--- Libc/Libc-320/sys/sigaction.c
+++ Libc/Libc-1669.40.2/sys/sigaction.c
@@ -1,9 +1,7 @@
 /*
- * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1999-2017 Apple Computer, Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
- * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
@@ -22,70 +20,41 @@
  * 
  * @APPLE_LICENSE_HEADER_END@
  */
-/*
- * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
- *
- *	@(#)sigaction.c	1.0
- */
 
-#include <sys/syscall.h>
+#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>
 
-/*
- *	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.
- */
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wstrict-prototypes"
 
-#if defined(__DYNAMIC__)
-extern int __in_sigtramp;
-#endif
-
-static int
-sigaction__ (sig, nsv, osv, bind)
-        int sig;
-	register struct sigaction *nsv, *osv;
-        int bind;
-{
-	extern void _sigtramp();
-	struct __sigaction sa;
-	struct __sigaction *sap;
-
-	if (sig <= 0 || sig >= NSIG || sig == SIGKILL || sig == SIGSTOP) {
-	        errno = EINVAL;
-	        return (-1);
-	}
-	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;
-	        if (nsv->sa_handler != (void (*)())SIG_DFL && nsv->sa_handler != (void (*)())SIG_IGN) {
-#ifdef __DYNAMIC__
-                    if (bind && (__in_sigtramp == 0))				// XXX
-		  _dyld_bind_fully_image_containing_address(nsv->sa_handler);
-#endif
-	        }
-	}
-	if (syscall (SYS_sigaction, sig, sap, osv) < 0) {
-	        return (-1);
-	}
-	return (0);
-}
-
+extern int __platform_sigaction (int sig,
+		const struct sigaction * __restrict nsv,
+		struct sigaction * __restrict osv);
 
 int
-sigaction (sig, nsv, osv)
-        int sig;
-	register const struct sigaction *nsv;
-        register struct sigaction *osv;
+sigaction (int sig, const struct sigaction * __restrict nsv,
+		struct sigaction * __restrict osv)
 {
-    return sigaction__(sig, nsv, osv, 1);
+	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();
+	}
+#endif
+	return ret;
 }
 
 // XXX
@@ -97,7 +66,8 @@
 	register const struct sigaction *nsv;
         register struct sigaction *osv;
 {
-    return sigaction__(sig, nsv, osv, 0);
+    return sigaction(sig, nsv, osv);
 }
 #endif
 
+#pragma clang diagnostic pop