[PATCH 4/8] binfmt_elf: open code copy_siginfo_to_user to kernelspace buffer

[Christoph Hellwig]

On Wed, Apr 15, 2020 at 01:01:59PM +1000, Michael Ellerman wrote:
> > +	to_compat_siginfo(csigdata, siginfo, compat_siginfo_flags());	\
> > +	fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata); \
> > +} while (0)
> 
> This doesn't build on ppc (cell_defconfig):
> 
>   ../fs/binfmt_elf.c: In function 'fill_note_info':
>   ../fs/compat_binfmt_elf.c:44:39: error: implicit declaration of function 'compat_siginfo_flags'; did you mean 'to_compat_siginfo'? [-Werror=implicit-function-d
>   eclaration]
>     to_compat_siginfo(csigdata, siginfo, compat_siginfo_flags()); \
>                                          ^~~~~~~~~~~~~~~~~~~~
>   ../fs/binfmt_elf.c:1846:2: note: in expansion of macro 'fill_siginfo_note'
>     fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
>     ^~~~~~~~~~~~~~~~~
>   cc1: some warnings being treated as errors
>   make[2]: *** [../scripts/Makefile.build:266: fs/compat_binfmt_elf.o] Error 1
> 
> 
> I guess the empty version from kernel/signal.c needs to move into a
> header somewhere.

Yes, it should.  Odd that the buildbut hasn't complained yet so far..