From nobody Wed Jun 29 14:40:57 2022 X-Original-To: dev-commits-src-branches@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 6EFEF86D7F9; Wed, 29 Jun 2022 14:40:58 +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 4LY3zt1dqPz4j4b; Wed, 29 Jun 2022 14:40:57 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1656513658; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=7nLzIm5zpq/bomyPAS9I3To1qTQtruepZT5HawSQDK0=; b=YkT+lUpc0EG5iXYDrsymIR+5ayqt2SZTxQXqi57bPatjMLFQyI+MCtXfatDeYAiKGQdjoF M6O/OnNwb1dXDpMyPoud1GC1hpqEwq8BXx9duvPk7qdpDskvtKw1UrtJy9qXMxCYeF3/iv 9V1ZJsUVOSom/LXhiQqlkYkNvcGFjKLq6CiIp7bYTQ2UWi2xFaDe6PvlxNIrvLnNab7LG4 gWIV3dpKptWdLlp745bV0D6g6Ubjk32ZtN7gsek4NtHZIMsUIoEUN2q1JDOfnD9GOlyyNS 8nR9I95Tx+AaKpXFW04EUvdFnwYF/W41/XR2yoTyqApjQeo/mHzhsuAHvNMgJQ== 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 A75CB13A9C; Wed, 29 Jun 2022 14:40:57 +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 25TEevGB031766; Wed, 29 Jun 2022 14:40:57 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 25TEevdS031765; Wed, 29 Jun 2022 14:40:57 GMT (envelope-from git) Date: Wed, 29 Jun 2022 14:40:57 GMT Message-Id: <202206291440.25TEevdS031765@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: f1400b2ecc73 - stable/13 - pmap: Keep PTI page table pages busy List-Id: Commits to the stable branches of the FreeBSD src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-branches List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-branches@freebsd.org X-BeenThere: dev-commits-src-branches@freebsd.org 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: f1400b2ecc736e20e419d22ac97754dc4d71387f Auto-Submitted: auto-generated ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1656513658; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=7nLzIm5zpq/bomyPAS9I3To1qTQtruepZT5HawSQDK0=; b=h6qlj8SdlddAcUPMhplFAZ0wVCU+unC30/V1Hu3kIyNe6qha8O+jPOYciiUprQvo3z8+2k 5wq1Egb3KMqm9XCGR3muxeGHX99LGYrSskTHFxlDyG2WYVI9JusCm/FSe3T/jj2RNCvQEg 4+TXpvud7fUBBybQj86Q6ZPUOytsMjVIyhPLSq8AsRcXTUmiEr3Dt6OsUdRJTmOrcVHlp6 8tSW2a+1kX5wCyGrofItdQ0YMgA1omn4gA0jR1ZHWFCUu+Tnx0PnF9P3zrUG5ofqvUHuC3 wsI4CGSyEQWhXMzGj5zZuHZxU2UaZp4McEKW6wRAq53IiHViqdMVCSNQNpI0zg== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1656513658; a=rsa-sha256; cv=none; b=iPrqewOsdoB9MlBCb1ygFR9Y2EC24JzyGxtAHx7/MKT8f20KiNCKrs09x/EtGw7OW+KUky KdKuDC5j3KQKfseyY0CtsW+sS5kxM9ean0gI6K68BaZz6gXBlOEicgPJs1UhD5crr5nD9v VOnvfAgB+tH0eq2ndzcOK8tpq7rB3J2GbDMCObNXeTyqwTa+8jtOHEDpj+rr6I0Ti0ZRpk k9xtsMRr3/jEOw0804e67Ammk1LcLg7WADihIaoLMpqivFXZYtSQ7rR17E8S35HicTrcRl GfA+emXZAKfZlnMbnBEvFOIkIhz5ESfjC2gts/jzi6fqxPY3OL7zds5kC2zvdQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N The branch stable/13 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=f1400b2ecc736e20e419d22ac97754dc4d71387f commit f1400b2ecc736e20e419d22ac97754dc4d71387f Author: Mark Johnston AuthorDate: 2022-06-15 14:19:01 +0000 Commit: Mark Johnston CommitDate: 2022-06-29 14:13:57 +0000 pmap: Keep PTI page table pages busy PTI page table pages are allocated from a VM object, so must be exclusively busied when they are freed, e.g., when a thread loses a race in pmap_pti_pde(). Simply keep PTPs busy at all times, as was done for some other kernel allocators in commit e9ceb9dd110e04fc19729b4e9fb1c8bfbb8398a3. Also remove some redundant assertions on "ref_count": vm_page_unwire_noq() already asserts that the page's reference count is greater than zero. Reported by: syzkaller Reviewed by: kib Sponsored by: The FreeBSD Foundation (cherry picked from commit c6d092b5107d1a3acefa977828b8130c0505fe7b) --- sys/amd64/amd64/pmap.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index f6b7238d39d7..79e61de490ae 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -10743,18 +10743,16 @@ pmap_pti_alloc_page(void) vm_page_t m; VM_OBJECT_ASSERT_WLOCKED(pti_obj); - m = vm_page_grab(pti_obj, pti_pg_idx++, VM_ALLOC_NOBUSY | - VM_ALLOC_WIRED | VM_ALLOC_ZERO); + m = vm_page_grab(pti_obj, pti_pg_idx++, VM_ALLOC_WIRED | VM_ALLOC_ZERO); return (m); } static bool pmap_pti_free_page(vm_page_t m) { - - KASSERT(m->ref_count > 0, ("page %p not referenced", m)); if (!vm_page_unwire_noq(m)) return (false); + vm_page_xbusy_claim(m); vm_page_free_zero(m); return (true); } @@ -10860,7 +10858,6 @@ pmap_pti_unwire_pde(void *pde, bool only_ref) VM_OBJECT_ASSERT_WLOCKED(pti_obj); m = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((uintptr_t)pde)); - MPASS(m->ref_count > 0); MPASS(only_ref || m->ref_count > 1); pmap_pti_free_page(m); } @@ -10873,7 +10870,6 @@ pmap_pti_unwire_pte(void *pte, vm_offset_t va) VM_OBJECT_ASSERT_WLOCKED(pti_obj); m = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((uintptr_t)pte)); - MPASS(m->ref_count > 0); if (pmap_pti_free_page(m)) { pde = pmap_pti_pde(va); MPASS((*pde & (X86_PG_PS | X86_PG_V)) == X86_PG_V);