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From:   Liam Howlett <liam.howlett@oracle.com>
To:     "maple-tree@lists.infradead.org" <maple-tree@lists.infradead.org>,
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        Rik van Riel <riel@surriel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Michel Lespinasse <walken.cr@gmail.com>,
        Liam Howlett <liam.howlett@oracle.com>
Subject: [PATCH 50/94] mm/mmap: Change do_brk_munmap() to use
 do_mas_align_munmap()
Thread-Topic: [PATCH 50/94] mm/mmap: Change do_brk_munmap() to use
 do_mas_align_munmap()
Thread-Index: AQHXPEQ4TcocQKxW4U6QeYGrHr1Pzg==
Date:   Wed, 28 Apr 2021 15:36:13 +0000
Message-ID: <20210428153542.2814175-51-Liam.Howlett@Oracle.com>
References: <20210428153542.2814175-1-Liam.Howlett@Oracle.com>
In-Reply-To: <20210428153542.2814175-1-Liam.Howlett@Oracle.com>
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do_brk_munmap() already has aligned addresses.

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---
 mm/mmap.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index cf4aa715eb63..3b1a9f6bc39b 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2965,12 +2965,16 @@ static int do_brk_munmap(struct ma_state *mas, stru=
ct vm_area_struct *vma,
 	struct mm_struct *mm =3D vma->vm_mm;
 	struct vm_area_struct unmap;
 	unsigned long unmap_pages;
-	int ret =3D 1;
+	int ret;
=20
 	arch_unmap(mm, newbrk, oldbrk);
=20
-	if (likely(vma->vm_start >=3D newbrk)) { // remove entire mapping(s)
-		ret =3D do_mas_munmap(mas, mm, newbrk, oldbrk-newbrk, uf, true);
+	if (likely((vma->vm_end < oldbrk) ||
+		   ((vma->vm_start =3D=3D newbrk) && (vma->vm_end =3D=3D oldbrk)))) {
+		// remove entire mapping(s)
+		mas->last =3D oldbrk - 1;
+		ret =3D do_mas_align_munmap(mas, vma, mm, newbrk, oldbrk, uf,
+					  true);
 		goto munmap_full_vma;
 	}
=20
--=20
2.30.2