From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-02.galae.net (smtpout-02.galae.net [185.246.84.56]) (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 E4DBE33468C for ; Mon, 16 Mar 2026 17:59:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.84.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773683984; cv=none; b=EonAt4Pm79Q31iKmVUSHOSNQBtD4Nx7uz5eBkMe4K39oBMGjBPvBsD9DnjlECCy/+F5uIRA7Btu17xp2ViDk81YehFGXx11vozeUIWcyhsODsjpJxsxn8xHbGFzSeBk3Qp9yK8E3wPo1ncY985xa739Y9F2LQerffesdgUNr++E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773683984; c=relaxed/simple; bh=Oikn5ffl/VaX2OsLfSocd5RjODglLKe8Gz/chAsnkOc=; h=Mime-Version:Content-Type:Date:Message-Id:Subject:Cc:To:From: References:In-Reply-To; b=LZ6FYwbR/Qk9dXs0hmhnVrFskx8gv04oCuX2Zhqs1MULOYEQxnjQt6LFa8kRPIjvEhRRun5+tslp4Ny1m/z9zXK/1WPDM9r3Bkgx+FSu4SK352i9ouRMaPvl68v3Q+Wu3/dZN4zevAxEpTqAXJS+dhJ+SB8pulsW0R21A4sJIp8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=UGvnVuwQ; arc=none smtp.client-ip=185.246.84.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="UGvnVuwQ" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id 69E451A2D93; Mon, 16 Mar 2026 17:59:40 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 2A8535FC4A; Mon, 16 Mar 2026 17:59:40 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 14FE91045036A; Mon, 16 Mar 2026 18:59:35 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1773683979; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=clL/OrjmO10dATzmOm9nSfKm5FhAN41WJ/3xWKMS08I=; b=UGvnVuwQdC0pUjK0rP5dpOakdyji5GEIQpgotWR4HPf5E2r25rHPcYDZUAK91YVXSVfXjH XsQOm+qYTKBgVbvrlj9Zeyc/tmJ8G/wBWrXPkuiuYjuJu1wihXBjOmg3MZHHKyGNbqOmfN rCWFrB61KSm1XHrSAOBwUE0OYsWRw6VG6mNnxLH8KQsUAqYRTFmu/Ev6LQusZvbVCSi9D/ fMPGz93vquPUMw0wxoINLjupb8NMzbA0dotYkApSw79u1ngJiuaFQuOK0kFd+nKjzByDwu 95BhJv02UqglpMJFwg3A3D7TxCc+FN/PxBx+CtiCocy5bZ2mVwLI5tJKXsyvrg== Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Mon, 16 Mar 2026 18:59:35 +0100 Message-Id: Subject: Re: [PATCH net 2/2] net: macb: Protect access to net_device::in_ptr with RCU lock Cc: "Nicolas Ferre" , "Claudiu Beznea" , "Andrew Lunn" , "David S. Miller" , "Eric Dumazet" , "Jakub Kicinski" , "Paolo Abeni" , "Vineeth Karumanchi" , "Harini Katakam" , To: "Kevin Hao" , From: =?utf-8?q?Th=C3=A9o_Lebrun?= X-Mailer: aerc 0.21.0-0-g5549850facc2 References: <20260315-macb-irq-v1-0-0154104cbf61@gmail.com> <20260315-macb-irq-v1-2-0154104cbf61@gmail.com> In-Reply-To: <20260315-macb-irq-v1-2-0154104cbf61@gmail.com> X-Last-TLS-Session-Version: TLSv1.3 Hello Kevin, On Sun Mar 15, 2026 at 12:44 PM CET, Kevin Hao wrote: > @@ -5915,13 +5915,16 @@ static int __maybe_unused macb_suspend(struct dev= ice *dev) > =20 > if (bp->wol & MACB_WOL_ENABLED) { > /* Check for IP address in WOL ARP mode */ > + rcu_read_lock(); > idev =3D __in_dev_get_rcu(bp->dev); > if (idev) > ifa =3D rcu_dereference(idev->ifa_list); > if ((bp->wolopts & WAKE_ARP) && !ifa) { > netdev_err(netdev, "IP address not assigned as required by WoL walk A= RP\n"); > + rcu_read_unlock(); > return -EOPNOTSUPP; > } > + > spin_lock_irqsave(&bp->lock, flags); > =20 > /* Disable Tx and Rx engines before disabling the queues, > @@ -5963,6 +5966,7 @@ static int __maybe_unused macb_suspend(struct devic= e *dev) > tmp |=3D MACB_BFEXT(IP, be32_to_cpu(ifa->ifa_local)); > } > spin_unlock_irqrestore(&bp->lock, flags); > + rcu_read_unlock(); > =20 > /* Change interrupt handler and > * Enable WoL IRQ on queue 0 Instead of making the RCU critical section extend so much, you could dereference ifa->ifa_local into a stack variable. In particular, it would avoid the RCU critical section covering a spinlock critical section. Thanks, -- Th=C3=A9o Lebrun, Bootlin Embedded Linux and Kernel engineering https://bootlin.com