Hi John,
On Tue, Sep 09, 2014 at 01:20:28PM +0800, John Sung wrote:
> When running a 32-bit inputattach utility in a 64-bit system, there will be error code "inputattach: can't set device type". This is caused by the serport device driver not supporting compat_ioctl, so that SPIOCSTYPE ioctl fails.
>
> Changes in v2:
> (1) Codes of the compat_ioctl are protected by #ifdef CONFIG_COMPAT.
> (2) Add a new function serport_set_type() for common codes used by serport_ldisc_ioctl() and serport_ldisc_compat_ioctl().
>
> Signed-off-by: John Sung <penmount.touch@xxxxxxxxx>
> ---
> drivers/input/serio/serport.c | 57 +++++++++++++++++++++++++++++++++--------
> 1 file changed, 46 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/input/serio/serport.c b/drivers/input/serio/serport.c
> index 0cb7ef5..1decaa2 100644
> --- a/drivers/input/serio/serport.c
> +++ b/drivers/input/serio/serport.c
> @@ -22,6 +22,10 @@
> #include <linux/serio.h>
> #include <linux/tty.h>
>
> +#ifdef CONFIG_COMPAT
> +#include <linux/compat.h>
> +#endif
> +
> MODULE_AUTHOR("Vojtech Pavlik <vojtech@xxxxxx>");
> MODULE_DESCRIPTION("Input device TTY line discipline");
> MODULE_LICENSE("GPL");
> @@ -40,6 +44,30 @@ struct serport {
> unsigned long flags;
> };
>
> +#ifdef CONFIG_COMPAT
> +#define SPIOCSTYPE32 (_IOW('q', 0x01, compat_ulong_t))
> +#endif
> +
> +/*
> + * serport_set_type() is called by serport_ldisc_ioctl() and
> + * serport_ldisc_compat_ioctl() to set up the serio_device_id values
> + */
> +
> +static int serport_set_type(struct tty_struct *tty, unsigned long arg)
> +{
> + struct serport *serport = (struct serport *) tty->disc_data;
> + unsigned long type;
> +
> + if (get_user(type, (unsigned long __user *) arg))
> + return -EFAULT;
I of not think we can do this. Kernel with try to fetch 64 bits from
where userland put only 32. It probbaly works on little-endian
architectures by chance, but won't on big endian.
Does the version of the patch below work for you?
Thanks.
--
Dmitry
Input: serport - add compat handling for SPIOCSTYPE ioctl
From: John Sung <penmount.touch@xxxxxxxxx>
When running a 32-bit inputattach utility in a 64-bit system, there will be
error code "inputattach: can't set device type". This is caused by the
serport device driver not supporting compat_ioctl, so that SPIOCSTYPE ioctl
fails.
Signed-off-by: John Sung <penmount.touch@xxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/input/serio/serport.c | 45 +++++++++++++++++++++++++++++++++++------
1 file changed, 38 insertions(+), 7 deletions(-)
diff --git a/drivers/input/serio/serport.c b/drivers/input/serio/serport.c
index 0cb7ef5..69175b8 100644
--- a/drivers/input/serio/serport.c
+++ b/drivers/input/serio/serport.c
@@ -21,6 +21,7 @@
#include <linux/init.h>
#include <linux/serio.h>
#include <linux/tty.h>
+#include <linux/compat.h>
MODULE_AUTHOR("Vojtech Pavlik <vojtech@xxxxxx>");
MODULE_DESCRIPTION("Input device TTY line discipline");
@@ -198,28 +199,55 @@ static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, u
return 0;
}
+static void serport_set_type(struct tty_struct *tty, unsigned long type)
+{
+ struct serport *serport = tty->disc_data;
+
+ serport->id.proto = type & 0x000000ff;
+ serport->id.id = (type & 0x0000ff00) >> 8;
+ serport->id.extra = (type & 0x00ff0000) >> 16;
+}
+
/*
* serport_ldisc_ioctl() allows to set the port protocol, and device ID
*/
-static int serport_ldisc_ioctl(struct tty_struct * tty, struct file * file, unsigned int cmd, unsigned long arg)
+static int serport_ldisc_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
{
- struct serport *serport = (struct serport*) tty->disc_data;
- unsigned long type;
-
if (cmd == SPIOCSTYPE) {
+ unsigned long type;
+
if (get_user(type, (unsigned long __user *) arg))
return -EFAULT;
- serport->id.proto = type & 0x000000ff;
- serport->id.id = (type & 0x0000ff00) >> 8;
- serport->id.extra = (type & 0x00ff0000) >> 16;
+ serport_set_type(tty, type);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+#ifdef CONFIG_COMPAT
+#define COMPAT_SPIOCSTYPE _IOW('q', 0x01, compat_ulong_t)
+static long serport_ldisc_compat_ioctl(struct tty_struct *tty,
+ struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ if (cmd == COMPAT_SPIOCSTYPE) {
+ void __user *uarg = compat_ptr(arg);
+ compat_ulong_t compat_type;
+
+ if (get_user(compat_type, (compat_ulong_t __user *)uarg))
+ return -EFAULT;
+ serport_set_type(tty, compat_type);
return 0;
}
return -EINVAL;
}
+#endif
static void serport_ldisc_write_wakeup(struct tty_struct * tty)
{
@@ -243,6 +271,9 @@ static struct tty_ldisc_ops serport_ldisc = {
.close = serport_ldisc_close,
.read = serport_ldisc_read,
.ioctl = serport_ldisc_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = serport_ldisc_compat_ioctl,
+#endif
.receive_buf = serport_ldisc_receive,
.write_wakeup = serport_ldisc_write_wakeup
};
--
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