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| author | Maciej W. Rozycki <macro@imgtec.com> | 2016-05-26 12:55:45 +0100 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2016-05-28 12:35:12 +0200 |
| commit | 94cc36b84acc29f543b48bc5ed786011b112a666 (patch) | |
| tree | 0693da19d725a35b41593c67335cba5c70e4de99 /arch/mips | |
| parent | 41cc07be42835a5c35b409af3914b8fcaedd0d72 (diff) | |
| download | linux-94cc36b84acc29f543b48bc5ed786011b112a666.tar.bz2 | |
MIPS: VDSO: Build with `-fno-strict-aliasing'
Avoid an aliasing issue causing a build error in VDSO:
In file included from include/linux/srcu.h:34:0,
from include/linux/notifier.h:15,
from ./arch/mips/include/asm/uprobes.h:9,
from include/linux/uprobes.h:61,
from include/linux/mm_types.h:13,
from ./arch/mips/include/asm/vdso.h:14,
from arch/mips/vdso/vdso.h:27,
from arch/mips/vdso/gettimeofday.c:11:
include/linux/workqueue.h: In function 'work_static':
include/linux/workqueue.h:186:2: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
return *work_data_bits(work) & WORK_STRUCT_STATIC;
^
cc1: all warnings being treated as errors
make[2]: *** [arch/mips/vdso/gettimeofday.o] Error 1
with a CONFIG_DEBUG_OBJECTS_WORK configuration and GCC 5.2.0. Include
`-fno-strict-aliasing' along with compiler options used, as required for
kernel code, fixing a problem present since the introduction of VDSO
with commit ebb5e78cc634 ("MIPS: Initial implementation of a VDSO").
Thanks to Tejun for diagnosing this properly!
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.3+
Patchwork: https://patchwork.linux-mips.org/patch/13357/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips')
| -rw-r--r-- | arch/mips/vdso/Makefile | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile index b369509e9753..fff01eddf3e9 100644 --- a/arch/mips/vdso/Makefile +++ b/arch/mips/vdso/Makefile @@ -8,7 +8,8 @@ ccflags-vdso := \ $(filter -march=%,$(KBUILD_CFLAGS)) cflags-vdso := $(ccflags-vdso) \ $(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \ - -O2 -g -fPIC -fno-common -fno-builtin -G 0 -DDISABLE_BRANCH_PROFILING \ + -O2 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \ + -DDISABLE_BRANCH_PROFILING \ $(call cc-option, -fno-stack-protector) aflags-vdso := $(ccflags-vdso) \ $(filter -I%,$(KBUILD_CFLAGS)) \ |