Re: [PATCH] powerpc: Link with -z notext

[Thomas Huth <thuth@redhat.com>]

Am 10.11.26 um 16:44 schrieb Amit Machhiwal:
> Building the powerpc tests with GNU ld 2.46.1 fails when linking the
> test binaries:
> 
>    /usr/bin/ld.bfd: error: read-only segment has dynamic relocations
> 
> The tests are linked with -pie and relocate themselves at boot (see
> relocate() in powerpc/reloc64.c, called from powerpc/cstart64.S).
> Newer GNU ld rejects relocations in read-only segments by default.  The
> Makefile already checks after linking that only R_PPC64_RELATIVE
> relocations are present.
> 
> Fix this by adding `-z notext` to the powerpc linker flags, as was done
> for arm64 in commit 5d67db4e1860 ("arm64: Link with -z notext").
> 
> Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
> ---
>   powerpc/Makefile | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/powerpc/Makefile b/powerpc/Makefile
> index 41e752b070bc..35fe58835726 100644
> --- a/powerpc/Makefile
> +++ b/powerpc/Makefile
> @@ -78,7 +78,7 @@ include $(SRCDIR)/scripts/asm-offsets.mak
>   
>   FLATLIBS = $(libcflat) $(LIBFDT_archive)
>   %.elf: CFLAGS += $(arch_CFLAGS)
> -%.elf: LDFLAGS += $(arch_LDFLAGS) -pie -n
> +%.elf: LDFLAGS += $(arch_LDFLAGS) -pie -n -z notext
>   %.elf: %.o $(FLATLIBS) $(SRCDIR)/powerpc/flat.lds $(cstart.o) $(reloc.o) %.aux.o
>   	$(LD) $(LDFLAGS) -o $@ \
>   		-T $(SRCDIR)/powerpc/flat.lds --build-id=none \
Another thought: Why are we only using -pie for the LDFLAGS, but we rather 
seem to compile with -fno-pic in the CFLAGS? That looks weird ... I guess 
the -fno-pic is required for certain targets (s390x and the non-EFI builds 
of the other targets?), but maybe we should only add it only where it is 
required and compile the targets that have relocation code with -fpie in the 
CFLAGS instead?

  Thomas