pty: fix compat ioctls

Al Viro · Al Viro · commit 50f45326afab · 2018-10-13T00:50:51.000-04:00
pointer-taking ones need compat_ptr(); int-taking one doesn't.

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
@@ -28,6 +28,7 @@
 #include <linux/mount.h>
 #include <linux/file.h>
 #include <linux/ioctl.h>
+#include <linux/compat.h>
 
 #undef TTY_DEBUG_HANGUP
 #ifdef TTY_DEBUG_HANGUP
@@ -488,15 +489,19 @@ static int pty_bsd_ioctl(struct tty_struct *tty,
 	return -ENOIOCTLCMD;
 }
 
+#ifdef CONFIG_COMPAT
 static long pty_bsd_compat_ioctl(struct tty_struct *tty,
 				 unsigned int cmd, unsigned long arg)
 {
 	/*
 	 * PTY ioctls don't require any special translation between 32-bit and
 	 * 64-bit userspace, they are already compatible.
 	 */
-	return pty_bsd_ioctl(tty, cmd, arg);
+	return pty_bsd_ioctl(tty, cmd, (unsigned long)compat_ptr(arg));
 }
+#else
+#define pty_bsd_compat_ioctl NULL
+#endif
 
 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
 /*
@@ -676,15 +681,20 @@ static int pty_unix98_ioctl(struct tty_struct *tty,
 	return -ENOIOCTLCMD;
 }
 
+#ifdef CONFIG_COMPAT
 static long pty_unix98_compat_ioctl(struct tty_struct *tty,
 				 unsigned int cmd, unsigned long arg)
 {
 	/*
 	 * PTY ioctls don't require any special translation between 32-bit and
 	 * 64-bit userspace, they are already compatible.
 	 */
-	return pty_unix98_ioctl(tty, cmd, arg);
+	return pty_unix98_ioctl(tty, cmd,
+		cmd == TIOCSIG ? arg : (unsigned long)compat_ptr(arg));
 }
+#else
+#define pty_unix98_compat_ioctl NULL
+#endif
 
 /**
  *	ptm_unix98_lookup	-	find a pty master
