[82/94] mm/mprotect: Use maple tree navigation instead of vma linked list

Commit Message

Liam R. Howlett April 28, 2021, 3:36 p.m. UTC

Signed-off-by: Liam R. Howlett <[e-mail]>
---
 mm/mprotect.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Patch

diff --git a/mm/mprotect.c b/mm/mprotect.c
index e7a443157988..c468a823627f 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -518,6 +518,7 @@  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);
 
@@ -549,11 +550,11 @@  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);
+	vma = mas_find(&mas, ULONG_MAX);
 	error = -ENOMEM;
 	if (!vma)
 		goto out;
-	prev = vma->vm_prev;
+	prev = mas_prev(&mas, 0);
 	if (unlikely(grows & PROT_GROWSDOWN)) {
 		if (vma->vm_start >= end)
 			goto out;
@@ -634,7 +635,7 @@  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;