From patchwork Mon Apr 15 10:49:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sasha Levin X-Patchwork-Id: 13630076 X-Patchwork-Delegate: kuba@kernel.org 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 7A96D78C86 for ; Mon, 15 Apr 2024 13:39:08 +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=1713188348; cv=none; b=pYJLveaZcepSmC6GiMSg47lVdFJRbhgYDF67ZHIHF6AKi0A24ptUJpRVbIuoOdUAMy+LTZb5famZEznazbXV7mTajQbejrPTDPIcsdiK5BJjYYRJhvJU+7bisGw3WE+3W0KOToU9Vk2hLrjtznxbjDhuKHByC1LTtiIWClO0itc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713188348; c=relaxed/simple; bh=wUDU6uq4326M5IWBqLjTW0pJC8zmKos54HmYUc3OsTM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=pixSoHND+II+00FlqdhFMSExpdMUY4kfQJd6sfoEAhVslonKUFOGLCbat+fX/lBShaaOqlXx1I1lNyy9R//PO9yMQhXdud1gC+ULCcgKQyXosF54yvhb1cO54DnVsH4UIoDFiR5PKwZmTSA5sYhfy7VMfDjz23gzv/1+/Z27Dyw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PUXn2Cjn; 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="PUXn2Cjn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE3BFC113CC; Mon, 15 Apr 2024 13:39:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713188348; bh=wUDU6uq4326M5IWBqLjTW0pJC8zmKos54HmYUc3OsTM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PUXn2Cjn+og/jGhKq8hJTt7QdYs3buSMHbUpAtmbjG41Rlw1IyD0FKFYcFngxg9GW T7TMqfX2SYgMSFcVQy00wwD1U3TubmPtc7McHB8ZhCaCQPOZu7QV+qOIgfpkI8wkIS hCbaE14tSKVU5qhswWjahznjXXQ5RMvaNNH0P+OIG3QJw5SITdnYvd5xUUfI6HK10r nt0pQS/m2eVSEAbGYAmILjz1nuoxkPoF4mEe7MWLk/m3YTnERnPePJdzUe1XDO25GO 3gAy+M0avi0P2MVJMCGWC2imsDll0IRYALvGHEF8khiNCVWTe8OBdRyzb5W5oya4Wd HP4wbXwavI/LQ== From: Sasha Levin To: kernel-lts@openela.org Cc: Mirsad Goran Todorovac , Heiner Kallweit , nic_swsd@realtek.com, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Marco Elver , netdev@vger.kernel.org, Sasha Levin Subject: [PATCH 4.14-openela 041/190] r8169: fix the KCSAN reported data-race in rtl_tx while reading TxDescArray[entry].opts1 Date: Mon, 15 Apr 2024 06:49:31 -0400 Message-ID: <20240415105208.3137874-42-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240415105208.3137874-1-sashal@kernel.org> References: <20240415105208.3137874-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org From: Mirsad Goran Todorovac [ Upstream commit dcf75a0f6bc136de94e88178ae5f51b7f879abc9 ] KCSAN reported the following data-race: ================================================================== BUG: KCSAN: data-race in rtl8169_poll (drivers/net/ethernet/realtek/r8169_main.c:4368 drivers/net/ethernet/realtek/r8169_main.c:4581) r8169 race at unknown origin, with read to 0xffff888140d37570 of 4 bytes by interrupt on cpu 21: rtl8169_poll (drivers/net/ethernet/realtek/r8169_main.c:4368 drivers/net/ethernet/realtek/r8169_main.c:4581) r8169 __napi_poll (net/core/dev.c:6527) net_rx_action (net/core/dev.c:6596 net/core/dev.c:6727) __do_softirq (kernel/softirq.c:553) __irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632) irq_exit_rcu (kernel/softirq.c:647) sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1074 (discriminator 14)) asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:645) cpuidle_enter_state (drivers/cpuidle/cpuidle.c:291) cpuidle_enter (drivers/cpuidle/cpuidle.c:390) call_cpuidle (kernel/sched/idle.c:135) do_idle (kernel/sched/idle.c:219 kernel/sched/idle.c:282) cpu_startup_entry (kernel/sched/idle.c:378 (discriminator 1)) start_secondary (arch/x86/kernel/smpboot.c:210 arch/x86/kernel/smpboot.c:294) secondary_startup_64_no_verify (arch/x86/kernel/head_64.S:433) value changed: 0xb0000042 -> 0x00000000 Reported by Kernel Concurrency Sanitizer on: CPU: 21 PID: 0 Comm: swapper/21 Tainted: G L 6.6.0-rc2-kcsan-00143-gb5cbe7c00aa0 #41 Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023 ================================================================== The read side is in drivers/net/ethernet/realtek/r8169_main.c ========================================= 4355 static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp, 4356 int budget) 4357 { 4358 unsigned int dirty_tx, bytes_compl = 0, pkts_compl = 0; 4359 struct sk_buff *skb; 4360 4361 dirty_tx = tp->dirty_tx; 4362 4363 while (READ_ONCE(tp->cur_tx) != dirty_tx) { 4364 unsigned int entry = dirty_tx % NUM_TX_DESC; 4365 u32 status; 4366 → 4367 status = le32_to_cpu(tp->TxDescArray[entry].opts1); 4368 if (status & DescOwn) 4369 break; 4370 4371 skb = tp->tx_skb[entry].skb; 4372 rtl8169_unmap_tx_skb(tp, entry); 4373 4374 if (skb) { 4375 pkts_compl++; 4376 bytes_compl += skb->len; 4377 napi_consume_skb(skb, budget); 4378 } 4379 dirty_tx++; 4380 } 4381 4382 if (tp->dirty_tx != dirty_tx) { 4383 dev_sw_netstats_tx_add(dev, pkts_compl, bytes_compl); 4384 WRITE_ONCE(tp->dirty_tx, dirty_tx); 4385 4386 netif_subqueue_completed_wake(dev, 0, pkts_compl, bytes_compl, 4387 rtl_tx_slots_avail(tp), 4388 R8169_TX_START_THRS); 4389 /* 4390 * 8168 hack: TxPoll requests are lost when the Tx packets are 4391 * too close. Let's kick an extra TxPoll request when a burst 4392 * of start_xmit activity is detected (if it is not detected, 4393 * it is slow enough). -- FR 4394 * If skb is NULL then we come here again once a tx irq is 4395 * triggered after the last fragment is marked transmitted. 4396 */ 4397 if (READ_ONCE(tp->cur_tx) != dirty_tx && skb) 4398 rtl8169_doorbell(tp); 4399 } 4400 } tp->TxDescArray[entry].opts1 is reported to have a data-race and READ_ONCE() fixes this KCSAN warning. 4366 → 4367 status = le32_to_cpu(READ_ONCE(tp->TxDescArray[entry].opts1)); 4368 if (status & DescOwn) 4369 break; 4370 Cc: Heiner Kallweit Cc: nic_swsd@realtek.com Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Marco Elver Cc: netdev@vger.kernel.org Link: https://lore.kernel.org/lkml/dc7fc8fa-4ea4-e9a9-30a6-7c83e6b53188@alu.unizg.hr/ Signed-off-by: Mirsad Goran Todorovac Acked-by: Marco Elver Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/realtek/r8169.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c index 191531a03415a..9e972c7d449ae 100644 --- a/drivers/net/ethernet/realtek/r8169.c +++ b/drivers/net/ethernet/realtek/r8169.c @@ -7313,7 +7313,7 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp) struct ring_info *tx_skb = tp->tx_skb + entry; u32 status; - status = le32_to_cpu(tp->TxDescArray[entry].opts1); + status = le32_to_cpu(READ_ONCE(tp->TxDescArray[entry].opts1)); if (status & DescOwn) break;