1 files changed, 3 insertions, 0 deletions

diff --git a/arch/sparc64/solaris/misc.c b/arch/sparc64/solaris/misc.c
index 642541769a17..9c581328e76a 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 @@ asmlinkage int solaris_procids(int cmd, s32 pid, s32 pgid)
                            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 */