Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/fix-kbuild

* git://git.kernel.org/pub/scm/linux/kernel/git/sam/fix-kbuild:
  kbuild: fix building with O=.. options
  kbuild: fix building with redirected output.

1 files changed, 6 insertions, 8 deletions

diff --git a/Makefile b/Makefile
index 92dc3cb5f43..7fb1a2c0830 100644
--- a/Makefile
+++ b/Makefile
@@ -108,6 +108,9 @@ endif
 PHONY := _all
 _all:
 
+# Cancel implicit rules on top Makefile
+$(CURDIR)/Makefile Makefile: ;
+
 ifneq ($(KBUILD_OUTPUT),)
 # Invoke a second make in the output directory, passing relevant variables
 # check that the output directory actually exists
@@ -115,13 +118,10 @@ saved-output := $(KBUILD_OUTPUT)
 KBUILD_OUTPUT := $(shell cd $(KBUILD_OUTPUT) && /bin/pwd)
 $(if $(KBUILD_OUTPUT),, \
      $(error output directory "$(saved-output)" does not exist))
-# Check that OUTPUT directory is not the same as where we have kernel src
-$(if $(filter-out $(KBUILD_OUTPUT),$(shell /bin/pwd)),, \
-     $(error Output directory (O=...) specifies kernel src dir))
 
 PHONY += $(MAKECMDGOALS) sub-make
 
-$(filter-out _all sub-make,$(MAKECMDGOALS)) _all: sub-make
+$(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
 	$(Q)@:
 
 sub-make: FORCE
@@ -291,7 +291,8 @@ export quiet Q KBUILD_VERBOSE
 # Look for make include files relative to root of kernel src
 MAKEFLAGS += --include-dir=$(srctree)
 
-# We need some generic definitions.
+# We need some generic definitions (do not try to remake the file).
+$(srctree)/scripts/Kbuild.include: ;
 include $(srctree)/scripts/Kbuild.include
 
 # Make variables (CC, etc...)
@@ -1560,9 +1561,6 @@ endif	# skip-makefile
 PHONY += FORCE
 FORCE:
 
-# Cancel implicit rules on top Makefile, `-rR' will apply to sub-makes.
-Makefile: ;
-
 # Declare the contents of the .PHONY variable as phony.  We keep that
 # information in a variable se we can use it in if_changed and friends.
 .PHONY: $(PHONY)