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From:   Liam Howlett <liam.howlett@oracle.com>
To:     "maple-tree@lists.infradead.org" <maple-tree@lists.infradead.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
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        Peter Zijlstra <peterz@infradead.org>,
        Michel Lespinasse <walken.cr@gmail.com>,
        Liam Howlett <liam.howlett@oracle.com>
Subject: [PATCH 58/94] arch/x86: Use maple tree iterators for vdso/vma
Thread-Topic: [PATCH 58/94] arch/x86: Use maple tree iterators for vdso/vma
Thread-Index: AQHXPEQ6vZzbkb6BrU2OY1jyGYUJSw==
Date:   Wed, 28 Apr 2021 15:36:17 +0000
Message-ID: <20210428153542.2814175-59-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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Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---
 arch/x86/entry/vdso/vma.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 235a5794296a..c0b160a9585d 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -128,15 +128,19 @@ int vdso_join_timens(struct task_struct *task, struct=
 time_namespace *ns)
 	struct mm_struct *mm =3D task->mm;
 	struct vm_area_struct *vma;
=20
+	MA_STATE(mas, &mm->mm_mt, 0, 0);
+
 	mmap_read_lock(mm);
+	rcu_read_lock();
=20
-	for (vma =3D mm->mmap; vma; vma =3D vma->vm_next) {
+	mas_for_each(&mas, vma, ULONG_MAX) {
 		unsigned long size =3D vma->vm_end - vma->vm_start;
=20
 		if (vma_is_special_mapping(vma, &vvar_mapping))
 			zap_page_range(vma, vma->vm_start, size);
 	}
=20
+	rcu_read_unlock();
 	mmap_read_unlock(mm);
 	return 0;
 }
@@ -354,6 +358,7 @@ int map_vdso_once(const struct vdso_image *image, unsig=
ned long addr)
 {
 	struct mm_struct *mm =3D current->mm;
 	struct vm_area_struct *vma;
+	MA_STATE(mas, &mm->mm_mt, 0, 0);
=20
 	mmap_write_lock(mm);
 	/*
@@ -363,13 +368,16 @@ int map_vdso_once(const struct vdso_image *image, uns=
igned long addr)
 	 * We could search vma near context.vdso, but it's a slowpath,
 	 * so let's explicitly check all VMAs to be completely sure.
 	 */
-	for (vma =3D mm->mmap; vma; vma =3D vma->vm_next) {
+	mas_lock(&mas);
+	mas_for_each(&mas, vma, ULONG_MAX) {
 		if (vma_is_special_mapping(vma, &vdso_mapping) ||
 				vma_is_special_mapping(vma, &vvar_mapping)) {
+			mas_unlock(&mas);
 			mmap_write_unlock(mm);
 			return -EEXIST;
 		}
 	}
+	mas_unlock(&mas);
 	mmap_write_unlock(mm);
=20
 	return map_vdso(image, addr);
--=20
2.30.2