ANDROID: vendor_hooks: add hooks for slab memory leak debugging

Add hooks and additional fields in vm_struct and track structs
to store and report additional information for slab memory leak
debugging.

Bug: 184928480

Change-Id: I6897a6a98d4eaaea492673cefd4111a7ba741940
Signed-off-by: Liujie Xie <xieliujie@oppo.com>

mm/slab.h

@@ -46,6 +46,7 @@ struct kmem_cache {
 #include <linux/kmemleak.h>
 #include <linux/random.h>
 #include <linux/sched/mm.h>
+#include <linux/android_vendor.h>
 
 /*
  * State of the slab allocator.
@@ -104,6 +105,9 @@ struct track {
 	int cpu;		/* Was running on cpu */
 	int pid;		/* Pid context */
 	unsigned long when;	/* When did the operation occur */
+#ifdef CONFIG_STACKTRACE
+	ANDROID_OEM_DATA(1);
+#endif
 };
 
 enum track_item { TRACK_ALLOC, TRACK_FREE };