linux-kernel - Re: [PATCH -next] audit: Use list_move instead of list_del/list_add

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Message-ID: <20210608150203.GB2268484@madcap2.tricolour.ca>
Date:   Tue, 8 Jun 2021 11:02:03 -0400
From:   Richard Guy Briggs <rgb@...hat.com>
To:     Baokun Li <libaokun1@...wei.com>
Cc:     linux-kernel@...r.kernel.org, Paul Moore <paul@...l-moore.com>,
        Eric Paris <eparis@...hat.com>, Hulk Robot <hulkci@...wei.com>,
        kernel-janitors@...r.kernel.org, yuehaibing@...wei.com,
        yangjihong1@...wei.com, linux-audit@...hat.com, yukuai3@...wei.com,
        weiyongjun1@...wei.com
Subject: Re: [PATCH -next] audit: Use list_move instead of list_del/list_add

On 2021-06-08 11:11, Baokun Li wrote:
> Using list_move() instead of list_del() + list_add().

This should be slightly more efficient since there is no need to poison
the pointers.

> Reported-by: Hulk Robot <hulkci@...wei.com>
> Signed-off-by: Baokun Li <libaokun1@...wei.com>

Acked-by: Richard Guy Briggs <rgb@...hat.com>

> ---
>  kernel/audit_tree.c | 12 ++++--------
>  1 file changed, 4 insertions(+), 8 deletions(-)
> 
> diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
> index 6c91902f4f45..b2be4e978ba3 100644
> --- a/kernel/audit_tree.c
> +++ b/kernel/audit_tree.c
> @@ -689,8 +689,7 @@ void audit_trim_trees(void)
>  
>  		tree = container_of(cursor.next, struct audit_tree, list);
>  		get_tree(tree);
> -		list_del(&cursor);
> -		list_add(&cursor, &tree->list);
> +		list_move(&cursor, &tree->list);
>  		mutex_unlock(&audit_filter_mutex);
>  
>  		err = kern_path(tree->pathname, 0, &path);
> @@ -899,8 +898,7 @@ int audit_tag_tree(char *old, char *new)
>  
>  		tree = container_of(cursor.next, struct audit_tree, list);
>  		get_tree(tree);
> -		list_del(&cursor);
> -		list_add(&cursor, &tree->list);
> +		list_move(&cursor, &tree->list);
>  		mutex_unlock(&audit_filter_mutex);
>  
>  		err = kern_path(tree->pathname, 0, &path2);
> @@ -925,8 +923,7 @@ int audit_tag_tree(char *old, char *new)
>  		mutex_lock(&audit_filter_mutex);
>  		spin_lock(&hash_lock);
>  		if (!tree->goner) {
> -			list_del(&tree->list);
> -			list_add(&tree->list, &tree_list);
> +			list_move(&tree->list, &tree_list);
>  		}
>  		spin_unlock(&hash_lock);
>  		put_tree(tree);
> @@ -937,8 +934,7 @@ int audit_tag_tree(char *old, char *new)
>  
>  		tree = container_of(barrier.prev, struct audit_tree, list);
>  		get_tree(tree);
> -		list_del(&tree->list);
> -		list_add(&tree->list, &barrier);
> +		list_move(&tree->list, &barrier);
>  		mutex_unlock(&audit_filter_mutex);
>  
>  		if (!failed) {
> 
> 
> --
> Linux-audit mailing list
> Linux-audit@...hat.com
> https://listman.redhat.com/mailman/listinfo/linux-audit

- RGB

--
Richard Guy Briggs <rgb@...hat.com>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635

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