From nobody Mon Apr 6 15:03:03 2026 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 56663C4332F for ; Tue, 8 Nov 2022 17:48:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234731AbiKHRsb (ORCPT ); Tue, 8 Nov 2022 12:48:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234683AbiKHRsP (ORCPT ); Tue, 8 Nov 2022 12:48:15 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB4845655A for ; Tue, 8 Nov 2022 09:47:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667929637; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NDs1IzHuZwBiKepSKbrZlERPsRkua37TGdaig5O5yJI=; b=TaALZR1vtLa1pgmm7Eb+0kDsG7aHaN5qPjpRvK3aryYR6xWAX06JOcmyarUGFCquegBugr JxgM9eBKC+DJhyuL6n9vNg1oLrqjvhdACDHKeX0B40FtqpdqbVtc0MqqsCG91RCgGZHhlD R2CCIrPFNukW8+/Bp1nL08RBMZ3WN90= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-15-wU7JcHhbNo6cqAi4ce8Eog-1; Tue, 08 Nov 2022 12:47:12 -0500 X-MC-Unique: wU7JcHhbNo6cqAi4ce8Eog-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E2F97811E67; Tue, 8 Nov 2022 17:47:11 +0000 (UTC) Received: from t480s.fritz.box (unknown [10.39.194.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id D5E6CC15BB5; Tue, 8 Nov 2022 17:47:08 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, David Hildenbrand , Linus Torvalds , Andrew Morton , Mel Gorman , Dave Chinner , Nadav Amit , Peter Xu , Andrea Arcangeli , Hugh Dickins , Vlastimil Babka , Michael Ellerman , Nicholas Piggin , Mike Rapoport , Anshuman Khandual Subject: [PATCH v2 4/7] mm/mprotect: factor out check whether manual PTE write upgrades are required Date: Tue, 8 Nov 2022 18:46:49 +0100 Message-Id: <20221108174652.198904-5-david@redhat.com> In-Reply-To: <20221108174652.198904-1-david@redhat.com> References: <20221108174652.198904-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Let's factor the check out into vma_wants_manual_pte_write_upgrade(), to be reused in NUMA hinting fault context soon. Signed-off-by: David Hildenbrand --- include/linux/mm.h | 16 ++++++++++++++-- mm/mprotect.c | 17 ++++------------- 2 files changed, 18 insertions(+), 15 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 517c8cc8ccb9..4a7c10bed8bd 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1975,6 +1975,20 @@ extern unsigned long move_page_tables(struct vm_area= _struct *vma, #define MM_CP_UFFD_WP_ALL (MM_CP_UFFD_WP | \ MM_CP_UFFD_WP_RESOLVE) =20 +int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_pro= t); +static inline bool vma_wants_manual_pte_write_upgrade(struct vm_area_struc= t *vma) +{ + /* + * We want to check manually if we can change individual PTEs writable + * if we can't do that automatically for all PTEs in a mapping. For + * private mappings, that's always the case when we have write + * permissions as we properly have to handle COW. + */ + if (vma->vm_flags & VM_SHARED) + return vma_wants_writenotify(vma, vma->vm_page_prot); + return !!(vma->vm_flags & VM_WRITE); + +} extern unsigned long change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long start, unsigned long end, pgprot_t newprot, @@ -2114,8 +2128,6 @@ static inline int pte_devmap(pte_t pte) } #endif =20 -int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_pro= t); - extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl); static inline pte_t *get_locked_pte(struct mm_struct *mm, unsigned long ad= dr, diff --git a/mm/mprotect.c b/mm/mprotect.c index 72aabffb7871..fe22db2c9cdd 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -558,8 +558,8 @@ mprotect_fixup(struct mmu_gather *tlb, struct vm_area_s= truct *vma, struct mm_struct *mm =3D vma->vm_mm; unsigned long oldflags =3D vma->vm_flags; long nrpages =3D (end - start) >> PAGE_SHIFT; + unsigned int mm_cp_flags =3D 0; unsigned long charged =3D 0; - bool try_change_writable; pgoff_t pgoff; int error; =20 @@ -637,20 +637,11 @@ mprotect_fixup(struct mmu_gather *tlb, struct vm_area= _struct *vma, * held in write mode. */ vma->vm_flags =3D newflags; - /* - * We want to check manually if we can change individual PTEs writable - * if we can't do that automatically for all PTEs in a mapping. For - * private mappings, that's always the case when we have write - * permissions as we properly have to handle COW. - */ - if (vma->vm_flags & VM_SHARED) - try_change_writable =3D vma_wants_writenotify(vma, vma->vm_page_prot); - else - try_change_writable =3D !!(vma->vm_flags & VM_WRITE); + if (vma_wants_manual_pte_write_upgrade(vma)) + mm_cp_flags |=3D MM_CP_TRY_CHANGE_WRITABLE; vma_set_page_prot(vma); =20 - change_protection(tlb, vma, start, end, vma->vm_page_prot, - try_change_writable ? MM_CP_TRY_CHANGE_WRITABLE : 0); + change_protection(tlb, vma, start, end, vma->vm_page_prot, mm_cp_flags); =20 /* * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major --=20 2.38.1