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=-8.8 required=3.0 tests=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,USER_AGENT_GIT autolearn=ham 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 5B2A0C43613 for ; Thu, 20 Jun 2019 18:03:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D06B21537 for ; Thu, 20 Jun 2019 18:03:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561053804; bh=S5vSnau8veV4jnNwBCLbUvZEBtP89lQiDn0A+dqi00E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Q5Rgp5fYWhtj6AFg3KupNy9SLkKJUC5g75z6sWnMlcyhn9IiIsKkZndP38PC4qI2H U2AVWCx4PZVTSBToGAmNr3S/00eTwGOnRchpJCYcDIDPwSjtgZXkYYJgvj4l29XQmn Hdl5KR4Xq1KY0lTbBINRrvxhGtloeNIyPgZfv9gY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727620AbfFTSDX (ORCPT ); Thu, 20 Jun 2019 14:03:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:54412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727581AbfFTSDT (ORCPT ); Thu, 20 Jun 2019 14:03:19 -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 BEDF521479; Thu, 20 Jun 2019 18:03:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561053798; bh=S5vSnau8veV4jnNwBCLbUvZEBtP89lQiDn0A+dqi00E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mU2zoeRIpZNg1sovYVawqXoag3Ri+s48wWGQeR93ajiRJ2mhMm6wfxbO2Sgg3yWM2 QQ1ROvToD3y/CGej2Q02IfNraewV+yjCVS5lut99yuFr3z3SVP6Hno9g4xYHXwjrIF INFzNhBgyMpCYIv/ySudjI71iT07Ow/dMNXLivTk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jorge Ramirez-Ortiz , Srinivas Kandagatla , Sasha Levin Subject: [PATCH 4.9 030/117] nvmem: core: fix read buffer in place Date: Thu, 20 Jun 2019 19:56:04 +0200 Message-Id: <20190620174353.789250695@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190620174351.964339809@linuxfoundation.org> References: <20190620174351.964339809@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 2fe518fecb3a4727393be286db9804cd82ee2d91 ] When the bit_offset in the cell is zero, the pointer to the msb will not be properly initialized (ie, will still be pointing to the first byte in the buffer). This being the case, if there are bits to clear in the msb, those will be left untouched while the mask will incorrectly clear bit positions on the first byte. This commit also makes sure that any byte unused in the cell is cleared. Signed-off-by: Jorge Ramirez-Ortiz Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/nvmem/core.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 824e282cd80e..bb2f79933b17 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -934,7 +934,7 @@ static inline void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, void *buf) { u8 *p, *b; - int i, bit_offset = cell->bit_offset; + int i, extra, bit_offset = cell->bit_offset; p = b = buf; if (bit_offset) { @@ -949,11 +949,16 @@ static inline void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, p = b; *b++ >>= bit_offset; } - - /* result fits in less bytes */ - if (cell->bytes != DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE)) - *p-- = 0; + } else { + /* point to the msb */ + p += cell->bytes - 1; } + + /* result fits in less bytes */ + extra = cell->bytes - DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE); + while (--extra >= 0) + *p-- = 0; + /* clear msb bits if any leftover in the last byte */ *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0); } -- 2.20.1