diff mbox series

[V1,1/1] Serial: core: Add compat ioctl support

Message ID 20221222044925.27846-1-quic_vdadhani@quicinc.com
State New
Headers show
Series [V1,1/1] Serial: core: Add compat ioctl support | expand

Commit Message

Viken Dadhaniya Dec. 22, 2022, 4:49 a.m. UTC
Current serial core driver doesn't support compat_ioctl
due to which 32-bit application is not able to send
ioctls to driver on a 64-bit platform.

Added compat_ioctl support in serial core to handle
ioctls from 32-bit applications on a 64-bit platform.

Signed-off-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
---
 drivers/tty/serial/serial_core.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

Comments

Greg Kroah-Hartman Dec. 22, 2022, 5:49 a.m. UTC | #1
On Thu, Dec 22, 2022 at 10:19:25AM +0530, Viken Dadhaniya wrote:
> Current serial core driver doesn't support compat_ioctl
> due to which 32-bit application is not able to send
> ioctls to driver on a 64-bit platform.

Are you sure?

> Added compat_ioctl support in serial core to handle
> ioctls from 32-bit applications on a 64-bit platform.
> 
> Signed-off-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
> ---
>  drivers/tty/serial/serial_core.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index b9fbbee598b8..5ffa0798db3b 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -1601,6 +1601,22 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
>  	return ret;
>  }
>  
> +/**
> + * uart_compat_ioctl: uart compat IOCTL function.
> + * @tty: pointer to tty structure.
> + * @cmd: command code passed by user-space.
> + * @arg: argument  passed by user-space.
> + *
> + * This function will call normal uart IOCTL.
> + *
> + * Return: 0 for success, Negative number for error condition.

Why create kernel doc for a static function?  uart_ioctl() does not have
this, right?

> + */
> +static long
> +uart_compat_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
> +{
> +	return (long)uart_ioctl(tty, cmd, arg);
> +};

Really?  Why has this never shown up before as an issue?

How was this tested?  What is currently broken that now works properly
(or the other way around?)

This patch implies that _every_ driver with an ioctl must create a
compat_ioctl() callback, are you sure that is the case?

thanks,

greg k-h
diff mbox series

Patch

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index b9fbbee598b8..5ffa0798db3b 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1601,6 +1601,22 @@  uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
 	return ret;
 }
 
+/**
+ * uart_compat_ioctl: uart compat IOCTL function.
+ * @tty: pointer to tty structure.
+ * @cmd: command code passed by user-space.
+ * @arg: argument  passed by user-space.
+ *
+ * This function will call normal uart IOCTL.
+ *
+ * Return: 0 for success, Negative number for error condition.
+ */
+static long
+uart_compat_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
+{
+	return (long)uart_ioctl(tty, cmd, arg);
+};
+
 static void uart_set_ldisc(struct tty_struct *tty)
 {
 	struct uart_state *state = tty->driver_data;
@@ -2670,6 +2686,7 @@  static const struct tty_operations uart_ops = {
 	.chars_in_buffer= uart_chars_in_buffer,
 	.flush_buffer	= uart_flush_buffer,
 	.ioctl		= uart_ioctl,
+	.compat_ioctl   = uart_compat_ioctl,
 	.throttle	= uart_throttle,
 	.unthrottle	= uart_unthrottle,
 	.send_xchar	= uart_send_xchar,