From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 155DBC25B6B for ; Wed, 25 Oct 2023 21:26:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230106AbjJYV0K (ORCPT ); Wed, 25 Oct 2023 17:26:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49374 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229881AbjJYV0I (ORCPT ); Wed, 25 Oct 2023 17:26:08 -0400 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 99363192; Wed, 25 Oct 2023 14:26:06 -0700 (PDT) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, fw@strlen.de Subject: [PATCH net-next 07/19] netfilter: conntrack: switch connlabels to atomic_t Date: Wed, 25 Oct 2023 23:25:43 +0200 Message-Id: <20231025212555.132775-8-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20231025212555.132775-1-pablo@netfilter.org> References: <20231025212555.132775-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org From: Florian Westphal The spinlock is back from the day when connabels did not have a fixed size and reallocation had to be supported. Remove it. This change also allows to call the helpers from softirq or timers without deadlocks. Also add WARN()s to catch refcounting imbalances. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_labels.h | 2 +- include/net/netns/conntrack.h | 2 +- net/netfilter/nf_conntrack_labels.c | 17 ++++++++--------- 3 files changed, 10 insertions(+), 11 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_labels.h b/include/net/netfilter/nf_conntrack_labels.h index fcb19a4e8f2b..6903f72bcc15 100644 --- a/include/net/netfilter/nf_conntrack_labels.h +++ b/include/net/netfilter/nf_conntrack_labels.h @@ -39,7 +39,7 @@ static inline struct nf_conn_labels *nf_ct_labels_ext_add(struct nf_conn *ct) #ifdef CONFIG_NF_CONNTRACK_LABELS struct net *net = nf_ct_net(ct); - if (net->ct.labels_used == 0) + if (atomic_read(&net->ct.labels_used) == 0) return NULL; return nf_ct_ext_add(ct, NF_CT_EXT_LABELS, GFP_ATOMIC); diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h index 1f463b3957c7..bae914815aa3 100644 --- a/include/net/netns/conntrack.h +++ b/include/net/netns/conntrack.h @@ -107,7 +107,7 @@ struct netns_ct { struct nf_ct_event_notifier __rcu *nf_conntrack_event_cb; struct nf_ip_net nf_ct_proto; #if defined(CONFIG_NF_CONNTRACK_LABELS) - unsigned int labels_used; + atomic_t labels_used; #endif }; #endif diff --git a/net/netfilter/nf_conntrack_labels.c b/net/netfilter/nf_conntrack_labels.c index 6e70e137a0a6..6c46aad23313 100644 --- a/net/netfilter/nf_conntrack_labels.c +++ b/net/netfilter/nf_conntrack_labels.c @@ -11,8 +11,6 @@ #include #include -static DEFINE_SPINLOCK(nf_connlabels_lock); - static int replace_u32(u32 *address, u32 mask, u32 new) { u32 old, tmp; @@ -60,23 +58,24 @@ EXPORT_SYMBOL_GPL(nf_connlabels_replace); int nf_connlabels_get(struct net *net, unsigned int bits) { + int v; + if (BIT_WORD(bits) >= NF_CT_LABELS_MAX_SIZE / sizeof(long)) return -ERANGE; - spin_lock(&nf_connlabels_lock); - net->ct.labels_used++; - spin_unlock(&nf_connlabels_lock); - BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE / sizeof(long) >= U8_MAX); + v = atomic_inc_return_relaxed(&net->ct.labels_used); + WARN_ON_ONCE(v <= 0); + return 0; } EXPORT_SYMBOL_GPL(nf_connlabels_get); void nf_connlabels_put(struct net *net) { - spin_lock(&nf_connlabels_lock); - net->ct.labels_used--; - spin_unlock(&nf_connlabels_lock); + int v = atomic_dec_return_relaxed(&net->ct.labels_used); + + WARN_ON_ONCE(v < 0); } EXPORT_SYMBOL_GPL(nf_connlabels_put); -- 2.30.2