| From 695c19cdd2fc24aaa7ed89976c4965b376707131 Mon Sep 17 00:00:00 2001 |
| From: Sebastian Lackner <sebastian@fds-team.de> |
| Date: Wed, 25 Feb 2015 22:45:42 +0100 |
| Subject: ntdll: Fix race-condition when threads are killed during shutdown. |
| |
| When exit_thread is executed, nb_threads is decremented before the thread is |
| fully shutdown. When another thread runs ExitProcess() this will cause a SIGQUIT |
| signal to all threads, effectively decrementing nb_threads twice. The process |
| will terminate with a wrong exitcode then because the refcount reaches zero too |
| early. |
| |
| Currently Wine has no locking protection of LdrShutdownProcess(), so it can |
| only be executed safely when all other threads have terminated before. Most |
| likely there are more Wine bugs in this area, but the attached patch should |
| fix the most critical one (messed up refcounting of threads) for now. |
| |
| [Alexandre Rostovtsev <tetromino@gentoo.org> : rebase to be applied after |
| Maarten Lankhorst's "override pthreads to fix gstreamer v5" patch.] |
| --- |
| dlls/ntdll/thread.c | 8 +++++++- |
| 1 file changed, 7 insertions(+), 1 deletion(-) |
| |
| diff --git a/dlls/ntdll/thread.c b/dlls/ntdll/thread.c |
| index 4f181dc..1bdbcbf 100755 |
| --- a/dlls/ntdll/thread.c |
| +++ b/dlls/ntdll/thread.c |
| @@ -461,6 +461,7 @@ static void exit_thread_common( int status ) |
| static void *prev_teb; |
| TEB *teb; |
| #endif |
| + sigset_t sigset; |
| |
| if (status) /* send the exit code to the server (0 is already the default) */ |
| { |
| @@ -473,7 +474,7 @@ static void exit_thread_common( int status ) |
| SERVER_END_REQ; |
| } |
| |
| - if (interlocked_xchg_add( &nb_threads, -1 ) <= 1) |
| + if (interlocked_xchg_add( &nb_threads, 0 ) <= 1) |
| { |
| LdrShutdownProcess(); |
| exit( status ); |
| @@ -499,6 +500,11 @@ static void exit_thread_common( int status ) |
| reap_thread(NtCurrentTeb()); |
| #endif |
| |
| + sigemptyset( &sigset ); |
| + sigaddset( &sigset, SIGQUIT ); |
| + pthread_sigmask( SIG_BLOCK, &sigset, NULL ); |
| + if (interlocked_xchg_add( &nb_threads, -1 ) <= 1) _exit( status ); |
| + |
| close( ntdll_get_thread_data()->wait_fd[0] ); |
| close( ntdll_get_thread_data()->wait_fd[1] ); |
| close( ntdll_get_thread_data()->reply_fd ); |
| -- |
| 2.3.1 |
| |