[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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 11 insertions, 98 deletions

diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
index 7a720745c3fa..db6ec3868347 100644
--- a/drivers/media/video/v4l2-ioctl.c
+++ b/drivers/media/video/v4l2-ioctl.c
@@ -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 @@ out:
         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);