Re: [PATCH net-next] netlink: gc useless variable in nlmsg_attrdata()

On Thu, Aug 12, 2021 at 03:05:52PM -0700, Jakub Kicinski wrote:

On Fri, 13 Aug 2021 00:24:01 +0300 Alexey Dobriyan wrote:

quoted

Kernel permits pointer arithmetic on "void*" so might as well use it
without casts back and forth.

But why change existing code? It's perfectly fine, right?

It is harder to read (marginally of course).

quoted

--- a/include/net/netlink.h
+++ b/include/net/netlink.h

@@ -587,8 +587,7 @@ static inline int nlmsg_len(const struct nlmsghdr *nlh)
 static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
 					    int hdrlen)
 {
-	unsigned char *data = nlmsg_data(nlh);
-	return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
+	return nlmsg_data(nlh) + NLMSG_ALIGN(hdrlen);
 }
 
 /**