drm: Do not drop root privileges for a fancier younger process (1020dc69) · Commits · 戴 / test

When a second process opens the device and master transferrence is complete, we walk the list of open devices and remove their authentication. This also revokes our root privilege. Instead of simply dropping the authentication, this patch reverts the authenticated state back to its original value. Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by:

David Herrmann <dh.herrmann@gmail.com> Signed-off-by:

Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_fops.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -239,7 +239,8 @@ static int drm_open_helper(struct inode inode, struct file filp,

		priv->ioctl_count = 0;
		/* for compatibility root is always authenticated */
		priv->authenticated = capable(CAP_SYS_ADMIN);
		priv->always_authenticated = capable(CAP_SYS_ADMIN);
		priv->authenticated = priv->always_authenticated;
		priv->lock_count = 0;

		INIT_LIST_HEAD(&priv->lhead);
		@@ -533,7 +534,7 @@ int drm_release(struct inode inode, struct file filp)
		list_for_each_entry(temp, &dev->filelist, lhead) {
		if ((temp->master == file_priv->master) &&
		(temp != file_priv))
		temp->authenticated = 0;
		temp->authenticated = temp->always_authenticated;
		}

		/**

include/drm/drmP.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -413,6 +413,7 @@ struct drm_prime_file_private {

		/** File private data */
		struct drm_file {
		int always_authenticated;
		int authenticated;
		struct pid *pid;
		kuid_t uid;

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