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| author |   Elliot Berman <quic_eberman@quicinc.com> | 2022-02-01 13:35:42 -0800 |
|---|---|---|
| committer |   Masahiro Yamada <masahiroy@kernel.org> | 2022-02-14 10:37:32 +0900 |
| commit | f67695c9962e5f444549b3437fb8d840ec6222c8 (patch) | |
| tree | 96a786f023dd51a8037a55bfc846dacd6c24cb06 /Documentation/kbuild | |
| parent | kbuild: unify cmd_copy and cmd_shipped (diff) | |
| download | linux-dev-f67695c9962e5f444549b3437fb8d840ec6222c8.tar.xz linux-dev-f67695c9962e5f444549b3437fb8d840ec6222c8.zip | |
kbuild: Add environment variables for userprogs flags
Allow additional arguments be passed to userprogs compilation.
Reproducible clang builds need to provide a sysroot and gcc path to
ensure the same toolchain is used across hosts. KCFLAGS is not currently
used for any user programs compilation, so add new USERCFLAGS and
USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS.
Clang 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 <quic_eberman@quicinc.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Diffstat (limited to 'Documentation/kbuild')
| -rw-r--r-- | Documentation/kbuild/kbuild.rst | 11 | ||||
| -rw-r--r-- | Documentation/kbuild/makefiles.rst | 2 |
2 files changed, 13 insertions, 0 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 ---------------------------------------------- |