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 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 35934C6FD1F for ; Fri, 29 Mar 2024 12:49:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0yKsQxcddYwYVFmPa+CcdY8wNJfESP+Cbpq9DqsCa2c=; b=wg3w6eS6HZjDR0 8PrtKqPZwz1s8K7LVlCBPuaNFA3vxTs6vKozjSa1fhjJEp/DB6ME785cQK9CIhyrG3XIicdYRRADF mqt/KJAtZP41Sopiw2klfEUkyWRT7cuNF7jU+cLwYoclNUqsy6BQVoSFDZAW6eNXyXvqWmlhebbZD Dr7N6ET5KllrTOIouI/fEmK0Qhlus4P9TiT1OjcmQ6fy+1B8D8PwYPA4vAC/LAXaFX567d/sQiI1e hIj6tFn3yWwENOimXN6qd128kzraO2UUUrX4tU4CcTjgA4mdtV830Nh5ZaefCjAq+oZQHCYcF/KY1 tutGJQShOCYb9AAx53MQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rqBfb-00000000Tj5-3jEr; Fri, 29 Mar 2024 12:49:19 +0000 Received: from sin.source.kernel.org ([145.40.73.55]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rqBeQ-00000000T49-2ty1; Fri, 29 Mar 2024 12:48:09 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id E545FCE2F9E; Fri, 29 Mar 2024 12:48:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E403C433C7; Fri, 29 Mar 2024 12:48:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711716484; bh=Kx+1H+QtnuCB8ciX29fyhB79zT4Lxwy5pONlNfKxAiY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gs6mSHp3QbkBXyZ9L/bXL4MJ2rhy5ykyO1XxzKwMmecRldVYVzPjyYqxgtUAeRnUc b+6Y7LzYBXaPru5Fp1xyjCaoFCuEYg6Ymntmk4c9T81Ye5tc0j4waCC37DmOtOS2FI FCVO6aogisEEVRmCaIdJVxQyaZMN64Q+gDT5I/herSREGW/8WhLqnf4nXU3/ANB3kG fkVLtaXXufA07oMgxCvsGM2kDoMbLYI5z/xtt86M3xUnDVBnbdP5xWv34837byNldD PL7asfdK3eRNK5PMh3Z7/eoTR7vzO9Vx+lDwAn5N6SO49ozp0nFrd5atWH4rzglEwW IX6TPnoOYlVcw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: C Cheng , Bo Ye , AngeloGioacchino Del Regno , "Rafael J . Wysocki" , Sasha Levin , rafael@kernel.org, daniel.lezcano@linaro.org, matthias.bgg@gmail.com, linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH AUTOSEL 5.15 09/34] cpuidle: Avoid potential overflow in integer multiplication Date: Fri, 29 Mar 2024 08:47:10 -0400 Message-ID: <20240329124750.3092394-9-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240329124750.3092394-1-sashal@kernel.org> References: <20240329124750.3092394-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.153 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240329_054807_286262_2B0192EC X-CRM114-Status: GOOD ( 13.66 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: C Cheng [ Upstream commit 88390dd788db485912ee7f9a8d3d56fc5265d52f ] In detail: In C language, when you perform a multiplication operation, if both operands are of int type, the multiplication operation is performed on the int type, and then the result is converted to the target type. This means that if the product of int type multiplication exceeds the range that int type can represent, an overflow will occur even if you store the result in a variable of int64_t type. For a multiplication of two int values, it is better to use mul_u32_u32() rather than s->exit_latency_ns = s->exit_latency * NSEC_PER_USEC to avoid potential overflow happenning. Signed-off-by: C Cheng Signed-off-by: Bo Ye Reviewed-by: AngeloGioacchino Del Regno [ rjw: New subject ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/cpuidle/driver.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index f70aa17e2a8e0..c594e28adddf3 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -16,6 +16,7 @@ #include #include #include +#include #include "cpuidle.h" @@ -185,7 +186,7 @@ static void __cpuidle_driver_init(struct cpuidle_driver *drv) s->target_residency_ns = 0; if (s->exit_latency > 0) - s->exit_latency_ns = s->exit_latency * NSEC_PER_USEC; + s->exit_latency_ns = mul_u32_u32(s->exit_latency, NSEC_PER_USEC); else if (s->exit_latency_ns < 0) s->exit_latency_ns = 0; } -- 2.43.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel