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=-8.7 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=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 DE10BC31E45 for ; Thu, 13 Jun 2019 16:23:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ACA6F21721 for ; Thu, 13 Jun 2019 16:23:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560443038; bh=ZGndjzQpcAoCRxlon7DC+AkKBhels1jY8c0itpcF84g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ITxSsp0jLrKOkRLi53FIDbdRFHDSFDuL+Ee8ogJGYeicq7zfx9FBuB4VLMWqs6x0N BVF+uATDQeDt4LxDcexekL1zusW0ctez7f4vy3aArfKfXHkLI+BCAaKV5Z6xS8Dpwx +P5FUqoimgNb9bRVHrtmZ038rZeinN+sV7jnoI+A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403805AbfFMQXv (ORCPT ); Thu, 13 Jun 2019 12:23:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:54930 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731010AbfFMIhc (ORCPT ); Thu, 13 Jun 2019 04:37:32 -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 1F69B2064A; Thu, 13 Jun 2019 08:37:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560415051; bh=ZGndjzQpcAoCRxlon7DC+AkKBhels1jY8c0itpcF84g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ln2ptqPeNxJqyuGDAXEaxAI8AJImNOK/ec2qB8w07BAkhEyPbyvxJ7BWycxm6zR44 g2+oZSO+n2BasIpdKpQcIfAYJlJEVg0oRecfKH+07B5u9RPQw8wTGZrYd4KLQPbcbd 1I0uaDjsFcwL0VNPzGMHISHgKeXD5K6rP8/MRABk= 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 4.14 42/81] nvmem: core: fix read buffer in place Date: Thu, 13 Jun 2019 10:33:25 +0200 Message-Id: <20190613075652.424569646@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190613075649.074682929@linuxfoundation.org> References: <20190613075649.074682929@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 635886e4835c..dba3f4d0a63d 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -954,7 +954,7 @@ 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) { @@ -969,11 +969,16 @@ 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