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Message-ID: <20240704182718.2653918-3-Liam.Howlett@oracle.com>
Date: Thu, 4 Jul 2024 14:27:04 -0400
From: "Liam R. Howlett" <Liam.Howlett@...cle.com>
To: linux-mm@...ck.org, Andrew Morton <akpm@...ux-foundation.org>
Cc: Suren Baghdasaryan <surenb@...gle.com>, Vlastimil Babka <vbabka@...e.cz>,
Lorenzo Stoakes <lstoakes@...il.com>,
Matthew Wilcox <willy@...radead.org>, sidhartha.kumar@...cle.com,
"Paul E . McKenney" <paulmck@...nel.org>,
Bert Karwatzki <spasswolf@....de>, Jiri Olsa <olsajiri@...il.com>,
linux-kernel@...r.kernel.org, Kees Cook <kees@...nel.org>,
"Liam R. Howlett" <Liam.Howlett@...cle.com>
Subject: [PATCH v3 02/16] mm/mmap: Introduce abort_munmap_vmas()
Extract clean up of failed munmap() operations from
do_vmi_align_munmap(). This simplifies later patches in the series.
Signed-off-by: Liam R. Howlett <Liam.Howlett@...cle.com>
---
mm/mmap.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 28a46d9ddde0..d572e1ff8255 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2586,6 +2586,25 @@ struct vm_area_struct *vma_merge_extend(struct vma_iterator *vmi,
vma->vm_userfaultfd_ctx, anon_vma_name(vma));
}
+/*
+ * abort_munmap_vmas - Undo any munmap work and free resources
+ *
+ * Reattach detached vmas, free up maple tree used to track the vmas.
+ */
+static inline void abort_munmap_vmas(struct ma_state *mas_detach)
+{
+ struct vm_area_struct *vma;
+ int limit;
+
+ limit = mas_detach->index;
+ mas_set(mas_detach, 0);
+ /* Re-attach any detached VMAs */
+ mas_for_each(mas_detach, vma, limit)
+ vma_mark_detached(vma, false);
+
+ __mt_destroy(mas_detach->tree);
+}
+
/*
* do_vmi_align_munmap() - munmap the aligned region from @start to @end.
* @vmi: The vma iterator
@@ -2740,11 +2759,7 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
userfaultfd_error:
munmap_gather_failed:
end_split_failed:
- mas_set(&mas_detach, 0);
- mas_for_each(&mas_detach, next, end)
- vma_mark_detached(next, false);
-
- __mt_destroy(&mt_detach);
+ abort_munmap_vmas(&mas_detach);
start_split_failed:
map_count_exceeded:
validate_mm(mm);
--
2.43.0
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