From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3318EC54FB3 for ; Mon, 26 May 2025 02:25:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=MHrrgO4T8/5vtp/a4llt3X0WdmaU+h5OTxvm6amIygc=; b=FaAtrn8X/nuRjhvF3NIkY8qfRn Jz6kzq1paCqWEBr+RJylbd+6FcKt04Ss/z+wi1CvQ/ugKVYHjz2kNMrPAcMVWF3nA9vLNDoJYYfYd 0EbL86qC6ScExs9K0eKrL1JSdh2Lq8xJlPGHQ1Qoj9gUsXKT4IMP2VKif1mox1BK6tGHjdfvuYTGX /hWJoOwmSihXA71g7tnuaMaCi6H53sTl/IEh0LevBOLJ5QH/0RaRGRfFQgl1qqu6lbTazv5ivZ13i AXFEzl0gNbEeDmonxCXnncjTERDBeXQyb1fXD96fc1eJZnhwYQl7JWJ9jecL0Rg9CapfpzQ2laXPh 6rxQ+xBA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uJNWe-00000007xmC-08As; Mon, 26 May 2025 02:25:16 +0000 Received: from out-188.mta1.migadu.com ([95.215.58.188]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uJNUW-00000007xYy-12SU for linux-arm-kernel@lists.infradead.org; Mon, 26 May 2025 02:23:05 +0000 Message-ID: <8f1928e5-472e-4140-875c-6b5743be8fd3@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1748226180; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=MHrrgO4T8/5vtp/a4llt3X0WdmaU+h5OTxvm6amIygc=; b=Zekzu02VUU4sA5O/Q7hlWJRDia/qU8bJPMeFs2zxqQb1BH6yp6B3EstCyGEgyCb5+PSHyn wh6v/EiZN01xVP96FIKAc8+OXWJ0aGTBTvPbw9lPiGnXDY3lSvOn8lSatgw238V+31C2YK JBEtsP+6KT1Cm55H4qHnrlMTw2x7V2c= Date: Mon, 26 May 2025 10:22:47 +0800 MIME-Version: 1.0 Subject: Re: [PATCH] net: stmmac: add explicit check and error on invalid PTP clock rate To: =?UTF-8?Q?Alexis_Lothor=C3=A9?= , Alexandre Torgue , Jose Abreu , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Maxime Coquelin , Richard Cochran Cc: Thomas Petazzoni , Maxime Chevallier , netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20250523-stmmac_tstamp_div-v1-1-bca8a5a3a477@bootlin.com> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yanteng Si In-Reply-To: <20250523-stmmac_tstamp_div-v1-1-bca8a5a3a477@bootlin.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250525_192304_582464_13E97B8E X-CRM114-Status: GOOD ( 17.54 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 在 5/23/25 7:46 PM, Alexis Lothoré 写道: > While some platforms implementing dwmac open-code the clk_ptp_rate > value, some others dynamically retrieve the value at runtime. If the > retrieved value happens to be 0 for any reason, it will eventually > propagate up to PTP initialization when bringing up the interface, > leading to a divide by 0: > > Division by zero in kernel. > CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.30-00001-g48313bd5768a #22 > Hardware name: STM32 (Device Tree Support) > Call trace: > unwind_backtrace from show_stack+0x18/0x1c > show_stack from dump_stack_lvl+0x6c/0x8c > dump_stack_lvl from Ldiv0_64+0x8/0x18 > Ldiv0_64 from stmmac_init_tstamp_counter+0x190/0x1a4 > stmmac_init_tstamp_counter from stmmac_hw_setup+0xc1c/0x111c > stmmac_hw_setup from __stmmac_open+0x18c/0x434 > __stmmac_open from stmmac_open+0x3c/0xbc > stmmac_open from __dev_open+0xf4/0x1ac > __dev_open from __dev_change_flags+0x1cc/0x224 > __dev_change_flags from dev_change_flags+0x24/0x60 > dev_change_flags from ip_auto_config+0x2e8/0x11a0 > ip_auto_config from do_one_initcall+0x84/0x33c > do_one_initcall from kernel_init_freeable+0x1b8/0x214 > kernel_init_freeable from kernel_init+0x24/0x140 > kernel_init from ret_from_fork+0x14/0x28 > Exception stack(0xe0815fb0 to 0xe0815ff8) > > Prevent this division by 0 by adding an explicit check and error log > about the actual issue. From your description, I cannot determine the scope of "some platforms". My point is: if there are only a few platforms, can we find a way to handle this in the directory of the corresponding platform? And there need a Fixes tag. Thanks, Yanteng > > Signed-off-by: Alexis Lothoré > --- > drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > index 918d7f2e8ba992208d7d6521a1e9dba01086058f..f68e3ece919cc88d0bf199a394bc7e44b5dee095 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > @@ -835,6 +835,11 @@ int stmmac_init_tstamp_counter(struct stmmac_priv *priv, u32 systime_flags) > if (!(priv->dma_cap.time_stamp || priv->dma_cap.atime_stamp)) > return -EOPNOTSUPP; > > + if (!priv->plat->clk_ptp_rate) { > + netdev_err(priv->dev, "Invalid PTP clock rate"); > + return -EINVAL; > + } > + > stmmac_config_hw_tstamping(priv, priv->ptpaddr, systime_flags); > priv->systime_flags = systime_flags; > > > --- > base-commit: e0e2f78243385e7188a57fcfceb6a19f723f1dff > change-id: 20250522-stmmac_tstamp_div-f55112f06029 > > Best regards,