From: Johan Hovold johan@kernel.org
[ Upstream commit 8871de06ff78e9333d86c87d7071452b690e7c9b ]
Drivers should return -ENOTTY ("Inappropriate I/O control operation") when an ioctl isn't supported, while -EINVAL is used for invalid arguments.
Support for termiox was added by commit 1d65b4a088de ("tty: Add termiox") in 2008 but no driver support ever followed and it was recently ripped out by commit e0efb3168d34 ("tty: Remove dead termiox code").
Fix the return value for the unsupported termiox ioctls, which have always returned -EINVAL, by explicitly returning -ENOTTY rather than removing them completely and falling back to the default unrecognised- ioctl handling.
Fixes: 1d65b4a088de ("tty: Add termiox") Signed-off-by: Johan Hovold johan@kernel.org Link: https://lore.kernel.org/r/20210407095208.31838-4-johan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/tty_ioctl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c index 4de1c6ddb8ff..803da2d111c8 100644 --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -774,8 +774,8 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file, case TCSETX: case TCSETXW: case TCSETXF: - return -EINVAL; -#endif + return -ENOTTY; +#endif case TIOCGSOFTCAR: copy_termios(real_tty, &kterm); ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,