From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 49EF1219E8; Mon, 13 Oct 2025 15:32:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760369549; cv=none; b=r4pMCvOz3FbF0bO6BBhb/OQt4CiVb8FxjfGsoCRH/RBSN4Y6/4YKS88XZJx3tKWabWqCyfBkngy4SA9SvmDymkO20ZfR2vpx62obHMr7qkRmy56PgwEYrZhfTdR/mzbHL0CuY34itEFi0w0TWvyMSbuW2VFmTo5Pzy/pi22e7BY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760369549; c=relaxed/simple; bh=J2e8GPTota0J29rmm8NDsAaTUO7DduoQtBTx4RbgCNo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nSHtxZ0d0BFY7jLmuO1FAFe/+xTs9pxaR2U2xAU2cMDNV/Tu8kTByNdL58Hmi5s0uoMzyZ+AHw9H3lR91uaa3qnOJi7mzF9v9AB+AjCi5bXJMVo4FIT4TSBaSD4yEzg9KjMXjFVobBlvIVC1uqgg4MRrANyOOzQiwSh63au1RUQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TvF6Dwr3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="TvF6Dwr3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC629C4CEE7; Mon, 13 Oct 2025 15:32:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760369549; bh=J2e8GPTota0J29rmm8NDsAaTUO7DduoQtBTx4RbgCNo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TvF6Dwr33YsH4bviA6pcoyGIQ9SPXvRf5unpBypkhzL2jNWO88GA0YmLQUxTT7z68 jMGPVUiPVQAYV/yOyM45TU3v6ukIbLaEzoX48XF4nqnlLabIfHA9EfVdJ2izxglgXT bMmK4i6uTLQqW6Sn0Ji4lebP8e04HXHMCDLua2rQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , David Ahern , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.17 286/563] ipv6: start using dst_dev_rcu() Date: Mon, 13 Oct 2025 16:42:27 +0200 Message-ID: <20251013144421.631230456@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251013144411.274874080@linuxfoundation.org> References: <20251013144411.274874080@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit b775ecf1655cedbc465fd6699ab18a2bc4e7a352 ] Refactor icmpv6_xrlim_allow() and ip6_dst_hoplimit() so that we acquire rcu_read_lock() a bit longer to be able to use dst_dev_rcu() instead of dst_dev(). __ip6_rt_update_pmtu() and rt6_do_redirect can directly use dst_dev_rcu() in sections already holding rcu_read_lock(). Small changes to use dst_dev_net_rcu() in ip6_default_advmss(), ipv6_sock_ac_join(), ip6_mc_find_dev() and ndisc_send_skb(). Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://patch.msgid.link/20250828195823.3958522-3-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/anycast.c | 2 +- net/ipv6/icmp.c | 6 +++--- net/ipv6/mcast.c | 2 +- net/ipv6/ndisc.c | 2 +- net/ipv6/output_core.c | 8 +++++--- net/ipv6/route.c | 7 +++---- 6 files changed, 14 insertions(+), 13 deletions(-) diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c index f8a8e46286b8e..52599584422bf 100644 --- a/net/ipv6/anycast.c +++ b/net/ipv6/anycast.c @@ -104,7 +104,7 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr) rcu_read_lock(); rt = rt6_lookup(net, addr, NULL, 0, NULL, 0); if (rt) { - dev = dst_dev(&rt->dst); + dev = dst_dev_rcu(&rt->dst); netdev_hold(dev, &dev_tracker, GFP_ATOMIC); ip6_rt_put(rt); } else if (ishost) { diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 44550957fd4e3..95cdd4cacb004 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -209,7 +209,8 @@ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, * this lookup should be more aggressive (not longer than timeout). */ dst = ip6_route_output(net, sk, fl6); - dev = dst_dev(dst); + rcu_read_lock(); + dev = dst_dev_rcu(dst); if (dst->error) { IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); @@ -224,11 +225,10 @@ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, if (rt->rt6i_dst.plen < 128) tmo >>= ((128 - rt->rt6i_dst.plen)>>5); - rcu_read_lock(); peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr); res = inet_peer_xrlim_allow(peer, tmo); - rcu_read_unlock(); } + rcu_read_unlock(); if (!res) __ICMP6_INC_STATS(net, ip6_dst_idev(dst), ICMP6_MIB_RATELIMITHOST); diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c index 55c49dc14b1bd..016b572e7d6f0 100644 --- a/net/ipv6/mcast.c +++ b/net/ipv6/mcast.c @@ -180,7 +180,7 @@ static struct net_device *ip6_mc_find_dev(struct net *net, rcu_read_lock(); rt = rt6_lookup(net, group, NULL, 0, NULL, 0); if (rt) { - dev = dst_dev(&rt->dst); + dev = dst_dev_rcu(&rt->dst); dev_hold(dev); ip6_rt_put(rt); } diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 7d5abb3158ec9..d6bb1e2f6192e 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -505,7 +505,7 @@ void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr, ip6_nd_hdr(skb, saddr, daddr, READ_ONCE(inet6_sk(sk)->hop_limit), skb->len); - dev = dst_dev(dst); + dev = dst_dev_rcu(dst); idev = __in6_dev_get(dev); IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS); diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c index d21fe27fe21e3..1c9b283a4132d 100644 --- a/net/ipv6/output_core.c +++ b/net/ipv6/output_core.c @@ -104,18 +104,20 @@ EXPORT_SYMBOL(ip6_find_1stfragopt); int ip6_dst_hoplimit(struct dst_entry *dst) { int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); + + rcu_read_lock(); if (hoplimit == 0) { - struct net_device *dev = dst_dev(dst); + struct net_device *dev = dst_dev_rcu(dst); struct inet6_dev *idev; - rcu_read_lock(); idev = __in6_dev_get(dev); if (idev) hoplimit = READ_ONCE(idev->cnf.hop_limit); else hoplimit = READ_ONCE(dev_net(dev)->ipv6.devconf_all->hop_limit); - rcu_read_unlock(); } + rcu_read_unlock(); + return hoplimit; } EXPORT_SYMBOL(ip6_dst_hoplimit); diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 3299cfa12e21c..3371f16b7a3e6 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2943,7 +2943,7 @@ static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk, if (res.f6i->nh) { struct fib6_nh_match_arg arg = { - .dev = dst_dev(dst), + .dev = dst_dev_rcu(dst), .gw = &rt6->rt6i_gateway, }; @@ -3238,7 +3238,6 @@ EXPORT_SYMBOL_GPL(ip6_sk_redirect); static unsigned int ip6_default_advmss(const struct dst_entry *dst) { - struct net_device *dev = dst_dev(dst); unsigned int mtu = dst_mtu(dst); struct net *net; @@ -3246,7 +3245,7 @@ static unsigned int ip6_default_advmss(const struct dst_entry *dst) rcu_read_lock(); - net = dev_net_rcu(dev); + net = dst_dev_net_rcu(dst); if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss) mtu = net->ipv6.sysctl.ip6_rt_min_advmss; @@ -4301,7 +4300,7 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu if (res.f6i->nh) { struct fib6_nh_match_arg arg = { - .dev = dst_dev(dst), + .dev = dst_dev_rcu(dst), .gw = &rt->rt6i_gateway, }; -- 2.51.0