The process that receives many SIGSTOP/SIGCONT signals sometimes hangs on exit in sig_dispatch_pending(). This patch skips processing signals in wait_sig() when exit_state > ES_EXIT_STARTING to avoid that situation.
Addresses: https://cygwin.com/pipermail/cygwin/2025-February/257473.html Fixes: d243e51ef1d3 ("Cygwin: signal: Fix deadlock between main thread and sig thread") Reported-by: Christian Franke <christian.fra...@t-online.de> Reviewed-by: Signed-off-by: Takashi Yano <takashi.y...@nifty.ne.jp> --- winsup/cygwin/sigproc.cc | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc index 8739f18f5..b519866d2 100644 --- a/winsup/cygwin/sigproc.cc +++ b/winsup/cygwin/sigproc.cc @@ -1374,7 +1374,11 @@ wait_sig (VOID *) sigq.retry = false; /* Don't process signals when we start exiting */ - if (exit_state > ES_EXIT_STARTING && pack.si.si_signo > 0) + if (exit_state > ES_EXIT_STARTING + && (pack.si.si_signo > 0 + || pack.si.si_signo == __SIGNOHOLD + || pack.si.si_signo == __SIGFLUSH + || pack.si.si_signo == __SIGFLUSHFAST)) goto skip_process_signal; sigset_t dummy_mask; -- 2.45.1
