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Date:   Wed, 30 Nov 2022 12:23:10 +0000
From:   Vincent Donnefort <vdonnefort@google.com>
To:     Nathan Chancellor <nathan@kernel.org>
Cc:     Masahiro Yamada <masahiroy@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, Nicolas Schier <nicolas@fjasle.eu>,
        Sami Tolvanen <samitolvanen@google.com>,
        linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev, patches@lists.linux.dev
Subject: Re: [PATCH 2/2] modpost: Include '.text.*' in TEXT_SECTIONS
Message-ID: <Y4dLLnc4LTX9UHaN@google.com>
References: <20221129190123.872394-1-nathan@kernel.org>
 <20221129190123.872394-3-nathan@kernel.org>
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On Tue, Nov 29, 2022 at 12:01:23PM -0700, Nathan Chancellor wrote:
> Commit 6c730bfc894f ("modpost: handle -ffunction-sections") added
> ".text.*" to the OTHER_TEXT_SECTIONS macro to fix certain section
> mismatch warnings. Unfortunately, this makes it impossible for modpost
> to warn about section mismatchs with LTO, which implies
> '-ffunction-sections', as all functions are put in their own
> '.text.<func_name>' sections, which may still reference functions in
> sections they are not supposed to, such as __init.
> 
> Fix this by moving ".text.*" into TEXT_SECTIONS, so that configurations
> with '-ffunction-sections' will see warnings about mismatched sections.
> 
> Link: https://lore.kernel.org/Y39kI3MOtVI5BAnV@google.com/
> Reported-by: Vincent Donnefort <vdonnefort@google.com>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Thanks!

Tested-by: Vincent Donnefort <vdonnefort@google.com>

> ---
>  scripts/mod/modpost.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 2c80da0220c3..c861beabc128 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -823,10 +823,10 @@ static void check_section(const char *modname, struct elf_info *elf,
>  #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
>  
>  #define DATA_SECTIONS ".data", ".data.rel"
> -#define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \
> +#define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
>  		".kprobes.text", ".cpuidle.text", ".noinstr.text"
>  #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
> -		".fixup", ".entry.text", ".exception.text", ".text.*", \
> +		".fixup", ".entry.text", ".exception.text", \
>  		".coldtext", ".softirqentry.text"
>  
>  #define INIT_SECTIONS      ".init.*"
> -- 
> 2.38.1
>