kbuild: change kbuild to not rely on incorrect GNU make behavior

[mirror_ubuntu-artful-kernel.git] / arch / um / Makefile

diff --git a/arch/um/Makefile b/arch/um/Makefile
index 6430a6383853494fecb56d562ada5918d9df424c..8d14c7a831bed0d7e6644a3883424356a40a2cbb 100644 (file)
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -1,4 +1,7 @@
-# 
+#
+# This file is included by the global makefile so that you can add your own
+# architecture-specific flags and dependencies.
+#
 # Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
 # Licensed under the GPL
 #
@@ -47,13 +50,16 @@ ARCH_INCLUDE        += -I$(srctree)/$(ARCH_DIR)/include
 endif
 SYS_DIR                := $(ARCH_DIR)/include/sysdep-$(SUBARCH)
 
-# -Dvmap=kernel_vmap affects everything, and prevents anything from
-# referencing the libpcap.o symbol so named.
+# -Dvmap=kernel_vmap prevents anything from referencing the libpcap.o symbol so
+# named - it's a common symbol in libpcap, so we get a binary which crashes.
 #
-# Same things for in6addr_loopback - found in libc.
+# Same things for in6addr_loopback and mktime - found in libc. For these two we
+# only get link-time error, luckily.
+#
+# These apply to USER_CFLAGS to.
 
-CFLAGS += $(CFLAGS-y) -D__arch_um__ -DSUBARCH=\"$(SUBARCH)\" \
-       $(ARCH_INCLUDE) $(MODE_INCLUDE) -Dvmap=kernel_vmap \
+CFLAGS += $(CFLAGS-y) -D__arch_um__ -DSUBARCH=\"$(SUBARCH)\"   \
+       $(ARCH_INCLUDE) $(MODE_INCLUDE) -Dvmap=kernel_vmap      \
        -Din6addr_loopback=kernel_in6addr_loopback
 
 AFLAGS += $(ARCH_INCLUDE)
@@ -66,6 +72,7 @@ USER_CFLAGS := $(patsubst -D__KERNEL__,,$(USER_CFLAGS)) $(ARCH_INCLUDE) \
 # kernel_errno to separate them from the libc errno.  This allows -fno-common
 # in CFLAGS.  Otherwise, it would cause ld to complain about the two different
 # errnos.
+# These apply to kernelspace only.
 
 CFLAGS += -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask \
        -Dmktime=kernel_mktime
@@ -84,7 +91,7 @@ CONFIG_KERNEL_HALF_GIGS ?= 0
 
 SIZE = (($(CONFIG_NEST_LEVEL) + $(CONFIG_KERNEL_HALF_GIGS)) * 0x20000000)
 
-.PHONY: linux
+PHONY += linux
 
 all: linux
 
@@ -168,10 +175,13 @@ else
        $(Q)cd $(TOPDIR)/include/asm-um && ln -sf ../asm-$(SUBARCH) arch
 endif
 
-$(ARCH_DIR)/include/sysdep:
+$(objtree)/$(ARCH_DIR)/include:
+       @echo '  MKDIR $@'
+       $(Q)mkdir -p $@
+
+$(ARCH_DIR)/include/sysdep: $(objtree)/$(ARCH_DIR)/include
        @echo '  SYMLINK $@'
 ifneq ($(KBUILD_SRC),)
-       $(Q)mkdir -p $(ARCH_DIR)/include
        $(Q)ln -fsn $(srctree)/$(ARCH_DIR)/include/sysdep-$(SUBARCH) $(ARCH_DIR)/include/sysdep
 else
        $(Q)cd $(ARCH_DIR)/include && ln -sf sysdep-$(SUBARCH) sysdep
@@ -214,7 +224,7 @@ $(ARCH_DIR)/include/user_constants.h: $(ARCH_DIR)/user-offsets.s
 
 CLEAN_FILES += $(ARCH_DIR)/user-offsets.s
 
-$(ARCH_DIR)/include/kern_constants.h:
+$(ARCH_DIR)/include/kern_constants.h: $(objtree)/$(ARCH_DIR)/include
        @echo '  SYMLINK $@'
        $(Q) ln -sf ../../../include/asm-um/asm-offsets.h $@