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 X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 579D1C433E1 for ; Wed, 29 Jul 2020 16:03:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A77F20FC3 for ; Wed, 29 Jul 2020 16:03:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596038624; bh=VZUYphEQUTYK+8UogBIYPgtkqViD/D0Xw8dBmHZUB3g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=nnjM5aJfwW0b2K7oTuLR25/1pwlbJa09CJuJCWCwRPRZjFci6OgrVlB+wtYnhc1y5 Y6/jTAi3/IVGRhzncojDmlUx04Yv3xILhHlvKROCjCfnT/SQWsqjJsq9r6FRoKarD5 4FsJNSriOMKuxB3M6g9YRI/nE3c8oEnfUQmHquEg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726857AbgG2QDn (ORCPT ); Wed, 29 Jul 2020 12:03:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:45854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726341AbgG2QDn (ORCPT ); Wed, 29 Jul 2020 12:03:43 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 215F8206D8; Wed, 29 Jul 2020 16:03:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596038622; bh=VZUYphEQUTYK+8UogBIYPgtkqViD/D0Xw8dBmHZUB3g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=H63B0KKsLXRaZEMqJMzY3dz4ZH/fCmTxVfzOf5H0WnP/kkqDO8WFZEFch22BlY253 2JOo6UlC6YiU79+fj9gs1z0cW6CBjRc1SEipPmRMbC8QyCPeglNLdm2HJ9urPQG1ZI 4cLj/0a3oNrIMMFnesuG4XvoT7r/466u4S2AnmOI= Date: Wed, 29 Jul 2020 18:03:33 +0200 From: Greg Kroah-Hartman To: B K Karthik Cc: Jiri Slaby , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, "Vabhav Sharma (OSS)" , "bhuvanchandra.dv@toradex.com" Subject: Re: [PATCH v2] tty: serial: fsl_lpuart.c: prevent a bad shift operation Message-ID: <20200729160333.GA3652767@kroah.com> References: <20200721174228.misj2mgqzcfz2lsj@pesu.pes.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200721174228.misj2mgqzcfz2lsj@pesu.pes.edu> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 21, 2020 at 11:12:29PM +0530, B K Karthik wrote: > prevent a bad shift operation by verifying that > the argument to fls is non zero. > > Reported-by: "Vabhav Sharma (OSS)" > Signed-off-by: B K Karthik > --- > v1 -> v2: > added Reported-by tag > > drivers/tty/serial/fsl_lpuart.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c > index 7ca642249224..0cc64279cd2d 100644 > --- a/drivers/tty/serial/fsl_lpuart.c > +++ b/drivers/tty/serial/fsl_lpuart.c > @@ -1168,7 +1168,8 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport) > * 10ms at any baud rate. > */ > sport->rx_dma_rng_buf_len = (DMA_RX_TIMEOUT * baud / bits / 1000) * 2; > - sport->rx_dma_rng_buf_len = (1 << (fls(sport->rx_dma_rng_buf_len) - 1)); > + if (sport->rx_dma_rng_buf_len != 0) How can this variable become 0? thanks, greg k-h