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: 13815833 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id CA936CF649D for ; Mon, 30 Sep 2024 10:52:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; 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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 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] X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240930_035013_593619_17A8B10C X-CRM114-Status: GOOD ( 12.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 = {