From patchwork Mon Sep 30 10:49:34 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandra Diupina X-Patchwork-Id: 13815835 Received: from mx.astralinux.ru (mx.astralinux.ru [89.232.161.68]) (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 5313918BB9E; Mon, 30 Sep 2024 10:50:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=89.232.161.68 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727693417; cv=none; b=fMrqRiYu7WbHrrH2QcSg2UsEFe4ZhmYTvJpH6pZWyJvWEh12fb2vFjakm60oPwW207S89He5frC8LfM8j4+hA0iI7GgpCTjDpc4FiC2X2w7pAyRt7CACK5VLbaRjANIWwFVgDZHEs+dzJuKlMQG7BgSj43UwX69rFrhQQ81Beeg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727693417; c=relaxed/simple; bh=w4J45orhsf8tZYcUUE666E7eYUVbtcrj8y83qf8plJw=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=qm7oHFUrG7hc+k3RuePLaJRx5enI16tMS29vSUFDURDY6J0kD/LPDk9zHvmRxyF008+UFYHGQTZQeWCyrW41VAKm4OU3iFXa2qBT0DAqqdg1/dQ+cNaeOIAoCJ7NuMC0OoXyrTP8iW3KDgfJKridbOD3gM8DexgAHbSacifqtqw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=astralinux.ru; spf=pass smtp.mailfrom=astralinux.ru; arc=none smtp.client-ip=89.232.161.68 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=astralinux.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=astralinux.ru Received: from [10.177.185.108] (helo=new-mail.astralinux.ru) by mx.astralinux.ru with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1svDwx-00Fdfn-N7; Mon, 30 Sep 2024 13:48:19 +0300 Received: from rbta-msk-lt-302690.astralinux.ru (unknown [10.198.42.81]) by new-mail.astralinux.ru (Postfix) with ESMTPA id 4XHHrt5xRnz1gwkc; Mon, 30 Sep 2024 13:49:50 +0300 (MSK) From: Alexandra Diupina To: Andrew Lunn Cc: Alexandra Diupina , Gregory Clement , Sebastian Hesselbarth , Michael Turquette , Stephen Boyd , linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org Subject: [PATCH v4] clk: mvebu: Prevent division by zero in clk_double_div_recalc_rate() Date: Mon, 30 Sep 2024 13:49:34 +0300 Message-Id: <20240930104934.4342-1-adiupina@astralinux.ru> X-Mailer: git-send-email 2.30.2 Precedence: bulk X-Mailing-List: linux-clk@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-DrWeb-SpamScore: 0 X-DrWeb-SpamState: legit X-DrWeb-SpamDetail: gggruggvucftvghtrhhoucdtuddrgedvfedrvdehuddgtddvucetufdoteggodetrfcurfhrohhfihhlvgemucfftfghgfeunecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhvfevufffkffoggfgsedtkeertdertddtnecuhfhrohhmpeetlhgvgigrnhgurhgrucffihhuphhinhgruceorgguihhuphhinhgrsegrshhtrhgrlhhinhhugidrrhhuqeenucggtffrrghtthgvrhhnpeduleetfeehffekueeuffektefgudfgffeutdefudfghedvieffheehleeuieehteenucffohhmrghinheplhhinhhugihtvghsthhinhhgrdhorhhgnecukfhppedutddrudelkedrgedvrdekudenucfrrghrrghmpehhvghloheprhgsthgrqdhmshhkqdhlthdqfedtvdeiledtrdgrshhtrhgrlhhinhhugidrrhhupdhinhgvthepuddtrdduleekrdegvddrkedumeegtdeludeipdhmrghilhhfrhhomheprgguihhuphhinhgrsegrshhtrhgrlhhinhhugidrrhhupdhnsggprhgtphhtthhopedutddprhgtphhtthhopegrnhgurhgvfieslhhunhhnrdgthhdprhgtphhtthhopegrughiuhhpihhnrgesrghsthhrrghlihhnuhigrdhruhdprhgtphhtthhopehgrhgvghhorhihrdgtlhgvmhgvnhhtsegsohhothhlihhnrdgtohhmpdhrtghpthhtohepshgvsggrshhtihgrnhdrhhgvshhsvghlsggrrhhthhesghhmrghilhdrtghomhdprhgtphhtthhope hmthhurhhquhgvthhtvgessggrhihlihgsrhgvrdgtohhmpdhrtghpthhtohepshgsohihugeskhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqrghrmhdqkhgvrhhnvghlsehlihhsthhsrdhinhhfrhgruggvrggurdhorhhgpdhrtghpthhtoheplhhinhhugidqtghlkhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlvhgtqdhprhhojhgvtghtsehlihhnuhigthgvshhtihhnghdrohhrghenucffrhdrhggvsgcutehnthhishhprghmmecunecuvfgrghhsme X-DrWeb-SpamVersion: Dr.Web Antispam 1.0.7.202406240#1727684630#02 X-AntiVirus: Checked by Dr.Web [MailD: 11.1.19.2307031128, SE: 11.1.12.2210241838, Core engine: 7.00.65.05230, Virus records: 12190301, Updated: 2024-Sep-30 09:34:50 UTC] get_div() may return zero, so it is necessary to check before calling DIV_ROUND_UP_ULL(). Return value of get_div() depends on reg1, reg2, shift1, shift2 fields of clk_double_div structure which are filled using the PERIPH_DOUBLEDIV macro. This macro is called from the PERIPH_CLK_FULL_DD and PERIPH_CLK_MUX_DD macros (the last 4 arguments). It is not known exactly what values can be contained in the registers at the addresses DIV_SEL0, DIV_SEL1, DIV_SEL2, so the final value of div can be zero. Print an error message and return 0 in this case. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 8ca4746a78ab ("clk: mvebu: Add the peripheral clock driver for Armada 3700") Signed-off-by: Alexandra Diupina --- v4: replace hw->init->name with clk_hw_get_name(hw) v3: fix indentation v2: added explanations to the commit message and printing of an error message when div==0 drivers/clk/mvebu/armada-37xx-periph.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/clk/mvebu/armada-37xx-periph.c b/drivers/clk/mvebu/armada-37xx-periph.c index 13906e31bef8..2f0145a76f22 100644 --- a/drivers/clk/mvebu/armada-37xx-periph.c +++ b/drivers/clk/mvebu/armada-37xx-periph.c @@ -343,7 +343,12 @@ static unsigned long clk_double_div_recalc_rate(struct clk_hw *hw, div = get_div(double_div->reg1, double_div->shift1); div *= get_div(double_div->reg2, double_div->shift2); - return DIV_ROUND_UP_ULL((u64)parent_rate, div); + if (!div) { + pr_err("Can't recalculate the rate of clock %s\n", clk_hw_get_name(hw)); + return 0; + } else { + return DIV_ROUND_UP_ULL((u64)parent_rate, div); + } } static const struct clk_ops clk_double_div_ops = {