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Commit fc0a8079 authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Mauro Carvalho Chehab
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[media] v4l: Share code between video_usercopy and video_ioctl2 



The two functions are mostly identical. They handle the copy_from_user
and copy_to_user operations related with V4L2 ioctls and call the real
ioctl handler.

Create a __video_usercopy function that implements the core of
video_usercopy and video_ioctl2, and call that function from both.

Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: default avatarHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 9f00edae

drivers/media/video/v4l2-ioctl.c

+11 −98
Original line number Diff line number Diff line
@@ -294,101 +294,6 @@ void v4l_printk_ioctl(unsigned int cmd) 
}

EXPORT_SYMBOL(v4l_printk_ioctl);



/*

 * helper function -- handles userspace copying for ioctl arguments

 * Obsolete usercopy function - Should be removed soon

 */

long

video_usercopy(struct file *file, unsigned int cmd, unsigned long arg,

		v4l2_kioctl func)

{

	char	sbuf[128];

	void    *mbuf = NULL;

	void	*parg = NULL;

	long	err  = -EINVAL;

	int     is_ext_ctrl;

	size_t  ctrls_size = 0;

	void __user *user_ptr = NULL;



	is_ext_ctrl = (cmd == VIDIOC_S_EXT_CTRLS || cmd == VIDIOC_G_EXT_CTRLS ||

		       cmd == VIDIOC_TRY_EXT_CTRLS);



	/*  Copy arguments into temp kernel buffer  */

	switch (_IOC_DIR(cmd)) {

	case _IOC_NONE:

		parg = NULL;

		break;

	case _IOC_READ:

	case _IOC_WRITE:

	case (_IOC_WRITE | _IOC_READ):

		if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {

			parg = sbuf;

		} else {

			/* too big to allocate from stack */

			mbuf = kmalloc(_IOC_SIZE(cmd), GFP_KERNEL);

			if (NULL == mbuf)

				return -ENOMEM;

			parg = mbuf;

		}



		err = -EFAULT;

		if (_IOC_DIR(cmd) & _IOC_WRITE)

			if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))

				goto out;

		break;

	}

	if (is_ext_ctrl) {

		struct v4l2_ext_controls *p = parg;



		/* In case of an error, tell the caller that it wasn't

		   a specific control that caused it. */

		p->error_idx = p->count;

		user_ptr = (void __user *)p->controls;

		if (p->count) {

			ctrls_size = sizeof(struct v4l2_ext_control) * p->count;

			/* Note: v4l2_ext_controls fits in sbuf[] so mbuf is still NULL. */

			mbuf = kmalloc(ctrls_size, GFP_KERNEL);

			err = -ENOMEM;

			if (NULL == mbuf)

				goto out_ext_ctrl;

			err = -EFAULT;

			if (copy_from_user(mbuf, user_ptr, ctrls_size))

				goto out_ext_ctrl;

			p->controls = mbuf;

		}

	}



	/* call driver */

	err = func(file, cmd, parg);

	if (err == -ENOIOCTLCMD)

		err = -EINVAL;

	if (is_ext_ctrl) {

		struct v4l2_ext_controls *p = parg;



		p->controls = (void *)user_ptr;

		if (p->count && err == 0 && copy_to_user(user_ptr, mbuf, ctrls_size))

			err = -EFAULT;

		goto out_ext_ctrl;

	}

	if (err < 0)

		goto out;



out_ext_ctrl:

	/*  Copy results into user buffer  */

	switch (_IOC_DIR(cmd)) {

	case _IOC_READ:

	case (_IOC_WRITE | _IOC_READ):

		if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))

			err = -EFAULT;

		break;

	}



out:

	kfree(mbuf);

	return err;

}

EXPORT_SYMBOL(video_usercopy);



static void dbgbuf(unsigned int cmd, struct video_device *vfd,

					struct v4l2_buffer *p)

{
@@ -2332,8 +2237,9 @@ static int check_array_args(unsigned int cmd, void *parg, size_t *array_size, 
	return ret;

}



long video_ioctl2(struct file *file,

	       unsigned int cmd, unsigned long arg)

long

video_usercopy(struct file *file, unsigned int cmd, unsigned long arg,

	       v4l2_kioctl func)

{

	char	sbuf[128];

	void    *mbuf = NULL;
@@ -2395,7 +2301,7 @@ long video_ioctl2(struct file *file, 
	}



	/* Handles IOCTL */

	err = __video_do_ioctl(file, cmd, parg);

	err = func(file, cmd, parg);

	if (err == -ENOIOCTLCMD)

		err = -EINVAL;
@@ -2422,4 +2328,11 @@ long video_ioctl2(struct file *file, 
	kfree(mbuf);

	return err;

}

EXPORT_SYMBOL(video_usercopy);



long video_ioctl2(struct file *file,

	       unsigned int cmd, unsigned long arg)

{

	return video_usercopy(file, cmd, arg, __video_do_ioctl);

}

EXPORT_SYMBOL(video_ioctl2);