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authorMarijn Suijten <marijn.suijten@somainline.org>2023-01-10 02:15:55 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-03-10 11:33:13 +0300
commit9e1e236acdc42b5c43ec8d7f03a39537e70cc309 (patch)
treeb5129b47f4e857f96e81ec4dbf67c49e2b75c8ec /drivers/gpu/drm/msm/disp
parent31c4251a20fd7addc1bf4fe801f95f9ba1b38990 (diff)
downloadlinux-9e1e236acdc42b5c43ec8d7f03a39537e70cc309.tar.xz
drm/msm/dpu: Disallow unallocated resources to be returned
[ Upstream commit abc40122d9a69f56c04efb5a7485795f5ac799d1 ] 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, until their allocation/assignment is being sanity-checked in "drm/msm/dpu: Reject topologies for which no DSC blocks are available") 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> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Patchwork: https://patchwork.freedesktop.org/patch/517636/ Link: https://lore.kernel.org/r/20230109231556.344977-1-marijn.suijten@somainline.org Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/gpu/drm/msm/disp')
-rw-r--r--drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
index 73b3442e7467..7ada957adbbb 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("Allocated resource %d unavailable to assign to enc %d\n",
+ type, enc_id);
+ break;
+ }
blks[num_blks++] = hw_blks[i];
}