On Tue, Feb 1, 2022 at 1:36 PM Elliot Berman <[email protected]> wrote:
>
> Allow additional arguments be passed to userprogs compilation.
> Reproducible clang builds need to provide a sysroot and gcc path to
> ensure same toolchain is used across hosts. KCFLAGS is not currently
^ ensure the same (maybe Masahiro can fix that up locally when applying)
> used for any user programs compilation, so add new USERCFLAGS and
> USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS.
>
> Clang 13+ might detect GCC installation on hosts which have it installed
> to a default location in /. With addition of these environment
> variables, you can specify flags such as:
>
> $ make USERCFLAGS=--sysroot=/path/to/sysroot
>
> This can also be used to specify different sysroots such as musl or
> bionic which may be installed on the host in paths that the compiler
> may not search by default.
>
> Signed-off-by: Elliot Berman <[email protected]>
Thanks for the patch!
Reviewed-by: Nick Desaulniers <[email protected]>
> ---
>
> Changes since v2:
> - Incorporated Nick's suggestions:
> - Addressed docs and commit text comments
> - Introduced KBUILD_USERHOSTCFLAGS as suggested
>
> Documentation/kbuild/kbuild.rst | 11 +++++++++++
> Documentation/kbuild/makefiles.rst | 2 ++
> Makefile | 10 ++++++----
> init/Kconfig | 8 ++++----
> usr/include/Makefile | 3 +++
> 5 files changed, 26 insertions(+), 8 deletions(-)
>
> diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst
> index 2d1fc03d346e..ef19b9c13523 100644
> --- a/Documentation/kbuild/kbuild.rst
> +++ b/Documentation/kbuild/kbuild.rst
> @@ -77,6 +77,17 @@ HOSTLDLIBS
> ----------
> Additional libraries to link against when building host programs.
>
> +.. _userkbuildflags:
> +
> +USERCFLAGS
> +----------
> +Additional options used for $(CC) when compiling userprogs.
> +
> +USERLDFLAGS
> +-----------
> +Additional options used for $(LD) when linking userprogs. userprogs are linked
> +with CC, so $(USERLDFLAGS) should include "-Wl," prefix as applicable.
> +
> KBUILD_KCONFIG
> --------------
> Set the top-level Kconfig file to the value of this environment
> diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
> index b008b90b92c9..11a296e52d68 100644
> --- a/Documentation/kbuild/makefiles.rst
> +++ b/Documentation/kbuild/makefiles.rst
> @@ -982,6 +982,8 @@ The syntax is quite similar. The difference is to use "userprogs" instead of
>
> When linking bpfilter_umh, it will be passed the extra option -static.
>
> + From command line, :ref:`USERCFLAGS and USERLDFLAGS <userkbuildflags>` will also be used.
> +
> 5.4 When userspace programs are actually built
> ----------------------------------------------
>
> diff --git a/Makefile b/Makefile
> index 45278d508d81..1d0172449355 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -431,11 +431,12 @@ HOSTCC = gcc
> HOSTCXX = g++
> endif
>
> -export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
> - -O2 -fomit-frame-pointer -std=gnu89
> -export KBUILD_USERLDFLAGS :=
> +KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
> + -O2 -fomit-frame-pointer -std=gnu89
> +KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
> +KBUILD_USERLDFLAGS := $(USERLDFLAGS)
>
> -KBUILD_HOSTCFLAGS := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
> +KBUILD_HOSTCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
> KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
> KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
> KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
> @@ -530,6 +531,7 @@ export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AW
> export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
> export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
> export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
> +export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
>
> export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
> export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
> diff --git a/init/Kconfig b/init/Kconfig
> index f2ae41e6717f..164706c38e8b 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -62,13 +62,13 @@ config LLD_VERSION
>
> config CC_CAN_LINK
> bool
> - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT
> - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag))
> + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT
> + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag))
>
> config CC_CAN_LINK_STATIC
> bool
> - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag) -static) if 64BIT
> - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag) -static)
> + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT
> + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static)
>
> config CC_HAS_ASM_GOTO
> def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
> diff --git a/usr/include/Makefile b/usr/include/Makefile
> index 1c2ae1368079..0322e567dc1e 100644
> --- a/usr/include/Makefile
> +++ b/usr/include/Makefile
> @@ -12,6 +12,9 @@ UAPI_CFLAGS := -std=c90 -Wall -Werror=implicit-function-declaration
> # It is here just because CONFIG_CC_CAN_LINK is tested with -m32 or -m64.
> UAPI_CFLAGS += $(filter -m32 -m64, $(KBUILD_CFLAGS))
>
> +# USERCFLAGS might contain sysroot location for CC.
> +UAPI_CFLAGS += $(USERCFLAGS)
> +
> override c_flags = $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I$(objtree)/usr/include
>
> # The following are excluded for now because they fail to build.
> --
> 2.25.1
>
--
Thanks,
~Nick Desaulniers
On Tue, Feb 1, 2022 at 1:38 PM Nick Desaulniers <[email protected]> wrote:
>
> On Tue, Feb 1, 2022 at 1:36 PM Elliot Berman <[email protected]> wrote:
> >
> > Allow additional arguments be passed to userprogs compilation.
> > Reproducible clang builds need to provide a sysroot and gcc path to
> > ensure same toolchain is used across hosts. KCFLAGS is not currently
>
> ^ ensure the same (maybe Masahiro can fix that up locally when applying)
>
> > used for any user programs compilation, so add new USERCFLAGS and
> > USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS.
> >
> > Clang 13+ might detect GCC installation on hosts which have it installed
> > to a default location in /. With addition of these environment
> > variables, you can specify flags such as:
s/Clang 13+/Clang/.
Clang has been detecting GCC installation for a long time.
Clang 13 just improved some detection, but may not be worth mentioning
in the message.
> > $ make USERCFLAGS=--sysroot=/path/to/sysroot
> >
> > This can also be used to specify different sysroots such as musl or
> > bionic which may be installed on the host in paths that the compiler
> > may not search by default.
> >
> > Signed-off-by: Elliot Berman <[email protected]>
>
> Thanks for the patch!
> Reviewed-by: Nick Desaulniers <[email protected]>
LGTM.
Reviewed-by: Fangrui Song <[email protected]>
> > ---
> >
> > Changes since v2:
> > - Incorporated Nick's suggestions:
> > - Addressed docs and commit text comments
> > - Introduced KBUILD_USERHOSTCFLAGS as suggested
> >
> > Documentation/kbuild/kbuild.rst | 11 +++++++++++
> > Documentation/kbuild/makefiles.rst | 2 ++
> > Makefile | 10 ++++++----
> > init/Kconfig | 8 ++++----
> > usr/include/Makefile | 3 +++
> > 5 files changed, 26 insertions(+), 8 deletions(-)
> >
> > diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst
> > index 2d1fc03d346e..ef19b9c13523 100644
> > --- a/Documentation/kbuild/kbuild.rst
> > +++ b/Documentation/kbuild/kbuild.rst
> > @@ -77,6 +77,17 @@ HOSTLDLIBS
> > ----------
> > Additional libraries to link against when building host programs.
> >
> > +.. _userkbuildflags:
> > +
> > +USERCFLAGS
> > +----------
> > +Additional options used for $(CC) when compiling userprogs.
> > +
> > +USERLDFLAGS
> > +-----------
> > +Additional options used for $(LD) when linking userprogs. userprogs are linked
> > +with CC, so $(USERLDFLAGS) should include "-Wl," prefix as applicable.
> > +
> > KBUILD_KCONFIG
> > --------------
> > Set the top-level Kconfig file to the value of this environment
> > diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
> > index b008b90b92c9..11a296e52d68 100644
> > --- a/Documentation/kbuild/makefiles.rst
> > +++ b/Documentation/kbuild/makefiles.rst
> > @@ -982,6 +982,8 @@ The syntax is quite similar. The difference is to use "userprogs" instead of
> >
> > When linking bpfilter_umh, it will be passed the extra option -static.
> >
> > + From command line, :ref:`USERCFLAGS and USERLDFLAGS <userkbuildflags>` will also be used.
> > +
> > 5.4 When userspace programs are actually built
> > ----------------------------------------------
> >
> > diff --git a/Makefile b/Makefile
> > index 45278d508d81..1d0172449355 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -431,11 +431,12 @@ HOSTCC = gcc
> > HOSTCXX = g++
> > endif
> >
> > -export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
> > - -O2 -fomit-frame-pointer -std=gnu89
> > -export KBUILD_USERLDFLAGS :=
> > +KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
> > + -O2 -fomit-frame-pointer -std=gnu89
> > +KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
> > +KBUILD_USERLDFLAGS := $(USERLDFLAGS)
> >
> > -KBUILD_HOSTCFLAGS := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
> > +KBUILD_HOSTCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
> > KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
> > KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
> > KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
> > @@ -530,6 +531,7 @@ export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AW
> > export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
> > export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
> > export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
> > +export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
> >
> > export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
> > export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
> > diff --git a/init/Kconfig b/init/Kconfig
> > index f2ae41e6717f..164706c38e8b 100644
> > --- a/init/Kconfig
> > +++ b/init/Kconfig
> > @@ -62,13 +62,13 @@ config LLD_VERSION
> >
> > config CC_CAN_LINK
> > bool
> > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT
> > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag))
> > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT
> > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag))
> >
> > config CC_CAN_LINK_STATIC
> > bool
> > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag) -static) if 64BIT
> > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag) -static)
> > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT
> > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static)
> >
> > config CC_HAS_ASM_GOTO
> > def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
> > diff --git a/usr/include/Makefile b/usr/include/Makefile
> > index 1c2ae1368079..0322e567dc1e 100644
> > --- a/usr/include/Makefile
> > +++ b/usr/include/Makefile
> > @@ -12,6 +12,9 @@ UAPI_CFLAGS := -std=c90 -Wall -Werror=implicit-function-declaration
> > # It is here just because CONFIG_CC_CAN_LINK is tested with -m32 or -m64.
> > UAPI_CFLAGS += $(filter -m32 -m64, $(KBUILD_CFLAGS))
> >
> > +# USERCFLAGS might contain sysroot location for CC.
> > +UAPI_CFLAGS += $(USERCFLAGS)
> > +
> > override c_flags = $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I$(objtree)/usr/include
> >
> > # The following are excluded for now because they fail to build.
> > --
> > 2.25.1
> >
>
>
> --
> Thanks,
> ~Nick Desaulniers
--
宋方睿
On Tue, Feb 1, 2022 at 1:38 PM Nick Desaulniers <[email protected]> wrote:
>
> On Tue, Feb 1, 2022 at 1:36 PM Elliot Berman <[email protected]> wrote:
> >
> > Allow additional arguments be passed to userprogs compilation.
> > Reproducible clang builds need to provide a sysroot and gcc path to
> > ensure same toolchain is used across hosts. KCFLAGS is not currently
>
> ^ ensure the same (maybe Masahiro can fix that up locally when applying)
Masahiro,
What are your thoughts on this patch? I think this would help Android
define a musl or bionic sysroot for CC_CAN_LINK and ultimately
UAPI_HEADER_TEST support.
>
> > used for any user programs compilation, so add new USERCFLAGS and
> > USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS.
> >
> > Clang 13+ might detect GCC installation on hosts which have it installed
> > to a default location in /. With addition of these environment
> > variables, you can specify flags such as:
> >
> > $ make USERCFLAGS=--sysroot=/path/to/sysroot
> >
> > This can also be used to specify different sysroots such as musl or
> > bionic which may be installed on the host in paths that the compiler
> > may not search by default.
> >
> > Signed-off-by: Elliot Berman <[email protected]>
>
> Thanks for the patch!
> Reviewed-by: Nick Desaulniers <[email protected]>
>
> > ---
> >
> > Changes since v2:
> > - Incorporated Nick's suggestions:
> > - Addressed docs and commit text comments
> > - Introduced KBUILD_USERHOSTCFLAGS as suggested
> >
> > Documentation/kbuild/kbuild.rst | 11 +++++++++++
> > Documentation/kbuild/makefiles.rst | 2 ++
> > Makefile | 10 ++++++----
> > init/Kconfig | 8 ++++----
> > usr/include/Makefile | 3 +++
> > 5 files changed, 26 insertions(+), 8 deletions(-)
> >
> > diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst
> > index 2d1fc03d346e..ef19b9c13523 100644
> > --- a/Documentation/kbuild/kbuild.rst
> > +++ b/Documentation/kbuild/kbuild.rst
> > @@ -77,6 +77,17 @@ HOSTLDLIBS
> > ----------
> > Additional libraries to link against when building host programs.
> >
> > +.. _userkbuildflags:
> > +
> > +USERCFLAGS
> > +----------
> > +Additional options used for $(CC) when compiling userprogs.
> > +
> > +USERLDFLAGS
> > +-----------
> > +Additional options used for $(LD) when linking userprogs. userprogs are linked
> > +with CC, so $(USERLDFLAGS) should include "-Wl," prefix as applicable.
> > +
> > KBUILD_KCONFIG
> > --------------
> > Set the top-level Kconfig file to the value of this environment
> > diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
> > index b008b90b92c9..11a296e52d68 100644
> > --- a/Documentation/kbuild/makefiles.rst
> > +++ b/Documentation/kbuild/makefiles.rst
> > @@ -982,6 +982,8 @@ The syntax is quite similar. The difference is to use "userprogs" instead of
> >
> > When linking bpfilter_umh, it will be passed the extra option -static.
> >
> > + From command line, :ref:`USERCFLAGS and USERLDFLAGS <userkbuildflags>` will also be used.
> > +
> > 5.4 When userspace programs are actually built
> > ----------------------------------------------
> >
> > diff --git a/Makefile b/Makefile
> > index 45278d508d81..1d0172449355 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -431,11 +431,12 @@ HOSTCC = gcc
> > HOSTCXX = g++
> > endif
> >
> > -export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
> > - -O2 -fomit-frame-pointer -std=gnu89
> > -export KBUILD_USERLDFLAGS :=
> > +KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
> > + -O2 -fomit-frame-pointer -std=gnu89
> > +KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
> > +KBUILD_USERLDFLAGS := $(USERLDFLAGS)
> >
> > -KBUILD_HOSTCFLAGS := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
> > +KBUILD_HOSTCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
> > KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
> > KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
> > KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
> > @@ -530,6 +531,7 @@ export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AW
> > export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
> > export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
> > export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
> > +export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
> >
> > export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
> > export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
> > diff --git a/init/Kconfig b/init/Kconfig
> > index f2ae41e6717f..164706c38e8b 100644
> > --- a/init/Kconfig
> > +++ b/init/Kconfig
> > @@ -62,13 +62,13 @@ config LLD_VERSION
> >
> > config CC_CAN_LINK
> > bool
> > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT
> > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag))
> > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT
> > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag))
> >
> > config CC_CAN_LINK_STATIC
> > bool
> > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag) -static) if 64BIT
> > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag) -static)
> > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT
> > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static)
> >
> > config CC_HAS_ASM_GOTO
> > def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
> > diff --git a/usr/include/Makefile b/usr/include/Makefile
> > index 1c2ae1368079..0322e567dc1e 100644
> > --- a/usr/include/Makefile
> > +++ b/usr/include/Makefile
> > @@ -12,6 +12,9 @@ UAPI_CFLAGS := -std=c90 -Wall -Werror=implicit-function-declaration
> > # It is here just because CONFIG_CC_CAN_LINK is tested with -m32 or -m64.
> > UAPI_CFLAGS += $(filter -m32 -m64, $(KBUILD_CFLAGS))
> >
> > +# USERCFLAGS might contain sysroot location for CC.
> > +UAPI_CFLAGS += $(USERCFLAGS)
> > +
> > override c_flags = $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I$(objtree)/usr/include
> >
> > # The following are excluded for now because they fail to build.
> > --
> > 2.25.1
> >
>
>
> --
> Thanks,
> ~Nick Desaulniers
--
Thanks,
~Nick Desaulniers
On Wed, Feb 9, 2022 at 7:53 AM Nick Desaulniers <[email protected]> wrote:
>
> On Tue, Feb 1, 2022 at 1:38 PM Nick Desaulniers <[email protected]> wrote:
> >
> > On Tue, Feb 1, 2022 at 1:36 PM Elliot Berman <[email protected]> wrote:
> > >
> > > Allow additional arguments be passed to userprogs compilation.
> > > Reproducible clang builds need to provide a sysroot and gcc path to
> > > ensure same toolchain is used across hosts. KCFLAGS is not currently
> >
> > ^ ensure the same (maybe Masahiro can fix that up locally when applying)
>
> Masahiro,
> What are your thoughts on this patch? I think this would help Android
> define a musl or bionic sysroot for CC_CAN_LINK and ultimately
> UAPI_HEADER_TEST support.
Sorry for delay.
Applied with two fixups in the commit log:
ensure same -> ensure the same
Clang 13+ might detect -> Clang might detect
> >
> > > used for any user programs compilation, so add new USERCFLAGS and
> > > USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS.
> > >
> > > Clang 13+ might detect GCC installation on hosts which have it installed
> > > to a default location in /. With addition of these environment
> > > variables, you can specify flags such as:
> > >
> > > $ make USERCFLAGS=--sysroot=/path/to/sysroot
> > >
> > > This can also be used to specify different sysroots such as musl or
> > > bionic which may be installed on the host in paths that the compiler
> > > may not search by default.
> > >
> > > Signed-off-by: Elliot Berman <[email protected]>
> >
> > Thanks for the patch!
> > Reviewed-by: Nick Desaulniers <[email protected]>
> >
> > > ---
> > >
> > > Changes since v2:
> > > - Incorporated Nick's suggestions:
> > > - Addressed docs and commit text comments
> > > - Introduced KBUILD_USERHOSTCFLAGS as suggested
> > >
> > > Documentation/kbuild/kbuild.rst | 11 +++++++++++
> > > Documentation/kbuild/makefiles.rst | 2 ++
> > > Makefile | 10 ++++++----
> > > init/Kconfig | 8 ++++----
> > > usr/include/Makefile | 3 +++
> > > 5 files changed, 26 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst
> > > index 2d1fc03d346e..ef19b9c13523 100644
> > > --- a/Documentation/kbuild/kbuild.rst
> > > +++ b/Documentation/kbuild/kbuild.rst
> > > @@ -77,6 +77,17 @@ HOSTLDLIBS
> > > ----------
> > > Additional libraries to link against when building host programs.
> > >
> > > +.. _userkbuildflags:
> > > +
> > > +USERCFLAGS
> > > +----------
> > > +Additional options used for $(CC) when compiling userprogs.
> > > +
> > > +USERLDFLAGS
> > > +-----------
> > > +Additional options used for $(LD) when linking userprogs. userprogs are linked
> > > +with CC, so $(USERLDFLAGS) should include "-Wl," prefix as applicable.
> > > +
> > > KBUILD_KCONFIG
> > > --------------
> > > Set the top-level Kconfig file to the value of this environment
> > > diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
> > > index b008b90b92c9..11a296e52d68 100644
> > > --- a/Documentation/kbuild/makefiles.rst
> > > +++ b/Documentation/kbuild/makefiles.rst
> > > @@ -982,6 +982,8 @@ The syntax is quite similar. The difference is to use "userprogs" instead of
> > >
> > > When linking bpfilter_umh, it will be passed the extra option -static.
> > >
> > > + From command line, :ref:`USERCFLAGS and USERLDFLAGS <userkbuildflags>` will also be used.
> > > +
> > > 5.4 When userspace programs are actually built
> > > ----------------------------------------------
> > >
> > > diff --git a/Makefile b/Makefile
> > > index 45278d508d81..1d0172449355 100644
> > > --- a/Makefile
> > > +++ b/Makefile
> > > @@ -431,11 +431,12 @@ HOSTCC = gcc
> > > HOSTCXX = g++
> > > endif
> > >
> > > -export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
> > > - -O2 -fomit-frame-pointer -std=gnu89
> > > -export KBUILD_USERLDFLAGS :=
> > > +KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
> > > + -O2 -fomit-frame-pointer -std=gnu89
> > > +KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
> > > +KBUILD_USERLDFLAGS := $(USERLDFLAGS)
> > >
> > > -KBUILD_HOSTCFLAGS := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
> > > +KBUILD_HOSTCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
> > > KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
> > > KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
> > > KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
> > > @@ -530,6 +531,7 @@ export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AW
> > > export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
> > > export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
> > > export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
> > > +export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
> > >
> > > export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
> > > export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
> > > diff --git a/init/Kconfig b/init/Kconfig
> > > index f2ae41e6717f..164706c38e8b 100644
> > > --- a/init/Kconfig
> > > +++ b/init/Kconfig
> > > @@ -62,13 +62,13 @@ config LLD_VERSION
> > >
> > > config CC_CAN_LINK
> > > bool
> > > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT
> > > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag))
> > > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT
> > > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag))
> > >
> > > config CC_CAN_LINK_STATIC
> > > bool
> > > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag) -static) if 64BIT
> > > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag) -static)
> > > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT
> > > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static)
> > >
> > > config CC_HAS_ASM_GOTO
> > > def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
> > > diff --git a/usr/include/Makefile b/usr/include/Makefile
> > > index 1c2ae1368079..0322e567dc1e 100644
> > > --- a/usr/include/Makefile
> > > +++ b/usr/include/Makefile
> > > @@ -12,6 +12,9 @@ UAPI_CFLAGS := -std=c90 -Wall -Werror=implicit-function-declaration
> > > # It is here just because CONFIG_CC_CAN_LINK is tested with -m32 or -m64.
> > > UAPI_CFLAGS += $(filter -m32 -m64, $(KBUILD_CFLAGS))
> > >
> > > +# USERCFLAGS might contain sysroot location for CC.
> > > +UAPI_CFLAGS += $(USERCFLAGS)
> > > +
> > > override c_flags = $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I$(objtree)/usr/include
> > >
> > > # The following are excluded for now because they fail to build.
> > > --
> > > 2.25.1
> > >
> >
> >
> > --
> > Thanks,
> > ~Nick Desaulniers
>
>
>
> --
> Thanks,
> ~Nick Desaulniers
--
Best Regards
Masahiro Yamada