On Fri, Oct 01, 2021 at 04:49:12PM +0300, Dan Carpenter wrote: > Hello Jeykumar Sankaran, > > This is a semi-automatic email about new static checker warnings. > > The patch 25fdd5933e4c: "drm/msm: Add SDM845 DPU support" from Jun > 27, 2018, leads to the following Smatch complaint: > > drivers/gpu/drm/msm/disp/dpu1/dpu_hw_sspp.c:422 _dpu_hw_sspp_setup_scaler3() > warn: variable dereferenced before check 'ctx->cap->sblk' (see line 421) > > drivers/gpu/drm/msm/disp/dpu1/dpu_hw_sspp.c > 420 (void)pe; > ^^^^^^^^^ > You should file a bug report with your compiler devs instead of adding > these sorts of statements to your code. This function is used as a > function pointer so unused parameters are normal. > > 421 if (_sspp_subblk_offset(ctx, DPU_SSPP_SCALER_QSEED3, &idx) || !sspp > ^^^^^^^^^^^^^^^^^^^^ > The _sspp_subblk_offset() dereferenced "ctx" before it is checked and > then it also derefereces "ctx->cap->sblk" without checking. > > 422 || !scaler3_cfg || !ctx || !ctx->cap || !ctx->cap->sblk) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > So these will have already crashed before we reach this point. > Same thing later as well. drivers/gpu/drm/msm/disp/dpu1/dpu_hw_sspp.c:591 dpu_hw_sspp_setup_creq_lut() warn: variable dereferenced before check 'ctx->cap' (see line 588) regards, dan carpenter
