[PATCH 1/2] s390/vdso: Pass --eh-frame-hdr to the linker

[Jens Remus <jremus@linux.ibm.com>]

Commit 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link
vDSO") accidentally broke the GNU_PTR_EH_FRAME program table entry in
the vDSO, causing it to be empty:

  $ readelf --program-headers arch/s390/kernel/vdso/vdso.so
  ...
  Program Headers:
    Type           Offset             VirtAddr           PhysAddr
                   FileSiz            MemSiz              Flags  Align
  ...
    GNU_EH_FRAME   0x0000000000000000 0x0000000000000000 0x0000000000000000
                   0x0000000000000000 0x0000000000000000         0x8
  ...

Originally, the compiler would implicitly add --eh-frame-hdr when
invoking the linker, but when this Makefile was converted from invoking
the linker via the compiler, to invoking it directly, the option was
missed.

This is the s390 variant of x86 commit cd01544a268a ("x86/vdso: Pass
--eh-frame-hdr to the linker").

Fixes: 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO")
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---
 arch/s390/kernel/vdso/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/s390/kernel/vdso/Makefile b/arch/s390/kernel/vdso/Makefile
index fece5d975eaf..35c834b895ec 100644
--- a/arch/s390/kernel/vdso/Makefile
+++ b/arch/s390/kernel/vdso/Makefile
@@ -30,7 +30,8 @@ KBUILD_CFLAGS_VDSO := $(filter-out -fno-asynchronous-unwind-tables,$(KBUILD_CFLA
 KBUILD_CFLAGS_VDSO += -fPIC -fno-common -fno-builtin -fasynchronous-unwind-tables
 KBUILD_CFLAGS_VDSO += -fno-stack-protector $(DISABLE_KSTACK_ERASE)
 ldflags-y := -shared -soname=linux-vdso.so.1 \
-	     --hash-style=both --build-id=sha1 -T
+	     --hash-style=both --build-id=sha1 \
+	     $(call ld-option, --eh-frame-hdr) -T
 
 $(targets:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_VDSO)
 $(targets:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_VDSO)
-- 
2.53.0