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 029F3C31E49 for ; Thu, 13 Jun 2019 16:17:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C492A2147A for ; Thu, 13 Jun 2019 16:17:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560442658; bh=RY3K97hgIygSZmWKtc8acPXQoYc/xygDw7BuIOA6zmg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MSopqaOEthBF6aKNlDZPFuykX8yP3RDc3tPirJtkrHt7IaqSNtaVOkktgKhgCEgUQ QIMsWZuLKatxpFjOZnQREOxwD1vjYydZa4RDQwgTL8ejdzMr7AMTpiXEpQNiz7hTas s+fekKk4IrQoc+iNzQnS/LD2KJC9Uf7Zf/QuIWs0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732877AbfFMQQ7 (ORCPT ); Thu, 13 Jun 2019 12:16:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:58424 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731145AbfFMIlJ (ORCPT ); Thu, 13 Jun 2019 04:41:09 -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 1F2F221473; Thu, 13 Jun 2019 08:41:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560415268; bh=RY3K97hgIygSZmWKtc8acPXQoYc/xygDw7BuIOA6zmg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V8y0XuL89AGRNJV/lpKh+GOz7OTtPh/zgyU7QyIZtJn8osbBTFFwxNNUP+DpifMbS K3Td92kvBTeXbiIP9nssUQTK9lCJRNNywPyKDMREhmjehRx3H6ozxZmxh8keOpnp5K 1Kp912v8I93eZIGR5ToRiK4mB6h+/Q08hFNXyIZI= 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 4.19 064/118] nvmem: core: fix read buffer in place Date: Thu, 13 Jun 2019 10:33:22 +0200 Message-Id: <20190613075647.575343570@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190613075643.642092651@linuxfoundation.org> References: <20190613075643.642092651@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 7c530c88b3fb..99de51e87f7f 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -1028,7 +1028,7 @@ EXPORT_SYMBOL_GPL(nvmem_cell_put); static 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) { @@ -1043,11 +1043,16 @@ static void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, void *buf) 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