From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [PATCH v2] Input: serport: Add compat_ioctl routine to support 32bit inputattach in 64bit systems Date: Tue, 9 Sep 2014 11:14:21 -0700 Message-ID: <20140909181421.GB28774@core.coreip.homeip.net> References: <1410240028-9377-1-git-send-email-penmount.touch@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1410240028-9377-1-git-send-email-penmount.touch@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: John Sung Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-input@vger.kernel.org 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 > --- > 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 > #include > > +#ifdef CONFIG_COMPAT > +#include > +#endif > + > MODULE_AUTHOR("Vojtech Pavlik "); > 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 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 Signed-off-by: Dmitry Torokhov --- 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 #include #include +#include MODULE_AUTHOR("Vojtech Pavlik "); 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 };