From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Mon, 4 Jan 2021 20:02:28 +0000 (-0500)
Subject: mm/mprotect: Use maple tree navigation instead of vma linked list
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=c6c6fae5c62af32ae111b427559dd8a204ce53e0;p=users%2Fjedix%2Flinux-maple.git

mm/mprotect: Use maple tree navigation instead of vma linked list

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 4cb240fd99366..92be32bf5f1db 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -568,6 +568,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 	const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP);
 	const bool rier = (current->personality & READ_IMPLIES_EXEC) &&
 				(prot & PROT_READ);
+	MA_STATE(mas, &current->mm->mm_mt, start, start);
 
 	start = untagged_addr(start);
 
@@ -599,11 +600,15 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 	if ((pkey != -1) && !mm_pkey_is_allocated(current->mm, pkey))
 		goto out;
 
-	vma = find_vma(current->mm, start);
+	rcu_read_lock();
+	vma = mas_find(&mas, ULONG_MAX);
 	error = -ENOMEM;
-	if (!vma)
+	if (!vma) {
+		rcu_read_unlock();
 		goto out;
-	prev = vma->vm_prev;
+	}
+	prev = mas_prev(&mas, 0);
+	rcu_read_unlock();
 	if (unlikely(grows & PROT_GROWSDOWN)) {
 		if (vma->vm_start >= end)
 			goto out;
@@ -684,7 +689,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 		if (nstart >= end)
 			goto out;
 
-		vma = prev->vm_next;
+		vma = vma_next(current->mm, prev);
 		if (!vma || vma->vm_start != nstart) {
 			error = -ENOMEM;
 			goto out;