Commit f0193d3e authored by Al Viro's avatar Al Viro
Browse files

change semantics of ldisc ->compat_ioctl() 



First of all, make it return int.  Returning long when native method
had never allowed that is ridiculous and inconvenient.

More importantly, change the caller; if ldisc ->compat_ioctl() is NULL
or returns -ENOIOCTLCMD, tty_compat_ioctl() will try to feed cmd and
compat_ptr(arg) to ldisc's native ->ioctl().

That simplifies ->compat_ioctl() instances quite a bit - they only
need to deal with ioctls that are neither generic tty ones (those
would get shunted off to tty_ioctl()) nor simple compat pointer ones.

Note that something like TCFLSH won't reach ->compat_ioctl(),
even if ldisc ->ioctl() does handle it - it will be recognized
earlier and passed to tty_ioctl() (and ultimately - ldisc ->ioctl()).

For many ldiscs it means that NULL ->compat_ioctl() does the
right thing.  Those where it won't serve (see e.g. n_r3964.c) are
also easily dealt with - we need to handle the numeric-argument
ioctls (calling the native instance) and, if such would exist,
the ioctls that need layout conversion, etc.

All in-tree ldiscs dealt with.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 7ee32965

drivers/bluetooth/hci_ldisc.c

+1 −0
Original line number Diff line number Diff line
@@ -821,6 +821,7 @@ static int __init hci_uart_init(void) 
	hci_uart_ldisc.read		= hci_uart_tty_read;

	hci_uart_ldisc.write		= hci_uart_tty_write;

	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;

	hci_uart_ldisc.compat_ioctl	= hci_uart_tty_ioctl;

	hci_uart_ldisc.poll		= hci_uart_tty_poll;

	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;

	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;

drivers/input/serio/serport.c

+1 −1
Original line number Diff line number Diff line
@@ -226,7 +226,7 @@ static int serport_ldisc_ioctl(struct tty_struct *tty, struct file *file, 


#ifdef CONFIG_COMPAT

#define COMPAT_SPIOCSTYPE	_IOW('q', 0x01, compat_ulong_t)

static long serport_ldisc_compat_ioctl(struct tty_struct *tty,

static int serport_ldisc_compat_ioctl(struct tty_struct *tty,

				       struct file *file,

				       unsigned int cmd, unsigned long arg)

{

drivers/net/hamradio/6pack.c

+0 −21
Original line number Diff line number Diff line
@@ -34,7 +34,6 @@ 
#include <linux/ip.h>

#include <linux/tcp.h>

#include <linux/semaphore.h>

#include <linux/compat.h>

#include <linux/refcount.h>



#define SIXPACK_VERSION    "Revision: 0.3.0"
@@ -752,23 +751,6 @@ static int sixpack_ioctl(struct tty_struct *tty, struct file *file, 
	return err;

}



#ifdef CONFIG_COMPAT

static long sixpack_compat_ioctl(struct tty_struct * tty, struct file * file,

				unsigned int cmd, unsigned long arg)

{

	switch (cmd) {

	case SIOCGIFNAME:

	case SIOCGIFENCAP:

	case SIOCSIFENCAP:

	case SIOCSIFHWADDR:

		return sixpack_ioctl(tty, file, cmd,

				(unsigned long)compat_ptr(arg));

	}



	return -ENOIOCTLCMD;

}

#endif



static struct tty_ldisc_ops sp_ldisc = {

	.owner		= THIS_MODULE,

	.magic		= TTY_LDISC_MAGIC,
@@ -776,9 +758,6 @@ static struct tty_ldisc_ops sp_ldisc = { 
	.open		= sixpack_open,

	.close		= sixpack_close,

	.ioctl		= sixpack_ioctl,

#ifdef CONFIG_COMPAT

	.compat_ioctl	= sixpack_compat_ioctl,

#endif

	.receive_buf	= sixpack_receive_buf,

	.write_wakeup	= sixpack_write_wakeup,

};

drivers/net/hamradio/mkiss.c

+0 −21
Original line number Diff line number Diff line
@@ -35,7 +35,6 @@ 
#include <linux/skbuff.h>

#include <linux/if_arp.h>

#include <linux/jiffies.h>

#include <linux/compat.h>



#include <net/ax25.h>
@@ -875,23 +874,6 @@ static int mkiss_ioctl(struct tty_struct *tty, struct file *file, 
	return err;

}



#ifdef CONFIG_COMPAT

static long mkiss_compat_ioctl(struct tty_struct *tty, struct file *file,

	unsigned int cmd, unsigned long arg)

{

	switch (cmd) {

	case SIOCGIFNAME:

	case SIOCGIFENCAP:

	case SIOCSIFENCAP:

	case SIOCSIFHWADDR:

		return mkiss_ioctl(tty, file, cmd,

				   (unsigned long)compat_ptr(arg));

	}



	return -ENOIOCTLCMD;

}

#endif



/*

 * Handle the 'receiver data ready' interrupt.

 * This function is called by the 'tty_io' module in the kernel when
@@ -966,9 +948,6 @@ static struct tty_ldisc_ops ax_ldisc = { 
	.open		= mkiss_open,

	.close		= mkiss_close,

	.ioctl		= mkiss_ioctl,

#ifdef CONFIG_COMPAT

	.compat_ioctl	= mkiss_compat_ioctl,

#endif

	.receive_buf	= mkiss_receive_buf,

	.write_wakeup	= mkiss_write_wakeup

};

drivers/net/slip/slip.c

+0 −25
Original line number Diff line number Diff line
@@ -79,7 +79,6 @@ 
#include <linux/rtnetlink.h>

#include <linux/if_arp.h>

#include <linux/if_slip.h>

#include <linux/compat.h>

#include <linux/delay.h>

#include <linux/init.h>

#include <linux/slab.h>
@@ -1167,27 +1166,6 @@ static int slip_ioctl(struct tty_struct *tty, struct file *file, 
	}

}



#ifdef CONFIG_COMPAT

static long slip_compat_ioctl(struct tty_struct *tty, struct file *file,

					unsigned int cmd, unsigned long arg)

{

	switch (cmd) {

	case SIOCGIFNAME:

	case SIOCGIFENCAP:

	case SIOCSIFENCAP:

	case SIOCSIFHWADDR:

	case SIOCSKEEPALIVE:

	case SIOCGKEEPALIVE:

	case SIOCSOUTFILL:

	case SIOCGOUTFILL:

		return slip_ioctl(tty, file, cmd,

				  (unsigned long)compat_ptr(arg));

	}



	return -ENOIOCTLCMD;

}

#endif



/* VSV changes start here */

#ifdef CONFIG_SLIP_SMART

/* function do_ioctl called from net/core/dev.c
@@ -1280,9 +1258,6 @@ static struct tty_ldisc_ops sl_ldisc = { 
	.close	 	= slip_close,

	.hangup	 	= slip_hangup,

	.ioctl		= slip_ioctl,

#ifdef CONFIG_COMPAT

	.compat_ioctl	= slip_compat_ioctl,

#endif

	.receive_buf	= slip_receive_buf,

	.write_wakeup	= slip_write_wakeup,

};

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