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 4B98810F6 for ; Thu, 30 Nov 2023 00:32:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="f3FK9HcP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C58FC433C7; Thu, 30 Nov 2023 00:32:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1701304329; bh=sWTZRFs3LpzmxPcfO3M2aIt9v0k5GfKcQDamobqt17I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=f3FK9HcPl3lhLpfF6lkcbEeA2aI0sYUCtwwghlEFKnuLYH6krMrGR81GpJY3MmJbT 80nRU8sIxCxJ9H5HfLmLQYqg0Zo56C8IxbToyb5Z4W7dO2ayMmXduy2zq7/LS4oGUe Cpkq5Tkd3qhwKt8O6W6WND6FWlpBPgPme9TePxSkCwxA/UDNDFysFcjrsC9BrehP7f IQM93kmasmjIu36h2mNO/7mbqm3u+ORiwCEONIh9nPKzwL9Cmv8amSnGHFx6lSyWBL b9R589WnaarzVSV548Q91I5rgRxVYBwarANnrPu770SVphzPxnntt6A7gmiTHT5Hw5 JOJA7mgCVp3LQ== Date: Wed, 29 Nov 2023 17:32:07 -0700 From: Nathan Chancellor To: Masahiro Yamada Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, Nicolas Schier Subject: Re: [PATCH 3/3] modpost: move exit(1) for fatal() to modpost.h Message-ID: <20231130003207.GD2513828@dev-arch.thelio-3990X> References: <20231125103116.797608-1-masahiroy@kernel.org> <20231125103116.797608-3-masahiroy@kernel.org> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231125103116.797608-3-masahiroy@kernel.org> On Sat, Nov 25, 2023 at 07:31:16PM +0900, Masahiro Yamada wrote: > fatal() never returns, but compilers are not aware of this fact because > exit(1) is called within the modpost_log() definition. > > Move exit(1) to the fatal() macro so that compilers can identify > unreachable code flows. > > Remove the initializer for 'taddr' in section_rel(), as compilers now > recognize this is not an uninitialized bug. > > Signed-off-by: Masahiro Yamada While I did not see any warnings when testing, it seems like this patch should come before patch 2 to avoid any potential problems from dropping the unreachable code (since the compiler won't be able to infer that fatal() is __noreturn without this change); doesn't really matter though so: Reviewed-by: Nathan Chancellor > --- > > scripts/mod/modpost.c | 4 +--- > scripts/mod/modpost.h | 2 +- > 2 files changed, 2 insertions(+), 4 deletions(-) > > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c > index 013fc5031bc7..696c583a14ec 100644 > --- a/scripts/mod/modpost.c > +++ b/scripts/mod/modpost.c > @@ -84,8 +84,6 @@ void modpost_log(enum loglevel loglevel, const char *fmt, ...) > vfprintf(stderr, fmt, arglist); > va_end(arglist); > > - if (loglevel == LOG_FATAL) > - exit(1); > if (loglevel == LOG_ERROR) > error_occurred = true; > } > @@ -1415,7 +1413,7 @@ static void section_rel(struct module *mod, struct elf_info *elf, > > for (rel = start; rel < stop; rel++) { > Elf_Sym *tsym; > - Elf_Addr taddr = 0, r_offset; > + Elf_Addr taddr, r_offset; > unsigned int r_type, r_sym; > void *loc; > > diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h > index 9fe974dc1a52..aaa67b24775e 100644 > --- a/scripts/mod/modpost.h > +++ b/scripts/mod/modpost.h > @@ -215,4 +215,4 @@ modpost_log(enum loglevel loglevel, const char *fmt, ...); > */ > #define warn(fmt, args...) modpost_log(LOG_WARN, fmt, ##args) > #define error(fmt, args...) modpost_log(LOG_ERROR, fmt, ##args) > -#define fatal(fmt, args...) modpost_log(LOG_FATAL, fmt, ##args) > +#define fatal(fmt, args...) do { modpost_log(LOG_FATAL, fmt, ##args); exit(1); } while (1) > -- > 2.40.1 >