diff --git a/arch/um/drivers/pty.c b/arch/um/drivers/pty.c
index 829a5eca8c07606b9b44ea393df4e4f32b94fd99..aa311afa966761c90e9229d4c8d6f57fa4ccb864 100644
--- a/arch/um/drivers/pty.c
+++ b/arch/um/drivers/pty.c
@@ -4,6 +4,7 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
 #include <errno.h>
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index 22666b4a8be76b1988bc133eea9c2a9319d55cae..394adcded0bfa356c10236a3824fe36d50a9a2aa 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -16,6 +16,8 @@
 #include "sysdep/tls.h"
 #include "sysdep/archsetjmp.h"
 
+#define CATCH_EINTR(expr) while ((errno = 0, ((expr) < 0)) && (errno == EINTR))
+
 #define OS_TYPE_FILE 1
 #define OS_TYPE_DIR 2
 #define OS_TYPE_SYMLINK 3
@@ -341,6 +343,10 @@ extern void maybe_sigio_broken(int fd, int read);
 extern void sig_handler_common_skas(int sig, void *sc_ptr);
 extern void user_signal(int sig, union uml_pt_regs *regs, int pid);
 
+/* sys-x86_64/prctl.c */
 extern int os_arch_prctl(int pid, int code, unsigned long *addr);
 
+/* tty.c */
+int get_pty(void);
+
 #endif
diff --git a/arch/um/include/user.h b/arch/um/include/user.h
index acadce3f271f05d2833790c82922140b539d4dc4..a6da626082544fcc3adbd71c199dd7bf1582c996 100644
--- a/arch/um/include/user.h
+++ b/arch/um/include/user.h
@@ -6,6 +6,14 @@
 #ifndef __USER_H__
 #define __USER_H__
 
+/*
+ * The usual definition - copied here because the kernel provides its own,
+ * fancier, type-safe, definition.  Using that one would require
+ * copying too much infrastructure for my taste, so userspace files
+ * get less checking than kernel files.
+ */
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
 extern void panic(const char *fmt, ...)
 	__attribute__ ((format (printf, 1, 2)));
 extern int printk(const char *fmt, ...)
@@ -18,14 +26,3 @@ extern unsigned long strlcpy(char *, const char *, unsigned long);
 extern unsigned long strlcat(char *, const char *, unsigned long);
 
 #endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/include/user_util.h b/arch/um/include/user_util.h
index f04776e2436f14da758ebd56bf31498792aa1e3f..7fa5c68f06200e40fda22d1f641f5d6d3f4150e1 100644
--- a/arch/um/include/user_util.h
+++ b/arch/um/include/user_util.h
@@ -8,31 +8,13 @@
 
 #include "sysdep/ptrace.h"
 
-/* Copied from kernel.h and compiler-gcc.h */
-
-/* Force a compilation error if condition is true, but also produce a
-   result (of value 0 and type size_t), so the expression can be used
-   e.g. in a structure initializer (or where-ever else comma expressions
-   aren't permitted). */
-#define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
-
-/* &a[0] degrades to a pointer: a different type from an array */
-#define __must_be_array(a) \
-  BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))
-
-#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
-
-#define CATCH_EINTR(expr) while ((errno = 0, ((expr) < 0)) && (errno == EINTR))
-
 extern int mode_tt;
 
 extern int grantpt(int __fd);
 extern int unlockpt(int __fd);
-extern char *ptsname(int __fd);
 
 extern void *add_signal_handler(int sig, void (*handler)(int));
 extern void input_cb(void (*proc)(void *), void *arg, int arg_len);
-extern int get_pty(void);
 extern int switcheroo(int fd, int prot, void *from, void *to, int size);
 extern void do_exec(int old_pid, int new_pid);
 extern void tracer_panic(char *msg, ...)
diff --git a/arch/um/os-Linux/sys-i386/tls.c b/arch/um/os-Linux/sys-i386/tls.c
index 256532034c62d11b64bc87db21773749a79e3d76..8ba1324829707c3cda2725180c268ef6d45232d2 100644
--- a/arch/um/os-Linux/sys-i386/tls.c
+++ b/arch/um/os-Linux/sys-i386/tls.c
@@ -5,6 +5,7 @@
 #include <unistd.h>
 
 #include "sysdep/tls.h"
+#include "user.h"
 #include "user_util.h"
 
 /* Checks whether host supports TLS, and sets *tls_min according to the value