Add API for obtaining extended machine context states that cannot be

fit into existing mcontext_t.

On i386 and amd64 do return the extended FPU states using
getcontextx(3). For other architectures, getcontextx(3) returns the
same information as getcontext(2).

Tested by:  pho
MFC after:  1 month

2 files changed, 70 insertions, 1 deletions

diff --git a/lib/libc/sparc64/gen/Makefile.inc b/lib/libc/sparc64/gen/Makefile.inc
index f82f225..d3fbfe4 100644
--- a/lib/libc/sparc64/gen/Makefile.inc
+++ b/lib/libc/sparc64/gen/Makefile.inc
@@ -2,5 +2,5 @@
 
 SRCS+=	_ctx_start.S _setjmp.S fabs.S fixunsdfsi.S flt_rounds.c fpgetmask.c \
 	fpgetround.c fpgetsticky.c fpsetmask.c fpsetround.c \
-	infinity.c ldexp.c makecontext.c \
+	getcontextx.c infinity.c ldexp.c makecontext.c \
 	signalcontext.c setjmp.S sigsetjmp.S _set_tp.c
diff --git a/lib/libc/sparc64/gen/getcontextx.c b/lib/libc/sparc64/gen/getcontextx.c
new file mode 100644
index 0000000..b701c18
--- /dev/null
+++ b/lib/libc/sparc64/gen/getcontextx.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2011 Konstantin Belousov <kib@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 ``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 <errno.h>
+#include <stdlib.h>
+
+size_t
+__getcontextx_size(void)
+{
+
+	return (sizeof(ucontext_t));
+}
+
+int
+__fillcontextx(char *ctx)
+{
+	ucontext_t *ucp;
+
+	ucp = (ucontext_t *)ctx;
+	return (getcontext(ucp));
+}
+
+__weak_reference(__getcontextx, getcontextx);
+
+ucontext_t *
+__getcontextx(void)
+{
+	char *ctx;
+	int error;
+
+	ctx = malloc(__getcontextx_size());
+	if (ctx == NULL)
+		return (NULL);
+	if (__fillcontextx(ctx) == -1) {
+		error = errno;
+		free(ctx);
+		errno = error;
+		return (NULL);
+	}
+	return ((ucontext_t *)ctx);
+}