Merge tag 'drm-intel-next-fixes-2019-11-14' of git://anongit.freedesktop.org/drm/drm-intel into drm-next

- PMU "Frequency" is reported as accumulated cycles
- Avoid OOPS in dumb_create IOCTL when no CRTCs
- Mitigation for userptr put_pages deadlock with trylock_page
- Fix to avoid freeing heartbeat request too early
- Fix LRC coherency issue
- Fix Bugzilla #112212: Avoid screen corruption on MST
- Error path fix to unlock context on failed context VM SETPARAM
- Always consider holding preemption a privileged op in perf/OA
- Preload LUTs if the hw isn't currently using them to avoid color flash on VLV/CHV
- Protect context while grabbing its name for the request
- Don't resize aliasing ppGTT size
- Smaller fixes picked by tooling

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191114085213.GA6440@jlahtine-desk.ger.corp.intel.com

2 files changed, 22 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 138c8e33d26b..09f84f0ad0f4 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -1141,7 +1141,7 @@ static int set_ppgtt(struct drm_i915_file_private *file_priv,
 
 	if (i915_gem_context_is_closed(ctx)) {
 		err = -ENOENT;
-		goto out;
+		goto unlock;
 	}
 
 	if (vm == rcu_access_pointer(ctx->vm))
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
index 1e045c337044..4c72d74d6576 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
@@ -646,8 +646,28 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj,
 		obj->mm.dirty = false;
 
 	for_each_sgt_page(page, sgt_iter, pages) {
-		if (obj->mm.dirty)
+		if (obj->mm.dirty && trylock_page(page)) {
+			/*
+			 * As this may not be anonymous memory (e.g. shmem)
+			 * but exist on a real mapping, we have to lock
+			 * the page in order to dirty it -- holding
+			 * the page reference is not sufficient to
+			 * prevent the inode from being truncated.
+			 * Play safe and take the lock.
+			 *
+			 * However...!
+			 *
+			 * The mmu-notifier can be invalidated for a
+			 * migrate_page, that is alreadying holding the lock
+			 * on the page. Such a try_to_unmap() will result
+			 * in us calling put_pages() and so recursively try
+			 * to lock the page. We avoid that deadlock with
+			 * a trylock_page() and in exchange we risk missing
+			 * some page dirtying.
+			 */
 			set_page_dirty(page);
+			unlock_page(page);
+		}
 
 		mark_page_accessed(page);
 		put_page(page);