Merge tag 'drm-misc-fixes-2018-10-19' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes

airlied · airlied · commit fe7acd1e303d · 2018-10-20T12:26:26.000+10:00
Second pull request for v4.19: - Fix ulong overflow in sun4i - Fix a serious GPF in waiting for flip_done from commit_tail(). Signed-off-by: Dave Airlie <airlied@redhat.com> From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/97d1ed42-1d99-fcc5-291e-cd1dc29a4252@linux.intel.com
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
@@ -174,6 +174,11 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state)
 		state->crtcs[i].state = NULL;
 		state->crtcs[i].old_state = NULL;
 		state->crtcs[i].new_state = NULL;
+
+		if (state->crtcs[i].commit) {
+			drm_crtc_commit_put(state->crtcs[i].commit);
+			state->crtcs[i].commit = NULL;
+		}
 	}
 
 	for (i = 0; i < config->num_total_plane; i++) {
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1408,15 +1408,16 @@ EXPORT_SYMBOL(drm_atomic_helper_wait_for_vblanks);
 void drm_atomic_helper_wait_for_flip_done(struct drm_device *dev,
 					  struct drm_atomic_state *old_state)
 {
-	struct drm_crtc_state *new_crtc_state;
 	struct drm_crtc *crtc;
 	int i;
 
-	for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i) {
-		struct drm_crtc_commit *commit = new_crtc_state->commit;
+	for (i = 0; i < dev->mode_config.num_crtc; i++) {
+		struct drm_crtc_commit *commit = old_state->crtcs[i].commit;
 		int ret;
 
-		if (!commit)
+		crtc = old_state->crtcs[i].ptr;
+
+		if (!crtc || !commit)
 			continue;
 
 		ret = wait_for_completion_timeout(&commit->flip_done, 10 * HZ);
@@ -1934,6 +1935,9 @@ int drm_atomic_helper_setup_commit(struct drm_atomic_state *state,
 		drm_crtc_commit_get(commit);
 
 		commit->abort_completion = true;
+
+		state->crtcs[i].commit = commit;
+		drm_crtc_commit_get(commit);
 	}
 
 	for_each_oldnew_connector_in_state(state, conn, old_conn_state, new_conn_state, i) {
diff --git a/drivers/gpu/drm/sun4i/sun4i_dotclock.c b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
@@ -81,9 +81,19 @@ static long sun4i_dclk_round_rate(struct clk_hw *hw, unsigned long rate,
 	int i;
 
 	for (i = tcon->dclk_min_div; i <= tcon->dclk_max_div; i++) {
-		unsigned long ideal = rate * i;
+		u64 ideal = (u64)rate * i;
 		unsigned long rounded;
 
+		/*
+		 * ideal has overflowed the max value that can be stored in an
+		 * unsigned long, and every clk operation we might do on a
+		 * truncated u64 value will give us incorrect results.
+		 * Let's just stop there since bigger dividers will result in
+		 * the same overflow issue.
+		 */
+		if (ideal > ULONG_MAX)
+			goto out;
+
 		rounded = clk_hw_round_rate(clk_hw_get_parent(hw),
 					    ideal);
 
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
@@ -153,6 +153,17 @@ struct __drm_planes_state {
 struct __drm_crtcs_state {
 	struct drm_crtc *ptr;
 	struct drm_crtc_state *state, *old_state, *new_state;
+
+	/**
+	 * @commit:
+	 *
+	 * A reference to the CRTC commit object that is kept for use by
+	 * drm_atomic_helper_wait_for_flip_done() after
+	 * drm_atomic_helper_commit_hw_done() is called. This ensures that a
+	 * concurrent commit won't free a commit object that is still in use.
+	 */
+	struct drm_crtc_commit *commit;
+
 	s32 __user *out_fence_ptr;
 	u64 last_vblank_count;
 };
