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 354D0C77B70 for ; Thu, 6 Apr 2023 02:45:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234972AbjDFCpX (ORCPT ); Wed, 5 Apr 2023 22:45:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37416 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235092AbjDFCo4 (ORCPT ); Wed, 5 Apr 2023 22:44:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 746368A5A for ; Wed, 5 Apr 2023 19:44:55 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EA03364266 for ; Thu, 6 Apr 2023 02:44:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E751C433D2; Thu, 6 Apr 2023 02:44:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1680749094; bh=wndE/XIl5c4v+wavy0VTOAOTn41EQPIy7g/raNeUFpM=; h=Date:To:From:Subject:From; b=I6kWC6wgFNe1xW5Wh7UxqAIQ3Iqyz/Ip7ygzbydT0D9I5fcumDCDkIICppPlDOofW yoocS5dpNgZRE1LefjZdT1l49RX1UgMvYhPTzX1bghCr6qSFMxFU223nxzS530c5HL mgqcpy2Gczkb2D7GMa5JYYZgLN1/AlaAtzy7f5SI= Date: Wed, 05 Apr 2023 19:44:53 -0700 To: mm-commits@vger.kernel.org, willy@infradead.org, surenb@google.com, lstoakes@gmail.com, Liam.Howlett@oracle.com, vbabka@suse.cz, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-mmap-vma_merge-set-mid-to-null-if-not-applicable.patch removed from -mm tree Message-Id: <20230406024454.4E751C433D2@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: mm/mmap/vma_merge: set mid to NULL if not applicable has been removed from the -mm tree. Its filename was mm-mmap-vma_merge-set-mid-to-null-if-not-applicable.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Vlastimil Babka Subject: mm/mmap/vma_merge: set mid to NULL if not applicable Date: Thu, 9 Mar 2023 12:12:54 +0100 There are several places where we test if 'mid' is really the area NNNN in the diagram and the tests have two variants and are non-obvious to follow. Instead, set 'mid' to NULL up-front if it's not the NNNN area, and simplify the tests. Also update the description in comment accordingly. [vbabka@suse.cz: adjust/add comments as suggested by Lorenzo] Link: https://lkml.kernel.org/r/def43190-53f7-a607-d1b0-b657565f4288@suse.cz Link: https://lkml.kernel.org/r/20230309111258.24079-7-vbabka@suse.cz Signed-off-by: Vlastimil Babka Reviewed-by: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton --- mm/mmap.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) --- a/mm/mmap.c~mm-mmap-vma_merge-set-mid-to-null-if-not-applicable +++ a/mm/mmap.c @@ -848,10 +848,12 @@ can_vma_merge_after(struct vm_area_struc * * The following mprotect cases have to be considered, where AAAA is * the area passed down from mprotect_fixup, never extending beyond one - * vma, PPPPPP is the prev vma specified, and NNNNNN the next vma after: + * vma, PPPP is the previous vma, NNNN is a vma that starts at the same + * address as AAAA and is of the same or larger span, and XXXX the next + * vma after AAAA: * * AAAA AAAA AAAA - * PPPPPPNNNNNN PPPPPPXXXXXX PPPPPPNNNNNN + * PPPPPPXXXXXX PPPPPPXXXXXX PPPPPPNNNNNN * cannot merge might become might become * PPXXXXXXXXXX PPPPPPPPPPNN * mmap, brk or case 4 below case 5 below @@ -879,9 +881,10 @@ can_vma_merge_after(struct vm_area_struc * * In the code below: * PPPP is represented by *prev - * NNNN is represented by *mid (and possibly equal to *next) - * XXXX is represented by *next or not represented at all. - * AAAA is not represented - it will be merged or the function will return NULL + * NNNN is represented by *mid or not represented at all (NULL) + * XXXX is represented by *next or not represented at all (NULL) + * AAAA is not represented - it will be merged and the vma containing the + * area is returned, or the function will return NULL */ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, struct vm_area_struct *prev, unsigned long addr, @@ -918,6 +921,10 @@ struct vm_area_struct *vma_merge(struct else next = mid; + /* In cases 1 - 4 there's no NNNN vma */ + if (mid && end <= mid->vm_start) + mid = NULL; + /* verify some invariant that must be enforced by the caller */ VM_WARN_ON(prev && addr <= prev->vm_start); VM_WARN_ON(mid && end > mid->vm_end); @@ -952,7 +959,7 @@ struct vm_area_struct *vma_merge(struct remove = next; /* case 1 */ vma_end = next->vm_end; err = dup_anon_vma(prev, next); - if (mid != next) { /* case 6 */ + if (mid) { /* case 6 */ remove = mid; remove2 = next; if (!next->anon_vma) @@ -960,7 +967,7 @@ struct vm_area_struct *vma_merge(struct } } else if (merge_prev) { err = 0; /* case 2 */ - if (mid && end > mid->vm_start) { + if (mid) { err = dup_anon_vma(prev, mid); if (end == mid->vm_end) { /* case 7 */ remove = mid; @@ -982,7 +989,7 @@ struct vm_area_struct *vma_merge(struct vma_end = next->vm_end; vma_pgoff = next->vm_pgoff; err = 0; - if (mid != next) { /* case 8 */ + if (mid) { /* case 8 */ vma_pgoff = mid->vm_pgoff; remove = mid; err = dup_anon_vma(next, mid); _ Patches currently in -mm which might be from vbabka@suse.cz are mm-page_alloc-use-check_pages_enabled-static-key-to-check-tail-pages.patch