| Message ID | 20221221231943.1961117-5-marijn.suijten@somainline.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | drm/msm: DSC Electric Boogaloo for sm8[12]50 | expand |
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c index 73b3442e7467..8471d04bff50 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c @@ -660,6 +660,11 @@ int dpu_rm_get_assigned_resources(struct dpu_rm *rm, blks_size, enc_id); break; } + if (!hw_blks[i]) { + DPU_ERROR("No more resource %d available to assign to enc %d\n", + type, enc_id); + break; + } blks[num_blks++] = hw_blks[i]; }
In the event that the topology requests resources that have not been created by the system (because they are typically not represented in dpu_mdss_cfg ^1), the resource(s) in global_state (in this case DSC blocks) remain NULL but will still be returned out of dpu_rm_get_assigned_resources, where the caller expects to get an array containing num_blks valid pointers (but instead gets these NULLs). To prevent this from happening, where null-pointer dereferences typically result in a hard-to-debug platform lockup, num_blks shouldn't increase past NULL blocks and will print an error and break instead. After all, max_blks represents the static size of the maximum number of blocks whereas the actual amount varies per platform. ^1: which can happen after a git rebase ended up moving additions to _dpu_cfg to a different struct which has the same patch context. Fixes: bb00a452d6f7 ("drm/msm/dpu: Refactor resource manager") Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org> --- drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c | 5 +++++ 1 file changed, 5 insertions(+)