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 CE1BE2ECEA2; Tue, 17 Jun 2025 16:25:52 +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=1750177552; cv=none; b=VJDvaY9HmZ177lUTFdK1tBxIhL04LcEujTAdPfcbHl5fQVs+10hhHgPXp1DIAKAT6JJItYTumzAyAyLG11+OI+MSfFLz0DR5aad2vwo41x732w+efH/AerzYRjRQKG2WjYd8lhukc4QEPMWHOoqFk8s7Ugg3JH0iqNnOwV2uZb8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750177552; c=relaxed/simple; bh=1ZiHetbPeToCTZoLqVGRT4hUyNAHCsopo+Yv8fGrPtM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=j5aB/r/UbvduLG0pnsU4tzs5O4L6AKT1sDnoCLjMjJSXf/kSKDwGOgskHtDhDXdQ1YPD4imZok9Et9oumltHqFqhRNmHaEo6a4LF5kMbZXtAxVYzSzxhl9zWdU6XABeviMUvRA/REsZbwDJz5iIeXNgoJgz/GpqM0899QvjSQMI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=u3dKjJOt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="u3dKjJOt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3CE9EC4CEE3; Tue, 17 Jun 2025 16:25:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1750177552; bh=1ZiHetbPeToCTZoLqVGRT4hUyNAHCsopo+Yv8fGrPtM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u3dKjJOtUXkl8iwsrP+ozVpRg3HQocpJyX+aLe40HA19pXKxMh++r4SZGVY0JWPip 1rshBjMa4p/1go/tJlHeMqLhOYv7QqV2pZK7qMRuf7jVfidMVO/C4s1JzIhYUTI+oO ekA3vnFFsx9knYmGKpYYY0vD1d+NYxlKG8ljctBQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Alexis=20Lothor=C3=A9?= , Yanteng Si , Maxime Chevallier , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12 362/512] net: stmmac: make sure that ptp_rate is not 0 before configuring timestamping Date: Tue, 17 Jun 2025 17:25:28 +0200 Message-ID: <20250617152434.247182993@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250617152419.512865572@linuxfoundation.org> References: <20250617152419.512865572@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexis Lothoré [ Upstream commit 030ce919e114a111e83b7976ecb3597cefd33f26 ] 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-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. 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 = 50Mhz.") Signed-off-by: Alexis Lothoré Reviewed-by: Yanteng Si Reviewed-by: Maxime Chevallier Link: https://patch.msgid.link/20250529-stmmac_tstamp_div-v4-1-d73340a794d5@bootlin.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- 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/net/ethernet/stmicro/stmmac/stmmac_main.c index 918d7f2e8ba99..f68e3ece919cc 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; diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c index a6b1de9a251dd..5c85040a1b937 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c @@ -303,7 +303,7 @@ void stmmac_ptp_register(struct stmmac_priv *priv) /* Calculate the clock domain crossing (CDC) error if necessary */ priv->plat->cdc_error_adj = 0; - if (priv->plat->has_gmac4 && priv->plat->clk_ptp_rate) + if (priv->plat->has_gmac4) priv->plat->cdc_error_adj = (2 * NSEC_PER_SEC) / priv->plat->clk_ptp_rate; stmmac_ptp_clock_ops.n_per_out = priv->dma_cap.pps_out_num; -- 2.39.5