From: Eric Dumazet <edumazet@google.com>
Date: Thu, 6 Apr 2023 19:46:34 +0000 (+0000)
Subject: net: make SO_BUSY_POLL available to all users
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=48b7ea1d22ddf657e2692fb2b399138a02d31c17;p=linux.git

net: make SO_BUSY_POLL available to all users

After commit 217f69743681 ("net: busy-poll: allow preemption
in sk_busy_loop()"), a thread willing to use busy polling
is not hurting other threads anymore in a non preempt kernel.

I think it is safe to remove CAP_NET_ADMIN check.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230406194634.1804691-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/net/core/sock.c b/net/core/sock.c
index c258887953905..5440e67bcfe3b 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1396,15 +1396,10 @@ set_sndbuf:
 
 #ifdef CONFIG_NET_RX_BUSY_POLL
 	case SO_BUSY_POLL:
-		/* allow unprivileged users to decrease the value */
-		if ((val > sk->sk_ll_usec) && !sockopt_capable(CAP_NET_ADMIN))
-			ret = -EPERM;
-		else {
-			if (val < 0)
-				ret = -EINVAL;
-			else
-				WRITE_ONCE(sk->sk_ll_usec, val);
-		}
+		if (val < 0)
+			ret = -EINVAL;
+		else
+			WRITE_ONCE(sk->sk_ll_usec, val);
 		break;
 	case SO_PREFER_BUSY_POLL:
 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))