From 3b139d2a1e47f5585bfabd47ca891e9b4c5e53d9 Mon Sep 17 00:00:00 2001 From: Timothy Pearson Date: Mon, 13 Apr 2015 15:05:11 -0500 Subject: [PATCH] Do not unblock signals in main thread when waiting for kdesktop_lock response This prevents incorrect cancellation of internal xcb poll() methods and subsequent deadlock (cherry picked from commit ab8dfbaaa482e8de7ebd3a5eec1065b38d5299f6) --- kdesktop/lock/lockprocess.cc | 1 - kdesktop/lockeng.cc | 11 ++++------- 2 files changed, 4 insertions(+), 8 deletions(-) diff --git a/kdesktop/lock/lockprocess.cc b/kdesktop/lock/lockprocess.cc index 85de4e0e1..37d2b8867 100644 --- a/kdesktop/lock/lockprocess.cc +++ b/kdesktop/lock/lockprocess.cc @@ -2092,7 +2092,6 @@ void LockProcess::slotPaintBackground(const TQPixmap &rpm) setGeometry(0, 0, mRootWidth, mRootHeight); erase(); } -// saverReadyIfNeeded(); } void LockProcess::preparePopup() diff --git a/kdesktop/lockeng.cc b/kdesktop/lockeng.cc index 27b57bc51..43930e9e7 100644 --- a/kdesktop/lockeng.cc +++ b/kdesktop/lockeng.cc @@ -837,15 +837,13 @@ bool SaverEngine::waitForLockProcessStart() { sigset_t empty_mask; sigemptyset(&empty_mask); - // wait for SIGUSR1, SIGUSR2, SIGTTIN, SIGCHLD + // ensure that SIGCHLD is not subjec to a race condition sigemptyset(&new_mask); - sigaddset(&new_mask, SIGUSR1); - sigaddset(&new_mask, SIGUSR2); - sigaddset(&new_mask, SIGTTIN); sigaddset(&new_mask, SIGCHLD); pthread_sigmask(SIG_BLOCK, &new_mask, NULL); while ((mLockProcess.isRunning()) && (!mSaverProcessReady)) { + // wait for any signal to arrive sigsuspend(&empty_mask); } pthread_sigmask(SIG_UNBLOCK, &new_mask, NULL); @@ -858,11 +856,10 @@ bool SaverEngine::waitForLockEngage() { sigemptyset(&empty_mask); // wait for SIGUSR1, SIGUSR2, SIGTTIN - pthread_sigmask(SIG_BLOCK, &mThreadBlockSet, NULL); while ((mLockProcess.isRunning()) && (mState != Waiting) && (mState != Saving)) { + // wait for any signal to arrive sigsuspend(&empty_mask); } - pthread_sigmask(SIG_UNBLOCK, &mThreadBlockSet, NULL); return mLockProcess.isRunning(); } @@ -882,4 +879,4 @@ void SaverEngineThreadHelperObject::terminateThread() { if (eventLoop) { eventLoop->exit(0); } -} \ No newline at end of file +}