[PATCH 01/16] lib/raid6/test: fix build on distros whose /bin/sh is not bash

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Masahiro Yamada

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Mar 24, 2020, 4:49:37 AM3/24/20
to linux-...@vger.kernel.org, David S . Miller, Linus Torvalds, Kees Cook, clang-bu...@googlegroups.com, Herbert Xu, linux-...@vger.kernel.org, Ingo Molnar, Thomas Gleixner, Borislav Petkov, Peter Zijlstra, H . Peter Anvin, x...@kernel.org, linux-...@vger.kernel.org, Masahiro Yamada, Jim Kukunas, NeilBrown, Yuanhan Liu
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 <masa...@kernel.org>
Acked-by: H. Peter Anvin (Intel) <h...@zytor.com>
---

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

Nick Desaulniers

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Mar 24, 2020, 12:36:50 PM3/24/20
to Masahiro Yamada, LKML, David S . Miller, Linus Torvalds, Kees Cook, clang-built-linux, Herbert Xu, open list:HARDWARE RANDOM NUMBER GENERATOR CORE, Ingo Molnar, Thomas Gleixner, Borislav Petkov, Peter Zijlstra, H . Peter Anvin, maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT), Linux Kbuild mailing list, Jim Kukunas, NeilBrown, Yuanhan Liu
These should all use $(CC) rather than hardcode gcc.

> 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
>
> --
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--
Thanks,
~Nick Desaulniers

Masahiro Yamada

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Mar 26, 2020, 2:49:55 AM3/26/20
to Nick Desaulniers, LKML, David S . Miller, Linus Torvalds, Kees Cook, clang-built-linux, Herbert Xu, open list:HARDWARE RANDOM NUMBER GENERATOR CORE, Ingo Molnar, Thomas Gleixner, Borislav Petkov, Peter Zijlstra, H . Peter Anvin, maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT), Linux Kbuild mailing list, Jim Kukunas, NeilBrown, Yuanhan Liu
Right, I had noticed this.

We often fall between
"let's fix this too while we are here"
vs
"do not do multiple things in a single patch"


If we replace gcc -> $(CC),
we also need to touch line 51 for consistency:

gcc -c -x c - >/dev/null && rm ./-.o && echo yes)

..., which is not our main interest now.

So, I leave it to a follow-up patch
if somebody has interest in it.


--
Best Regards
Masahiro Yamada

Masahiro Yamada

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Mar 26, 2020, 4:02:21 AM3/26/20
to linux-...@vger.kernel.org, Thomas Gleixner, Nick Desaulniers, Borislav Petkov, Peter Zijlstra, H . Peter Anvin, x...@kernel.org, Jason A . Donenfeld, clang-bu...@googlegroups.com, Masahiro Yamada, Jim Kukunas, NeilBrown, Yuanhan Liu, linux-...@vger.kernel.org
You can build a test program to 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 specify the shell by passing SHELL=<shell> from command line)

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 <masa...@kernel.org>
Acked-by: H. Peter Anvin (Intel) <h...@zytor.com>
---

Changes in v2: None

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 && \

Nick Desaulniers

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Mar 26, 2020, 1:27:46 PM3/26/20
to Masahiro Yamada, LKML, David S . Miller, Linus Torvalds, Kees Cook, clang-built-linux, Herbert Xu, open list:HARDWARE RANDOM NUMBER GENERATOR CORE, Ingo Molnar, Thomas Gleixner, Borislav Petkov, Peter Zijlstra, H . Peter Anvin, maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT), Linux Kbuild mailing list, Jim Kukunas, NeilBrown, Yuanhan Liu
Haha, ok, no worries.
Reviewed-by: Nick Desaulniers <ndesau...@google.com>

--
Thanks,
~Nick Desaulniers
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