785ec056cb8462a037a480e Author: Mark Johnston AuthorDate: 2021-02-25 23:49:47 +0000 Commit: Mark Johnston CommitDate: 2021-02-28 20:51:51 +0000 pmap: Fix largemap restart checks in the kernel_maps sysctl handler The purpose of these checks is to ensure that the address of the next-level page table page is valid, since nothing is synchronizing with a concurrent update of the large map and large map PTPs are freed to the system. However, if PG_PS is set, there is no next level. Reported by: rpokala Reviewed by: kib Tested by: rpokala Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D28922 (cherry picked from commit aac25e222525780db8939d07a594d3e090c0a148) --- sys/amd64/amd64/pmap.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index 0e1d1c02d1fc..bd23fd176e88 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -11349,9 +11349,6 @@ restart: continue; } pa = pdpe & PG_FRAME; - if (PMAP_ADDRESS_IN_LARGEMAP(sva) && - vm_phys_paddr_to_vm_page(pa) == NULL) - goto restart; if ((pdpe & PG_PS) != 0) { sva = rounddown2(sva, NBPDP); sysctl_kmaps_check(sb, &range, sva, pml4e, pdpe, @@ -11360,6 +11357,15 @@ restart: sva += NBPDP; continue; } + if (PMAP_ADDRESS_IN_LARGEMAP(sva) && + vm_phys_paddr_to_vm_page(pa) == NULL) { + /* + * Page table pages for the large map may be + * freed. Validate the next-level address + * before descending. + */ + goto restart; + } pd = (pd_entry_t *)PHYS_TO_DMAP(pa); for (k = pmap_pde_index(sva); k < NPDEPG; k++) { @@ -11371,9 +11377,6 @@ restart: continue; } pa = pde & PG_FRAME; - if (PMAP_ADDRESS_IN_LARGEMAP(sva) && - vm_phys_paddr_to_vm_page(pa) == NULL) - goto restart; if ((pde & PG_PS) != 0) { sva = rounddown2(sva, NBPDR); sysctl_kmaps_check(sb, &range, sva, @@ -11382,6 +11385,15 @@ restart: sva += NBPDR; continue; } + if (PMAP_ADDRESS_IN_LARGEMAP(sva) && + vm_phys_paddr_to_vm_page(pa) == NULL) { + /* + * Page table pages for the large map + * may be freed. Validate the + * next-level address before descending. + */ + goto restart; + } pt = (pt_entry_t *)PHYS_TO_DMAP(pa); for (l = pmap_pte_index(sva); l < NPTEPG; l++,