Index: eval_intern.h
===================================================================
--- eval_intern.h	(revision 32019)
+++ eval_intern.h	(working copy)
@@ -212,7 +212,6 @@
 void rb_thread_terminate_all(void);
 VALUE rb_vm_top_self();
 VALUE rb_vm_cbase(void);
-void rb_trap_restore_mask(void);
 
 #ifndef CharNext		/* defined as CharNext[AW] on Windows. */
 #define CharNext(p) ((p) + mblen((p), RUBY_MBCHAR_MAXSIZE))
Index: thread_pthread.c
===================================================================
--- thread_pthread.c	(revision 32019)
+++ thread_pthread.c	(working copy)
@@ -1029,8 +1029,6 @@
 static void
 rb_thread_create_timer_thread(void)
 {
-    rb_enable_interrupt();
-
     if (!timer_thread_id) {
 	pthread_attr_t attr;
 	int err;
@@ -1051,7 +1049,6 @@
 	native_cond_wait(&timer_thread_cond, &timer_thread_lock);
 	native_mutex_unlock(&timer_thread_lock);
     }
-    rb_disable_interrupt(); /* only timer thread recieve signal */
 }
 
 static int
Index: vm_core.h
===================================================================
--- vm_core.h	(revision 32019)
+++ vm_core.h	(working copy)
@@ -640,8 +640,6 @@
 #endif
 VALUE rb_iseq_eval(VALUE iseqval);
 VALUE rb_iseq_eval_main(VALUE iseqval);
-void rb_enable_interrupt(void);
-void rb_disable_interrupt(void);
 #if defined __GNUC__ && __GNUC__ >= 4
 #pragma GCC visibility pop
 #endif
Index: vm_eval.c
===================================================================
--- vm_eval.c	(revision 32019)
+++ vm_eval.c	(working copy)
@@ -1442,7 +1442,6 @@
 	RB_GC_GUARD(desc);
 	rb_raise(rb_eArgError, "uncaught throw %s", RSTRING_PTR(desc));
     }
-    rb_trap_restore_mask();
     th->errinfo = NEW_THROW_OBJECT(tag, 0, TAG_THROW);
 
     JUMP_TAG(TAG_THROW);
Index: eval.c
===================================================================
--- eval.c	(revision 32019)
+++ eval.c	(working copy)
@@ -439,8 +439,6 @@
 	JUMP_TAG(TAG_FATAL);
     }
 
-    rb_trap_restore_mask();
-
     if (tag != TAG_FATAL) {
 	EXEC_EVENT_HOOK(th, RUBY_EVENT_RAISE, th->cfp->self, 0, 0);
     }
Index: process.c
===================================================================
--- process.c	(revision 32019)
+++ process.c	(working copy)
@@ -990,12 +990,6 @@
 
 static void before_exec(void)
 {
-    /*
-     * signalmask is inherited across exec() and almost system commands don't
-     * work if signalmask is blocked.
-     */
-    rb_enable_interrupt();
-
 #ifdef SIGPIPE
     /*
      * Some OS commands don't initialize signal handler properly. Thus we have
@@ -1026,7 +1020,6 @@
 #endif
 
     forked_child = 0;
-    rb_disable_interrupt();
 }
 
 #define before_fork() before_exec()
@@ -2947,43 +2940,13 @@
 void
 rb_syswait(rb_pid_t pid)
 {
-    static int overriding;
-#ifdef SIGHUP
-    RETSIGTYPE (*hfunc)(int) = 0;
-#endif
-#ifdef SIGQUIT
-    RETSIGTYPE (*qfunc)(int) = 0;
-#endif
-    RETSIGTYPE (*ifunc)(int) = 0;
     int status;
-    int i, hooked = FALSE;
+    int err;
 
-    if (!overriding) {
-#ifdef SIGHUP
-	hfunc = signal(SIGHUP, SIG_IGN);
-#endif
-#ifdef SIGQUIT
-	qfunc = signal(SIGQUIT, SIG_IGN);
-#endif
-	ifunc = signal(SIGINT, SIG_IGN);
-	overriding = TRUE;
-	hooked = TRUE;
-    }
-
     do {
-	i = rb_waitpid(pid, &status, 0);
-    } while (i == -1 && errno == EINTR);
+	err = rb_waitpid(pid, &status, 0);
+    } while (err == -1 && errno == EINTR);
 
-    if (hooked) {
-#ifdef SIGHUP
-	signal(SIGHUP, hfunc);
-#endif
-#ifdef SIGQUIT
-	signal(SIGQUIT, qfunc);
-#endif
-	signal(SIGINT, ifunc);
-	overriding = FALSE;
-    }
 }
 
 static VALUE
Index: signal.c
===================================================================
--- signal.c	(revision 32019)
+++ signal.c	(working copy)
@@ -517,31 +517,21 @@
     return signal_buff.size;
 }
 
-#if USE_TRAP_MASK
-# ifdef HAVE_SIGPROCMASK
-static sigset_t trap_last_mask;
-# else
-static int trap_last_mask;
-# endif
-#endif
-
 #if HAVE_PTHREAD_H
 #include <pthread.h>
 #endif
 
-void
+static void
 rb_disable_interrupt(void)
 {
 #if USE_TRAP_MASK
     sigset_t mask;
     sigfillset(&mask);
-    sigdelset(&mask, SIGVTALRM);
-    sigdelset(&mask, SIGSEGV);
     pthread_sigmask(SIG_SETMASK, &mask, NULL);
 #endif
 }
 
-void
+static void
 rb_enable_interrupt(void)
 {
 #if USE_TRAP_MASK
@@ -867,19 +857,10 @@
 {
     /* enable interrupt */
     pthread_sigmask(SIG_SETMASK, &arg->mask, NULL);
-    trap_last_mask = arg->mask;
     return 0;
 }
 #endif
 
-void
-rb_trap_restore_mask(void)
-{
-#if USE_TRAP_MASK
-    pthread_sigmask(SIG_SETMASK, &trap_last_mask, NULL);
-#endif
-}
-
 /*
  * call-seq:
  *   Signal.trap( signal, command ) -> obj
@@ -986,34 +967,13 @@
 init_sigchld(int sig)
 {
     sighandler_t oldfunc;
-#if USE_TRAP_MASK
-# ifdef HAVE_SIGPROCMASK
-    sigset_t mask;
-    sigset_t fullmask;
-# else
-    int mask;
-    int fullmask;
-# endif
-#endif
 
-#if USE_TRAP_MASK
-    /* disable interrupt */
-    sigfillset(&fullmask);
-    pthread_sigmask(SIG_BLOCK, &fullmask, &mask);
-#endif
-
     oldfunc = ruby_signal(sig, SIG_DFL);
     if (oldfunc != SIG_DFL && oldfunc != SIG_IGN) {
 	ruby_signal(sig, oldfunc);
     } else {
 	GET_VM()->trap_list[sig].cmd = 0;
     }
-
-#if USE_TRAP_MASK
-    sigdelset(&mask, sig);
-    pthread_sigmask(SIG_SETMASK, &mask, NULL);
-    trap_last_mask = mask;
-#endif
 }
 #endif