[PATCH] solaris emulation: incorrect tty locking

[akpm@osdl.org: build fix]
[akpm@osdl.org: warning fix]
Signed-off-by: Alan Cox <alan@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

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 */

drivers/char/tty_io.c

@@ -129,6 +129,7 @@ LIST_HEAD(tty_drivers);			/* linked list of tty drivers */
 /* 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 */