Fake modpost stage for LINUX_COMPILE.

Currently, when building a test case, we're compiling an entire Linux
module from beginning to end. This includes the MODPOST stage, which
generates a "conftest.mod.c" file with some boilerplate module
declaration code.

This poses a problem when configuring for built-in on kernels which have
loadable module support disabled. In this case conftest.mod.c is
referencing disabled code, resulting in a compilation failure, thus
breaking the tests.

This patch fixes the issue by faking the modpost stage when the
--enable-linux-builtin option is provided.  It does so by forcing the
modpost command to be /bin/true, and using an empty conftest.mod.c file.
The test module still compiles fine, although the result isn't loadable,
but we don't really care at this point.

Note it is important to preserve the modpost stage when building out of
tree.  This allows for the posibility of configure checks to leverage
this phase to identify GPL-only symbols.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue zfsonlinux/zfs#851

diff --git a/config/spl-build.m4 b/config/spl-build.m4
index eaca8f113c8852e0577edb5f18f1ac8549e8b20e..466d9eb502ec8ffc86d4297643737aef4a2d4d94 100644 (file)
--- a/config/spl-build.m4
+++ b/config/spl-build.m4
@@ -631,12 +631,14 @@ dnl # SPL_LINUX_COMPILE_IFELSE / like AC_COMPILE_IFELSE
 dnl #
 AC_DEFUN([SPL_LINUX_COMPILE_IFELSE], [
        m4_ifvaln([$1], [SPL_LINUX_CONFTEST([$1])])
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
        AS_IF(
-               [AC_TRY_COMMAND(cp conftest.c build && make [$2] -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build) >/dev/null && AC_TRY_COMMAND([$3])],
-               [$4],
-               [_AC_MSG_LOG_CONFTEST m4_ifvaln([$5],[$5])]
+               [AC_TRY_COMMAND(cp conftest.c build && make [$2] -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag) >/dev/null && AC_TRY_COMMAND([$3])],
+               [$4],
+               [_AC_MSG_LOG_CONFTEST m4_ifvaln([$5],[$5])]
        )
        rm -Rf build
 ])

diff --git a/configure b/configure
index 35d46e17b8a2c736f8f66140f681db5e4d59257e..04acdf1b1c07263c2e95f0d3eb5ccd09cdf899d2 100755 (executable)
--- a/configure
+++ b/configure
@@ -11934,9 +11934,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -12134,9 +12136,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -12213,9 +12217,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -12328,9 +12334,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -12392,9 +12400,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -12456,9 +12466,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -12521,9 +12533,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -12585,9 +12599,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -12650,9 +12666,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -12722,9 +12740,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -12790,9 +12810,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -12897,9 +12919,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -12963,9 +12987,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -13027,9 +13053,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -13135,9 +13163,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -13283,9 +13313,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -13351,9 +13383,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -13417,9 +13451,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -13482,9 +13518,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -13556,9 +13594,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -13624,9 +13664,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -13689,9 +13731,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -13758,9 +13802,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -13866,9 +13912,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -13932,9 +13980,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -14000,9 +14050,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -14068,9 +14120,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -14133,9 +14187,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -14463,9 +14519,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -14529,9 +14587,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -14595,9 +14655,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -14660,9 +14722,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -14725,9 +14789,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -14791,9 +14857,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -14856,9 +14924,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -14921,9 +14991,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -14999,9 +15071,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -15186,9 +15260,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -15250,9 +15326,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -15314,9 +15392,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -15420,9 +15500,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -15489,9 +15571,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -15556,9 +15640,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -15703,9 +15789,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -15929,9 +16017,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -16144,9 +16234,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -16212,9 +16304,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -16281,9 +16375,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -16360,9 +16456,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -16588,9 +16686,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -16788,9 +16888,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -16867,9 +16969,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -16982,9 +17086,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -17046,9 +17152,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -17110,9 +17218,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -17175,9 +17285,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -17239,9 +17351,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -17304,9 +17418,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -17376,9 +17492,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -17444,9 +17562,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -17551,9 +17671,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -17617,9 +17739,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -17681,9 +17805,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -17789,9 +17915,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -17937,9 +18065,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -18005,9 +18135,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -18071,9 +18203,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -18136,9 +18270,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -18210,9 +18346,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -18278,9 +18416,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -18343,9 +18483,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -18412,9 +18554,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -18520,9 +18664,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -18586,9 +18732,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -18654,9 +18802,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -18722,9 +18872,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -18787,9 +18939,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -19117,9 +19271,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -19183,9 +19339,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -19249,9 +19407,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -19314,9 +19474,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -19379,9 +19541,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -19445,9 +19609,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -19510,9 +19676,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -19575,9 +19743,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -19653,9 +19823,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -19840,9 +20012,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -19904,9 +20078,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -19968,9 +20144,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -20074,9 +20252,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -20143,9 +20323,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -20210,9 +20392,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -20357,9 +20541,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -20583,9 +20769,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -20798,9 +20986,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -20866,9 +21056,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -20935,9 +21127,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -21014,9 +21208,11 @@ main (void)
 _ACEOF
 
 
-       rm -Rf build && mkdir -p build
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
        echo "obj-m := conftest.o" >build/Makefile
-       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?