Merge remote branch 'intel/drm-intel-next' of /ssd/git/drm-next into drm-core-next

* 'intel/drm-intel-next' of /ssd/git/drm-next: (230 commits)
  drm/i915: Clear the Ironlake dithering flags when the pipe doesn't want it.
  drm/agp/i915: trim stolen space to 32M
  drm/i915: Unset cursor if out-of-bounds upon mode change (v4)
  drm/i915: Unreference object not handle on creation
  drm/i915: Attempt to uncouple object after catastrophic failure in unbind
  drm/i915: Repeat unbinding during free if interrupted (v6)
  drm/i915: Refactor i915_gem_retire_requests()
  drm/i915: Warn if we run out of FIFO space for a mode
  drm/i915: Round up the watermark entries (v3)
  drm/i915: Typo in (unused) register mask for overlay.
  drm/i915: Check overlay stride errata for i830 and i845
  drm/i915: Validate the mode for eDP by using fixed panel size
  drm/i915: Always use the fixed panel timing for eDP
  drm/i915: Enable panel fitting for eDP
  drm/i915: Add fixed panel mode parsed from EDID for eDP without fixed mode in VBT
  drm/i915/sdvo: Set sync polarity based on actual mode
  drm/i915/hdmi: Set sync polarity based on actual mode
  drm/i915/pch: Set transcoder sync polarity for DP based on actual mode
  drm/i915: Initialize LVDS and eDP outputs before anything else
  drm/i915/dp: Correctly report eDP in the core connector type
  ...

1 files changed, 25 insertions, 0 deletions

diff --git a/kernel/cred.c b/kernel/cred.c
index a2d5504..60bc8b1 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -209,6 +209,31 @@ void exit_creds(struct task_struct *tsk)
 	}
 }
 
+/**
+ * get_task_cred - Get another task's objective credentials
+ * @task: The task to query
+ *
+ * Get the objective credentials of a task, pinning them so that they can't go
+ * away.  Accessing a task's credentials directly is not permitted.
+ *
+ * The caller must also make sure task doesn't get deleted, either by holding a
+ * ref on task or by holding tasklist_lock to prevent it from being unlinked.
+ */
+const struct cred *get_task_cred(struct task_struct *task)
+{
+	const struct cred *cred;
+
+	rcu_read_lock();
+
+	do {
+		cred = __task_cred((task));
+		BUG_ON(!cred);
+	} while (!atomic_inc_not_zero(&((struct cred *)cred)->usage));
+
+	rcu_read_unlock();
+	return cred;
+}
+
 /*
  * Allocate blank credentials, such that the credentials can be filled in at a
  * later date without risk of ENOMEM.