Re: [PATCH v2 01/13] powerpc: Move 'struct ppc64_opd_entry' back into asm/elf.h

From: Daniel Axtens <dja@axtens.net>
To: Christophe Leroy <christophe.leroy@csgroup.eu>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Andrew Morton <akpm@linux-foundation.org>,
	"James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
	Helge Deller <deller@gmx.de>, Arnd Bergmann <arnd@arndb.de>,
	Kees Cook <keescook@chromium.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-arch@vger.kernel.org, linux-ia64@vger.kernel.org,
	linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org,
	linux-api@vger.kernel.org
Subject: Re: [PATCH v2 01/13] powerpc: Move 'struct ppc64_opd_entry' back into asm/elf.h
Date: Fri, 15 Oct 2021 08:26:22 +1100	[thread overview]
Message-ID: <87czo747sx.fsf@dja-thinkpad.axtens.net> (raw)
In-Reply-To: <42d2a571677e60082c0a5b3e52e855aa58c0b1fc.1634190022.git.christophe.leroy@csgroup.eu>

Hi Christophe,

> 'struct ppc64_opd_entry' doesn't belong to uapi/asm/elf.h
>
> It was initially in module_64.c and commit 2d291e902791 ("Fix compile
> failure with non modular builds") moved it into asm/elf.h
>
> But it was by mistake added outside of __KERNEL__ section,
> therefore commit c3617f72036c ("UAPI: (Scripted) Disintegrate
> arch/powerpc/include/asm") moved it to uapi/asm/elf.h

As Michael said on v1, I'm a little nervous about moving it out of uAPI
after so long, although I do take the points of Arnd and Kees that we're
not breaking compiled binaries, nor should people be using this struct
to begin with...

I've cc:ed the linux-api@ list.

Kind regards,
Daniel

> Move it back into asm/elf.h, this brings it back in line with
> IA64 and PARISC architectures.
>
> Fixes: 2d291e902791 ("Fix compile failure with non modular builds")
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/include/asm/elf.h      | 6 ++++++
>  arch/powerpc/include/uapi/asm/elf.h | 8 --------
>  2 files changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
> index b8425e3cfd81..a4406714c060 100644
> --- a/arch/powerpc/include/asm/elf.h
> +++ b/arch/powerpc/include/asm/elf.h
> @@ -176,4 +176,10 @@ do {									\
>  /* Relocate the kernel image to @final_address */
>  void relocate(unsigned long final_address);
>  
> +/* There's actually a third entry here, but it's unused */
> +struct ppc64_opd_entry {
> +	unsigned long funcaddr;
> +	unsigned long r2;
> +};
> +
>  #endif /* _ASM_POWERPC_ELF_H */
> diff --git a/arch/powerpc/include/uapi/asm/elf.h b/arch/powerpc/include/uapi/asm/elf.h
> index 860c59291bfc..308857123a08 100644
> --- a/arch/powerpc/include/uapi/asm/elf.h
> +++ b/arch/powerpc/include/uapi/asm/elf.h
> @@ -289,12 +289,4 @@ typedef elf_fpreg_t elf_vsrreghalf_t32[ELF_NVSRHALFREG];
>  /* Keep this the last entry.  */
>  #define R_PPC64_NUM		253
>  
> -/* There's actually a third entry here, but it's unused */
> -struct ppc64_opd_entry
> -{
> -	unsigned long funcaddr;
> -	unsigned long r2;
> -};
> -
> -
>  #endif /* _UAPI_ASM_POWERPC_ELF_H */
> -- 
> 2.31.1