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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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        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 71/94] kernel/events/uprobes: Use maple tree iterators instead
 of linked list
Thread-Topic: [PATCH 71/94] kernel/events/uprobes: Use maple tree iterators
 instead of linked list
Thread-Index: AQHXPEQ+75E4B2HUXkOM5VQTLsLxRw==
Date:   Wed, 28 Apr 2021 15:36:22 +0000
Message-ID: <20210428153542.2814175-72-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>
---
 kernel/events/uprobes.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 907d4ee00cb2..8d3248ffbd68 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -355,13 +355,16 @@ static bool valid_ref_ctr_vma(struct uprobe *uprobe,
 static struct vm_area_struct *
 find_ref_ctr_vma(struct uprobe *uprobe, struct mm_struct *mm)
 {
-	struct vm_area_struct *tmp;
+	struct vm_area_struct *tmp =3D NULL;
+	MA_STATE(mas, &mm->mm_mt, 0, 0);
=20
-	for (tmp =3D mm->mmap; tmp; tmp =3D tmp->vm_next)
+	rcu_read_lock();
+	mas_for_each(&mas, tmp, ULONG_MAX)
 		if (valid_ref_ctr_vma(uprobe, tmp))
-			return tmp;
+			break;
+	rcu_read_unlock();
=20
-	return NULL;
+	return tmp;
 }
=20
 static int
@@ -1237,9 +1240,10 @@ static int unapply_uprobe(struct uprobe *uprobe, str=
uct mm_struct *mm)
 {
 	struct vm_area_struct *vma;
 	int err =3D 0;
+	MA_STATE(mas, &mm->mm_mt, 0, 0);
=20
 	mmap_read_lock(mm);
-	for (vma =3D mm->mmap; vma; vma =3D vma->vm_next) {
+	mas_for_each(&mas, vma, ULONG_MAX) {
 		unsigned long vaddr;
 		loff_t offset;
=20
@@ -1988,8 +1992,10 @@ bool uprobe_deny_signal(void)
 static void mmf_recalc_uprobes(struct mm_struct *mm)
 {
 	struct vm_area_struct *vma;
+	MA_STATE(mas, &mm->mm_mt, 0, 0);
=20
-	for (vma =3D mm->mmap; vma; vma =3D vma->vm_next) {
+	rcu_read_lock();
+	mas_for_each(&mas, vma, ULONG_MAX) {
 		if (!valid_vma(vma, false))
 			continue;
 		/*
@@ -1999,10 +2005,15 @@ static void mmf_recalc_uprobes(struct mm_struct *mm=
)
 		 * Or this uprobe can be filtered out.
 		 */
 		if (vma_has_uprobes(vma, vma->vm_start, vma->vm_end))
-			return;
+			goto completed;
 	}
+	rcu_read_unlock();
=20
 	clear_bit(MMF_HAS_UPROBES, &mm->flags);
+	return;
+
+completed:
+	rcu_read_unlock();
 }
=20
 static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr)
--=20
2.30.2