From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932316AbeCLXNv (ORCPT ); Mon, 12 Mar 2018 19:13:51 -0400 Received: from mail-wr0-f195.google.com ([209.85.128.195]:47098 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751695AbeCLXNt (ORCPT ); Mon, 12 Mar 2018 19:13:49 -0400 X-Google-Smtp-Source: AG47ELudDmrmFQjsbfpXKwUsyURddAqrj1wdhmsL93eFvKYsQ09+R8bZ3jRMsUycqtz4iQLrpr8/YA== From: Stefano Manni To: a.zummo@towertech.it, alexandre.belloni@free-electrons.com Cc: linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, Stefano Manni Subject: [PATCH] rtc: mcp795: remove VLA usage Date: Tue, 13 Mar 2018 00:13:38 +0100 Message-Id: <20180312231338.3756-1-stefano.manni@gmail.com> X-Mailer: git-send-email 2.9.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In preparation to enabling -Wvla, remove VLAs and replace them with fixed-length arrays instead. rtc-mcp795.c uses a variable-length array declaration to contain the command to write the rtcc; this can be replaced by a fixed- size array of length 2 (instruction, address) + 32 (data out), assuming a maximum data length of 32 bytes before wrap up. This was prompted by https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Stefano Manni --- drivers/rtc/rtc-mcp795.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-mcp795.c b/drivers/rtc/rtc-mcp795.c index 77f21331ae21..a5f504e2364c 100644 --- a/drivers/rtc/rtc-mcp795.c +++ b/drivers/rtc/rtc-mcp795.c @@ -61,6 +61,9 @@ #define SEC_PER_DAY (24 * 60 * 60) +/* Maximum length for data out in write operation to RTCC */ +#define MCP795_MAX_DATAOUT_LEN 32 + static int mcp795_rtcc_read(struct device *dev, u8 addr, u8 *buf, u8 count) { struct spi_device *spi = to_spi_device(dev); @@ -82,7 +85,10 @@ static int mcp795_rtcc_write(struct device *dev, u8 addr, u8 *data, u8 count) { struct spi_device *spi = to_spi_device(dev); int ret; - u8 tx[2 + count]; + u8 tx[2 + MCP795_MAX_DATAOUT_LEN]; + + if (count > MCP795_MAX_DATAOUT_LEN) + return -EINVAL; tx[0] = MCP795_WRITE; tx[1] = addr; -- 2.14.3