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

* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes:
  kbuild: revert "save ARCH & CROSS_COMPILE ..."
  warn about use of uninstalled kernel headers
  kbuild: mkcompile_h: trivial cleanups
  kbuild: fix warning when domainname is not available
  kbuild: Fix size_append issue for bzip2/lzma kernel
  kbuild,scripts: use non-builtin echo for '-e'
  kbuild: fix the binrpm-pkg target to work with KBUILD_OUTPUT set

include/linux/kernel.h

@@ -659,6 +659,12 @@ extern int do_sysinfo(struct sysinfo *info);
 
 #endif /* __KERNEL__ */
 
+#ifndef __EXPORTED_HEADERS__
+#ifndef __KERNEL__
+#warning Attempt to use kernel headers from user space, see http://kernelnewbies.org/KernelHeaders
+#endif /* __KERNEL__ */
+#endif /* __EXPORTED_HEADERS__ */
+
 #define SI_LOAD_SHIFT	16
 struct sysinfo {
 	long uptime;			/* Seconds since boot */