You can test raid6 library code from user-space, like this: $ cd lib/raid6/test $ make The command in $(shell ...) function is evaluated by /bin/sh by default. (or, you can change the default shell by setting 'SHELL' in Makefile) Currently '>&/dev/null' is used to sink both stdout and stderr. Because this code is bash-ism, it only works when /bin/sh is a symbolic link to bash (this is the case on RHEL etc.) This does not work on Ubuntu where /bin/sh is a symbolic link to dash. I see lots of /bin/sh: 1: Syntax error: Bad fd number and warning "your version of binutils lacks ... support" Replace it with portable '>/dev/null 2>&1'. Fixes: 4f8c55c5ad49 ("lib/raid6: build proper files on corresponding arch") Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> --- Changes in v2: - New patch lib/raid6/test/Makefile | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/lib/raid6/test/Makefile b/lib/raid6/test/Makefile index 3ab8720aa2f8..b9e6c3648be1 100644 --- a/lib/raid6/test/Makefile +++ b/lib/raid6/test/Makefile @@ -35,13 +35,13 @@ endif ifeq ($(IS_X86),yes) OBJS += mmx.o sse1.o sse2.o avx2.o recov_ssse3.o recov_avx2.o avx512.o recov_avx512.o CFLAGS += $(shell echo "pshufb %xmm0, %xmm0" | \ - gcc -c -x assembler - >&/dev/null && \ + gcc -c -x assembler - >/dev/null 2>&1 && \ rm ./-.o && echo -DCONFIG_AS_SSSE3=1) CFLAGS += $(shell echo "vpbroadcastb %xmm0, %ymm1" | \ - gcc -c -x assembler - >&/dev/null && \ + gcc -c -x assembler - >/dev/null 2>&1 && \ rm ./-.o && echo -DCONFIG_AS_AVX2=1) CFLAGS += $(shell echo "vpmovm2b %k1, %zmm5" | \ - gcc -c -x assembler - >&/dev/null && \ + gcc -c -x assembler - >/dev/null 2>&1 && \ rm ./-.o && echo -DCONFIG_AS_AVX512=1) else ifeq ($(HAS_NEON),yes) OBJS += neon.o neon1.o neon2.o neon4.o neon8.o recov_neon.o recov_neon_inner.o -- 2.17.1