uvc_v4l2: Simplify compat ioctl implementation
The uvc compat ioctl implementation seems to have copied user data
for no good reason. Remove a bunch of copies.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 12690c1..c04bc6a 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -1274,8 +1274,6 @@
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)) ||
@@ -1292,17 +1290,7 @@
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;
+ kp->menu_info = compat_ptr(p);
return 0;
}
@@ -1310,10 +1298,6 @@
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))
@@ -1322,16 +1306,6 @@
if (__clear_user(up->reserved, sizeof(up->reserved)))
return -EFAULT;
- if (kp->menu_count == 0)
- return 0;
-
- if (get_user(p, &up->menu_info))
- return -EFAULT;
- umenus = compat_ptr(p);
-
- if (copy_in_user(umenus, kmenus, kp->menu_count * sizeof(*umenus)))
- return -EFAULT;
-
return 0;
}
@@ -1346,8 +1320,6 @@
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)) ||
@@ -1361,17 +1333,7 @@
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;
+ kp->data = compat_ptr(p);
return 0;
}
@@ -1379,26 +1341,10 @@
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;
}