Re: [PATCH] tty: mxser: Remove __counted_by from mxser_board.ports[] - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Jiri Slaby <jirislaby@kernel.org>, Nathan Chancellor <nathan@kernel.org>
Cc: Kees Cook <keescook@chromium.org>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	Bill Wendling <morbo@google.com>,
	Justin Stitt <justinstitt@google.com>,
	linux-serial@vger.kernel.org, imx@lists.linux.dev,
	linux-arm-kernel@lists.infradead.org,
	linux-hardening@vger.kernel.org, llvm@lists.linux.dev,
	patches@lists.linux.dev, stable@vger.kernel.org
Subject: Re: [PATCH] tty: mxser: Remove __counted_by from mxser_board.ports[]
Date: Thu, 30 May 2024 09:40:13 +0200	[thread overview]
Message-ID: <2024053008-sadly-skydiver-92be@gregkh> (raw)
In-Reply-To: <d7c19866-6883-4f98-b178-a5ccf8726895@kernel.org>

On Thu, May 30, 2024 at 08:22:03AM +0200, Jiri Slaby wrote:
> >  This will be an error in a future compiler version [-Werror,-Wbounds-safety-counted-by-elt-type-unknown-size]
> >      291 |         struct mxser_port ports[] __counted_by(nports);
> >          |         ^~~~~~~~~~~~~~~~~~~~~~~~~
> >    1 error generated.
> > 
> > Remove this use of __counted_by to fix the warning/error. However,
> > rather than remove it altogether, leave it commented, as it may be
> > possible to support this in future compiler releases.
> 
> This looks like a compiler bug/deficiency.

I agree, why not just turn that option off in the compiler so that these
"warnings" will not show up?

> What does gcc say BTW?
> 
> > Cc: stable@vger.kernel.org
> > Closes: https://github.com/ClangBuiltLinux/linux/issues/2026
> > Fixes: f34907ecca71 ("mxser: Annotate struct mxser_board with __counted_by")
> 
> I would not say "Fixes" here. It only works around a broken compiler.

Agreed, don't add Fixes: for this, it's a compiler bug, not a kernel
issue.

thanks,

greg k-h