From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 968862AE77 for ; Sat, 30 Aug 2025 21:29:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756589390; cv=none; b=OzT7XgRxuosFNhRk5Dcbbq6Y5zcRXECC218fG2MIIf3DPAMghBY6WRAMuwWYU21s1MUHTQkpfwaOzBjUkRXb5iJ6A6kkOnmxDE9S3SzKaClvc7gatb73oaRjNgKkBThrLo4JkvfntXiPx3nRHfi1CTz1CWslvSfSydeAJTMIoAc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756589390; c=relaxed/simple; bh=nazjNil7c6YoIWTwvr8MF0GJzNNzswGy21FyNw0czQ4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=d5/zC8Kmhw9MLdAyMbzAmC8j7uKf1aqqsklNTTpW92/85PwhWhogRvugywCx1FiAmFBKkvPTHpxx2PAYedwXDgR/Zs48dAGvrZKAxXGVCBn31YvPM+gp1hqBkOhBUb45M8mxmC/Z0uKoourJesBzOh1IaQI3i26yW+5kVEvZLes= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=coZsIh5J; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="coZsIh5J" Received: from pendragon.ideasonboard.com (237.69-130-109.adsl-dyn.isp.belgacom.be [109.130.69.237]) by perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id 16DE4337C; Sat, 30 Aug 2025 23:28:39 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1756589319; bh=nazjNil7c6YoIWTwvr8MF0GJzNNzswGy21FyNw0czQ4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=coZsIh5JzjfqVisAaGMLyp5r3GM20OUCq708856ovzdu6b8NgKEA/LDIg//jBFcP0 mfOCQ3HFvKWfn0LCAMQshiidRtUEWNvZKqdkD+7VF7GwY4qdCh2aWCVsVdy7ikrctI NLu8VHtXbco5TeC5FJpaGl1jWjf8LrXEKYIObNN8= Date: Sat, 30 Aug 2025 23:29:23 +0200 From: Laurent Pinchart To: Masaharu Noguchi Cc: gregkh@linuxfoundation.org, linux-staging@lists.linux.dev, vaibhav.sr@gmail.com, mgreer@animalcreek.com, johan@kernel.org, elder@kernel.org, greybus-dev@lists.linaro.org, florian.fainelli@broadcom.com, rjui@broadcom.com, sbranden@broadcom.com, bcm-kernel-feedback-list@broadcom.com, dave.stevenson@raspberrypi.com, hverkuil@kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] staging: vc04_services: bcm2835-camera: avoid -Wformat-truncation Message-ID: <20250830212923.GB16364@pendragon.ideasonboard.com> References: <20250830173850.323897-1-nogunix@gmail.com> <20250830173850.323897-3-nogunix@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20250830173850.323897-3-nogunix@gmail.com> On Sun, Aug 31, 2025 at 02:38:50AM +0900, Masaharu Noguchi wrote: > - Fix -Wformat-truncation in vidioc_querycap() when composing bus_info. > - Use scnprintf() for the prefix and strscpy() for the remainder. > > Signed-off-by: Masaharu Noguchi > --- > .../staging/vc04_services/bcm2835-camera/bcm2835-camera.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c > index fa7ea4ca4c36..c2788659af12 100644 > --- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c > +++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c > @@ -874,13 +874,14 @@ static int vidioc_querycap(struct file *file, void *priv, > struct bcm2835_mmal_dev *dev = video_drvdata(file); > u32 major; > u32 minor; > + int n; > > vchiq_mmal_version(dev->instance, &major, &minor); > > strscpy(cap->driver, "bcm2835 mmal", sizeof(cap->driver)); > snprintf((char *)cap->card, sizeof(cap->card), "mmal service %d.%d", major, minor); > - > - snprintf((char *)cap->bus_info, sizeof(cap->bus_info), "platform:%s", dev->v4l2_dev.name); > + n = scnprintf((char *)cap->bus_info, sizeof(cap->bus_info), "platform:"); > + strscpy((char *)cap->bus_info + n, dev->v4l2_dev.name, sizeof(cap->bus_info) - n); The fact that we need such a complicated construct is a sign that there's something wrong in our APIs. The above code is too complicated for what it does, making it less readable, more difficult to maintain, and more bug-prone. I don't know if we need yet another sprintf variant in the kernel, or something else, but this doens't seem to be what we need. > return 0; > } > -- Regards, Laurent Pinchart