[PATCH v2 -next] neigh: Adjustment calculation method of neighbour path symbols

[PATCH v2 -next] neigh: Adjustment calculation method of neighbour path symbols

[Zhang Qilong]

Using size of "net//neigh/" is not clear, the use
of stitching("net/" + /neigh") should be clearer.

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
---
 net/core/neighbour.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 8e39e28b0a8d..0474e73c4f9f 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -3623,7 +3623,14 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
 	int i;
 	struct neigh_sysctl_table *t;
 	const char *dev_name_source;
-	char neigh_path[ sizeof("net//neigh/") + IFNAMSIZ + IFNAMSIZ ];
+
+	/*
+	 * The path pattern is as follows
+	 * "net/%s/neigh/%s", minusing one
+	 * is for unnecessary terminators.
+	 */
+	char neigh_path[sizeof("net/") - 1 + IFNAMSIZ +
+			sizeof("/neigh/") + IFNAMSIZ];
 	char *p_name;
 
 	t = kmemdup(&neigh_sysctl_template, sizeof(*t), GFP_KERNEL);
-- 
2.17.1

Re: [PATCH v2 -next] neigh: Adjustment calculation method of neighbour path symbols

[Jakub Kicinski]

On Mon, 26 Oct 2020 10:21:26 +0800 Zhang Qilong wrote:
> Using size of "net//neigh/" is not clear, the use
> of stitching("net/" + /neigh") should be clearer.
> 
> Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
> ---
>  net/core/neighbour.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/net/core/neighbour.c b/net/core/neighbour.c
> index 8e39e28b0a8d..0474e73c4f9f 100644
> --- a/net/core/neighbour.c
> +++ b/net/core/neighbour.c
> @@ -3623,7 +3623,14 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
>  	int i;
>  	struct neigh_sysctl_table *t;
>  	const char *dev_name_source;
> -	char neigh_path[ sizeof("net//neigh/") + IFNAMSIZ + IFNAMSIZ ];
> +
> +	/*
> +	 * The path pattern is as follows
> +	 * "net/%s/neigh/%s", minusing one
> +	 * is for unnecessary terminators.
> +	 */
> +	char neigh_path[sizeof("net/") - 1 + IFNAMSIZ +
> +			sizeof("/neigh/") + IFNAMSIZ];

Let's leave this. The code is fine, the re-factoring is not worth the 
back an forth.

>  	char *p_name;
>  
>  	t = kmemdup(&neigh_sysctl_template, sizeof(*t), GFP_KERNEL);