Merge branch 'fbcon-locking-fixes' of ssh://people.freedesktop.org/~airlied/linux into drm-next

This pulls in most of Linus tree up to -rc6, this fixes the worst lockdep
reported issues and re-enables fbcon lockdep.

(not the fbcon maintainer)
* 'fbcon-locking-fixes' of ssh://people.freedesktop.org/~airlied/linux: (529 commits)
  Revert "Revert "console: implement lockdep support for console_lock""
  fbcon: fix locking harder
  fb: Yet another band-aid for fixing lockdep mess
  fb: rework locking to fix lock ordering on takeover

1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 27269103b621..2f2daebd0eef 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -615,6 +615,8 @@ i915_gem_execbuffer_relocate_slow(struct drm_device *dev,
 	total = 0;
 	for (i = 0; i < count; i++) {
 		struct drm_i915_gem_relocation_entry __user *user_relocs;
+		u64 invalid_offset = (u64)-1;
+		int j;
 
 		user_relocs = (void __user *)(uintptr_t)exec[i].relocs_ptr;
 
@@ -625,6 +627,25 @@ i915_gem_execbuffer_relocate_slow(struct drm_device *dev,
 			goto err;
 		}
 
+		/* As we do not update the known relocation offsets after
+		 * relocating (due to the complexities in lock handling),
+		 * we need to mark them as invalid now so that we force the
+		 * relocation processing next time. Just in case the target
+		 * object is evicted and then rebound into its old
+		 * presumed_offset before the next execbuffer - if that
+		 * happened we would make the mistake of assuming that the
+		 * relocations were valid.
+		 */
+		for (j = 0; j < exec[i].relocation_count; j++) {
+			if (copy_to_user(&user_relocs[j].presumed_offset,
+					 &invalid_offset,
+					 sizeof(invalid_offset))) {
+				ret = -EFAULT;
+				mutex_lock(&dev->struct_mutex);
+				goto err;
+			}
+		}
+
 		reloc_offset[i] = total;
 		total += exec[i].relocation_count;
 	}