Kbuild: Handle PREEMPT_RT for version string and magic

Update the build scripts and the version magic to reflect when
CONFIG_PREEMPT_RT is enabled in the same way as CONFIG_PREEMPT is treated.

The resulting version strings:

  Linux m 5.3.0-rc1+ #100 SMP Fri Jul 26 ...
  Linux m 5.3.0-rc1+ #101 SMP PREEMPT Fri Jul 26 ...
  Linux m 5.3.0-rc1+ #102 SMP PREEMPT_RT Fri Jul 26 ...

The module vermagic:

  5.3.0-rc1+ SMP mod_unload modversions
  5.3.0-rc1+ SMP preempt mod_unload modversions
  5.3.0-rc1+ SMP preempt_rt mod_unload modversions
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

include/linux/vermagic.h

@@ -9,6 +9,8 @@
 #endif
 #ifdef CONFIG_PREEMPT
 #define MODULE_VERMAGIC_PREEMPT "preempt "
+#elif defined(CONFIG_PREEMPT_RT)
+#define MODULE_VERMAGIC_PREEMPT "preempt_rt "
 #else
 #define MODULE_VERMAGIC_PREEMPT ""
 #endif

init/Makefile

@@ -34,4 +34,5 @@ silent_chk_compile.h = :
 include/generated/compile.h: FORCE
 	@$($(quiet)chk_compile.h)
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@	\
-	"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CC) $(KBUILD_CFLAGS)"
+	"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)"	\
+	"$(CONFIG_PREEMPT_RT)" "$(CC) $(KBUILD_CFLAGS)"

scripts/Makefile.modpost

@@ -23,7 +23,7 @@
 #   Version magic (see include/linux/vermagic.h for full details)
 #     - Kernel release
 #     - SMP is CONFIG_SMP
-#     - PREEMPT is CONFIG_PREEMPT
+#     - PREEMPT is CONFIG_PREEMPT[_RT]
 #     - GCC Version
 #   Module info
 #     - Module version (MODULE_VERSION)

scripts/mkcompile_h

@@ -5,7 +5,8 @@ TARGET=$1
 ARCH=$2
 SMP=$3
 PREEMPT=$4
-CC=$5
+PREEMPT_RT=$5
+CC=$6
 
 vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }
 
@@ -53,6 +54,7 @@ UTS_VERSION="#$VERSION"
 CONFIG_FLAGS=""
 if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi
 if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi
+if [ -n "$PREEMPT_RT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT_RT"; fi
 UTS_VERSION="$UTS_VERSION $CONFIG_FLAGS $TIMESTAMP"
 
 # Truncate to maximum length