tty: fix return value for unsupported ioctls

Drivers should return -ENOTTY ("Inappropriate I/O control operation")
when an ioctl isn't supported, while -EINVAL is used for invalid
arguments.

Fix up the TIOCMGET, TIOCMSET and TIOCGICOUNT helpers which returned
-EINVAL when a tty driver did not implement the corresponding
operations.

Note that the TIOCMGET and TIOCMSET helpers predate git and do not get a
corresponding Fixes tag below.

Fixes: d281da7ff6 ("tty: Make tiocgicount a handler")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2021-04-07 11:52:02 +02:00 committed by Greg Kroah-Hartman
parent d09845e98a
commit 1b8b20868a
2 changed files with 6 additions and 6 deletions

View File

@ -2529,14 +2529,14 @@ out:
* @p: pointer to result
*
* Obtain the modem status bits from the tty driver if the feature
* is supported. Return -EINVAL if it is not available.
* is supported. Return -ENOTTY if it is not available.
*
* Locking: none (up to the driver)
*/
static int tty_tiocmget(struct tty_struct *tty, int __user *p)
{
int retval = -EINVAL;
int retval = -ENOTTY;
if (tty->ops->tiocmget) {
retval = tty->ops->tiocmget(tty);
@ -2554,7 +2554,7 @@ static int tty_tiocmget(struct tty_struct *tty, int __user *p)
* @p: pointer to desired bits
*
* Set the modem status bits from the tty driver if the feature
* is supported. Return -EINVAL if it is not available.
* is supported. Return -ENOTTY if it is not available.
*
* Locking: none (up to the driver)
*/
@ -2566,7 +2566,7 @@ static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd,
unsigned int set, clear, val;
if (tty->ops->tiocmset == NULL)
return -EINVAL;
return -ENOTTY;
retval = get_user(val, p);
if (retval)
@ -2606,7 +2606,7 @@ int tty_get_icount(struct tty_struct *tty,
if (tty->ops->get_icount)
return tty->ops->get_icount(tty, icount);
else
return -EINVAL;
return -ENOTTY;
}
EXPORT_SYMBOL_GPL(tty_get_icount);

View File

@ -228,7 +228,7 @@
*
* Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel
* structure to complete. This method is optional and will only be called
* if provided (otherwise EINVAL will be returned).
* if provided (otherwise ENOTTY will be returned).
*/
#include <linux/export.h>