From nobody Tue Dec 16 22:20:44 2025 Received: from relay1-d.mail.gandi.net (relay1-d.mail.gandi.net [217.70.183.193]) (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 982D521B1AA; Thu, 29 May 2025 09:07:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.193 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748509658; cv=none; b=uMjppxIRTefGt/jozNZYMK/RreTsJqsRkkUh2XlhxX3LpqwSIvKoYn+AbrLvDOG3KjBTs/iSxZv0TeP8SD2UXScZCmYv3Y2fkcYXmP9De4kgW8BpWSdCGgVVCUh4AhJ01bezkPB+v7n60tBxE5oUD9SbBx3RxfM/0VNAwsuQdsI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748509658; c=relaxed/simple; bh=KEumXAZHtIdByXzdtyPyruQVUSJnwTNNkGkXKtpL1rY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=TtJnuTif0mSAjxGGatCQPDPvTKwYGO3fZriMDbCTtmqewXCHShfb4zgqlRMnhlchv8NeTPAkdL8hObb2CNfooi32s9AOML/3aUS3HpJMuDwM4/U/qQeGcA3vvybdu0R1nJNtHNh60Sst0Dq/tJ2fnsJihfd+0Sk7u8i1a1l8/RE= 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=GaPZpePN; arc=none smtp.client-ip=217.70.183.193 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="GaPZpePN" Received: by mail.gandi.net (Postfix) with ESMTPSA id F30EB432D3; Thu, 29 May 2025 09:07:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1748509653; 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=sZ5g3I4d37jxzucB0S/BPKc0rUivwWTnKR29i4Eh0CA=; b=GaPZpePNw8prIZNu615qj2NhtPPgDuotlWnLtfK9GciP0L/HMGKJmp4FcRVimc19LNoCMk E2apjGAw+tRO/kImXPRfT8tPyVJW+CBl5rii9heI2tD/UyC9mqWmLdaZhNu/19DAHN5o53 Xp3ZFZZIgELwmgdUNCp0SoxBPIa1QcRcx6IROnpwjV4j+Df6LaxigZqWMgclPYUVhDAp2/ wAAJ4/zCkb0EZpBGJ5LZcR+nBydiJgkVzaKrW8zHVaheCVlZ0yqqW1SW3ZG/YHSogunXy/ o6B9X7ZtmmSonLPAbdB46yXjspTPWQiCrYFjp+n38HOHrxYZTUN3+257hx8jTA== From: =?utf-8?q?Alexis_Lothor=C3=A9?= Date: Thu, 29 May 2025 11:07:23 +0200 Subject: [PATCH v4 1/2] net: stmmac: make sure that ptp_rate is not 0 before configuring timestamping Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250529-stmmac_tstamp_div-v4-1-d73340a794d5@bootlin.com> References: <20250529-stmmac_tstamp_div-v4-0-d73340a794d5@bootlin.com> In-Reply-To: <20250529-stmmac_tstamp_div-v4-0-d73340a794d5@bootlin.com> To: Alexandre Torgue , Jose Abreu , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Maxime Coquelin , Richard Cochran , Phil Reid 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, Jose Abreu , Yanteng Si , =?utf-8?q?Alexis_Lothor=C3=A9?= X-Mailer: b4 0.14.2 X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtddtgddvheejfeculddtuddrgeefvddrtddtmdcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephfffufggtgfgkfhfjgfvvefosehtkeertdertdejnecuhfhrohhmpeetlhgvgihishcunfhothhhohhrrocuoegrlhgvgihishdrlhhothhhohhrvgessghoohhtlhhinhdrtghomheqnecuggftrfgrthhtvghrnhepgeevgefhteffuefhheekkeelffffvdeugffgveejffdtvdffudehtedtieevteetnecukfhppedvrgdtvdemkeegvdekmehfleegtgemvgdttdemmehfkeehnecuvehluhhsthgvrhfuihiivgepvdenucfrrghrrghmpehinhgvthepvdgrtddvmeekgedvkeemfhelgegtmegvtddtmeemfhekhedphhgvlhhopegludelvddrudeikedruddrvddtkegnpdhmrghilhhfrhhomheprghlvgigihhsrdhlohhthhhorhgvsegsohhothhlihhnrdgtohhmpdhnsggprhgtphhtthhopeduledprhgtphhtthhopehrihgthhgrrhgutghotghhrhgrnhesghhmrghilhdrtghomhdprhgtphhtthhopehmtghoqhhuvghlihhnrdhsthhmfedvsehgmhgrihhlrdgtohhmpdhrtghpthhtohepmhgrgihimhgvrdgthhgvvhgrlhhlihgvrhessghoohhtlhhinhdrtghomhdprhgtphhtthhop ehkuhgsrgeskhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplfhoshgvrdetsghrvghusehshihnohhpshihshdrtghomhdprhgtphhtthhopehprggsvghnihesrhgvughhrghtrdgtohhmpdhrtghpthhtohepjhhorggsrhgvuhesshihnhhophhshihsrdgtohhmpdhrtghpthhtohepnhgvthguvghvsehvghgvrhdrkhgvrhhnvghlrdhorhhg X-GND-Sasl: alexis.lothore@bootlin.com The stmmac platform drivers that do not open-code the clk_ptp_rate value after having retrieved the default one from the device-tree can end up with 0 in clk_ptp_rate (as clk_get_rate can return 0). 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-g48313bd576= 8a #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. While at it, remove the same check from stmmac_ptp_register, which then becomes duplicate Fixes: 19d857c9038e ("stmmac: Fix calculations for ptp counters when clock = input =3D 50Mhz.") Signed-off-by: Alexis Lothor=C3=A9 Reviewed-by: Yanteng Si Reviewed-by: Maxime Chevallier --- Changes in v4: - collect RB tags - rebased on net/main Changes in v3: - remove now-duplicate check - reword commit message --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 5 +++++ drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/ne= t/ethernet/stmicro/stmmac/stmmac_main.c index 085c09039af4a5ebfbb86a3743960d9747367588..1369fa70bc587e5c9e22fc33f69= bc9ca0774be86 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -805,6 +805,11 @@ int stmmac_init_tstamp_counter(struct stmmac_priv *pri= v, u32 systime_flags) if (!(priv->dma_cap.time_stamp || priv->dma_cap.atime_stamp)) return -EOPNOTSUPP; =20 + 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 =3D systime_flags; =20 diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c b/drivers/net= /ethernet/stmicro/stmmac/stmmac_ptp.c index 429b2d357813c8023fc853299f206208f15642e1..3767ba495e78d210b0529ee1754= e5331f2dd0a47 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c @@ -317,7 +317,7 @@ void stmmac_ptp_register(struct stmmac_priv *priv) =20 /* Calculate the clock domain crossing (CDC) error if necessary */ priv->plat->cdc_error_adj =3D 0; - if (priv->plat->has_gmac4 && priv->plat->clk_ptp_rate) + if (priv->plat->has_gmac4) priv->plat->cdc_error_adj =3D (2 * NSEC_PER_SEC) / priv->plat->clk_ptp_r= ate; =20 /* Update the ptp clock parameters based on feature discovery, when --=20 2.49.0