4 files changed, 33 insertions, 2 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index a2632fd97d00..b65144c392b0 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -407,6 +407,30 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
 		access = VM_WRITE;
 	if (access == VM_WRITE)
 		flags |= FAULT_FLAG_WRITE;
+#ifdef CONFIG_PER_VMA_LOCK
+	if (!(flags & FAULT_FLAG_USER))
+		goto lock_mmap;
+	vma = lock_vma_under_rcu(mm, address);
+	if (!vma)
+		goto lock_mmap;
+	if (!(vma->vm_flags & access)) {
+		vma_end_read(vma);
+		goto lock_mmap;
+	}
+	fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK, regs);
+	vma_end_read(vma);
+	if (!(fault & VM_FAULT_RETRY)) {
+		count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
+		goto out;
+	}
+	count_vm_vma_lock_event(VMA_LOCK_RETRY);
+	/* Quick path to respond to signals */
+	if (fault_signal_pending(fault, regs)) {
+		fault = VM_FAULT_SIGNAL;
+		goto out;
+	}
+lock_mmap:
+#endif /* CONFIG_PER_VMA_LOCK */
 	mmap_read_lock(mm);
 
 	gmap = NULL;
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 5a716bdcba05..0949811761e6 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -2591,6 +2591,13 @@ int gmap_mark_unmergeable(void)
 	int ret;
 	VMA_ITERATOR(vmi, mm, 0);
 
+	/*
+	 * Make sure to disable KSM (if enabled for the whole process or
+	 * individual VMAs). Note that nothing currently hinders user space
+	 * from re-enabling it.
+	 */
+	clear_bit(MMF_VM_MERGE_ANY, &mm->flags);
+
 	for_each_vma(vmi, vma) {
 		/* Copy vm_flags to avoid partial modifications in ksm_madvise */
 		vm_flags = vma->vm_flags;
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index c299a18273ff..c718f2a0de94 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -273,7 +273,7 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
 
 	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
 	info.length = len;
-	info.low_limit = max(PAGE_SIZE, mmap_min_addr);
+	info.low_limit = PAGE_SIZE;
 	info.high_limit = current->mm->mmap_base;
 	info.align_mask = PAGE_MASK & ~huge_page_mask(h);
 	info.align_offset = 0;
diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index 3327c47bc181..fc9a7dc26c5e 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -136,7 +136,7 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp, unsigned long ad
 
 	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
 	info.length = len;
-	info.low_limit = max(PAGE_SIZE, mmap_min_addr);
+	info.low_limit = PAGE_SIZE;
 	info.high_limit = mm->mmap_base;
 	if (filp || (flags & MAP_SHARED))
 		info.align_mask = MMAP_ALIGN_MASK << PAGE_SHIFT;