2 files changed, 12 insertions, 4 deletions

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 796c9320c709..5d8324cd866b 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -505,6 +505,9 @@ static int gmap_connect_pgtable(unsigned long address, unsigned long segment,
         if (!pmd_present(*pmd) &&
             __pte_alloc(mm, vma, pmd, vmaddr))
                 return -ENOMEM;
+        /* large pmds cannot yet be handled */
+        if (pmd_large(*pmd))
+                return -EFAULT;
         /* pmd now points to a valid segment table entry. */
         rmap = kmalloc(sizeof(*rmap), GFP_KERNEL|__GFP_REPEAT);
         if (!rmap)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 6ac89e9f82ef..a2f4981418fc 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1891,17 +1891,22 @@ out:
 int hugepage_madvise(struct vm_area_struct *vma,
                      unsigned long *vm_flags, int advice)
 {
-        struct mm_struct *mm = vma->vm_mm;
-
         switch (advice) {
         case MADV_HUGEPAGE:
+#ifdef CONFIG_S390
+                /*
+                 * qemu blindly sets MADV_HUGEPAGE on all allocations, but s390
+                 * can't handle this properly after s390_enable_sie, so we simply
+                 * ignore the madvise to prevent qemu from causing a SIGSEGV.
+                 */
+                if (mm_has_pgste(vma->vm_mm))
+                        return 0;
+#endif
                 /*
                  * Be somewhat over-protective like KSM for now!
                  */
                 if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP))
                         return -EINVAL;
-                if (mm->def_flags & VM_NOHUGEPAGE)
-                        return -EINVAL;
                 *vm_flags &= ~VM_NOHUGEPAGE;
                 *vm_flags |= VM_HUGEPAGE;
                 /*