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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E91FC67871 for ; Mon, 16 Jan 2023 17:03:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231221AbjAPRDy (ORCPT ); Mon, 16 Jan 2023 12:03:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234093AbjAPRDM (ORCPT ); Mon, 16 Jan 2023 12:03:12 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 105B33F2A7 for ; Mon, 16 Jan 2023 08:45:17 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A1E566104F for ; Mon, 16 Jan 2023 16:45:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B73E5C433D2; Mon, 16 Jan 2023 16:45:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673887516; bh=cG2QT/WO6tPbVZL/288eS3Dm/V0fLybOgSWlUm3TO2I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q8XN2qf4HsV11LNf0z89bEvftfCL3SlCX2ryw9+MdsoTq1Ry5vI0yVPmpx2TcXq8J pK/fTgDZPySQiCmbjvTkf+z+Ha3eiN4azj06KntxmkrWB15Yz6IpJdr7B1UaUqW8Iv ue5IRAYiHb4K1jfgkDg3tuZwWwKpkpydoJPjE4Aw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Piergiorgio Beruto , Andrew Lunn , Jakub Kicinski , Sasha Levin Subject: [PATCH 4.19 179/521] stmmac: fix potential division by 0 Date: Mon, 16 Jan 2023 16:47:21 +0100 Message-Id: <20230116154855.091269020@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116154847.246743274@linuxfoundation.org> References: <20230116154847.246743274@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Piergiorgio Beruto [ Upstream commit ede5a389852d3640a28e7187fb32b7f204380901 ] When the MAC is connected to a 10 Mb/s PHY and the PTP clock is derived from the MAC reference clock (default), the clk_ptp_rate becomes too small and the calculated sub second increment becomes 0 when computed by the stmmac_config_sub_second_increment() function within stmmac_init_tstamp_counter(). Therefore, the subsequent div_u64 in stmmac_init_tstamp_counter() operation triggers a divide by 0 exception as shown below. [ 95.062067] socfpga-dwmac ff700000.ethernet eth0: Register MEM_TYPE_PAGE_POOL RxQ-0 [ 95.076440] socfpga-dwmac ff700000.ethernet eth0: PHY [stmmac-0:08] driver [NCN26000] (irq=49) [ 95.095964] dwmac1000: Master AXI performs any burst length [ 95.101588] socfpga-dwmac ff700000.ethernet eth0: No Safety Features support found [ 95.109428] Division by zero in kernel. [ 95.113447] CPU: 0 PID: 239 Comm: ifconfig Not tainted 6.1.0-rc7-centurion3-1.0.3.0-01574-gb624218205b7-dirty #77 [ 95.123686] Hardware name: Altera SOCFPGA [ 95.127695] unwind_backtrace from show_stack+0x10/0x14 [ 95.132938] show_stack from dump_stack_lvl+0x40/0x4c [ 95.137992] dump_stack_lvl from Ldiv0+0x8/0x10 [ 95.142527] Ldiv0 from __aeabi_uidivmod+0x8/0x18 [ 95.147232] __aeabi_uidivmod from div_u64_rem+0x1c/0x40 [ 95.152552] div_u64_rem from stmmac_init_tstamp_counter+0xd0/0x164 [ 95.158826] stmmac_init_tstamp_counter from stmmac_hw_setup+0x430/0xf00 [ 95.165533] stmmac_hw_setup from __stmmac_open+0x214/0x2d4 [ 95.171117] __stmmac_open from stmmac_open+0x30/0x44 [ 95.176182] stmmac_open from __dev_open+0x11c/0x134 [ 95.181172] __dev_open from __dev_change_flags+0x168/0x17c [ 95.186750] __dev_change_flags from dev_change_flags+0x14/0x50 [ 95.192662] dev_change_flags from devinet_ioctl+0x2b4/0x604 [ 95.198321] devinet_ioctl from inet_ioctl+0x1ec/0x214 [ 95.203462] inet_ioctl from sock_ioctl+0x14c/0x3c4 [ 95.208354] sock_ioctl from vfs_ioctl+0x20/0x38 [ 95.212984] vfs_ioctl from sys_ioctl+0x250/0x844 [ 95.217691] sys_ioctl from ret_fast_syscall+0x0/0x4c [ 95.222743] Exception stack(0xd0ee1fa8 to 0xd0ee1ff0) [ 95.227790] 1fa0: 00574c4f be9aeca4 00000003 00008914 be9aeca4 be9aec50 [ 95.235945] 1fc0: 00574c4f be9aeca4 0059f078 00000036 be9aee8c be9aef7a 00000015 00000000 [ 95.244096] 1fe0: 005a01f0 be9aec38 004d7484 b6e67d74 Signed-off-by: Piergiorgio Beruto Fixes: 91a2559c1dc5 ("net: stmmac: Fix sub-second increment") Reviewed-by: Andrew Lunn Link: https://lore.kernel.org/r/de4c64ccac9084952c56a06a8171d738604c4770.1670678513.git.piergiorgio.beruto@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c | 3 ++- drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c index 08a058e1bc75..541c0449f31c 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c @@ -53,7 +53,8 @@ static void config_sub_second_increment(void __iomem *ioaddr, if (!(value & PTP_TCR_TSCTRLSSR)) data = (data * 1000) / 465; - data &= PTP_SSIR_SSINC_MASK; + if (data > PTP_SSIR_SSINC_MAX) + data = PTP_SSIR_SSINC_MAX; reg_value = data; if (gmac4) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h index ecccf895fd7e..306ebf1a495e 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h @@ -66,7 +66,7 @@ #define PTP_TCR_TSENMACADDR BIT(18) /* SSIR defines */ -#define PTP_SSIR_SSINC_MASK 0xff +#define PTP_SSIR_SSINC_MAX 0xff #define GMAC4_PTP_SSIR_SSINC_SHIFT 16 #endif /* __STMMAC_PTP_H__ */ -- 2.35.1