ppc book3s64: Fix subpage rcu lock

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

diff --git a/arch/powerpc/mm/book3s64/subpage_prot.c b/arch/powerpc/mm/book3s64/subpage_prot.c
index ada1531f81be999e390055fb2314da3575d581fb..51722199408e7da662019ee68ef5c8f7b2c0f69f 100644 (file)
--- a/arch/powerpc/mm/book3s64/subpage_prot.c
+++ b/arch/powerpc/mm/book3s64/subpage_prot.c
@@ -155,10 +155,12 @@ static void subpage_mark_vma_nohuge(struct mm_struct *mm, unsigned long addr,
         * We don't try too hard, we just mark all the vma in that range
         * VM_NOHUGEPAGE and split them.
         */
+       rcu_read_lock();
        mas_for_each(&mas, vma, addr + len) {
                vma->vm_flags |= VM_NOHUGEPAGE;
                walk_page_vma(vma, &subpage_walk_ops, NULL);
        }
+       rcu_read_unlock();
 }
 #else
 static void subpage_mark_vma_nohuge(struct mm_struct *mm, unsigned long addr,