1 files changed, 22 insertions, 10 deletions

diff --git a/Makefile b/Makefile
index c2f78a5a5493..8406d02c6385 100644
--- a/Makefile
+++ b/Makefile
@@ -309,9 +309,6 @@ CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
 
 CFLAGS          := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
                    -fno-strict-aliasing -fno-common
-# Force gcc to behave correct even for buggy distributions
-CFLAGS          += $(call cc-option, -fno-stack-protector)
-
 AFLAGS          := -D__ASSEMBLY__
 
 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
@@ -436,12 +433,13 @@ core-y		:= usr/
 endif # KBUILD_EXTMOD
 
 ifeq ($(dot-config),1)
-# In this section, we need .config
+# Read in config
+-include include/config/auto.conf
 
+ifeq ($(KBUILD_EXTMOD),)
 # Read in dependencies to all Kconfig* files, make sure to run
 # oldconfig if changes are detected.
 -include include/config/auto.conf.cmd
--include include/config/auto.conf
 
 # To avoid any implicit rule to kick in, define an empty command
 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
@@ -451,16 +449,27 @@ $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
 # if auto.conf.cmd is missing then we are probably in a cleaned tree so
 # we execute the config step to be sure to catch updated Kconfig files
 include/config/auto.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
-ifeq ($(KBUILD_EXTMOD),)
         $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig
 else
-        $(error kernel configuration not valid - run 'make prepare' in $(srctree) to update it)
-endif
+# external modules needs include/linux/autoconf.h and include/config/auto.conf
+# but do not care if they are up-to-date. Use auto.conf to trigger the test
+PHONY += include/config/auto.conf
+
+include/config/auto.conf:
+        $(Q)test -e include/linux/autoconf.h -a -e $@ || (              \
+        echo;                                                           \
+        echo "  ERROR: Kernel configuration is invalid.";               \
+        echo "         include/linux/autoconf.h or $@ are missing.";    \
+        echo "         Run 'make oldconfig && make prepare' on kernel src to fix it.";  \
+        echo;                                                           \
+        /bin/false)
+
+endif # KBUILD_EXTMOD
 
 else
 # Dummy target needed, because used as prerequisite
 include/config/auto.conf: ;
-endif
+endif # $(dot-config)
 
 # The all: target is the default when no target is given on the
 # command line.
@@ -474,6 +483,8 @@ else
 CFLAGS          += -O2
 endif
 
+include $(srctree)/arch/$(ARCH)/Makefile
+
 ifdef CONFIG_FRAME_POINTER
 CFLAGS          += -fno-omit-frame-pointer $(call cc-option,-fno-optimize-sibling-calls,)
 else
@@ -488,7 +499,8 @@ ifdef CONFIG_DEBUG_INFO
 CFLAGS          += -g
 endif
 
-include $(srctree)/arch/$(ARCH)/Makefile
+# Force gcc to behave correct even for buggy distributions
+CFLAGS          += $(call cc-option, -fno-stack-protector)
 
 # arch Makefile may override CC so keep this after arch Makefile is included
 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)