[bug report] drm/msm: Add SDM845 DPU support

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello MSM Devs,

The patch 25fdd5933e4c: "drm/msm: Add SDM845 DPU support" from Jun
27, 2018, leads to the following Smatch static checker warnings:

drivers/gpu/drm/msm/msm_gpu.c:301 msm_gpu_crashstate_capture() error: potential null dereference 'state->bos'.  (kcalloc returns null)
drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c:177 msm_disp_snapshot_add_block() error: potential null dereference 'new_blk'.  (kzalloc returns null)
drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c:96 mdp5_plane_reset() error: potential null dereference 'mdp5_state'.  (kzalloc returns null)
drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c:98 mdp5_plane_reset() error: potential null dereference 'mdp5_state'.  (kzalloc returns null)
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:963 dpu_crtc_atomic_check() error: potential null dereference 'pstates'.  (kzalloc returns null)
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:1009 dpu_crtc_atomic_check() error: potential null dereference 'pstates'.  (kzalloc returns null)
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:1075 dpu_crtc_atomic_check() error: potential null dereference 'pstates'.  (kzalloc returns null)
drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c:214 dpu_core_irq_preinstall() error: potential null dereference 'dpu_kms->irq_obj.irq_cb_tbl'.  (kcalloc returns null)
drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c:215 dpu_core_irq_preinstall() error: potential null dereference 'dpu_kms->irq_obj.irq_counts'.  (kcalloc returns null)

drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
    901 static int dpu_crtc_atomic_check(struct drm_crtc *crtc,
    902                 struct drm_atomic_state *state)
    903 {
    904         struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
    905                                                                           crtc);
    906         struct dpu_crtc *dpu_crtc = to_dpu_crtc(crtc);
    907         struct dpu_crtc_state *cstate = to_dpu_crtc_state(crtc_state);
    908         struct plane_state *pstates;
    909 
    910         const struct drm_plane_state *pstate;
    911         struct drm_plane *plane;
    912         struct drm_display_mode *mode;
    913 
    914         int cnt = 0, rc = 0, mixer_width = 0, i, z_pos;
    915 
    916         struct dpu_multirect_plane_states multirect_plane[DPU_STAGE_MAX * 2];
    917         int multirect_count = 0;
    918         const struct drm_plane_state *pipe_staged[SSPP_MAX];
    919         int left_zpos_cnt = 0, right_zpos_cnt = 0;
    920         struct drm_rect crtc_rect = { 0 };
    921 
    922         pstates = kzalloc(sizeof(*pstates) * DPU_STAGE_MAX * 4, GFP_KERNEL);
                ^^^^^^^^^^^^^^^^^
There are a bunch of allocations with no checks for NULL

    923 
    924         if (!crtc_state->enable || !crtc_state->active) {
    925                 DRM_DEBUG_ATOMIC("crtc%d -> enable %d, active %d, skip atomic_check\n",
    926                                 crtc->base.id, crtc_state->enable,
    927                                 crtc_state->active);
    928                 memset(&cstate->new_perf, 0, sizeof(cstate->new_perf));
    929                 goto end;
    930         }
    931 
    932         mode = &crtc_state->adjusted_mode;
    933         DRM_DEBUG_ATOMIC("%s: check\n", dpu_crtc->name);
    934 
    935         /* force a full mode set if active state changed */
    936         if (crtc_state->active_changed)
    937                 crtc_state->mode_changed = true;
    938 
    939         memset(pipe_staged, 0, sizeof(pipe_staged));
    940 
    941         if (cstate->num_mixers) {
    942                 mixer_width = mode->hdisplay / cstate->num_mixers;
    943 
    944                 _dpu_crtc_setup_lm_bounds(crtc, crtc_state);
    945         }
    946 
    947         crtc_rect.x2 = mode->hdisplay;
    948         crtc_rect.y2 = mode->vdisplay;
    949 
    950          /* get plane state for all drm planes associated with crtc state */
    951         drm_atomic_crtc_state_for_each_plane_state(plane, pstate, crtc_state) {
    952                 struct drm_rect dst, clip = crtc_rect;
    953 
    954                 if (IS_ERR_OR_NULL(pstate)) {
    955                         rc = PTR_ERR(pstate);
    956                         DPU_ERROR("%s: failed to get plane%d state, %d\n",
    957                                         dpu_crtc->name, plane->base.id, rc);
    958                         goto end;
    959                 }
    960                 if (cnt >= DPU_STAGE_MAX * 4)
    961                         continue;
    962 
--> 963                 pstates[cnt].dpu_pstate = to_dpu_plane_state(pstate);
                        ^^^^^^^^^^^^

    964                 pstates[cnt].drm_pstate = pstate;
    965                 pstates[cnt].stage = pstate->normalized_zpos;
    966                 pstates[cnt].pipe_id = dpu_plane_pipe(plane);
    967 

regards,
dan carpenter