[media] uvcvideo: Implement compat_ioctl32 for custom ioctls

Support 32-bit/64-bit compatibility for the the UVCIOC_ ioctls.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 205 insertions, 0 deletions

diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c
index f09ee8b2ea5..ff2cdddf9bc 100644
--- a/drivers/media/video/uvc/uvc_v4l2.c
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -11,6 +11,7 @@
  *
  */
 
+#include <linux/compat.h>
 #include <linux/kernel.h>
 #include <linux/version.h>
 #include <linux/list.h>
@@ -1030,6 +1031,207 @@ static long uvc_v4l2_ioctl(struct file *file,
         return video_usercopy(file, cmd, arg, uvc_v4l2_do_ioctl);
 }
 
+#ifdef CONFIG_COMPAT
+struct uvc_xu_control_mapping32 {
+        __u32 id;
+        __u8 name[32];
+        __u8 entity[16];
+        __u8 selector;
+
+        __u8 size;
+        __u8 offset;
+        __u32 v4l2_type;
+        __u32 data_type;
+
+        compat_caddr_t menu_info;
+        __u32 menu_count;
+
+        __u32 reserved[4];
+};
+
+static int uvc_v4l2_get_xu_mapping(struct uvc_xu_control_mapping *kp,
+                        const struct uvc_xu_control_mapping32 __user *up)
+{
+        struct uvc_menu_info __user *umenus;
+        struct uvc_menu_info __user *kmenus;
+        compat_caddr_t p;
+
+        if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
+            __copy_from_user(kp, up, offsetof(typeof(*up), menu_info)) ||
+            __get_user(kp->menu_count, &up->menu_count))
+                return -EFAULT;
+
+        memset(kp->reserved, 0, sizeof(kp->reserved));
+
+        if (kp->menu_count == 0) {
+                kp->menu_info = NULL;
+                return 0;
+        }
+
+        if (__get_user(p, &up->menu_info))
+                return -EFAULT;
+        umenus = compat_ptr(p);
+        if (!access_ok(VERIFY_READ, umenus, kp->menu_count * sizeof(*umenus)))
+                return -EFAULT;
+
+        kmenus = compat_alloc_user_space(kp->menu_count * sizeof(*kmenus));
+        if (kmenus == NULL)
+                return -EFAULT;
+        kp->menu_info = kmenus;
+
+        if (copy_in_user(kmenus, umenus, kp->menu_count * sizeof(*umenus)))
+                return -EFAULT;
+
+        return 0;
+}
+
+static int uvc_v4l2_put_xu_mapping(const struct uvc_xu_control_mapping *kp,
+                        struct uvc_xu_control_mapping32 __user *up)
+{
+        struct uvc_menu_info __user *umenus;
+        struct uvc_menu_info __user *kmenus = kp->menu_info;
+        compat_caddr_t p;
+
+        if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
+            __copy_to_user(up, kp, offsetof(typeof(*up), menu_info)) ||
+            __put_user(kp->menu_count, &up->menu_count))
+                return -EFAULT;
+
+        __clear_user(up->reserved, sizeof(up->reserved));
+
+        if (kp->menu_count == 0)
+                return 0;
+
+        if (get_user(p, &up->menu_info))
+                return -EFAULT;
+        umenus = compat_ptr(p);
+        if (!access_ok(VERIFY_WRITE, umenus, kp->menu_count * sizeof(*umenus)))
+                return -EFAULT;
+
+        if (copy_in_user(umenus, kmenus, kp->menu_count * sizeof(*umenus)))
+                return -EFAULT;
+
+        return 0;
+}
+
+struct uvc_xu_control_query32 {
+        __u8 unit;
+        __u8 selector;
+        __u8 query;
+        __u16 size;
+        compat_caddr_t data;
+};
+
+static int uvc_v4l2_get_xu_query(struct uvc_xu_control_query *kp,
+                        const struct uvc_xu_control_query32 __user *up)
+{
+        u8 __user *udata;
+        u8 __user *kdata;
+        compat_caddr_t p;
+
+        if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
+            __copy_from_user(kp, up, offsetof(typeof(*up), data)))
+                return -EFAULT;
+
+        if (kp->size == 0) {
+                kp->data = NULL;
+                return 0;
+        }
+
+        if (__get_user(p, &up->data))
+                return -EFAULT;
+        udata = compat_ptr(p);
+        if (!access_ok(VERIFY_READ, udata, kp->size))
+                return -EFAULT;
+
+        kdata = compat_alloc_user_space(kp->size);
+        if (kdata == NULL)
+                return -EFAULT;
+        kp->data = kdata;
+
+        if (copy_in_user(kdata, udata, kp->size))
+                return -EFAULT;
+
+        return 0;
+}
+
+static int uvc_v4l2_put_xu_query(const struct uvc_xu_control_query *kp,
+                        struct uvc_xu_control_query32 __user *up)
+{
+        u8 __user *udata;
+        u8 __user *kdata = kp->data;
+        compat_caddr_t p;
+
+        if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
+            __copy_to_user(up, kp, offsetof(typeof(*up), data)))
+                return -EFAULT;
+
+        if (kp->size == 0)
+                return 0;
+
+        if (get_user(p, &up->data))
+                return -EFAULT;
+        udata = compat_ptr(p);
+        if (!access_ok(VERIFY_READ, udata, kp->size))
+                return -EFAULT;
+
+        if (copy_in_user(udata, kdata, kp->size))
+                return -EFAULT;
+
+        return 0;
+}
+
+#define UVCIOC_CTRL_MAP32       _IOWR('u', 0x20, struct uvc_xu_control_mapping32)
+#define UVCIOC_CTRL_QUERY32     _IOWR('u', 0x21, struct uvc_xu_control_query32)
+
+static long uvc_v4l2_compat_ioctl32(struct file *file,
+                     unsigned int cmd, unsigned long arg)
+{
+        union {
+                struct uvc_xu_control_mapping xmap;
+                struct uvc_xu_control_query xqry;
+        } karg;
+        void __user *up = compat_ptr(arg);
+        mm_segment_t old_fs;
+        long ret;
+
+        switch (cmd) {
+        case UVCIOC_CTRL_MAP32:
+                cmd = UVCIOC_CTRL_MAP;
+                ret = uvc_v4l2_get_xu_mapping(&karg.xmap, up);
+                break;
+
+        case UVCIOC_CTRL_QUERY32:
+                cmd = UVCIOC_CTRL_QUERY;
+                ret = uvc_v4l2_get_xu_query(&karg.xqry, up);
+                break;
+
+        default:
+                return -ENOIOCTLCMD;
+        }
+
+        old_fs = get_fs();
+        set_fs(KERNEL_DS);
+        ret = uvc_v4l2_ioctl(file, cmd, (unsigned long)&karg);
+        set_fs(old_fs);
+
+        if (ret < 0)
+                return ret;
+
+        switch (cmd) {
+        case UVCIOC_CTRL_MAP:
+                ret = uvc_v4l2_put_xu_mapping(&karg.xmap, up);
+                break;
+
+        case UVCIOC_CTRL_QUERY:
+                ret = uvc_v4l2_put_xu_query(&karg.xqry, up);
+                break;
+        }
+
+        return ret;
+}
+#endif
+
 static ssize_t uvc_v4l2_read(struct file *file, char __user *data,
                     size_t count, loff_t *ppos)
 {
@@ -1076,6 +1278,9 @@ const struct v4l2_file_operations uvc_fops = {
         .open           = uvc_v4l2_open,
         .release        = uvc_v4l2_release,
         .unlocked_ioctl = uvc_v4l2_ioctl,
+#ifdef CONFIG_COMPAT
+        .compat_ioctl32 = uvc_v4l2_compat_ioctl32,
+#endif
         .read           = uvc_v4l2_read,
         .mmap           = uvc_v4l2_mmap,
         .poll           = uvc_v4l2_poll,