diff options
| author | Vlastimil Babka <vbabka@suse.cz> | 2023-03-09 12:12:51 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-04-05 19:42:48 -0700 |
| commit | 5ff783f15176e85323e9d9349fefcd4de6e435bb (patch) | |
| tree | 01e21b2947fa0312fa910fb4127bf6e7066e2534 /mm/mmap.c | |
| parent | 097d70c6272f236eb4a29b3fb74b72df3a5344cf (diff) | |
mm/mmap/vma_merge: use the proper vma pointers in cases 1 and 6
Case 1 is now shown in the comment as next vma being merged with prev, so
use 'next' instead of 'mid'. In case 1 they both point to the same vma.
As a consequence, in case 6, the dup_anon_vma() is now tried first on
'next' and then on 'mid', before it was the opposite order. This is not a
functional change, as those two vma's cannnot have a different anon_vma,
as that would have prevented the merging in the first place.
Link: https://lkml.kernel.org/r/20230309111258.24079-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index be8338318cfb..d1352a653df5 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -605,7 +605,7 @@ again: /* * In mprotect's case 6 (see comments on vma_merge), - * we must remove the one after next as well. + * we are removing both mid and next vmas */ if (vp->remove2) { vp->remove = vp->remove2; @@ -948,13 +948,14 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, /* Can we merge both the predecessor and the successor? */ if (merge_prev && merge_next && is_mergeable_anon_vma(prev->anon_vma, next->anon_vma, NULL)) { - remove = mid; /* case 1 */ + remove = next; /* case 1 */ vma_end = next->vm_end; - err = dup_anon_vma(prev, mid); + err = dup_anon_vma(prev, next); if (mid != next) { /* case 6 */ + remove = mid; remove2 = next; - if (!mid->anon_vma) - err = dup_anon_vma(prev, next); + if (!next->anon_vma) + err = dup_anon_vma(prev, mid); } } else if (merge_prev) { err = 0; /* case 2 */ |