gpu: nvgpu: fix clk_arb completion file private data access race

clk_arb completion file descriptor can get closed immediately after
poll finishes in the work item gp10b_clk_arb_run_arbiter_cb. In
that case, the refcount for nvgpu_clk_dev can become zero in
the work item and can lead to invalid access while removing
nvgpu_clk_dev from the lists.

Remove nvgpu_clk_dev from the list before dropping the reference to
it.

Also, delete the nvgpu_clk_dev in completion file release handler
within the session and requests spinlocks to avoid race with
gp10b_clk_arb_run_arbiter_cb using it.

bug 200757277

Change-Id: I054eee547f2a6fa633d7ef55df216ec36647a826
Signed-off-by: Sagar Kamble <skamble@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvgpu/+/2569522
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
Reviewed-by: Debarshi Dutta <ddutta@nvidia.com>
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-by: Bibek Basu <bbasu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>

0 files changed, 0 insertions, 0 deletions