Add signalcontext(), which adds a signal frame to a ucontext_t.

1 files changed, 80 insertions, 0 deletions

diff --git a/lib/libc/i386/gen/signalcontext.c b/lib/libc/i386/gen/signalcontext.c
new file mode 100644
index 0000000..1e2df66
--- /dev/null
+++ b/lib/libc/i386/gen/signalcontext.c
@@ -0,0 +1,80 @@
+/*-
+ * Copyright (c) 2002 Jonathan Mini <mini@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD");
+
+#include <sys/param.h>
+#include <sys/signal.h>
+#include <sys/signalvar.h>
+#include <sys/ucontext.h>
+#include <machine/psl.h>
+#include <machine/sigframe.h>
+
+extern void _ctx_start(ucontext_t *, int argc, ...);
+
+int
+signalcontext(ucontext_t *ucp, int sig, __sighandler_t *func)
+{
+	struct sigframe *sfp;
+	int *p;
+
+	/*
+	 * Set up stack.
+	 * (n = sizeof(int))
+	 * 2n+sizeof(struct sigframe)	ucp
+	 * 2n				struct sigframe
+	 * 1n				&func
+	 * 0n				&_ctx_start
+	 */
+	p = (int *)ucp->uc_mcontext.mc_esp;
+	*--p = (int)ucp;
+	p -= sizeof(struct sigframe);
+	sfp = (struct sigframe *)p;
+	bzero(sfp, sizeof(struct sigframe));
+	sfp->sf_signum = sig;
+	sfp->sf_siginfo = (int)&sfp->sf_si;
+	sfp->sf_ucontext = (int)&sfp->sf_uc;
+	sfp->sf_ahu.sf_action = (__siginfohandler_t *)func;
+	bcopy(ucp, &sfp->sf_uc, sizeof(ucontext_t));
+	sfp->sf_si.si_signo = sig;
+
+	*--p = (int)func;
+
+	/*
+	 * Set up ucontext_t.
+	 */
+	ucp->uc_mcontext.mc_ebp = ucp->uc_mcontext.mc_esp - sizeof(int);
+	ucp->uc_mcontext.mc_esp = (int)p;
+	ucp->uc_mcontext.mc_eip = (int)_ctx_start;
+	ucp->uc_mcontext.mc_eflags &= ~PSL_T;
+	ucp->uc_link = &sfp->sf_uc;
+	SIGDELSET(ucp->uc_sigmask, sig);
+	return (0);
+}
+