um: remove vma linked list walk

Use the VMA iterator instead.

Link: https://lkml.kernel.org/r/20220906194824.2110408-40-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
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: 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>

arch/um/kernel/tlb.c

@@ -584,21 +584,19 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
 
 void flush_tlb_mm(struct mm_struct *mm)
 {
-	struct vm_area_struct *vma = mm->mmap;
+	struct vm_area_struct *vma;
+	VMA_ITERATOR(vmi, mm, 0);
 
-	while (vma != NULL) {
+	for_each_vma(vmi, vma)
 		fix_range(mm, vma->vm_start, vma->vm_end, 0);
-		vma = vma->vm_next;
-	}
 }
 
 void force_flush_all(void)
 {
 	struct mm_struct *mm = current->mm;
-	struct vm_area_struct *vma = mm->mmap;
+	struct vm_area_struct *vma;
+	VMA_ITERATOR(vmi, mm, 0);
 
-	while (vma != NULL) {
+	for_each_vma(vmi, vma)
 		fix_range(mm, vma->vm_start, vma->vm_end, 1);
-		vma = vma->vm_next;
-	}
 }