drm/i915: Avoid drm_atomic_state_put(NULL) on error paths
The error paths in hsw_trans_edp_pipe_A_crc_wa() and
intel_prepare_reset() would potentially call drm_atomic_state_put with a
NULL state, which would lead to a NULL pointer dereference.
Found by coverity.
v2: Improve the error paths. (Chris)
Fixes: 0853695c3ba4 ("drm: Add reference counting to drm_atomic_state")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: <drm-intel-fixes@lists.freedesktop.org> # v4.10-rc1+
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1484742868-9551-1-git-send-email-ander.conselvan.de.oliveira@intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_pipe_crc.c b/drivers/gpu/drm/i915/intel_pipe_crc.c
index 0f1da81..c0b1f99 100644
--- a/drivers/gpu/drm/i915/intel_pipe_crc.c
+++ b/drivers/gpu/drm/i915/intel_pipe_crc.c
@@ -560,14 +560,14 @@ static void hsw_trans_edp_pipe_A_crc_wa(struct drm_i915_private *dev_priv,
state = drm_atomic_state_alloc(dev);
if (!state) {
ret = -ENOMEM;
- goto out;
+ goto unlock;
}
state->acquire_ctx = drm_modeset_legacy_acquire_ctx(&crtc->base);
pipe_config = intel_atomic_get_crtc_state(state, crtc);
if (IS_ERR(pipe_config)) {
ret = PTR_ERR(pipe_config);
- goto out;
+ goto put_state;
}
pipe_config->pch_pfit.force_thru = enable;
@@ -576,10 +576,12 @@ static void hsw_trans_edp_pipe_A_crc_wa(struct drm_i915_private *dev_priv,
pipe_config->base.connectors_changed = true;
ret = drm_atomic_commit(state);
-out:
+
+put_state:
+ drm_atomic_state_put(state);
+unlock:
WARN(ret, "Toggling workaround to %i returns %i\n", enable, ret);
drm_modeset_unlock_all(dev);
- drm_atomic_state_put(state);
}
static int ivb_pipe_crc_ctl_reg(struct drm_i915_private *dev_priv,