diff --git a/arch/sparc64/solaris/misc.c b/arch/sparc64/solaris/misc.c
index 6425417..9c58132 100644
--- a/arch/sparc64/solaris/misc.c
+++ b/arch/sparc64/solaris/misc.c
@@ -11,6 +11,7 @@
 #include <linux/limits.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
+#include <linux/tty.h>
 #include <linux/mman.h>
 #include <linux/file.h>
 #include <linux/timex.h>
@@ -422,7 +423,9 @@
 			   Solaris setpgrp and setsid? */
 			ret = sys_setpgid(0, 0);
 			if (ret) return ret;
+			mutex_lock(&tty_mutex);
 			current->signal->tty = NULL;
+			mutex_unlock(&tty_mutex);
 			return process_group(current);
 		}
 	case 2: /* getsid */
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 142427c..48b5900 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -129,6 +129,7 @@
 /* Semaphore to protect creating and releasing a tty. This is shared with
    vt.c for deeply disgusting hack reasons */
 DEFINE_MUTEX(tty_mutex);
+EXPORT_SYMBOL(tty_mutex);
 
 #ifdef CONFIG_UNIX98_PTYS
 extern struct tty_driver *ptm_driver;	/* Unix98 pty masters; for /dev/ptmx */