arm64: vdso: fix build error when switching from LE to BE
authorArun Chandran <achandran@mvista.com>
Thu, 26 Jun 2014 09:46:03 +0000 (15:16 +0530)
committerWill Deacon <will.deacon@arm.com>
Wed, 30 Jul 2014 14:06:35 +0000 (15:06 +0100)
commit1915e2ad1cf548217c963121e4076b3d44dd0169
treede6a874c51fa4e9ff318bd66b53bae5ee6fff219
parentaf9b99647cd2a6a2b8a4a1c9ba6193dd375218b5
arm64: vdso: fix build error when switching from LE to BE

Building a kernel with CPU_BIG_ENDIAN fails if there are stale objects
from a !CPU_BIG_ENDIAN build. Due to a missing FORCE prerequisite on an
if_changed rule in the VDSO Makefile, we attempt to link a stale LE
object into the new BE kernel.

According to Documentation/kbuild/makefiles.txt, FORCE is required for
if_changed rules and forgetting it is a common mistake, so fix it by
'Forcing' the build of vdso. This patch fixes build errors like these:

arch/arm64/kernel/vdso/note.o: compiled for a little endian system and target is big endian
failed to merge target specific data of file arch/arm64/kernel/vdso/note.o

arch/arm64/kernel/vdso/sigreturn.o: compiled for a little endian system and target is big endian
failed to merge target specific data of file arch/arm64/kernel/vdso/sigreturn.o

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Arun Chandran <achandran@mvista.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arch/arm64/kernel/vdso/Makefile