定义一个内核panic问题

出现问题时的反汇编为：

/usr/src/debug/kernel-4.1.44-.aarch64/net/core/dev.c: 1780
0xffff800000860724 <__netif_receive_skb_core+420>: ldr x0, [x1,x0]
0xffff800000860728 <__netif_receive_skb_core+424>: str x0, [x29,#128]
0xffff80000086072c <__netif_receive_skb_core+428>: ldr x20, [x29,#128]
0xffff800000860730 <__netif_receive_skb_core+432>: cmp x25, x20
0xffff800000860734 <__netif_receive_skb_core+436>: sub x20, x20, #0x28
0xffff800000860738 <__netif_receive_skb_core+440>: b.eq 0xffff800000860760 <__netif_receive_skb_core+480>
/usr/src/debug/kernel-4.1.44-.aarch64/net/core/dev.c: 1781
0xffff80000086073c <__netif_receive_skb_core+444>: ldrh w0, [x20]

代码为：

static inline void deliver_ptype_list_skb(struct sk_buff *skb,
                      struct packet_type **pt,
                      struct net_device *orig_dev,
                      __be16 type,
                      struct list_head *ptype_list)
{
    struct packet_type *ptype, *pt_prev = *pt;

1780    list_for_each_entry_rcu(ptype, ptype_list, list) {
1781        if (ptype->type != type)
            continue;
        if (pt_prev)
            deliver_skb(skb, pt_prev, orig_dev);
        pt_prev = ptype;
    }
    *pt = pt_prev;
}

list_for_each_entry_rcu函数为：

#define list_for_each_entry_rcu(pos, head, member) 
    for (pos = list_entry_rcu((head)->next, typeof(*pos), member); 
        &pos->member != (head); 
        pos = list_entry_rcu(pos->member.next, typeof(*pos), member))

list_entry_rcu为：

#define list_entry_rcu(ptr, type, member) 
({ 
    typeof(*ptr) __rcu *__ptr = (typeof(*ptr) __rcu __force *)ptr; 
    container_of((typeof(ptr))rcu_dereference_raw(__ptr), type, member); 
})

container_of

#define container_of(ptr, type, member) ({            
    const typeof( ((type *)0)->member ) *__mptr = (ptr);    
    (type *)( (char *)__mptr - offsetof(type,member) );})