Set the next of the returned node of llist_del_first
to NULL, which can prevent subsequent nodes in llist
from being exposed, and is more consistent with the
logic of this interface.

Signed-off-by: liqiang <liqiang64@huawei.com>
---
 lib/llist.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/llist.c b/lib/llist.c
index f21d0cf..c33fff5 100644
--- a/lib/llist.c
+++ b/lib/llist.c
@@ -61,6 +61,7 @@ struct llist_node *llist_del_first(struct llist_head *head)
 		next = READ_ONCE(entry->next);
 	} while (!try_cmpxchg(&head->first, &entry, next));
 
+	entry->next = NULL;
 	return entry;
 }
 EXPORT_SYMBOL_GPL(llist_del_first);
-- 
2.23.0.windows.1

liqiang <liqiang64@huawei.com> writes:

> Set the next of the returned node of llist_del_first
> to NULL, which can prevent subsequent nodes in llist
> from being exposed, and is more consistent with the
> logic of this interface.
>
> Signed-off-by: liqiang <liqiang64@huawei.com>
> ---
>  lib/llist.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/lib/llist.c b/lib/llist.c
> index f21d0cf..c33fff5 100644
> --- a/lib/llist.c
> +++ b/lib/llist.c
> @@ -61,6 +61,7 @@ struct llist_node *llist_del_first(struct llist_head *head)
>  		next = READ_ONCE(entry->next);
>  	} while (!try_cmpxchg(&head->first, &entry, next));
>  
> +	entry->next = NULL;
>  	return entry;
>  }
>  EXPORT_SYMBOL_GPL(llist_del_first);

This isn't needed for functionality correctness.  Many users of llist
ask for performance.  So, it may be better to let the users to decide
whether to set entry->next to NULL.

--
Best Regards,
Huang, Ying

在 2024/2/18 15:43, Huang, Ying 写道:
> liqiang <liqiang64@huawei.com> writes:
> 
>> Set the next of the returned node of llist_del_first
>> to NULL, which can prevent subsequent nodes in llist
>> from being exposed, and is more consistent with the
>> logic of this interface.
>>
>> Signed-off-by: liqiang <liqiang64@huawei.com>
>> ---
>>  lib/llist.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/lib/llist.c b/lib/llist.c
>> index f21d0cf..c33fff5 100644
>> --- a/lib/llist.c
>> +++ b/lib/llist.c
>> @@ -61,6 +61,7 @@ struct llist_node *llist_del_first(struct llist_head *head)
>>  		next = READ_ONCE(entry->next);
>>  	} while (!try_cmpxchg(&head->first, &entry, next));
>>  
>> +	entry->next = NULL;
>>  	return entry;
>>  }
>>  EXPORT_SYMBOL_GPL(llist_del_first);
> 
> This isn't needed for functionality correctness.  Many users of llist
> ask for performance.  So, it may be better to let the users to decide
> whether to set entry->next to NULL.
> 

Ok, get it, thanks for your reply.

-- 
Best regards,
Li Qiang