uprobes: Use kzalloc to allocate xol area

To prevent unitialized members, use kzalloc to allocate
the xol area.

Fixes: b059a45 ("x86/vdso: Add mremap hook to vm_special_mapping")
Signed-off-by: Sven Schnelle <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Oleg Nesterov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: svens-s390

kernel/events/uprobes.c

@@ -1489,7 +1489,7 @@ static struct xol_area *__create_xol_area(unsigned long vaddr)
 	struct xol_area *area;
 	void *insns;
 
-	area = kmalloc(sizeof(*area), GFP_KERNEL);
+	area = kzalloc(sizeof(*area), GFP_KERNEL);
 	if (unlikely(!area))
 		goto out;
 
@@ -1499,7 +1499,6 @@ static struct xol_area *__create_xol_area(unsigned long vaddr)
 		goto free_area;
 
 	area->xol_mapping.name = "[uprobes]";
-	area->xol_mapping.fault = NULL;
 	area->xol_mapping.pages = area->pages;
 	area->pages[0] = alloc_page(GFP_HIGHUSER);
 	if (!area->pages[0])