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 2C2D53351EC; Mon, 5 May 2025 22:36:28 +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=1746484588; cv=none; b=PvBQyobmVkX0/y6LlEfHnlvTQONQe8xE79uxQatXYzpkuFOYQ367YBGLqKBpHAkvDPyqxOGr+CNtPycg/KujKaHbLrKapb5TcDrcPUhxnp78sUR6WtkjQaBi82VbX9CRZlkUjMT7AtkpiI6Aq5R6A394qywnmpNPuAWYLATwE0M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746484588; c=relaxed/simple; bh=draOwFBFNcaHflDS1pe0L0aBvAHCvnEuSOQlYQwhciM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=rRXheogDXeCC0LeRs1qeDf/1IjlQcg8nODSHtBLe3czF3EZk1eX1zVcFHyODzXH3+MaTAYNdSG71iiM+r7mhms6u/3TGWZclC+nLAG3FM8D5zhiuSqwI6PIaC1tZa3pAYfrITGhNe9xUhh/HwEn/kt7/cOw62w8os0sv5BWcxkA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DuYj5twa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DuYj5twa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66328C4CEE4; Mon, 5 May 2025 22:36:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746484588; bh=draOwFBFNcaHflDS1pe0L0aBvAHCvnEuSOQlYQwhciM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DuYj5twaY3PlydW/IfIq+JHmScaG86jXKjplAn+q+1QtYKt1GNJEB9Pf3wOHQfccq eMOKzMf32h9ZGEZP4/BHvkqNnYJ4bNTZUkLlEtPJmlGgdrl53XBjAE9DOcVhFra2zv 2orpserAH4TcZy3ksJ1Z6z7zQIlSYNlaSXb/5P9FyuSy8ZeqiUI//D6ouHFKO/BSRc z0OkjLC9GzH6TbYMnYx3NfN8eIE+HVBwXBfq4qhGpk+POGOTMtR6funTSIRpgwUC4p noH1ZvLfB9H0SQgvusaEb1ul7w7zfct6gs7cxaCwS/gW1cEj8xO0ae3DYEUMtc4ihR Haw7odDn9LHgQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , Jason Xing , Jakub Kicinski , Sasha Levin , davem@davemloft.net, pabeni@redhat.com, kuniyu@amazon.com, sdf@fomichev.me, ahmed.zaki@intel.com, aleksander.lobakin@intel.com, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 6.14 550/642] net: flush_backlog() small changes Date: Mon, 5 May 2025 18:12:46 -0400 Message-Id: <20250505221419.2672473-550-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505221419.2672473-1-sashal@kernel.org> References: <20250505221419.2672473-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.14.5 Content-Transfer-Encoding: 8bit From: Eric Dumazet [ Upstream commit cbe08724c18078564abefbf6591078a7c98e5e0f ] Add READ_ONCE() around reads of skb->dev->reg_state, because this field can be changed from other threads/cpus. Instead of calling dev_kfree_skb_irq() and kfree_skb() while interrupts are masked and locks held, use a temporary list and use __skb_queue_purge_reason() Use SKB_DROP_REASON_DEV_READY drop reason to better describe why these skbs are dropped. Signed-off-by: Eric Dumazet Reviewed-by: Jason Xing Link: https://patch.msgid.link/20250204144825.316785-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/core/dev.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 2f7f5fd9ffec7..77306b522966c 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6187,16 +6187,18 @@ EXPORT_SYMBOL(netif_receive_skb_list); static void flush_backlog(struct work_struct *work) { struct sk_buff *skb, *tmp; + struct sk_buff_head list; struct softnet_data *sd; + __skb_queue_head_init(&list); local_bh_disable(); sd = this_cpu_ptr(&softnet_data); backlog_lock_irq_disable(sd); skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) { - if (skb->dev->reg_state == NETREG_UNREGISTERING) { + if (READ_ONCE(skb->dev->reg_state) == NETREG_UNREGISTERING) { __skb_unlink(skb, &sd->input_pkt_queue); - dev_kfree_skb_irq(skb); + __skb_queue_tail(&list, skb); rps_input_queue_head_incr(sd); } } @@ -6204,14 +6206,16 @@ static void flush_backlog(struct work_struct *work) local_lock_nested_bh(&softnet_data.process_queue_bh_lock); skb_queue_walk_safe(&sd->process_queue, skb, tmp) { - if (skb->dev->reg_state == NETREG_UNREGISTERING) { + if (READ_ONCE(skb->dev->reg_state) == NETREG_UNREGISTERING) { __skb_unlink(skb, &sd->process_queue); - kfree_skb(skb); + __skb_queue_tail(&list, skb); rps_input_queue_head_incr(sd); } } local_unlock_nested_bh(&softnet_data.process_queue_bh_lock); local_bh_enable(); + + __skb_queue_purge_reason(&list, SKB_DROP_REASON_DEV_READY); } static bool flush_required(int cpu) -- 2.39.5