mm/kmemleak: move set_track_prepare() outside raw_spinlocks

set_track_prepare() will call __alloc_pages() which attempts to acquire
zone->lock(spinlocks), so move it outside object->lock(raw_spinlocks)
because it's not right to acquire spinlocks while holding raw_spinlocks in
RT mode.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Liu Shixin <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Kefeng Wang <[email protected]>
Cc: Patrick Wang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: Liu Shixin

mm/kmemleak.c

@@ -1152,6 +1152,7 @@ EXPORT_SYMBOL_GPL(kmemleak_free_percpu);
 void __ref kmemleak_update_trace(const void *ptr)
 {
 	struct kmemleak_object *object;
+	depot_stack_handle_t trace_handle;
 	unsigned long flags;
 
 	pr_debug("%s(0x%px)\n", __func__, ptr);
@@ -1168,8 +1169,9 @@ void __ref kmemleak_update_trace(const void *ptr)
 		return;
 	}
 
+	trace_handle = set_track_prepare();
 	raw_spin_lock_irqsave(&object->lock, flags);
-	object->trace_handle = set_track_prepare();
+	object->trace_handle = trace_handle;
 	raw_spin_unlock_irqrestore(&object->lock, flags);
 
 	put_object(object);