clear-pkgs-linux-iot-lts2018/0670-drm-i915-gvt-check-the-pointer-before-using.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Xinyun Liu <xinyun.liu@intel.com>
Date: Wed, 24 Oct 2018 19:50:08 +0800
Subject: [PATCH] drm/i915/gvt: check the pointer before using

fix issues reported by smatch:

drivers/gpu/drm/i915/intel_pm.c:828 intel_wm_plane_visible() error: we previously assumed 'plane_state' could be null (see line 815)
drivers/gpu/drm/i915/intel_pm.c:3998 skl_plane_downscale_amount() error: we previously assumed 'pstate' could be null (see line 3985)
drivers/gpu/drm/i915/intel_pm.c:4534 skl_compute_plane_wm_params() error: we previously assumed 'fb' could be null (see line 4510)
drivers/gpu/drm/i915/intel_pm.c:4544 skl_compute_plane_wm_params() error: we previously assumed 'intel_pstate' could be null (see line 4521)
drivers/gpu/drm/i915/intel_pm.c:4565 skl_compute_plane_wm_params() error: we previously assumed 'pstate' could be null (see line 4501)

Tracked-On: projectacrn/acrn-hypervisor#1581

Signed-off-by: Xinyun Liu <xinyun.liu@intel.com>
Reviewed-by: He, Min <min.he@intel.com>
---
 drivers/gpu/drm/i915/intel_atomic_plane.c |  3 ++-
 drivers/gpu/drm/i915/intel_display.c      |  4 ++++
 drivers/gpu/drm/i915/intel_pm.c           | 15 ++++++++++++++-
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_atomic_plane.c b/drivers/gpu/drm/i915/intel_atomic_plane.c
index dcba645cabb8..b950fabb4bbf 100644
--- a/drivers/gpu/drm/i915/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
@@ -182,7 +182,8 @@ int intel_plane_atomic_check_with_state(const struct intel_crtc_state *old_crtc_
 	else
 		crtc_state->active_planes &= ~BIT(intel_plane->id);
 
-	if (state->visible && state->fb->format->format == DRM_FORMAT_NV12)
+	if (state->visible && state->fb &&
+			state->fb->format->format == DRM_FORMAT_NV12)
 		crtc_state->nv12_planes |= BIT(intel_plane->id);
 	else
 		crtc_state->nv12_planes &= ~BIT(intel_plane->id);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index d73183a23c7d..f3a65581b9fb 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4976,6 +4976,10 @@ static int skl_update_scaler_plane(struct intel_crtc_state *crtc_state,
 	}
 
 	/* Check src format */
+	if (!fb) {
+		DRM_ERROR("skl_update_scaler_plane(): fb is invalid\n");
+		return 0;
+	}
 	switch (fb->format->format) {
 	case DRM_FORMAT_RGB565:
 	case DRM_FORMAT_XBGR8888:
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 54979509e44c..39cef1485a2e 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -824,6 +824,11 @@ static bool intel_wm_plane_visible(const struct intel_crtc_state *crtc_state,
 		return true;
 	}
 
+	if(!plane_state) {
+		DRM_ERROR("intel_wm_plane_visible(): plane_state==NULL and return 0\n");
+		return false;
+	}
+
 	/*
 	 * Treat cursor with fb as always visible since cursor updates
 	 * can happen faster than the vrefresh rate, and the current
@@ -4033,6 +4038,10 @@ skl_plane_downscale_amount(const struct intel_crtc_state *cstate,
 		return mul_fixed16(u32_to_fixed16(1), u32_to_fixed16(1));
 	}
 
+	if (WARN_ON_ONCE(!pstate)) {
+		return u32_to_fixed16(0);
+	}
+
 	if (WARN_ON(!intel_wm_plane_visible(cstate, pstate)))
 		return u32_to_fixed16(0);
 
@@ -4578,6 +4587,10 @@ skl_compute_plane_wm_params(const struct drm_i915_private *dev_priv,
 		goto calculate_wm;
 	}
 
+	if (!fb || !intel_pstate) {
+		DRM_ERROR("invalid fb:%p intel_pstate:%p\n", fb, intel_pstate);
+		return -EINVAL;
+	}
 	wp->y_tiled = fb->modifier == I915_FORMAT_MOD_Y_TILED ||
 		      fb->modifier == I915_FORMAT_MOD_Yf_TILED ||
 		      fb->modifier == I915_FORMAT_MOD_Y_TILED_CCS ||
@@ -4609,7 +4622,7 @@ skl_compute_plane_wm_params(const struct drm_i915_private *dev_priv,
 	else
 		wp->dbuf_block_size = 512;
 
-	if (drm_rotation_90_or_270(pstate->rotation)) {
+	if (pstate && drm_rotation_90_or_270(pstate->rotation)) {
 
 		switch (wp->cpp) {
 		case 1:
-- 
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