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 A40812EA14E; Tue, 17 Jun 2025 16:03:39 +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=1750176219; cv=none; b=uz7RZ66/L1QUP9kIpeEnSfg7C9GWbGNWx0lwYOCWZVpO1AoVbynWJyRzS4xv+NUjhMS6LjZpfQcKXzxjArfzcQb3VpeFJgEVA5m752wU9LwSrepFvr8e8uw9NOdOWNj9uen5DN/YtTaGB83kOqg0rv9gqQvEiRH0ggx5CcsEFJ8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750176219; c=relaxed/simple; bh=1RevyJ5EXpXvP21XP7opYpHn03lcPj3wRmLD2ZaKY0M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=NX4wlcwxKXg6DKq1ZCTiC1JVQVWzMgrgUTcyQjl4pDlL7uPaW8lj3xu6cmFLTVxouD34/GGMdfrAXx7LLlIo+lX1zsehAiddAtyIXkCO4ayGKbWYaumJoBb/vEJxjgEmh6NW1Th5tQElIP5hzAwVGgvxhlphwhB/G9WVHLt1bc4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=G9wJTLiw; 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="G9wJTLiw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15950C4CEE3; Tue, 17 Jun 2025 16:03:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1750176219; bh=1RevyJ5EXpXvP21XP7opYpHn03lcPj3wRmLD2ZaKY0M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G9wJTLiwXpw91VUgTwuf53VbWsQ5JU5dCdjKo9W9LH1/u46YLhTpzMnZUzdfBjtJm Xm+naK0i9PpoYALjB1cRdz/o/NqiKeXQstuH8KNwDn9iNr/AT8rI9jPi3sMmTrzQWs +XiOz/nfoIqtjOuNG4ITDnLUMeQlMe1L8tLFd3T8= 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 6.6 256/356] net: stmmac: make sure that ptp_rate is not 0 before configuring timestamping Date: Tue, 17 Jun 2025 17:26:11 +0200 Message-ID: <20250617152348.513356935@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250617152338.212798615@linuxfoundation.org> References: <20250617152338.212798615@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 6.6-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 d3d5c01f6dcba..615d25a0e46be 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -842,6 +842,11 @@ 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 a04bb2e42c4ee..80ecbd73333d9 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c @@ -295,7 +295,7 @@ 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