Add amd64 versions of makecontext() and signalcontext() needed

for libkse (makecontext() is also needed for libthr).
These probably will need some tweaking.

3 files changed, 208 insertions, 1 deletions

diff --git a/lib/libc/amd64/gen/Makefile.inc b/lib/libc/amd64/gen/Makefile.inc
index 15a1f2f..e50bbe6 100644
--- a/lib/libc/amd64/gen/Makefile.inc
+++ b/lib/libc/amd64/gen/Makefile.inc
@@ -3,4 +3,5 @@
 
 SRCS+=	_setjmp.S setjmp.S sigsetjmp.S \
 	fabs.S modf.S \
-	frexp.c infinity.c isinf.c ldexp.c
+	frexp.c infinity.c isinf.c ldexp.c \
+	makecontext.c signalcontext.c
diff --git a/lib/libc/amd64/gen/makecontext.c b/lib/libc/amd64/gen/makecontext.c
new file mode 100644
index 0000000..87cf7bf
--- /dev/null
+++ b/lib/libc/amd64/gen/makecontext.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2003 Marcel Moolenaar
+ * 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 ``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 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/ucontext.h>
+#include <stdarg.h>
+#include <stdlib.h>
+
+typedef void (*func_t)(uint64_t, uint64_t, uint64_t, uint64_t, uint64_t,
+    uint64_t);
+
+/* Prototypes */
+static void ctx_wrapper(ucontext_t *ucp, func_t func, uint64_t *args);
+
+__weak_reference(__makecontext, makecontext);
+
+void
+__makecontext(ucontext_t *ucp, void (*start)(void), int argc, ...)
+{
+	uint64_t *args;
+	uint64_t *sp;
+	va_list ap;
+	int i;
+
+	/* A valid context is required. */
+	if ((ucp == NULL) || (ucp->uc_mcontext.mc_len != sizeof(mcontext_t)))
+		return;
+	else if ((argc < 0) || (argc > 6) || (ucp->uc_stack.ss_sp == NULL) ||
+	    (ucp->uc_stack.ss_size < MINSIGSTKSZ)) {
+		/*
+		 * This should really return -1 with errno set to ENOMEM
+		 * or something, but the spec says that makecontext is
+		 * a void function.   At least make sure that the context
+		 * isn't valid so it can't be used without an error.
+		 */
+		ucp->uc_mcontext.mc_len = 0;
+		return;
+	}
+
+	/* Align the stack to 16 bytes. */
+	sp = (uint64_t *)(ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
+	sp = (uint64_t *)((uint64_t)sp & -15UL);
+
+	/* Allocate space for a maximum of 6 arguments on the stack. */
+	args = sp - 6;
+
+	/* Account for arguments on stack and align to 16 bytes. */
+	sp -= 8;
+
+	/* Add the arguments: */
+	va_start(ap, argc);
+	for (i = 0; i < argc; i++)
+		args[i] = va_arg(ap, uint64_t);
+	va_end(ap);
+	for (i = argc; i < 6; i++)
+		args[i] = 0;
+
+	ucp->uc_mcontext.mc_rdi = (register_t)ucp;
+	ucp->uc_mcontext.mc_rsi = (register_t)start;
+	ucp->uc_mcontext.mc_rdx = (register_t)args;
+	ucp->uc_mcontext.mc_rbp = (register_t)sp;
+	ucp->uc_mcontext.mc_rbx = (register_t)sp;
+	ucp->uc_mcontext.mc_rsp = (register_t)sp;
+	ucp->uc_mcontext.mc_rip = (register_t)ctx_wrapper;
+}
+
+static void
+ctx_wrapper(ucontext_t *ucp, func_t func, uint64_t *args)
+{
+	(*func)(args[0], args[1], args[2], args[3], args[4], args[5]);
+	if (ucp->uc_link == NULL)
+		exit(0);
+	setcontext((const ucontext_t *)ucp->uc_link);
+	/* should never get here */
+	abort();
+	/* NOTREACHED */
+}
diff --git a/lib/libc/amd64/gen/signalcontext.c b/lib/libc/amd64/gen/signalcontext.c
new file mode 100644
index 0000000..c713a4e
--- /dev/null
+++ b/lib/libc/amd64/gen/signalcontext.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2003 Marcel Moolenaar
+ * 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 ``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 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/ucontext.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <strings.h>
+
+typedef void (*handler_t)(uint64_t, uint64_t, uint64_t);
+
+/* Prototypes */
+static void ctx_wrapper(ucontext_t *ucp, handler_t func, uint64_t *args);
+
+__weak_reference(__signalcontext, signalcontext);
+
+int
+__signalcontext(ucontext_t *ucp, int sig, __sighandler_t *func)
+{
+	uint64_t *args;
+	siginfo_t *sig_si;
+	ucontext_t *sig_uc;
+	uint64_t sp;
+
+	/* Bail out if we don't have a valid ucontext pointer. */
+	if (ucp == NULL)
+		abort();
+
+	/*
+	 * Build a signal frame and copy the arguments of signal handler
+	 * 'func' onto the stack. We only need 3 arguments, but we
+	 * create room for 4 so that we are 16-byte aligned.
+	 */
+	sp = (ucp->uc_mcontext.mc_rsp - sizeof(ucontext_t)) & ~15UL;
+	sig_uc = (ucontext_t *)sp;
+	bcopy(ucp, sig_uc, sizeof(*sig_uc));
+	sp = (sp - sizeof(siginfo_t)) & ~15UL;
+	sig_si = (siginfo_t *)sp;
+	bzero(sig_si, sizeof(*sig_si));
+	sig_si->si_signo = sig;
+	sp -= 4 * sizeof(uint64_t);
+	args = (uint64_t *)sp;
+	args[0] = sig;
+	args[1] = (intptr_t)sig_si;
+	args[2] = (intptr_t)sig_uc;
+	args[3] = 0;
+	sp -= 16;
+
+	/*
+	 * Setup the ucontext of the signal handler.
+	 */
+	bzero(&ucp->uc_mcontext, sizeof(ucp->uc_mcontext));
+	ucp->uc_link = sig_uc;
+	sigdelset(&ucp->uc_sigmask, sig);
+
+	ucp->uc_mcontext.mc_rdi = (register_t)ucp;
+	ucp->uc_mcontext.mc_rsi = (register_t)func;
+	ucp->uc_mcontext.mc_rdx = (register_t)args;
+	ucp->uc_mcontext.mc_rbp = (register_t)sp;
+	ucp->uc_mcontext.mc_rbx = (register_t)sp;
+	ucp->uc_mcontext.mc_rsp = (register_t)sp;
+	ucp->uc_mcontext.mc_rip = (register_t)ctx_wrapper;
+	return (0);
+}
+
+static void
+ctx_wrapper(ucontext_t *ucp, handler_t func, uint64_t *args)
+{
+
+	(*func)(args[0], args[1], args[2]);
+	if (ucp->uc_link == NULL)
+		exit(0);
+	setcontext((const ucontext_t *)ucp->uc_link);
+	/* should never get here */
+	abort();
+	/* NOTREACHED */
+}