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Date:   Wed, 28 Dec 2022 09:34:48 -0700
From:   Nathan Chancellor <nathan@kernel.org>
To:     Samuel Holland <samuel@sholland.org>
Cc:     Masahiro Yamada <masahiroy@kernel.org>,
        linux-kbuild@vger.kernel.org,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nicolas Schier <nicolas@fjasle.eu>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kbuild: Fix running modpost with musl libc
Message-ID: <Y6xwKFwtTrZ4Uzqk@dev-arch.thelio-3990X>
References: <20221227214821.16495-1-samuel@sholland.org>
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On Tue, Dec 27, 2022 at 03:48:21PM -0600, Samuel Holland wrote:
> commit 3d57e1b7b1d4 ("kbuild: refactor the prerequisites of the modpost
> rule") moved 'vmlinux.o' inside modpost-args, possibly before some of
> the other options. However, getopt() in musl libc follows POSIX and
> stops looking for options upon reaching the first non-option argument.
> As a result, the '-T' option is misinterpreted as a positional argument,
> and the build fails:
> 
>   make -f ./scripts/Makefile.modpost
>      scripts/mod/modpost   -E   -o Module.symvers vmlinux.o -T modules.order
>   -T: No such file or directory
>   make[1]: *** [scripts/Makefile.modpost:137: Module.symvers] Error 1
>   make: *** [Makefile:1960: modpost] Error 2
> 
> The fix is to move all options before 'vmlinux.o' in modpost-args.
> 
> Fixes: 3d57e1b7b1d4 ("kbuild: refactor the prerequisites of the modpost rule")
> Signed-off-by: Samuel Holland <samuel@sholland.org>

Seems reasonable to me.

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
> 
>  scripts/Makefile.modpost | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
> index 5eb5e8280379..0ee296cf520c 100644
> --- a/scripts/Makefile.modpost
> +++ b/scripts/Makefile.modpost
> @@ -55,6 +55,17 @@ ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
>  modpost-args += -n
>  endif
>  
> +ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
> +modpost-args += -w
> +endif
> +
> +# Read out modules.order to pass in modpost.
> +# Otherwise, allmodconfig would fail with "Argument list too long".
> +ifdef KBUILD_MODULES
> +modpost-args += -T $(MODORDER)
> +modpost-deps += $(MODORDER)
> +endif
> +
>  ifeq ($(KBUILD_EXTMOD),)
>  
>  # Generate the list of in-tree objects in vmlinux
> @@ -113,17 +124,6 @@ modpost-args += -e $(addprefix -i , $(KBUILD_EXTRA_SYMBOLS))
>  
>  endif # ($(KBUILD_EXTMOD),)
>  
> -ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
> -modpost-args += -w
> -endif
> -
> -ifdef KBUILD_MODULES
> -modpost-args += -T $(MODORDER)
> -modpost-deps += $(MODORDER)
> -endif
> -
> -# Read out modules.order to pass in modpost.
> -# Otherwise, allmodconfig would fail with "Argument list too long".
>  quiet_cmd_modpost = MODPOST $@
>        cmd_modpost = \
>  	$(if $(missing-input), \
> -- 
> 2.37.4
>