s390/vmem: fix vmem_add_range for 4-level paging

The kernel currently crashes if 4-level paging is used. Add missing
p4d_populate for just allocated pud entry.

Fixes: 3e0d3e408e63 ("s390/vmem: consolidate vmem_add_range() and vmem_remove_range()")
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 1aed1a4..eddf71c 100644 (file)
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -402,6 +402,7 @@ static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end,
                        pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
                        if (!pud)
                                goto out;
+                       p4d_populate(&init_mm, p4d, pud);
                }
                ret = modify_pud_table(p4d, addr, next, add, direct);
                if (ret)