mm/madvise: use vma_find() instead of vma linked list

madvise_walk_vmas() no longer uses linked list.

Link: https://lkml.kernel.org/r/20220906194824.2110408-55-Liam.Howlett@oracle.comSigned-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
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: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/madvise.c

@@ -1245,7 +1245,7 @@ int madvise_walk_vmas(struct mm_struct *mm, unsigned long start,
 		if (start >= end)
 			break;
 		if (prev)
-			vma = prev->vm_next;
+			vma = find_vma(mm, prev->vm_end);
 		else	/* madvise_remove dropped mmap_lock */
 			vma = find_vma(mm, start);
 	}