+ mm-mmap-vma_merge-set-mid-to-null-if-not-applicable-fix.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm-mmap-vma_merge-set-mid-to-null-if-not-applicable-fix
has been added to the -mm mm-unstable branch.  Its filename is
     mm-mmap-vma_merge-set-mid-to-null-if-not-applicable-fix.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mmap-vma_merge-set-mid-to-null-if-not-applicable-fix.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Vlastimil Babka <vbabka@suse.cz>
Subject: mm-mmap-vma_merge-set-mid-to-null-if-not-applicable-fix

adjust/add comments as suggested by Lorenzo

Link: https://lkml.kernel.org/r/def43190-53f7-a607-d1b0-b657565f4288@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/mm/mmap.c~mm-mmap-vma_merge-set-mid-to-null-if-not-applicable-fix
+++ a/mm/mmap.c
@@ -861,8 +861,9 @@ 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, NNNN is a vma that overlaps
- * the area AAAA and XXXXXX the next vma after AAAA:
+ * 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
  *    PPPPPPXXXXXX    PPPPPPXXXXXX       PPPPPPNNNNNN
@@ -933,6 +934,7 @@ 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;
 
_

Patches currently in -mm which might be from vbabka@suse.cz are

mm-page_alloc-reduce-page-alloc-free-sanity-checks.patch
mm-mmap-vma_merge-use-only-primary-pointers-for-preparing-merge.patch
mm-mmap-vma_merge-use-the-proper-vma-pointer-in-case-3.patch
mm-mmap-vma_merge-use-the-proper-vma-pointers-in-cases-1-and-6.patch
mm-mmap-vma_merge-use-the-proper-vma-pointer-in-case-4.patch
mm-mmap-vma_merge-initialize-mid-and-next-in-natural-order.patch
mm-mmap-vma_merge-set-mid-to-null-if-not-applicable.patch
mm-mmap-vma_merge-set-mid-to-null-if-not-applicable-fix.patch
mm-mmap-vma_merge-rename-adj_next-to-adj_start.patch
mm-mmap-vma_merge-convert-mergeability-checks-to-return-bool.patch
mm-mmap-start-distinguishing-if-vma-can-be-removed-in-mergeability-test.patch
mm-mmap-start-distinguishing-if-vma-can-be-removed-in-mergeability-test-fix.patch
mm-mremap-simplify-vma-expansion-again.patch