From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 04C4E14294; Thu, 28 Mar 2024 14:11:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711635101; cv=none; b=h/CXaKqMiEIC4p8e9QFveFjFkh2DGQ3IW/59qxLRygnzTLCxtLsI2XdDcGhz1ra8Ei5YCU3yLyus0MEobecnVUxYeDwHmmtsMgfXEO27EUrDUP+laxoIgJBT9bsZM4tXJN14lbCS00DHTD4VfIhWt77LQfS8xpmTEQsqpedEIkE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711635101; c=relaxed/simple; bh=tQsOJkvXX4/JlxEm1if34+dTH/cbHDaopNV04LTB0NI=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=GcWre7txweTUCRZYY6k1CpE66f9Cd/EWhUacVFhgi8jLNve3yl4zye0SPkfaN6Y85hmj9fzhn8BDVQY4j7/6U0gH/hDKgI17VzFQ4V4jpVLcUCAC7MSI5OjgJdLND8ImWhI6DHYEXAHgb5xtrGvY8rkZjLniEdebyMyukKzldLE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9488DC433F1; Thu, 28 Mar 2024 14:11:39 +0000 (UTC) Date: Thu, 28 Mar 2024 10:14:22 -0400 From: Steven Rostedt To: Arnd Bergmann Cc: linux-kernel@vger.kernel.org, Jens Axboe , Masami Hiramatsu , Arnd Bergmann , Mathieu Desnoyers , linux-block@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH 08/11] blktrace: convert strncpy() to strscpy_pad() Message-ID: <20240328101422.37e1c4f0@gandalf.local.home> In-Reply-To: <20240328140512.4148825-9-arnd@kernel.org> References: <20240328140512.4148825-1-arnd@kernel.org> <20240328140512.4148825-9-arnd@kernel.org> X-Mailer: Claws Mail 3.19.1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 28 Mar 2024 15:04:52 +0100 Arnd Bergmann wrote: > From: Arnd Bergmann > > gcc-9 warns about a possibly non-terminated string copy: > > kernel/trace/blktrace.c: In function 'do_blk_trace_setup': > kernel/trace/blktrace.c:527:2: error: 'strncpy' specified bound 32 equals destination size [-Werror=stringop-truncation] > > Newer versions are fine here because they see the following explicit > nul-termination. Using strscpy_pad() avoids the warning and > simplifies the code a little. The padding helps give a clean > buffer to userspace. > > Signed-off-by: Arnd Bergmann > --- > kernel/trace/blktrace.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c > index d5d94510afd3..95a00160d465 100644 > --- a/kernel/trace/blktrace.c > +++ b/kernel/trace/blktrace.c > @@ -524,8 +524,7 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, > if (!buts->buf_size || !buts->buf_nr) > return -EINVAL; > > - strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); > - buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; > + strscpy(buts->name, name, BLKTRACE_BDEV_SIZE); The commit message says "Using strscpy_pad()" but it doesn't do so in the patch. Rule 12 of debugging: "When the comment and the code do not match, they are probably both wrong" -- Steve > > /* > * some device names have larger paths - convert the slashes