--- Libc/Libc-1725.40.4/sys/sigaction.c
+++ Libc/Libc-583/sys/sigaction.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999-2017 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
@@ -20,41 +20,44 @@
  * 
  * @APPLE_LICENSE_HEADER_END@
  */
+/*
+ * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
+ *
+ *	@(#)sigaction.c	1.0
+ */
 
-#if __has_include(<CrashReporterClient.h>)
-#include <CrashReporterClient.h>
-#else
-#define CRSetCrashLogMessage(...)
-#endif
-#include <stdlib.h>
-#include <stdio.h>
 #include <unistd.h>
 #include <signal.h>
 #include <sys/signal.h>
 #include <errno.h>
 
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wstrict-prototypes"
-
-extern int __platform_sigaction (int sig,
-		const struct sigaction * __restrict nsv,
-		struct sigaction * __restrict osv);
+/*
+ *	Intercept the sigaction syscall and use our signal trampoline
+ *	as the signal handler instead.  The code here is derived
+ *	from sigvec in sys/kern_sig.c.
+ */
+extern int __sigaction (int, struct __sigaction * __restrict, struct sigaction * __restrict);
 
 int
-sigaction (int sig, const struct sigaction * __restrict nsv,
-		struct sigaction * __restrict osv)
+sigaction (int sig, const struct sigaction * __restrict nsv, struct sigaction * __restrict osv)
 {
-	int ret = __platform_sigaction(sig, nsv, osv);
-#ifdef FEATURE_SIGNAL_RESTRICTION
-	// Note: The "sig != 0" here is to force the compiler to maintain that "sig"
-	// is live, and in a register, after __sigaction so it is visible in the
-	// crashing register state.
-	if (ret == -1 && errno == ENOTSUP && sig != 0) {
-		CRSetCrashLogMessage("sigaction on fatal signals is not supported");
-		__builtin_trap();
+	extern void _sigtramp();
+	struct __sigaction sa;
+	struct __sigaction *sap;
+
+	if (sig <= 0 || sig >= NSIG || sig == SIGKILL || sig == SIGSTOP) {
+	        errno = EINVAL;
+	        return (-1);
 	}
-#endif
-	return ret;
+	sap = (struct __sigaction *)0;
+	if (nsv) {
+		sa.sa_handler = nsv->sa_handler;
+		sa.sa_tramp = _sigtramp;
+		sa.sa_mask = nsv->sa_mask;
+		sa.sa_flags = nsv->sa_flags;	
+		sap = &sa;
+	}
+	return __sigaction(sig, sap, osv);
 }
 
 // XXX
@@ -70,4 +73,3 @@
 }
 #endif
 
-#pragma clang diagnostic pop