49dc28b4b2e28ef7564e355c91487996c1cbebd7

[ Upstream commit d59be579fa932c46b908f37509f319cbd4ca9a68 ]
mdp5_get_global_state runs the risk of hitting a -EDEADLK when acquiring
the modeset lock, but currently mdp5_pipe_release doesn't check for if
an error is returned. Because of this, there is a possibility of
mdp5_pipe_release hitting a NULL dereference error.
To avoid this, let's have mdp5_pipe_release check if
mdp5_get_global_state returns an error and propogate that error.
Changes since v1:
- Separated declaration and initialization of *new_state to avoid
compiler warning
- Fixed some spelling mistakes in commit message
Changes since v2:
- Return 0 in case where hwpipe is NULL as this is considered normal
behavior
- Added 2nd patch in series to fix a similar NULL dereference issue in
mdp5_mixer_release
Reported-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Fixes: 7907a0d77c
("drm/msm/mdp5: Use the new private_obj state")
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/485179/
Link: https://lore.kernel.org/r/20220505214051.155-1-quic_jesszhan@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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