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new helper: drm_ioctl_kernel()

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drm_ioctl() guts sans copying the structure to/from userland
and parsing the ioctl cmd.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2017-05-24 12:31:12 -04:00
parent 2ea659a9ef
commit 7f0dfc1625
2 changed files with 28 additions and 14 deletions
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41
drivers/gpu/drm/drm_ioctl.c
View File

@@ -694,6 +694,32 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
* structure.
*/
long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
u32 flags)
{
struct drm_file *file_priv = file->private_data;
struct drm_device *dev = file_priv->minor->dev;
int retcode;
if (drm_device_is_unplugged(dev))
return -ENODEV;
retcode = drm_ioctl_permit(flags, file_priv);
if (unlikely(retcode))
return retcode;
/* Enforce sane locking for modern driver ioctls. */
if (!drm_core_check_feature(dev, DRIVER_LEGACY) ||
(flags & DRM_UNLOCKED))
retcode = func(dev, kdata, file_priv);
else {
mutex_lock(&drm_global_mutex);
retcode = func(dev, kdata, file_priv);
mutex_unlock(&drm_global_mutex);
}
return retcode;
}
/**
* drm_ioctl - ioctl callback implementation for DRM drivers
* @filp: file this ioctl is called on
@@ -762,10 +788,6 @@ long drm_ioctl(struct file *filp,
goto err_i1;
}
retcode = drm_ioctl_permit(ioctl->flags, file_priv);
if (unlikely(retcode))
goto err_i1;
if (ksize <= sizeof(stack_kdata)) {
kdata = stack_kdata;
} else {
@@ -784,16 +806,7 @@ long drm_ioctl(struct file *filp,
if (ksize > in_size)
memset(kdata + in_size, 0, ksize - in_size);
/* Enforce sane locking for modern driver ioctls. */
if (!drm_core_check_feature(dev, DRIVER_LEGACY) ||
(ioctl->flags & DRM_UNLOCKED))
retcode = func(dev, kdata, file_priv);
else {
mutex_lock(&drm_global_mutex);
retcode = func(dev, kdata, file_priv);
mutex_unlock(&drm_global_mutex);
}
retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags);
if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
retcode = -EFAULT;