From nobody Tue Jun 30 21:22:29 2026 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 BF01AC43217 for ; Sun, 9 Jan 2022 06:38:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235229AbiAIGh0 (ORCPT ); Sun, 9 Jan 2022 01:37:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235220AbiAIGhZ (ORCPT ); Sun, 9 Jan 2022 01:37:25 -0500 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35D57C061401; Sat, 8 Jan 2022 22:37:25 -0800 (PST) Received: by mail-pj1-x102d.google.com with SMTP id 59-20020a17090a09c100b001b34a13745eso11359656pjo.5; Sat, 08 Jan 2022 22:37:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=+Way90yUz+/oARc0V+ElMdCYBNNb7orbnuEP+2suGKw=; b=gNqXY4fk14C8cThWFuzOgCWn2id4XYgRUgBYjlNWmxwjMt7SrXBKqWNp4xVf44l8Il FkEjsly7mSkilUzyexxtkHw7shNBYTmrffzJ7gxh+MpZeWOZhPnM8v7dWwVXZbABw1LV RUgh6lp3e0puwCEvIInVBTa8nNlX7a56TXe/tQeIix2CLTQCXUNZwV3LzDqzNkcr81tD VhfRz1r6dG8SEKRzIJWvKxa+w+HQ1B5vsU5iFSuRy626pVz8k/MMZG9up+CkCSJXHjx4 qsEHueT+pZxHvBZgFuKnPtrN1Ovyr9U3m9pjifGnRL6Kiqofog2YoTT/uSfTCgi3Dj6J ngoA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=+Way90yUz+/oARc0V+ElMdCYBNNb7orbnuEP+2suGKw=; b=XXspmUZUH2CZLw4gKVMeMyCTQxoF0xXJrU4BRlUsQ9ZPlghlNjC6pVxJXnGT+gejS7 ecHVBEGV1QZbhEGRvRMbL2s0N0pH0h25aWdw2R47vbHWlsDMdxzgRpkAQfsSvCusOu56 RTRnkcok7Sl31yEV72cYZXI6qS9cALkKJ6DpaPqyo84X2InX5/DlNULZloX7vZovAyWh NHWR7/WtbX4ibpO8oEdaSQO8uflbufPpzvfpzVWJZDcun8h/wIkNYe2r0vlm1c0GlDR+ L7aOCAmkDTfK95TbBPEGxP4Aq+yXE6ZjOWM9unWBQBPEvQ0gbnaQ4UWJ8fb9vZ9Sss1V 6E3A== X-Gm-Message-State: AOAM532R0dznIMSSs8vX/b2ZaJhEH5FavhOo0aqiPSJVIXpb+FUw+SrG J2GAKhuiTChg/VpIcxfCWTKbmk2cT2U= X-Google-Smtp-Source: ABdhPJw80g9m/42eGalDFyQ+9uLUwf4qBPbQwsfRb/h150WFC9fJ3B23cGoq1DmNPZUottDaf3fDSA== X-Received: by 2002:a17:90b:688:: with SMTP id m8mr18207838pjz.62.1641710244689; Sat, 08 Jan 2022 22:37:24 -0800 (PST) Received: from localhost.localdomain ([43.132.141.4]) by smtp.gmail.com with ESMTPSA id my5sm5892042pjb.5.2022.01.08.22.37.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 08 Jan 2022 22:37:24 -0800 (PST) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: rostedt@goodmis.org, dsahern@kernel.org Cc: mingo@redhat.com, davem@davemloft.net, kuba@kernel.org, nhorman@tuxdriver.com, edumazet@google.com, yoshfuji@linux-ipv6.org, alobakin@pm.me, willemb@google.com, cong.wang@bytedance.com, keescook@chromium.org, pabeni@redhat.com, talalahmad@google.com, haokexin@gmail.com, ilias.apalodimas@linaro.org, memxor@gmail.com, atenart@kernel.org, bigeasy@linutronix.de, weiwan@google.com, arnd@arndb.de, vvs@virtuozzo.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, jonathan.lemon@gmail.com, imagedong@tencent.com Subject: [PATCH v4 net-next 1/3] net: skb: introduce kfree_skb_reason() Date: Sun, 9 Jan 2022 14:36:26 +0800 Message-Id: <20220109063628.526990-2-imagedong@tencent.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220109063628.526990-1-imagedong@tencent.com> References: <20220109063628.526990-1-imagedong@tencent.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Menglong Dong Introduce the interface kfree_skb_reason(), which is able to pass the reason why the skb is dropped to 'kfree_skb' tracepoint. Add the 'reason' field to 'trace_kfree_skb', therefor user can get more detail information about abnormal skb with 'drop_monitor' or eBPF. All drop reasons are defined in the enum 'skb_drop_reason', and they will be print as string in 'kfree_skb' tracepoint in format of 'reason: XXX'. ( Maybe the reasons should be defined in a uapi header file, so that user space can use them? ) Signed-off-by: Menglong Dong --- v4: - fix some code style in skb.h v3: - rename kfree_skb_with_reason() to kfree_skb_reason() - turn kfree_skb() into a static inline calling kfree_skb_reason() --- include/linux/skbuff.h | 23 ++++++++++++++++++++++- include/trace/events/skb.h | 36 +++++++++++++++++++++++++++++------- net/core/dev.c | 3 ++- net/core/drop_monitor.c | 10 +++++++--- net/core/skbuff.c | 12 +++++++----- 5 files changed, 67 insertions(+), 17 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 642acb0d1646..ef0870abc791 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -305,6 +305,17 @@ struct sk_buff_head { =20 struct sk_buff; =20 +/* The reason of skb drop, which is used in kfree_skb_reason(). + * en...maybe they should be splited by group? + * + * Each item here should also be in 'TRACE_SKB_DROP_REASON', which is + * used to translate the reason to string. + */ +enum skb_drop_reason { + SKB_DROP_REASON_NOT_SPECIFIED, + SKB_DROP_REASON_MAX, +}; + /* To allow 64K frame to be packed as single skb without frag_list we * require 64K/PAGE_SIZE pages plus 1 additional page to allow for * buffers which do not start on a page boundary. @@ -1085,8 +1096,18 @@ static inline bool skb_unref(struct sk_buff *skb) return true; } =20 +void kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason); + +/** + * kfree_skb - free an sk_buff with 'NOT_SPECIFIED' reason + * @skb: buffer to free + */ +static inline void kfree_skb(struct sk_buff *skb) +{ + kfree_skb_reason(skb, SKB_DROP_REASON_NOT_SPECIFIED); +} + void skb_release_head_state(struct sk_buff *skb); -void kfree_skb(struct sk_buff *skb); void kfree_skb_list(struct sk_buff *segs); void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt); void skb_tx_error(struct sk_buff *skb); diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index 9e92f22eb086..294c61bbe44b 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -9,29 +9,51 @@ #include #include =20 +#define TRACE_SKB_DROP_REASON \ + EM(SKB_DROP_REASON_NOT_SPECIFIED, NOT_SPECIFIED) \ + EMe(SKB_DROP_REASON_MAX, MAX) + +#undef EM +#undef EMe + +#define EM(a, b) TRACE_DEFINE_ENUM(a); +#define EMe(a, b) TRACE_DEFINE_ENUM(a); + +TRACE_SKB_DROP_REASON + +#undef EM +#undef EMe +#define EM(a, b) { a, #b }, +#define EMe(a, b) { a, #b } + /* * Tracepoint for free an sk_buff: */ TRACE_EVENT(kfree_skb, =20 - TP_PROTO(struct sk_buff *skb, void *location), + TP_PROTO(struct sk_buff *skb, void *location, + enum skb_drop_reason reason), =20 - TP_ARGS(skb, location), + TP_ARGS(skb, location, reason), =20 TP_STRUCT__entry( - __field( void *, skbaddr ) - __field( void *, location ) - __field( unsigned short, protocol ) + __field(void *, skbaddr) + __field(void *, location) + __field(unsigned short, protocol) + __field(enum skb_drop_reason, reason) ), =20 TP_fast_assign( __entry->skbaddr =3D skb; __entry->location =3D location; __entry->protocol =3D ntohs(skb->protocol); + __entry->reason =3D reason; ), =20 - TP_printk("skbaddr=3D%p protocol=3D%u location=3D%p", - __entry->skbaddr, __entry->protocol, __entry->location) + TP_printk("skbaddr=3D%p protocol=3D%u location=3D%p reason: %s", + __entry->skbaddr, __entry->protocol, __entry->location, + __print_symbolic(__entry->reason, + TRACE_SKB_DROP_REASON)) ); =20 TRACE_EVENT(consume_skb, diff --git a/net/core/dev.c b/net/core/dev.c index 83a4089990a0..84a0d9542fe9 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4899,7 +4899,8 @@ static __latent_entropy void net_tx_action(struct sof= tirq_action *h) if (likely(get_kfree_skb_cb(skb)->reason =3D=3D SKB_REASON_CONSUMED)) trace_consume_skb(skb); else - trace_kfree_skb(skb, net_tx_action); + trace_kfree_skb(skb, net_tx_action, + SKB_DROP_REASON_NOT_SPECIFIED); =20 if (skb->fclone !=3D SKB_FCLONE_UNAVAILABLE) __kfree_skb(skb); diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index 3d0ab2eec916..7b288a121a41 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -110,7 +110,8 @@ static u32 net_dm_queue_len =3D 1000; =20 struct net_dm_alert_ops { void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb, - void *location); + void *location, + enum skb_drop_reason reason); void (*napi_poll_probe)(void *ignore, struct napi_struct *napi, int work, int budget); void (*work_item_func)(struct work_struct *work); @@ -262,7 +263,9 @@ static void trace_drop_common(struct sk_buff *skb, void= *location) spin_unlock_irqrestore(&data->lock, flags); } =20 -static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, void *l= ocation) +static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, + void *location, + enum skb_drop_reason reason) { trace_drop_common(skb, location); } @@ -490,7 +493,8 @@ static const struct net_dm_alert_ops net_dm_alert_summa= ry_ops =3D { =20 static void net_dm_packet_trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, - void *location) + void *location, + enum skb_drop_reason reason) { ktime_t tstamp =3D ktime_get_real(); struct per_cpu_dm_data *data; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index e514a36bcffc..0118f0afaa4f 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -759,21 +759,23 @@ void __kfree_skb(struct sk_buff *skb) EXPORT_SYMBOL(__kfree_skb); =20 /** - * kfree_skb - free an sk_buff + * kfree_skb_reason - free an sk_buff with special reason * @skb: buffer to free + * @reason: reason why this skb is dropped * * Drop a reference to the buffer and free it if the usage count has - * hit zero. + * hit zero. Meanwhile, pass the drop reason to 'kfree_skb' + * tracepoint. */ -void kfree_skb(struct sk_buff *skb) +void kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason) { if (!skb_unref(skb)) return; =20 - trace_kfree_skb(skb, __builtin_return_address(0)); + trace_kfree_skb(skb, __builtin_return_address(0), reason); __kfree_skb(skb); } -EXPORT_SYMBOL(kfree_skb); +EXPORT_SYMBOL(kfree_skb_reason); =20 void kfree_skb_list(struct sk_buff *segs) { --=20 2.34.1 From nobody Tue Jun 30 21:22:29 2026 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 DF644C43219 for ; Sun, 9 Jan 2022 06:38:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235244AbiAIGhd (ORCPT ); Sun, 9 Jan 2022 01:37:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235232AbiAIGhb (ORCPT ); Sun, 9 Jan 2022 01:37:31 -0500 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 39FD7C06173F; Sat, 8 Jan 2022 22:37:31 -0800 (PST) Received: by mail-pj1-x1030.google.com with SMTP id rj2-20020a17090b3e8200b001b1944bad25so12739801pjb.5; Sat, 08 Jan 2022 22:37:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=UcJQ/igXAjjb9zNSIv1UStOkEDIB31SAlch2s5VfL8E=; b=b0zG8TMNq3nA8wFcRolEprDd4XNA3SPwY4VAAbPkyPIuz1jdhggxVNSo/1CuBuDTN+ dtHyoZVQpkZdMmMAMA4KhuAtCharfnSKJ4l/YUQYy1j0Zl3X1FXOifsOgaUHUvSF2kP4 +bC97V/uZCb6VOYyDL8Lv6DRcpixfmGxTj3dJPXxvNtPWn+JSAjvZHFRLe6YT9vS0dCA 2Dx2XDH75JNxNWlGqc5dkMxGiQpPQl64iwiWlvlCXKBhyzx56Cppy1iap0v5RrXT1iTq zOXjYkqM/5cbdTbEzuu/4HxDWv3wN3A9QenKXpBR6JodINWSd3lldQepLgIIUmMH777S w57Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=UcJQ/igXAjjb9zNSIv1UStOkEDIB31SAlch2s5VfL8E=; b=5GhkPCtYuV/xGTxkGGwhMMWGEOm0zEwKyVLoiR809hceQ2J0e3GrZtTIDjiREM4xxZ lJVmyVeQ3YKht5J3Dn9n5urVARg7C5vnxtOGjomHJV+e5VhBsOOab7r3DPeNq2nVVS8g 673pXxo11JJ2tNOZ3eOm5wnFsQm6L9N1ug25Jqa0HP5V5wmeQ5z2dxGpzwYlEahVprp8 p/4Ai78qwyLqUfUh4qWVGpwUuWGbedA8j03k32i+2o3jZWmMTQKdJKPjecGd0RGsjHD4 ooZz3IXvyMktgRc4oQcUWCsh0ntnp2XApho6knFaWLiKtLyAhfmfUPjWkQmpiMNvdKr4 uiBQ== X-Gm-Message-State: AOAM5324uFI6AwT5swKD0BEx2WR8SDoFjCjYENkp+t+NK8QQeEKGe/H7 Xu3JbjyN+qSi9xiPs9fVGNk= X-Google-Smtp-Source: ABdhPJxYaoPNAgqxcQgPhtgvwmWfjK2iJdfLj1vXmnMpMQ73BUjhgWGuQn9FIh0bomxs/D0R/U01wQ== X-Received: by 2002:a17:90a:c254:: with SMTP id d20mr1961989pjx.226.1641710250797; Sat, 08 Jan 2022 22:37:30 -0800 (PST) Received: from localhost.localdomain ([43.132.141.4]) by smtp.gmail.com with ESMTPSA id my5sm5892042pjb.5.2022.01.08.22.37.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 08 Jan 2022 22:37:30 -0800 (PST) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: rostedt@goodmis.org, dsahern@kernel.org Cc: mingo@redhat.com, davem@davemloft.net, kuba@kernel.org, nhorman@tuxdriver.com, edumazet@google.com, yoshfuji@linux-ipv6.org, alobakin@pm.me, willemb@google.com, cong.wang@bytedance.com, keescook@chromium.org, pabeni@redhat.com, talalahmad@google.com, haokexin@gmail.com, ilias.apalodimas@linaro.org, memxor@gmail.com, atenart@kernel.org, bigeasy@linutronix.de, weiwan@google.com, arnd@arndb.de, vvs@virtuozzo.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, jonathan.lemon@gmail.com, imagedong@tencent.com Subject: [PATCH v4 net-next 2/3] net: skb: use kfree_skb_reason() in tcp_v4_rcv() Date: Sun, 9 Jan 2022 14:36:27 +0800 Message-Id: <20220109063628.526990-3-imagedong@tencent.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220109063628.526990-1-imagedong@tencent.com> References: <20220109063628.526990-1-imagedong@tencent.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Menglong Dong Replace kfree_skb() with kfree_skb_reason() in tcp_v4_rcv(). Following drop reasons are added: SKB_DROP_REASON_NO_SOCKET SKB_DROP_REASON_PKT_TOO_SMALL SKB_DROP_REASON_TCP_CSUM SKB_DROP_REASON_TCP_FILTER After this patch, 'kfree_skb' event will print message like this: $ TASK-PID CPU# ||||| TIMESTAMP FUNCTION $ | | | ||||| | | -0 [000] ..s1. 36.113438: kfree_skb: skbaddr=3D(__= __ptrval____) protocol=3D2048 location=3D(____ptrval____) reason: NO_SOCKET The reason of skb drop is printed too. Signed-off-by: Menglong Dong --- v3: - rename kfree_skb_with_reason() to kfree_skb_reason() v2: - rename some reason name as David suggested - add the new reason: SKB_DROP_REASON_TCP_FILTER --- include/linux/skbuff.h | 4 ++++ include/trace/events/skb.h | 4 ++++ net/ipv4/tcp_ipv4.c | 14 +++++++++++--- 3 files changed, 19 insertions(+), 3 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index ef0870abc791..c9c97b0d0fe9 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -313,6 +313,10 @@ struct sk_buff; */ enum skb_drop_reason { SKB_DROP_REASON_NOT_SPECIFIED, + SKB_DROP_REASON_NO_SOCKET, + SKB_DROP_REASON_PKT_TOO_SMALL, + SKB_DROP_REASON_TCP_CSUM, + SKB_DROP_REASON_TCP_FILTER, SKB_DROP_REASON_MAX, }; =20 diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index b5ef652e5a93..c16febea9f62 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -11,6 +11,10 @@ =20 #define TRACE_SKB_DROP_REASON \ EM(SKB_DROP_REASON_NOT_SPECIFIED, NOT_SPECIFIED) \ + EM(SKB_DROP_REASON_NO_SOCKET, NO_SOCKET) \ + EM(SKB_DROP_REASON_PKT_TOO_SMALL, PKT_TOO_SMALL) \ + EM(SKB_DROP_REASON_TCP_CSUM, TCP_CSUM) \ + EM(SKB_DROP_REASON_TCP_FILTER, TCP_FILTER) \ EMe(SKB_DROP_REASON_MAX, MAX) =20 #undef EM diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index ac10e4cdd8d0..f83efcc6e76e 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1971,8 +1971,10 @@ int tcp_v4_rcv(struct sk_buff *skb) const struct tcphdr *th; bool refcounted; struct sock *sk; + int drop_reason; int ret; =20 + drop_reason =3D SKB_DROP_REASON_NOT_SPECIFIED; if (skb->pkt_type !=3D PACKET_HOST) goto discard_it; =20 @@ -1984,8 +1986,10 @@ int tcp_v4_rcv(struct sk_buff *skb) =20 th =3D (const struct tcphdr *)skb->data; =20 - if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) + if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) { + drop_reason =3D SKB_DROP_REASON_PKT_TOO_SMALL; goto bad_packet; + } if (!pskb_may_pull(skb, th->doff * 4)) goto discard_it; =20 @@ -2090,8 +2094,10 @@ int tcp_v4_rcv(struct sk_buff *skb) =20 nf_reset_ct(skb); =20 - if (tcp_filter(sk, skb)) + if (tcp_filter(sk, skb)) { + drop_reason =3D SKB_DROP_REASON_TCP_FILTER; goto discard_and_relse; + } th =3D (const struct tcphdr *)skb->data; iph =3D ip_hdr(skb); tcp_v4_fill_cb(skb, iph, th); @@ -2124,6 +2130,7 @@ int tcp_v4_rcv(struct sk_buff *skb) return ret; =20 no_tcp_socket: + drop_reason =3D SKB_DROP_REASON_NO_SOCKET; if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) goto discard_it; =20 @@ -2131,6 +2138,7 @@ int tcp_v4_rcv(struct sk_buff *skb) =20 if (tcp_checksum_complete(skb)) { csum_error: + drop_reason =3D SKB_DROP_REASON_TCP_CSUM; trace_tcp_bad_csum(skb); __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); bad_packet: @@ -2141,7 +2149,7 @@ int tcp_v4_rcv(struct sk_buff *skb) =20 discard_it: /* Discard frame. */ - kfree_skb(skb); + kfree_skb_reason(skb, drop_reason); return 0; =20 discard_and_relse: --=20 2.30.2 From nobody Tue Jun 30 21:22:29 2026 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 EE09CC4167B for ; Sun, 9 Jan 2022 06:38:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235257AbiAIGhi (ORCPT ); Sun, 9 Jan 2022 01:37:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34876 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235248AbiAIGhh (ORCPT ); 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Sat, 08 Jan 2022 22:37:36 -0800 (PST) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: rostedt@goodmis.org, dsahern@kernel.org Cc: mingo@redhat.com, davem@davemloft.net, kuba@kernel.org, nhorman@tuxdriver.com, edumazet@google.com, yoshfuji@linux-ipv6.org, alobakin@pm.me, willemb@google.com, cong.wang@bytedance.com, keescook@chromium.org, pabeni@redhat.com, talalahmad@google.com, haokexin@gmail.com, ilias.apalodimas@linaro.org, memxor@gmail.com, atenart@kernel.org, bigeasy@linutronix.de, weiwan@google.com, arnd@arndb.de, vvs@virtuozzo.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, jonathan.lemon@gmail.com, imagedong@tencent.com Subject: [PATCH v4 net-next 3/3] net: skb: use kfree_skb_reason() in __udp4_lib_rcv() Date: Sun, 9 Jan 2022 14:36:28 +0800 Message-Id: <20220109063628.526990-4-imagedong@tencent.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220109063628.526990-1-imagedong@tencent.com> References: <20220109063628.526990-1-imagedong@tencent.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Menglong Dong Replace kfree_skb() with kfree_skb_reason() in __udp4_lib_rcv. New drop reason 'SKB_DROP_REASON_UDP_CSUM' is added for udp csum error. Signed-off-by: Menglong Dong --- v3: - rename kfree_skb_with_reason() to kfree_skb_reason() --- include/linux/skbuff.h | 1 + include/trace/events/skb.h | 1 + net/ipv4/udp.c | 10 ++++++++-- 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index c9c97b0d0fe9..af64c7de9b53 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -317,6 +317,7 @@ enum skb_drop_reason { SKB_DROP_REASON_PKT_TOO_SMALL, SKB_DROP_REASON_TCP_CSUM, SKB_DROP_REASON_TCP_FILTER, + SKB_DROP_REASON_UDP_CSUM, SKB_DROP_REASON_MAX, }; =20 diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index c16febea9f62..75075512ae19 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -15,6 +15,7 @@ EM(SKB_DROP_REASON_PKT_TOO_SMALL, PKT_TOO_SMALL) \ EM(SKB_DROP_REASON_TCP_CSUM, TCP_CSUM) \ EM(SKB_DROP_REASON_TCP_FILTER, TCP_FILTER) \ + EM(SKB_DROP_REASON_UDP_CSUM, UDP_CSUM) \ EMe(SKB_DROP_REASON_MAX, MAX) =20 #undef EM diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 7b18a6f42f18..22f277cbd97c 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2411,6 +2411,9 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_ta= ble *udptable, __be32 saddr, daddr; struct net *net =3D dev_net(skb->dev); bool refcounted; + int drop_reason; + + drop_reason =3D SKB_DROP_REASON_NOT_SPECIFIED; =20 /* * Validate the packet. @@ -2466,6 +2469,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_ta= ble *udptable, if (udp_lib_checksum_complete(skb)) goto csum_error; =20 + drop_reason =3D SKB_DROP_REASON_NO_SOCKET; __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto =3D=3D IPPROTO_UDPLITE); icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); =20 @@ -2473,10 +2477,11 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_= table *udptable, * Hmm. We got an UDP packet to a port to which we * don't wanna listen. Ignore it. */ - kfree_skb(skb); + kfree_skb_reason(skb, drop_reason); return 0; =20 short_packet: + drop_reason =3D SKB_DROP_REASON_PKT_TOO_SMALL; net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n= ", proto =3D=3D IPPROTO_UDPLITE ? "Lite" : "", &saddr, ntohs(uh->source), @@ -2489,6 +2494,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_ta= ble *udptable, * RFC1122: OK. Discards the bad packet silently (as far as * the network is concerned, anyway) as per 4.1.3.4 (MUST). */ + drop_reason =3D SKB_DROP_REASON_UDP_CSUM; net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d= \n", proto =3D=3D IPPROTO_UDPLITE ? "Lite" : "", &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), @@ -2496,7 +2502,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_ta= ble *udptable, __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto =3D=3D IPPROTO_UDPLITE); drop: __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto =3D=3D IPPROTO_UDPLITE); - kfree_skb(skb); + kfree_skb_reason(skb, drop_reason); return 0; } =20 --=20 2.30.2