From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E9BCC761AF for ; Tue, 4 Apr 2023 14:00:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235793AbjDDOAV (ORCPT ); Tue, 4 Apr 2023 10:00:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59942 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235892AbjDDOAD (ORCPT ); Tue, 4 Apr 2023 10:00:03 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C31DE5267 for ; Tue, 4 Apr 2023 06:59:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=Fp3DXW4B3dj0QEKkbnSR4pkaFzIpRXPOad7xMgXDJaQ=; b=TxwFEXAtSCPKXbeHQbszWeprHo VxqiwXK91lJo0UbDX3RXW4XNyqSskCcZ+9c6WpaI49UbctxbS8wZqEs3nPaFmlxhiHDuV8vPlJax2 YyzP6h7vKnv5ar2DQ7nkf41EsuJBzI5y3wKFEZhWVvhRMEWky3yvIorFwMObUfedc0Ox57hBgNG4L hJdS5UNhY9mxtMwjqVdTEK1iqVrDNyxYcuLW4sE/QpfuP1jUoT8MUTWkYQUjLGPjz2slZ/+T3Dmu8 uN5UE/fYsoduKgaE2VcvgZ2054Ku5h1J2ox/V4pURx85nuWl/nVa5VEMNVMnWzhBlMND2LjjWjjuw v1Yks0fw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pjhBU-00FPcl-Co; Tue, 04 Apr 2023 13:58:52 +0000 From: "Matthew Wilcox (Oracle)" To: Suren Baghdasaryan Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Punit Agrawal Subject: [PATCH 4/6] mm: Move FAULT_FLAG_VMA_LOCK check down in handle_pte_fault() Date: Tue, 4 Apr 2023 14:58:48 +0100 Message-Id: <20230404135850.3673404-5-willy@infradead.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20230404135850.3673404-1-willy@infradead.org> References: <20230404135850.3673404-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Call do_pte_missing(), do_wp_page() and do_numa_page() under the VMA lock. The first two gain the check, but do_numa_page() looks safe to run outside the mmap lock. Signed-off-by: Matthew Wilcox (Oracle) --- mm/memory.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index a2e27403e4f1..dc2baddc6040 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3329,6 +3329,9 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf) struct vm_area_struct *vma = vmf->vma; struct folio *folio = NULL; + if ((vmf->flags & FAULT_FLAG_VMA_LOCK) && !vma_is_anonymous(vma)) + return VM_FAULT_RETRY; + if (likely(!unshare)) { if (userfaultfd_pte_wp(vma, *vmf->pte)) { pte_unmap_unlock(vmf->pte, vmf->ptl); @@ -3644,6 +3647,8 @@ static vm_fault_t do_pte_missing(struct vm_fault *vmf) { if (vma_is_anonymous(vmf->vma)) return do_anonymous_page(vmf); + else if (vmf->flags & FAULT_FLAG_VMA_LOCK) + return VM_FAULT_RETRY; else return do_fault(vmf); } @@ -4896,9 +4901,6 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf) { pte_t entry; - if ((vmf->flags & FAULT_FLAG_VMA_LOCK) && !vma_is_anonymous(vmf->vma)) - return VM_FAULT_RETRY; - if (unlikely(pmd_none(*vmf->pmd))) { /* * Leave __pte_alloc() until later: because vm_ops->fault may @@ -4957,6 +4959,9 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf) if (pte_protnone(vmf->orig_pte) && vma_is_accessible(vmf->vma)) return do_numa_page(vmf); + if ((vmf->flags & FAULT_FLAG_VMA_LOCK) && !vma_is_anonymous(vmf->vma)) + return VM_FAULT_RETRY; + vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd); spin_lock(vmf->ptl); entry = vmf->orig_pte; -- 2.39.2