From 18ddda696137106eaa397a01bc06fc97c59df02d Mon Sep 17 00:00:00 2001 From: Jon Turney Date: Sun, 16 Jul 2023 14:46:00 +0100 Subject: [PATCH] Cygwin: Restore signal handlers on thread cancellation during system() Add back the restoration of signal handlers modified during system() on thread cancellation. Removed in 3cb9da14 which describes it as 'ill-conceived' (additional context doesn't appear to be available). We use internal implementation helpers for pthread cleanup chain, so we can neatly tuck it inside the object, and keep the point when we restore the signal handlers the same. The pthread_cleanup_push/pop() functions are implemented as macros which must appear in the same lexical scope.) Fixes: 3cb9da14617c ("Put signals on hold and use system_call_cleanup class to set and restore signals rather than doing it prior to to running the program. Remove the ill-conceived pthread_cleanup stuff.") Signed-off-by: Jon Turney --- winsup/cygwin/spawn.cc | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/winsup/cygwin/spawn.cc b/winsup/cygwin/spawn.cc index 84dd74e28..c16fe269a 100644 --- a/winsup/cygwin/spawn.cc +++ b/winsup/cygwin/spawn.cc @@ -228,6 +228,8 @@ struct system_call_handle _sig_func_ptr oldint; _sig_func_ptr oldquit; sigset_t oldmask; + __pthread_cleanup_handler cleanup_handler; + bool is_system_call () { return oldint != ILLEGAL_SIG_FUNC_PTR; @@ -253,18 +255,27 @@ struct system_call_handle sigaddset (&child_block, SIGCHLD); sigprocmask (SIG_BLOCK, &child_block, &oldmask); sig_send (NULL, __SIGNOHOLD); + + cleanup_handler = { system_call_handle::cleanup, this, NULL }; + _pthread_cleanup_push (&cleanup_handler); } } ~system_call_handle () { if (is_system_call ()) + _pthread_cleanup_pop (1); + } + static void cleanup (void *arg) + { +# define this_ ((system_call_handle *) arg) + if (this_->is_system_call ()) { - signal (SIGINT, oldint); - signal (SIGQUIT, oldquit); - sigprocmask (SIG_SETMASK, &oldmask, NULL); + signal (SIGINT, this_->oldint); + signal (SIGQUIT, this_->oldquit); + sigprocmask (SIG_SETMASK, &(this_->oldmask), NULL); } } -# undef cleanup +# undef this_ }; child_info_spawn NO_COPY ch_spawn; -- 2.39.0