um: Stop abusing __KERNEL__

Currently UML is abusing __KERNEL__ to distinguish between
kernel and host code (os-Linux). It is better to use a custom
define such that existing users of __KERNEL__ don't get confused.
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/um/Makefile

@@ -68,9 +68,10 @@ KBUILD_CFLAGS += $(CFLAGS) $(CFLAGS-y) -D__arch_um__ \
 
 KBUILD_AFLAGS += $(ARCH_INCLUDE)
 
-USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -D__KERNEL__,,\
-	$(patsubst -I%,,$(KBUILD_CFLAGS)))) $(ARCH_INCLUDE) $(MODE_INCLUDE) \
-	$(filter -I%,$(CFLAGS)) -D_FILE_OFFSET_BITS=64 -idirafter include
+USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -I%,,$(KBUILD_CFLAGS))) \
+		$(ARCH_INCLUDE) $(MODE_INCLUDE) $(filter -I%,$(CFLAGS)) \
+		-D_FILE_OFFSET_BITS=64 -idirafter include \
+		-D__KERNEL__ -D__UM_HOST__
 
 #This will adjust *FLAGS accordingly to the platform.
 include $(ARCH_DIR)/Makefile-os-$(OS)

arch/um/drivers/mconsole.h

@@ -7,7 +7,7 @@
 #ifndef __MCONSOLE_H__
 #define __MCONSOLE_H__
 
-#ifndef __KERNEL__
+#ifdef __UM_HOST__
 #include <stdint.h>
 #define u32 uint32_t
 #endif

arch/um/include/shared/init.h

@@ -40,7 +40,7 @@
 typedef int (*initcall_t)(void);
 typedef void (*exitcall_t)(void);
 
-#ifndef __KERNEL__
+#ifdef __UM_HOST__
 #ifndef __section
 # define __section(S) __attribute__ ((__section__(#S)))
 #endif
@@ -131,7 +131,7 @@ extern struct uml_param __uml_setup_start, __uml_setup_end;
 #define __uml_postsetup_call	__used __section(.uml.postsetup.init)
 #define __uml_exit_call		__used __section(.uml.exitcall.exit)
 
-#ifndef __KERNEL__
+#ifdef __UM_HOST__
 
 #define __define_initcall(level,fn) \
 	static initcall_t __initcall_##fn __used \

arch/um/include/shared/user.h

@@ -17,7 +17,7 @@
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 
 /* This is to get size_t */
-#ifdef __KERNEL__
+#ifndef __UM_HOST__
 #include <linux/types.h>
 #else
 #include <stddef.h>

arch/x86/um/shared/sysdep/tls.h

 #ifndef _SYSDEP_TLS_H
 #define _SYSDEP_TLS_H
 
-# ifndef __KERNEL__
+#ifdef __UM_HOST__
 
 /* Change name to avoid conflicts with the original one from <asm/ldt.h>, which
  * may be named user_desc (but in 2.4 and in header matching its API was named
@@ -22,11 +22,11 @@ typedef struct um_dup_user_desc {
 #endif
 } user_desc_t;
 
-# else /* __KERNEL__ */
+#else /* __UM_HOST__ */
 
 typedef struct user_desc user_desc_t;
 
-# endif /* __KERNEL__ */
+#endif /* __UM_HOST__ */
 
 extern int os_set_thread_area(user_desc_t *info, int pid);
 extern int os_get_thread_area(user_desc_t *info, int pid);