[PATCH v7 59/70] mm/mprotect: Use maple tree navigation instead of vma linked list

Liam Howlett liam.howlett at oracle.com
Mon Apr 4 07:35:55 PDT 2022


From: "Liam R. Howlett" <Liam.Howlett at Oracle.com>

Signed-off-by: Liam R. Howlett <Liam.Howlett at Oracle.com>
Acked-by: Vlastimil Babka <vbabka at suse.cz>
---
 mm/mprotect.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/mm/mprotect.c b/mm/mprotect.c
index b69ce7a7b2b7..81e5392ab13e 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -539,6 +539,7 @@ 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);
 
@@ -570,7 +571,7 @@ 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;
@@ -596,7 +597,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 	if (start > vma->vm_start)
 		prev = vma;
 	else
-		prev = vma->vm_prev;
+		prev = mas_prev(&mas, 0);
 
 	for (nstart = start ; ; ) {
 		unsigned long mask_off_old_flags;
@@ -658,7 +659,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 		if (nstart >= end)
 			goto out;
 
-		vma = prev->vm_next;
+		vma = find_vma(current->mm, prev->vm_end);
 		if (!vma || vma->vm_start != nstart) {
 			error = -ENOMEM;
 			goto out;
-- 
2.34.1



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