From 5f34c6a4429025ee71616e677e0e59342bee17b0 Mon Sep 17 00:00:00 2001 From: Sebastian Lackner Date: Wed, 25 Feb 2015 22:45:42 +0100 Subject: [PATCH] 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. --- 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 bb11521cf69..fee26ccd21d 100644 --- a/dlls/ntdll/thread.c +++ b/dlls/ntdll/thread.c @@ -298,6 +298,7 @@ TEB *thread_init(void) void WINAPI RtlExitUserThread( ULONG status ) { static void *prev_teb; + sigset_t sigset; TEB *teb; if (status) /* send the exit code to the server (0 is already the default) */ @@ -311,7 +312,7 @@ void WINAPI RtlExitUserThread( ULONG status ) SERVER_END_REQ; } - if (InterlockedDecrement( &nb_threads ) <= 0) + if (InterlockedCompareExchange( &nb_threads, 0, 0 ) <= 0) { LdrShutdownProcess(); unix_funcs->exit_process( status ); @@ -333,6 +334,11 @@ void WINAPI RtlExitUserThread( ULONG status ) } } + sigemptyset( &sigset ); + sigaddset( &sigset, SIGQUIT ); + pthread_sigmask( SIG_BLOCK, &sigset, NULL ); + if (!InterlockedDecrement( &nb_threads )) _exit( status ); + for (;;) unix_funcs->exit_thread( status ); } -- 2.26.2