From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754837AbeCGVZU (ORCPT ); Wed, 7 Mar 2018 16:25:20 -0500 Received: from mail.bootlin.com ([62.4.15.54]:53837 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754497AbeCGVZS (ORCPT ); Wed, 7 Mar 2018 16:25:18 -0500 Date: Wed, 7 Mar 2018 22:25:06 +0100 From: Alexandre Belloni To: "Gustavo A. R. Silva" Cc: Alessandro Zummo , linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: Re: [PATCH] rtc: remove VLA usage Message-ID: <20180307212506.GO3035@piout.net> References: <20180307201133.GA5860@embeddedgus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180307201133.GA5860@embeddedgus> User-Agent: Mutt/1.9.3 (2018-01-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/03/2018 at 14:11:33 -0600, Gustavo A. R. Silva wrote: > In preparation to enabling -Wvla, remove VLA and replace it > with a fixed-length array instead. > You should probably explain what VLA is and why this is important to do. > Signed-off-by: Gustavo A. R. Silva > --- > drivers/rtc/rtc-bq32k.c | 2 +- > drivers/rtc/rtc-mcp795.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/rtc/rtc-bq32k.c b/drivers/rtc/rtc-bq32k.c > index e8698e9..e4b234a 100644 > --- a/drivers/rtc/rtc-bq32k.c > +++ b/drivers/rtc/rtc-bq32k.c > @@ -74,7 +74,7 @@ static int bq32k_read(struct device *dev, void *data, uint8_t off, uint8_t len) > static int bq32k_write(struct device *dev, void *data, uint8_t off, uint8_t len) > { > struct i2c_client *client = to_i2c_client(dev); > - uint8_t buffer[len + 1]; > + uint8_t buffer[256]; > You chose to change len to 255, probably because this is a uint8_t but this is way too much for this rtc, it only has 10 consecutive registers. > buffer[0] = off; > memcpy(&buffer[1], data, len); > diff --git a/drivers/rtc/rtc-mcp795.c b/drivers/rtc/rtc-mcp795.c > index 79e24ea..00e11c1 100644 > --- a/drivers/rtc/rtc-mcp795.c > +++ b/drivers/rtc/rtc-mcp795.c > @@ -82,7 +82,7 @@ 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[257]; > > tx[0] = MCP795_WRITE; > tx[1] = addr; > -- > 2.7.4 > -- Alexandre Belloni, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com