graesslin created this revision. graesslin added reviewers: KWin, Plasma, subdiff. Restricted Application added a project: KWin. Restricted Application added subscribers: kwin, plasma-devel.
REVISION SUMMARY The gbm_surface is owned by the EglGbmBackend, but it's not the only one using it. The DrmSurfaceBuffer is also using it and needs it to destroy the gbm_bo. Now this can become a problem in the following situation: - a page flip is still pending - the EglGbmBackend destroys the gbm_surface -> when the page flip happens the DrmSurfaceBuffer will try to destroy the gbm_bo and crash as the gbm_surface is no longer valid. This situation can happen when switching screens or when switching compositing backend (OpenGL 2 -> OpenGL 3). To address this problem a class GbmSurface is added which wrapps the gbm_surface pointer. The EglGbmBackend creates and holds a shared pointer to the GbmSurface and passes that one to the DrmSurfaceBuffer. So when cleaning up the gbm_surface only the shared pointer is reset and in case the DrmSurfaceBuffer still needs it, it can access it without problems. BUG: 385372 FIXED-IN: 5.11.0 TEST PLAN Not yet REPOSITORY R108 KWin BRANCH shared-gbm-surface-5.11 REVISION DETAIL https://phabricator.kde.org/D8152 AFFECTED FILES plugins/platforms/drm/CMakeLists.txt plugins/platforms/drm/drm_backend.cpp plugins/platforms/drm/drm_backend.h plugins/platforms/drm/drm_buffer_gbm.cpp plugins/platforms/drm/drm_buffer_gbm.h plugins/platforms/drm/egl_gbm_backend.cpp plugins/platforms/drm/egl_gbm_backend.h plugins/platforms/drm/gbm_surface.cpp plugins/platforms/drm/gbm_surface.h To: graesslin, #kwin, #plasma, subdiff Cc: plasma-devel, kwin, bwowk, ZrenBot, progwolff, lesliezhai, ali-mohamed, hardening, jensreuterberg, abetts, sebas, apol, mart