From patchwork Sun Dec 15 11:47:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Remi Pommarel X-Patchwork-Id: 11292751 X-Patchwork-Delegate: neil.armstrong@linaro.org Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5C0936C1 for ; Sun, 15 Dec 2019 11:38:59 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 38EBA20700 for ; Sun, 15 Dec 2019 11:38:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="cMPM7Ij0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 38EBA20700 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=triplefau.lt Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-amlogic-bounces+patchwork-linux-amlogic=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=YEUTu9O8P/0BEoR+TSrINoPOaWARypy5T3Qjse2aFZE=; b=cMPM7Ij0qsFac6 5VcRJOmU1GHIICperRIu0MQb7X2V/tYG4N7h8MDQLhBG6C5eHdCAgSNcR+xTGb5qnoR8ehQcc28Vi dXoEy/PSV4d3ZStXQl1+TYgcoDcmoCTDNwpfjfiHF9CQ9gleYq4OZrUsu0UeZU5qIzzMMxviiptb3 O4qQf/3KQB6hR+y3Nqwz6gIvWEfCks4E8IPoPKretBIeO736aq6z4d+vrWg8aUGBMtCOZW0Si1VvD pZI1y/1hQRaUj985x5WSMnlsegXwyQZEYni72PZqIVCNgEW/GKuGZ1xom4P5eaJUp+15vn86acMPP ReI+3xumw0EUPleshX2Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1igSEk-0003BB-SE; Sun, 15 Dec 2019 11:38:58 +0000 Received: from relay12.mail.gandi.net ([217.70.178.232]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1igSEh-0003AO-FZ; Sun, 15 Dec 2019 11:38:56 +0000 Received: from localhost (unknown [88.190.179.123]) (Authenticated sender: repk@triplefau.lt) by relay12.mail.gandi.net (Postfix) with ESMTPSA id 1CEFD200003; Sun, 15 Dec 2019 11:38:51 +0000 (UTC) From: Remi Pommarel To: Neil Armstrong , Jerome Brunet Subject: [PATCH v2] clk: meson: pll: Fix by 0 division in __pll_params_to_rate() Date: Sun, 15 Dec 2019 12:47:05 +0100 Message-Id: <20191215114705.24401-1-repk@triplefau.lt> X-Mailer: git-send-email 2.24.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191215_033855_656603_000B558F X-CRM114-Status: UNSURE ( 7.52 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at https://www.dnswl.org/, low trust [217.70.178.232 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-BeenThere: linux-amlogic@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Stephen Boyd , Kevin Hilman , Michael Turquette , linux-kernel@vger.kernel.org, Remi Pommarel , linux-amlogic@lists.infradead.org, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-amlogic" Errors-To: linux-amlogic-bounces+patchwork-linux-amlogic=patchwork.kernel.org@lists.infradead.org Some meson pll registers can be initialized with 0 as N value, introducing the following division by 0 when computing rate : UBSAN: Undefined behaviour in drivers/clk/meson/clk-pll.c:75:9 division by zero CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc3-608075-g86c9af8630e1-dirty #400 Call trace: dump_backtrace+0x0/0x1c0 show_stack+0x14/0x20 dump_stack+0xc4/0x100 ubsan_epilogue+0x14/0x68 __ubsan_handle_divrem_overflow+0x98/0xb8 __pll_params_to_rate+0xdc/0x140 meson_clk_pll_recalc_rate+0x278/0x3a0 __clk_register+0x7c8/0xbb0 devm_clk_hw_register+0x54/0xc0 meson_eeclkc_probe+0xf4/0x1a0 platform_drv_probe+0x54/0xd8 really_probe+0x16c/0x438 driver_probe_device+0xb0/0xf0 device_driver_attach+0x94/0xa0 __driver_attach+0x70/0x108 bus_for_each_dev+0xd8/0x128 driver_attach+0x30/0x40 bus_add_driver+0x1b0/0x2d8 driver_register+0xbc/0x1d0 __platform_driver_register+0x78/0x88 axg_driver_init+0x18/0x20 do_one_initcall+0xc8/0x24c kernel_init_freeable+0x2b0/0x344 kernel_init+0x10/0x128 ret_from_fork+0x10/0x18 This checks if N is null before doing the division. Fixes: 7a29a869434e ("clk: meson: Add support for Meson clock controller") Signed-off-by: Remi Pommarel Reviewed-by: Martin Blumenstingl --- Changes since v1: - Change Fix tag - Move null test to .recalc_rate() --- drivers/clk/meson/clk-pll.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c index ddb1e5634739..4d3a8003ca20 100644 --- a/drivers/clk/meson/clk-pll.c +++ b/drivers/clk/meson/clk-pll.c @@ -77,6 +77,10 @@ static unsigned long meson_clk_pll_recalc_rate(struct clk_hw *hw, unsigned int m, n, frac; n = meson_parm_read(clk->map, &pll->n); + /* Some hw may have n set to 0 at init, avoid div by 0 in that case */ + if (n == 0) + return 0; + m = meson_parm_read(clk->map, &pll->m); frac = MESON_PARM_APPLICABLE(&pll->frac) ?