Messages in this thread | | | Date | Mon, 9 Jan 2023 01:28:52 +0200 | Subject | Re: [PATCH v2 4/8] drm/msm/dpu: Disallow unallocated resources to be returned | From | Dmitry Baryshkov <> |
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On 22/12/2022 01:19, Marijn Suijten wrote: > 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(+)
I think the patch is not fully correct. Please check resource availability during allocation. I wouldn't expect an error from get_assigned_resources because of resource exhaustion.
-- With best wishes Dmitry
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