drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:395 dc_stream_set_cursor_position() warn: variable dereferenced before check 'stream' (see line 392)
From: Dan Carpenter
Date: Thu Aug 18 2022 - 07:07:26 EST
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 3cc40a443a04d52b0c95255dce264068b01e9bfe
commit: a141d2083b462505727e14d98db5fc3cd43d59c6 drm/amd/display: Add debug option for exiting idle optimizations on cursor updates
config: ia64-randconfig-m031-20220814 (https://download.01.org/0day-ci/archive/20220817/202208171701.gFan3WQE-lkp@xxxxxxxxx/config)
compiler: ia64-linux-gcc (GCC) 12.1.0
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
smatch warnings:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:395 dc_stream_set_cursor_position() warn: variable dereferenced before check 'stream' (see line 392)
vim +/stream +395 drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c
ab2541b6739508 Aric Cyr 2016-12-29 388 bool dc_stream_set_cursor_position(
0971c40e180696 Harry Wentland 2017-07-27 389 struct dc_stream_state *stream,
beb16b6a0f921f Dmytro Laktyushkin 2017-04-21 390 const struct dc_cursor_position *position)
ab2541b6739508 Aric Cyr 2016-12-29 391 {
a141d2083b4625 Alvin Lee 2022-06-03 @392 struct dc *dc = stream->ctx->dc;
^^^^^^^^^^^
Dereference
4d55b0dd1cdd85 Bhawanpreet Lakha 2020-05-21 393 bool reset_idle_optimizations = false;
ab2541b6739508 Aric Cyr 2016-12-29 394
4fa086b9b66408 Leo (Sunpeng Li 2017-07-25 @395) if (NULL == stream) {
^^^^^^^^^^^^^^^
NULL check too late. Presumably it can be deleted.
ab2541b6739508 Aric Cyr 2016-12-29 396 dm_error("DC: dc_stream is NULL!\n");
ab2541b6739508 Aric Cyr 2016-12-29 397 return false;
ab2541b6739508 Aric Cyr 2016-12-29 398 }
ab2541b6739508 Aric Cyr 2016-12-29 399
ab2541b6739508 Aric Cyr 2016-12-29 400 if (NULL == position) {
ab2541b6739508 Aric Cyr 2016-12-29 401 dm_error("DC: cursor position is NULL!\n");
ab2541b6739508 Aric Cyr 2016-12-29 402 return false;
ab2541b6739508 Aric Cyr 2016-12-29 403 }
ab2541b6739508 Aric Cyr 2016-12-29 404
2b77dcc5e5aa38 Anthony Koo 2019-11-05 405 dc = stream->ctx->dc;
bae1f0b8a5b189 Nicholas Kazlauskas 2021-05-19 406 dc_z10_restore(dc);
4d55b0dd1cdd85 Bhawanpreet Lakha 2020-05-21 407
4d55b0dd1cdd85 Bhawanpreet Lakha 2020-05-21 408 /* disable idle optimizations if enabling cursor */
a141d2083b4625 Alvin Lee 2022-06-03 409 if (dc->idle_optimizations_allowed && (!stream->cursor_position.enable || dc->debug.exit_idle_opt_for_cursor_updates)
a141d2083b4625 Alvin Lee 2022-06-03 410 && position->enable) {
4b675aad969507 Joshua Aberback 2020-08-31 411 dc_allow_idle_optimizations(dc, false);
4d55b0dd1cdd85 Bhawanpreet Lakha 2020-05-21 412 reset_idle_optimizations = true;
4d55b0dd1cdd85 Bhawanpreet Lakha 2020-05-21 413 }
4d55b0dd1cdd85 Bhawanpreet Lakha 2020-05-21 414
33fd17d9125c00 Eric Yang 2018-01-18 415 stream->cursor_position = *position;
ab2541b6739508 Aric Cyr 2016-12-29 416
4fd771ea441ed9 Roy Chan 2021-07-19 417 program_cursor_position(dc, stream, position);
4d55b0dd1cdd85 Bhawanpreet Lakha 2020-05-21 418 /* re-enable idle optimizations if necessary */
4d55b0dd1cdd85 Bhawanpreet Lakha 2020-05-21 419 if (reset_idle_optimizations)
4b675aad969507 Joshua Aberback 2020-08-31 420 dc_allow_idle_optimizations(dc, true);
4d55b0dd1cdd85 Bhawanpreet Lakha 2020-05-21 421
beb16b6a0f921f Dmytro Laktyushkin 2017-04-21 422 return true;
ab2541b6739508 Aric Cyr 2016-12-29 423 }
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