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>
This commit is contained in:
Andy Lutomirski 2016-05-11 17:41:27 -07:00
parent a44323e2a8
commit f89dec72e9

View file

@ -1274,8 +1274,6 @@ struct uvc_xu_control_mapping32 {
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 @@ static int uvc_v4l2_get_xu_mapping(struct uvc_xu_control_mapping *kp,
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_get_xu_mapping(struct uvc_xu_control_mapping *kp,
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 @@ static int uvc_v4l2_put_xu_mapping(const struct uvc_xu_control_mapping *kp,
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 @@ struct uvc_xu_control_query32 {
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 @@ static int uvc_v4l2_get_xu_query(struct uvc_xu_control_query *kp,
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_get_xu_query(struct uvc_xu_control_query *kp,
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;
}