diff options
authorMaciej W. Rozycki <>2016-05-26 12:55:45 +0100
committerRalf Baechle <>2016-05-28 12:35:12 +0200
commit94cc36b84acc29f543b48bc5ed786011b112a666 (patch)
parent41cc07be42835a5c35b409af3914b8fcaedd0d72 (diff)
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 <> Reviewed-by: James Hogan <> Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Cc: Tejun Heo <> Cc: Cc: # v4.3+ Patchwork: Signed-off-by: Ralf Baechle <>
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 \
$(call cc-option, -fno-stack-protector)
aflags-vdso := $(ccflags-vdso) \
$(filter -I%,$(KBUILD_CFLAGS)) \