From ad2aca113daccb4d0e9299b7c37d61f2d9b1f930 Mon Sep 17 00:00:00 2001 From: Thomas Senyk Date: Mon, 12 Dec 2022 15:03:00 +0100 Subject: eglfs-kms/gbm: fix segfault and add qScopeGuard As framebufferForBufferObject has a code-path which returns a nullptr, it's vital to check on that and return early in that case. As this is the third segment in this function that does gbm_surface_release_buffer, a qScopeGuard was introduced to reduce code duplication. This also makes this function saver/easier to maintain long term. The platform on which this segfault was reported is QEMU Pick-to: 6.2 6.4 6.5 Change-Id: I5ee1ad4073712349b7475bce3a7978961fea2344 Reviewed-by: Laszlo Agocs --- .../eglfs_kms/qeglfskmsgbmscreen.cpp | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) (limited to 'src/plugins/platforms/eglfs/deviceintegration') diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp index 0f829ee00c..e6fd627823 100644 --- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp +++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp @@ -352,7 +352,17 @@ void QEglFSKmsGbmScreen::flip() return; } + auto gbmRelease = qScopeGuard([this]{ + m_flipPending = false; + gbm_surface_release_buffer(m_gbm_surface, m_gbm_bo_next); + m_gbm_bo_next = nullptr; + }); + FrameBuffer *fb = framebufferForBufferObject(m_gbm_bo_next); + if (!fb) { + qWarning("FrameBuffer not available. Cannot flip"); + return; + } ensureModeSet(fb->fb); const QKmsOutput &thisOutput(output()); @@ -384,9 +394,6 @@ void QEglFSKmsGbmScreen::flip() this); if (ret) { qErrnoWarning("Could not queue DRM page flip on screen %s", qPrintable(name())); - m_flipPending = false; - gbm_surface_release_buffer(m_gbm_surface, m_gbm_bo_next); - m_gbm_bo_next = nullptr; return; } } @@ -429,12 +436,12 @@ void QEglFSKmsGbmScreen::flip() if (device()->hasAtomicSupport()) { #if QT_CONFIG(drm_atomic) if (!device()->threadLocalAtomicCommit(this)) { - m_flipPending = false; - gbm_surface_release_buffer(m_gbm_surface, m_gbm_bo_next); - m_gbm_bo_next = nullptr; + return; } #endif } + + gbmRelease.dismiss(); } void QEglFSKmsGbmScreen::flipFinished() -- cgit v1.2.3