netdev - [PATCH net-next 6/6] net: __sock_gen

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Date:   Tue, 15 Nov 2022 09:11:01 +0000
From:   Eric Dumazet <edumazet@...gle.com>
To:     "David S . Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>
Cc:     netdev@...r.kernel.org, eric.dumazet@...il.com,
        Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH net-next 6/6] net: __sock_gen_cookie() cleanup

Adopt atomic64_try_cmpxchg() and remove the loop,
to make the intent more obvious.

Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
 net/core/sock_diag.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
index f7cf74cdd3db1f7f0783db88fc28fd876fbac4b6..b11593cae5a09b15a10d6ba35bccc22263cb8fc8 100644
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -25,14 +25,14 @@ DEFINE_COOKIE(sock_cookie);
 
 u64 __sock_gen_cookie(struct sock *sk)
 {
-	while (1) {
-		u64 res = atomic64_read(&sk->sk_cookie);
+	u64 res = atomic64_read(&sk->sk_cookie);
 
-		if (res)
-			return res;
-		res = gen_cookie_next(&sock_cookie);
-		atomic64_cmpxchg(&sk->sk_cookie, 0, res);
+	if (!res) {
+		u64 new = gen_cookie_next(&sock_cookie);
+
+		atomic64_try_cmpxchg(&sk->sk_cookie, &res, new);
 	}
+	return res;
 }
 
 int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie)
-- 
2.38.1.431.g37b22c650d-goog