1 files changed, 18 insertions, 8 deletions

diff --git a/Makefile b/Makefile
index 529b9048d97e..feca34c26145 100644
--- a/Makefile
+++ b/Makefile
@@ -903,14 +903,24 @@ prepare: prepare0
 
 export CPPFLAGS_vmlinux.lds += -P -C -U$(ARCH)
 
-# FIXME: The asm symlink changes when $(ARCH) changes. That's
-# hard to detect, but I suppose "make mrproper" is a good idea
-# before switching between archs anyway.
-
-include/asm:
-        @echo '  SYMLINK $@ -> include/asm-$(SRCARCH)'
-        $(Q)if [ ! -d include ]; then mkdir -p include; fi;
-        @ln -fsn asm-$(SRCARCH) $@
+# The asm symlink changes when $(ARCH) changes.
+# Detect this and ask user to run make mrproper
+
+include/asm: FORCE
+        $(Q)set -e; asmlink=`readlink include/asm | cut -d '-' -f 2`;   \
+        if [ -L include/asm ]; then                                     \
+                if [ "$$asmlink" != "$(SRCARCH)" ]; then                \
+                        echo "ERROR: the symlink $@ points to asm-$$asmlink but asm-$(SRCARCH) was expected"; \
+                        echo "       set ARCH or save .config and run 'make mrproper' to fix it";             \
+                        exit 1;                                         \
+                fi;                                                     \
+        else                                                            \
+                echo '  SYMLINK $@ -> include/asm-$(SRCARCH)';          \
+                if [ ! -d include ]; then                               \
+                        mkdir -p include;                               \
+                fi;                                                     \
+                ln -fsn asm-$(SRCARCH) $@;                              \
+        fi
 
 # Generate some files
 # ---------------------------------------------------------------------------