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Date:   Sun, 10 Jan 2021 19:05:43 -0700
From:   Nathan Chancellor <natechancellor@gmail.com>
To:     Alexander Lobakin <alobakin@pm.me>
Cc:     Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Arnd Bergmann <arnd@arndb.de>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Huacai Chen <chenhuacai@kernel.org>,
        Pei Huang <huangpei@loongson.cn>,
        Kees Cook <keescook@chromium.org>,
        Fangrui Song <maskray@google.com>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        Ralf Baechle <ralf@linux-mips.org>,
        Corey Minyard <cminyard@mvista.com>,
        linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arch@vger.kernel.org, stable@vger.kernel.org,
        clang-built-linux@googlegroups.com
Subject: Re: [PATCH v5 mips-next 8/9] vmlinux.lds.h: catch UBSAN's "unnamed
 data" into data
Message-ID: <20210111020543.GB2918900@ubuntu-m3-large-x86>
References: <20210110115245.30762-1-alobakin@pm.me>
 <20210110115546.30970-1-alobakin@pm.me>
 <20210110115546.30970-8-alobakin@pm.me>
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On Sun, Jan 10, 2021 at 11:56:54AM +0000, Alexander Lobakin wrote:
> When building kernel with both LD_DEAD_CODE_DATA_ELIMINATION and
> UBSAN, LLVM stack generates lots of "unnamed data" sections:
> 
> ld.lld: warning: net/built-in.a(netfilter/utils.o): (.data.$__unnamed_2)
> is being placed in '.data.$__unnamed_2'
> ld.lld: warning: net/built-in.a(netfilter/utils.o): (.data.$__unnamed_3)
> is being placed in '.data.$__unnamed_3'
> ld.lld: warning: net/built-in.a(netfilter/utils.o): (.data.$__unnamed_4)
> is being placed in '.data.$__unnamed_4'
> ld.lld: warning: net/built-in.a(netfilter/utils.o): (.data.$__unnamed_5)
> is being placed in '.data.$__unnamed_5'
> 
> [...]
> 
> Also handle this by adding the related sections to generic definitions.
> 
> Signed-off-by: Alexander Lobakin <alobakin@pm.me>

Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>

> ---
>  include/asm-generic/vmlinux.lds.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
> index 5f2f5b1db84f..cc659e77fcb0 100644
> --- a/include/asm-generic/vmlinux.lds.h
> +++ b/include/asm-generic/vmlinux.lds.h
> @@ -95,7 +95,7 @@
>   */
>  #ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
>  #define TEXT_MAIN .text .text.[0-9a-zA-Z_]*
> -#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral*
> +#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral* .data.$__unnamed_*
>  #define SDATA_MAIN .sdata .sdata.[0-9a-zA-Z_]*
>  #define RODATA_MAIN .rodata .rodata.[0-9a-zA-Z_]* .rodata..L*
>  #define BSS_MAIN .bss .bss.[0-9a-zA-Z_]* .bss..compoundliteral*
> -- 
> 2.30.0
> 
>