[PATCH] powerpc: link error on orphan sections

[Michael Ellerman]

Nicholas Piggin <npiggin at gmail.com> writes:

> Add --orphan-handling=error to final link flags. This ensures we have to
> handle all sections. This would have caught subtle breakage such as
> 7de3b27bac47da9de08409df1d69664acbb72197 at build-time.
>
> Also bring some wayward sections into the fold:
> - .text.hot and .text.unlikely are compiler generated sections.
> - .sfpr is a linker generated section for register save functions.
> - .sdata2, .dynsbss, .plt are used by PPC32
> - We previously did not specify DWARF_DEBUG or STABS_DEBUG
> - DWARF_DEBUG did not include DWARF3 .debug_ranges
> - A number of sections are unused.
>
> I don't know if I've exactly got everything right here, particularly
> with ppc32, so would appreciate people casting their eye over it.
>
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
> ---
>  arch/powerpc/Makefile             |  2 +-
>  arch/powerpc/kernel/vmlinux.lds.S | 16 ++++++++++++++--
>  include/asm-generic/vmlinux.lds.h |  3 +++
>  3 files changed, 18 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
> index 50d020a..a3f2784 100644
> --- a/arch/powerpc/Makefile
> +++ b/arch/powerpc/Makefile
> @@ -90,7 +90,7 @@ endif
>  
>  LDFLAGS_vmlinux-y := -Bstatic
>  LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie
> -LDFLAGS_vmlinux	:= $(LDFLAGS_vmlinux-y)
> +LDFLAGS_vmlinux	:= $(LDFLAGS_vmlinux-y) --orphan-handling=error

At least some old(er) toolchains don't support that:

  /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld: unrecognized option '--orphan-handling=error'

So we'll need an ld-option wrapper around it.

cheers