libplatform-177.200.16.tar.gz

[apple/libplatform.git] / src / setjmp / generic / sigaction.c

diff --git a/src/setjmp/generic/sigaction.c b/src/setjmp/generic/sigaction.c
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+++ b/src/setjmp/generic/sigaction.c
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+/*
+ * Copyright (c) 1999-2017 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+/*
+ * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
+ *
+ *     @(#)sigaction.c 1.0
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/signal.h>
+#include <errno.h>
+
+// keep in sync with BSD_KERNEL_PRIVATE value in xnu/bsd/sys/signal.h
+#define SA_VALIDATE_SIGRETURN_FROM_SIGTRAMP 0x0400
+
+/*
+ *     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
+__platform_sigaction (int sig, const struct sigaction * __restrict nsv,
+               struct sigaction * __restrict osv)
+{
+       extern void _sigtramp();
+       struct __sigaction sa;
+       struct __sigaction *sap;
+       int ret;
+
+       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 | SA_VALIDATE_SIGRETURN_FROM_SIGTRAMP;
+               sap = &sa;
+       }
+       ret = __sigaction(sig, sap, osv);
+       return ret;
+}