From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
Subject: mm/mprotect: use maple tree navigation instead of vma linked list

Link: https://lkml.kernel.org/r/20220426150616.3937571-60-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mprotect.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/mm/mprotect.c~mm-mprotect-use-maple-tree-navigation-instead-of-vma-linked-list
+++ a/mm/mprotect.c
@@ -621,6 +621,7 @@ static int do_mprotect_pkey(unsigned lon
 	const bool rier = (current->personality & READ_IMPLIES_EXEC) &&
 				(prot & PROT_READ);
 	struct mmu_gather tlb;
+	MA_STATE(mas, &current->mm->mm_mt, start, start);
 
 	start = untagged_addr(start);
 
@@ -652,7 +653,7 @@ static int do_mprotect_pkey(unsigned lon
 	if ((pkey != -1) && !mm_pkey_is_allocated(current->mm, pkey))
 		goto out;
 
-	vma = find_vma(current->mm, start);
+	vma = mas_find(&mas, ULONG_MAX);
 	error = -ENOMEM;
 	if (!vma)
 		goto out;
@@ -678,7 +679,7 @@ static int do_mprotect_pkey(unsigned lon
 	if (start > vma->vm_start)
 		prev = vma;
 	else
-		prev = vma->vm_prev;
+		prev = mas_prev(&mas, 0);
 
 	tlb_gather_mmu(&tlb, current->mm);
 	for (nstart = start ; ; ) {
@@ -741,7 +742,7 @@ static int do_mprotect_pkey(unsigned lon
 		if (nstart >= end)
 			break;
 
-		vma = prev->vm_next;
+		vma = find_vma(current->mm, prev->vm_end);
 		if (!vma || vma->vm_start != nstart) {
 			error = -ENOMEM;
 			break;
_