On 2024-05-22 11:36, Srinivasan Shanmugam wrote:
> The fix involves adding a null check for 'stream' at the beginning of
> the function. If 'stream' is NULL, the function immediately returns
> false. This ensures that 'stream' is not NULL when we dereference it to
> access 'ctx' in 'dc = stream->ctx->dc;' the function.
>
> Fixes the below:
> drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:398 dc_stream_program_cursor_position()
> error: we previously assumed 'stream' could be null (see line 397)
>
> drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c
> 389 bool dc_stream_program_cursor_position(
> 390 struct dc_stream_state *stream,
> 391 const struct dc_cursor_position *position)
> 392 {
> 393 struct dc *dc;
> 394 bool reset_idle_optimizations = false;
> 395 const struct dc_cursor_position *old_position;
> 396
> 397 old_position = stream ? &stream->cursor_position : NULL;
> ^^^^^^^^
> The patch adds a NULL check
>
> --> 398 dc = stream->ctx->dc;
> ^^^^^^^^
> The old code didn't check
>
> 399
> 400 if (dc_stream_set_cursor_position(stream, position)) {
> 401 dc_z10_restore(dc);
> 402
> 403 /* disable idle optimizations if enabling cursor */
> 404 if (dc->idle_optimizations_allowed &&
> 405 (!old_position->enable || dc->debug.exit_idle_opt_for_cursor_updates) &&
> 406 position->enable) {
> 407 dc_allow_idle_optimizations(dc, false);
>
> Fixes: f63f86b5affc ("drm/amd/display: Separate setting and programming of cursor")
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Cc: Harry Wentland <harry.wentland@xxxxxxx>
> Cc: Tom Chung <chiahsuan.chung@xxxxxxx>
> Cc: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
> Cc: Roman Li <roman.li@xxxxxxx>
> Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx>
Harry
> ---
> drivers/gpu/drm/amd/display/dc/core/dc_stream.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
> index de48084eac25..55e1c19b97f1 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
> @@ -394,7 +394,10 @@ bool dc_stream_program_cursor_position(
> bool reset_idle_optimizations = false;
> const struct dc_cursor_position *old_position;
>
> - old_position = stream ? &stream->cursor_position : NULL;
> + if (!stream)
> + return false;
> +
> + old_position = &stream->cursor_position;
> dc = stream->ctx->dc;
>
> if (dc_stream_set_cursor_position(stream, position)) {
