From 524e00b36e8c547f5582eef3fb645a8d9fc5e3df Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
Date: Tue, 6 Sep 2022 19:48:48 +0000
Subject: mm: remove rb tree.

Remove the RB tree and start using the maple tree for vm_area_struct
tracking.

Drop validate_mm() calls in expand_upwards() and expand_downwards() as the
lock is not held.

Link: https://lkml.kernel.org/r/20220906194824.2110408-18-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/util.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

(limited to 'mm/util.c')

diff --git a/mm/util.c b/mm/util.c
index 8d944ce71e94..10effe256dfa 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -288,6 +288,8 @@ void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
 	vma->vm_next = next;
 	if (next)
 		next->vm_prev = vma;
+	else
+		mm->highest_vm_end = vm_end_gap(vma);
 }
 
 void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma)
@@ -300,8 +302,14 @@ void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma)
 		prev->vm_next = next;
 	else
 		mm->mmap = next;
-	if (next)
+	if (next) {
 		next->vm_prev = prev;
+	} else {
+		if (prev)
+			mm->highest_vm_end = vm_end_gap(prev);
+		else
+			mm->highest_vm_end = 0;
+	}
 }
 
 /* Check if the vma is being used as a stack by this task */
-- 
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