[PATCH v5] kbuild: add variables for compression tools

From: Denis Efremov
Date: Fri Jun 05 2020 - 03:40:29 EST


Allow user to use alternative implementations of compression tools,
such as pigz, pbzip2, pxz. For example, multi-threaded tools to
speed up the build:
$ make GZIP=pigz BZIP2=pbzip2

Variables _GZIP, _BZIP2, _LZOP are used internally because original env
vars are reserved by the tools. The use of GZIP in gzip tool is obsolete
since 2015. However, alternative implementations (e.g., pigz) still rely
on it. BZIP2, BZIP, LZOP vars are not obsolescent.

The credit goes to @grsecurity.

As a sidenote, for multi-threaded lzma, xz compression one can use:
$ export XZ_OPT="--threads=0"

Signed-off-by: Denis Efremov <efremov@xxxxxxxxx>
---
Changes in v2:
- _GZIP used instead of GZIP
- tar commands altered to use tools from the vars
Changes in v3:
- _BZIP2 used instead of BZIP2
- _LZOP used instead of LZOP
Changes in v4:
- Unexports removed from Kbuild.include
- MAKEOVERRIDES used in top Makefile
- All variables checks removed from scripts
Changes in v5:
- Conflict with removed LASAT resolved

Makefile | 25 +++++++++++++++++++++++--
arch/arm/boot/deflate_xip_data.sh | 2 +-
arch/ia64/Makefile | 2 +-
arch/m68k/Makefile | 8 ++++----
arch/parisc/Makefile | 2 +-
kernel/gen_kheaders.sh | 2 +-
scripts/Makefile.lib | 12 ++++++------
scripts/Makefile.package | 8 ++++----
scripts/package/buildtar | 6 +++---
scripts/xz_wrap.sh | 2 +-
10 files changed, 45 insertions(+), 24 deletions(-)

diff --git a/Makefile b/Makefile
index a7bc91cbac8f..7920404950c3 100644
--- a/Makefile
+++ b/Makefile
@@ -447,6 +447,26 @@ PYTHON = python
PYTHON3 = python3
CHECK = sparse
BASH = bash
+GZIP = gzip
+BZIP2 = bzip2
+LZOP = lzop
+LZMA = lzma
+LZ4 = lz4c
+XZ = xz
+
+# GZIP, BZIP2, LZOP env vars are used by the tools. Support them as the command
+# line interface, but use _GZIP, _BZIP2, _LZOP internally.
+_GZIP := $(GZIP)
+_BZIP2 := $(BZIP2)
+_LZOP := $(LZOP)
+
+# Reset GZIP, BZIP2, LZOP in this Makefile
+override GZIP=
+override BZIP2=
+override LZOP=
+
+# Reset GZIP, BZIP2, LZOP in recursive invocations
+MAKEOVERRIDES += GZIP= BZIP2= LZOP=

CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
-Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
@@ -495,6 +515,7 @@ CLANG_FLAGS :=
export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
export CPP AR NM STRIP OBJCOPY OBJDUMP OBJSIZE READELF PAHOLE LEX YACC AWK INSTALLKERNEL
export PERL PYTHON PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
+export _GZIP _BZIP2 _LZOP LZMA LZ4 XZ
export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE

export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
@@ -1011,10 +1032,10 @@ export mod_strip_cmd
mod_compress_cmd = true
ifdef CONFIG_MODULE_COMPRESS
ifdef CONFIG_MODULE_COMPRESS_GZIP
- mod_compress_cmd = gzip -n -f
+ mod_compress_cmd = $(_GZIP) -n -f
endif # CONFIG_MODULE_COMPRESS_GZIP
ifdef CONFIG_MODULE_COMPRESS_XZ
- mod_compress_cmd = xz -f
+ mod_compress_cmd = $(XZ) -f
endif # CONFIG_MODULE_COMPRESS_XZ
endif # CONFIG_MODULE_COMPRESS
export mod_compress_cmd
diff --git a/arch/arm/boot/deflate_xip_data.sh b/arch/arm/boot/deflate_xip_data.sh
index 40937248cebe..739f0464321e 100755
--- a/arch/arm/boot/deflate_xip_data.sh
+++ b/arch/arm/boot/deflate_xip_data.sh
@@ -56,7 +56,7 @@ trap 'rm -f "$XIPIMAGE.tmp"; exit 1' 1 2 3
# substitute the data section by a compressed version
$DD if="$XIPIMAGE" count=$data_start iflag=count_bytes of="$XIPIMAGE.tmp"
$DD if="$XIPIMAGE" skip=$data_start iflag=skip_bytes |
-gzip -9 >> "$XIPIMAGE.tmp"
+$_GZIP -9 >> "$XIPIMAGE.tmp"

# replace kernel binary
mv -f "$XIPIMAGE.tmp" "$XIPIMAGE"
diff --git a/arch/ia64/Makefile b/arch/ia64/Makefile
index 32240000dc0c..f817f3d5e758 100644
--- a/arch/ia64/Makefile
+++ b/arch/ia64/Makefile
@@ -40,7 +40,7 @@ $(error Sorry, you need a newer version of the assember, one that is built from
endif

quiet_cmd_gzip = GZIP $@
-cmd_gzip = cat $(real-prereqs) | gzip -n -f -9 > $@
+cmd_gzip = cat $(real-prereqs) | $(_GZIP) -n -f -9 > $@

quiet_cmd_objcopy = OBJCOPY $@
cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
diff --git a/arch/m68k/Makefile b/arch/m68k/Makefile
index 5d9288384096..ce6db5e5a5a3 100644
--- a/arch/m68k/Makefile
+++ b/arch/m68k/Makefile
@@ -135,10 +135,10 @@ vmlinux.gz: vmlinux
ifndef CONFIG_KGDB
cp vmlinux vmlinux.tmp
$(STRIP) vmlinux.tmp
- gzip -9c vmlinux.tmp >vmlinux.gz
+ $(_GZIP) -9c vmlinux.tmp >vmlinux.gz
rm vmlinux.tmp
else
- gzip -9c vmlinux >vmlinux.gz
+ $(_GZIP) -9c vmlinux >vmlinux.gz
endif

bzImage: vmlinux.bz2
@@ -148,10 +148,10 @@ vmlinux.bz2: vmlinux
ifndef CONFIG_KGDB
cp vmlinux vmlinux.tmp
$(STRIP) vmlinux.tmp
- bzip2 -1c vmlinux.tmp >vmlinux.bz2
+ $(_BZIP2) -1c vmlinux.tmp >vmlinux.bz2
rm vmlinux.tmp
else
- bzip2 -1c vmlinux >vmlinux.bz2
+ $(_BZIP2) -1c vmlinux >vmlinux.bz2
endif

archclean:
diff --git a/arch/parisc/Makefile b/arch/parisc/Makefile
index fadbbd010337..182a5bca3e2c 100644
--- a/arch/parisc/Makefile
+++ b/arch/parisc/Makefile
@@ -162,7 +162,7 @@ vmlinuz: bzImage
$(OBJCOPY) $(boot)/bzImage $@
else
vmlinuz: vmlinux
- @gzip -cf -9 $< > $@
+ @$(_GZIP) -cf -9 $< > $@
endif

install:
diff --git a/kernel/gen_kheaders.sh b/kernel/gen_kheaders.sh
index e13ca842eb7e..c1510f0ab3ea 100755
--- a/kernel/gen_kheaders.sh
+++ b/kernel/gen_kheaders.sh
@@ -88,7 +88,7 @@ find $cpio_dir -type f -print0 |
find $cpio_dir -printf "./%P\n" | LC_ALL=C sort | \
tar "${KBUILD_BUILD_TIMESTAMP:+--mtime=$KBUILD_BUILD_TIMESTAMP}" \
--owner=0 --group=0 --numeric-owner --no-recursion \
- -Jcf $tarfile -C $cpio_dir/ -T - > /dev/null
+ -I $XZ -cf $tarfile -C $cpio_dir/ -T - > /dev/null

echo $headers_md5 > kernel/kheaders.md5
echo "$this_file_md5" >> kernel/kheaders.md5
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 4b799737722c..a1c1424e6b52 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -241,7 +241,7 @@ cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
# ---------------------------------------------------------------------------

quiet_cmd_gzip = GZIP $@
- cmd_gzip = cat $(real-prereqs) | gzip -n -f -9 > $@
+ cmd_gzip = cat $(real-prereqs) | $(_GZIP) -n -f -9 > $@

# DTC
# ---------------------------------------------------------------------------
@@ -334,19 +334,19 @@ printf "%08x\n" $$dec_size | \
)

quiet_cmd_bzip2 = BZIP2 $@
- cmd_bzip2 = { cat $(real-prereqs) | bzip2 -9; $(size_append); } > $@
+ cmd_bzip2 = { cat $(real-prereqs) | $(_BZIP2) -9; $(size_append); } > $@

# Lzma
# ---------------------------------------------------------------------------

quiet_cmd_lzma = LZMA $@
- cmd_lzma = { cat $(real-prereqs) | lzma -9; $(size_append); } > $@
+ cmd_lzma = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@

quiet_cmd_lzo = LZO $@
- cmd_lzo = { cat $(real-prereqs) | lzop -9; $(size_append); } > $@
+ cmd_lzo = { cat $(real-prereqs) | $(_LZOP) -9; $(size_append); } > $@

quiet_cmd_lz4 = LZ4 $@
- cmd_lz4 = { cat $(real-prereqs) | lz4c -l -c1 stdin stdout; \
+ cmd_lz4 = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \
$(size_append); } > $@

# U-Boot mkimage
@@ -393,7 +393,7 @@ quiet_cmd_xzkern = XZKERN $@
$(size_append); } > $@

quiet_cmd_xzmisc = XZMISC $@
- cmd_xzmisc = cat $(real-prereqs) | xz --check=crc32 --lzma2=dict=1MiB > $@
+ cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@

# ASM offsets
# ---------------------------------------------------------------------------
diff --git a/scripts/Makefile.package b/scripts/Makefile.package
index 02135d2671a6..b2b6153af63a 100644
--- a/scripts/Makefile.package
+++ b/scripts/Makefile.package
@@ -45,7 +45,7 @@ if test "$(objtree)" != "$(srctree)"; then \
false; \
fi ; \
$(srctree)/scripts/setlocalversion --save-scmversion; \
-tar -cz $(RCS_TAR_IGNORE) -f $(2).tar.gz \
+tar -I $(_GZIP) -c $(RCS_TAR_IGNORE) -f $(2).tar.gz \
--transform 's:^:$(2)/:S' $(TAR_CONTENT) $(3); \
rm -f $(objtree)/.scmversion

@@ -127,9 +127,9 @@ util/PERF-VERSION-GEN $(CURDIR)/$(perf-tar)/); \
tar rf $(perf-tar).tar $(perf-tar)/HEAD $(perf-tar)/PERF-VERSION-FILE; \
rm -r $(perf-tar); \
$(if $(findstring tar-src,$@),, \
-$(if $(findstring bz2,$@),bzip2, \
-$(if $(findstring gz,$@),gzip, \
-$(if $(findstring xz,$@),xz, \
+$(if $(findstring bz2,$@),$(_BZIP2), \
+$(if $(findstring gz,$@),$(_GZIP), \
+$(if $(findstring xz,$@),$(XZ), \
$(error unknown target $@)))) \
-f -9 $(perf-tar).tar)

diff --git a/scripts/package/buildtar b/scripts/package/buildtar
index 77c7caefede1..ad62c6879622 100755
--- a/scripts/package/buildtar
+++ b/scripts/package/buildtar
@@ -28,15 +28,15 @@ case "${1}" in
opts=
;;
targz-pkg)
- opts=--gzip
+ opts="-I ${_GZIP}"
tarball=${tarball}.gz
;;
tarbz2-pkg)
- opts=--bzip2
+ opts="-I ${_BZIP2}"
tarball=${tarball}.bz2
;;
tarxz-pkg)
- opts=--xz
+ opts="-I ${XZ}"
tarball=${tarball}.xz
;;
*)
diff --git a/scripts/xz_wrap.sh b/scripts/xz_wrap.sh
index 7a2d372f4885..76e9cbcfbeab 100755
--- a/scripts/xz_wrap.sh
+++ b/scripts/xz_wrap.sh
@@ -20,4 +20,4 @@ case $SRCARCH in
sparc) BCJ=--sparc ;;
esac

-exec xz --check=crc32 $BCJ --lzma2=$LZMA2OPTS,dict=32MiB
+exec $XZ --check=crc32 $BCJ --lzma2=$LZMA2OPTS,dict=32MiB
--
2.26.2