V4L/DVB (4189): Add videodev support for VIDIOC_S/G/TRY_EXT_CTRLS.

videodev.c copies the control list specified in struct v4l2_ext_controls
to kernel space.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

2 files changed, 109 insertions, 2 deletions

diff --git a/drivers/media/video/videodev.c b/drivers/media/video/videodev.c
index 43152297e6d5..763e178555d0 100644
--- a/drivers/media/video/videodev.c
+++ b/drivers/media/video/videodev.c
@@ -190,10 +190,15 @@ video_usercopy(struct inode *inode, struct file *file,
         void    *mbuf = NULL;
         void    *parg = NULL;
         int     err  = -EINVAL;
+        int     is_ext_ctrl;
+        size_t  ctrls_size = 0;
+        void __user *user_ptr = NULL;
 
 #ifdef __OLD_VIDIOC_
         cmd = video_fix_command(cmd);
 #endif
+        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)) {
@@ -215,19 +220,47 @@ video_usercopy(struct inode *inode, struct file *file,
 
                 err = -EFAULT;
                 if (_IOC_DIR(cmd) & _IOC_WRITE)
-                        if (copy_from_user(parg, (void __user *)arg,
-                                                        _IOC_SIZE(cmd)))
+                        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(inode, 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))
         {
@@ -993,6 +1026,39 @@ static int __video_do_ioctl(struct inode *inode, struct file *file,
                 ret=vfd->vidioc_s_ctrl(file, fh, p);
                 break;
         }
+        case VIDIOC_G_EXT_CTRLS:
+        {
+                struct v4l2_ext_controls *p = arg;
+
+                if (vfd->vidioc_g_ext_ctrls) {
+                        dbgarg(cmd, "count=%d\n", p->count);
+
+                        ret=vfd->vidioc_g_ext_ctrls(file, fh, p);
+                }
+                break;
+        }
+        case VIDIOC_S_EXT_CTRLS:
+        {
+                struct v4l2_ext_controls *p = arg;
+
+                if (vfd->vidioc_s_ext_ctrls) {
+                        dbgarg(cmd, "count=%d\n", p->count);
+
+                        ret=vfd->vidioc_s_ext_ctrls(file, fh, p);
+                }
+                break;
+        }
+        case VIDIOC_TRY_EXT_CTRLS:
+        {
+                struct v4l2_ext_controls *p = arg;
+
+                if (vfd->vidioc_try_ext_ctrls) {
+                        dbgarg(cmd, "count=%d\n", p->count);
+
+                        ret=vfd->vidioc_try_ext_ctrls(file, fh, p);
+                }
+                break;
+        }
         case VIDIOC_QUERYMENU:
         {
                 struct v4l2_querymenu *p=arg;
@@ -1326,10 +1392,15 @@ int video_ioctl2 (struct inode *inode, struct file *file,
         void    *mbuf = NULL;
         void    *parg = NULL;
         int     err  = -EINVAL;
+        int     is_ext_ctrl;
+        size_t  ctrls_size = 0;
+        void __user *user_ptr = NULL;
 
 #ifdef __OLD_VIDIOC_
         cmd = video_fix_command(cmd);
 #endif
+        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)) {
@@ -1356,13 +1427,43 @@ int video_ioctl2 (struct inode *inode, struct file *file,
                 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;
+                }
+        }
+
         /* Handles IOCTL */
         err = __video_do_ioctl(inode, 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))
         {
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index dec6b24e4c42..a1b473190e65 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -232,6 +232,12 @@ struct video_device
                                         struct v4l2_control *a);
         int (*vidioc_s_ctrl)           (struct file *file, void *fh,
                                         struct v4l2_control *a);
+        int (*vidioc_g_ext_ctrls)      (struct file *file, void *fh,
+                                        struct v4l2_ext_controls *a);
+        int (*vidioc_s_ext_ctrls)      (struct file *file, void *fh,
+                                        struct v4l2_ext_controls *a);
+        int (*vidioc_try_ext_ctrls)    (struct file *file, void *fh,
+                                        struct v4l2_ext_controls *a);
         int (*vidioc_querymenu)        (struct file *file, void *fh,
                                         struct v4l2_querymenu *a);