From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sipsolutions.net (s3.sipsolutions.net [168.119.38.16]) (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 D264D539790; Tue, 22 Sep 2026 11:10:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.38.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790075412; cv=none; b=DL+EIaM5XYDpjkR39JU2XpgGv6HfTCaKGzrX8+POrgsDMVx70bDLHDkSMtCd3AIoNpAT9ASY6aWu+XaBT5+mSmhYY3Tfn9ihwbANGHmuHcPicfzAp94tQyoR+XDH9NvZ4DNbqN6HRWG+MRBQWCp5Vs+gA4w63cXUE8PbVhbRtjs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790075412; c=relaxed/simple; bh=gEMS3jWqMG+zrAYTQfEyWwP8W1cn3KnjMjRQEkuaZxE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jCVMSDo8p9WUSxgyKdAJCOxiklpNt9DbS6X7Cj6csiHGCtliVDGPF4dohGmI4y2jF8ALTKaUF8IpJy636zUh4iHW3yFnTFA8ThjbvzMvHbSXN5RsqqyKiYln9Q7goaeIZXrJNKcNG1WChM40oW+C047T3H7nxUHGWvePEJ7VlP4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=permerror header.from=sipsolutions.net; spf=pass smtp.mailfrom=sipsolutions.net; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b=PCV+V2bD; arc=none smtp.client-ip=168.119.38.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=permerror header.from=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="PCV+V2bD" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Content-Type:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=8PaboYWla8SkdWZNCuEDUE3IfbM43aIIHI27y/D6iQ0=; t=1790075409; x=1791285009; b=PCV+V2bDdEL8UUeD5lal6rdjRVwHjBcDpAH8ygca21jyG9N Jib+5xq+LH1DK5yJYr9GgOPMSy0F3hKpg9NEOW2fS/J3lPRRbwR7CDBKrwpXiKz2DyOePWcB4DhRy unb9FCCoqKD3D+gaXQPUm+Urrh15+uGINKsFFk9egJ1+5hSs8wce0cfu5uk/wQWYTKLAn6EKYiRt3 /yOtsmfqpbUq27dCTWPwW3UKWAF70Wdpa4zdU3KSzxRyp0adtrplzaXVav0mesC5iC5OxOmYN4Jds U70drUXTNmJ8l/6RXCvKvIWsgCpCl4A8Jf+vMXHk+7lOvWxpzR23a/cE+wLU+oiA==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__ECDSA_SECP256R1_SHA256__AES_256_GCM:256) (Exim 4.98.2) (envelope-from ) id 1x8yNw-00000006qo8-3dtU; Tue, 22 Sep 2026 13:10:05 +0200 From: Johannes Berg To: linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Ilya Maximets , Matthieu Baerts , Aaron Conole , Eelco Chaudron , dev@openvswitch.org, Adrian Moreno , Antoine Tenart , Johannes Berg Subject: [PATCH v7 4/4] net: drop_monitor: use drop_reason_lookup() Date: Tue, 22 Sep 2026 13:08:43 +0200 Message-ID: <20260922110955.363677-10-johannes@sipsolutions.net> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260922110955.363677-6-johannes@sipsolutions.net> References: <20260922110955.363677-6-johannes@sipsolutions.net> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Johannes Berg Now that we have drop_reason_lookup(), we can just use it for drop_monitor as well, rather than exporting the list itself. Signed-off-by: Johannes Berg --- v7: don't hide drop_reason_show() prototype (sashiko, but it got it the wrong way around) --- include/net/dropreason.h | 5 +---- net/core/drop_monitor.c | 20 +++++--------------- net/core/skbuff.c | 6 +++--- 3 files changed, 9 insertions(+), 22 deletions(-) diff --git a/include/net/dropreason.h b/include/net/dropreason.h index dc4a60130c09..537428c72642 100644 --- a/include/net/dropreason.h +++ b/include/net/dropreason.h @@ -38,12 +38,9 @@ struct drop_reason_list { size_t n_reasons; }; -/* Note: due to dynamic registrations, access must be under RCU */ -extern const struct drop_reason_list __rcu * -drop_reasons_by_subsys[SKB_DROP_REASON_SUBSYS_NUM]; +const char *drop_reason_lookup(unsigned long long value); #ifdef CONFIG_TRACEPOINTS -const char *drop_reason_lookup(unsigned long long value); void drop_reason_show(struct seq_file *m); #endif diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index edc660778408..5aa7692c5df2 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -611,9 +611,8 @@ static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb, size_t payload_len) { struct net_dm_skb_cb *cb = NET_DM_SKB_CB(skb); - const struct drop_reason_list *list = NULL; - unsigned int subsys, subsys_reason; char buf[NET_DM_MAX_SYMBOL_LEN]; + const char *reason_str; struct nlattr *attr; void *hdr; int rc; @@ -631,19 +630,10 @@ static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb, goto nla_put_failure; rcu_read_lock(); - subsys = u32_get_bits(cb->reason, SKB_DROP_REASON_SUBSYS_MASK); - if (subsys < SKB_DROP_REASON_SUBSYS_NUM) - list = rcu_dereference(drop_reasons_by_subsys[subsys]); - subsys_reason = cb->reason & ~SKB_DROP_REASON_SUBSYS_MASK; - if (!list || - subsys_reason >= list->n_reasons || - !list->reasons[subsys_reason] || - strlen(list->reasons[subsys_reason]) > NET_DM_MAX_REASON_LEN) { - list = rcu_dereference(drop_reasons_by_subsys[SKB_DROP_REASON_SUBSYS_CORE]); - subsys_reason = SKB_DROP_REASON_NOT_SPECIFIED; - } - if (nla_put_string(msg, NET_DM_ATTR_REASON, - list->reasons[subsys_reason])) { + reason_str = drop_reason_lookup(cb->reason); + if (unlikely(!reason_str)) + reason_str = drop_reason_lookup(SKB_DROP_REASON_NOT_SPECIFIED); + if (nla_put_string(msg, NET_DM_ATTR_REASON, reason_str)) { rcu_read_unlock(); goto nla_put_failure; } diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 8c8f7a05dea4..c675d3330937 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -148,13 +148,11 @@ static const struct drop_reason_list drop_reasons_core = { .n_reasons = ARRAY_SIZE(drop_reasons), }; -const struct drop_reason_list __rcu * +static const struct drop_reason_list __rcu * drop_reasons_by_subsys[SKB_DROP_REASON_SUBSYS_NUM] = { [SKB_DROP_REASON_SUBSYS_CORE] = RCU_INITIALIZER(&drop_reasons_core), }; -EXPORT_SYMBOL(drop_reasons_by_subsys); -#ifdef CONFIG_TRACEPOINTS const char *drop_reason_lookup(unsigned long long value) { unsigned long long subsys_id = value >> SKB_DROP_REASON_SUBSYS_SHIFT; @@ -171,7 +169,9 @@ const char *drop_reason_lookup(unsigned long long value) return NULL; return subsys->reasons[reason]; } +EXPORT_SYMBOL(drop_reason_lookup); +#ifdef CONFIG_TRACEPOINTS void drop_reason_show(struct seq_file *m) { u32 subsys_id; -- 2.55.0