[PATCH] mm/sparse: Check the return value of first_present_section_nr()

[Liam Ni <zhiguangni01@xxxxxxxxx>]

first_present_section_nr() may return -1,
which means there is no present section in system,or other errors,
so we cause panic here.

Signed-off-by: Liam Ni <zhiguangni01@xxxxxxxxx>
---
 mm/sparse.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/sparse.c b/mm/sparse.c
index b8d5d58fe240..175727e10deb 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -564,6 +564,8 @@ void __init sparse_init(void)
 	memblocks_present();
 
 	pnum_begin = first_present_section_nr();
+	if (pnum_begin == -1)
+		panic("There is no present section in system\n");
 	nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
 
 	/* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
-- 
2.25.1