[PATCH] uml: remove os_isatty

os_isatty can be made to disappear by moving maybe_sigio_broken from kernel to
user code.  This also lets write_sigio_workaround become static.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
index 00e9388..0d2422a 100644
--- a/arch/um/os-Linux/sigio.c
+++ b/arch/um/os-Linux/sigio.c
@@ -233,7 +233,7 @@
 	return p;
 }
 
-void write_sigio_workaround(void)
+static void write_sigio_workaround(void)
 {
 	unsigned long stack;
 	struct pollfd *p;
@@ -314,6 +314,18 @@
 	close(l_write_sigio_fds[1]);
 }
 
+void maybe_sigio_broken(int fd, int read)
+{
+	if(!isatty(fd))
+		return;
+
+	if((read || pty_output_sigio) && (!read || pty_close_sigio))
+		return;
+
+	write_sigio_workaround();
+	add_sigio_fd(fd, read);
+}
+
 void sigio_cleanup(void)
 {
 	if(write_sigio_pid != -1){