Save VFP state in getcontext(3) on ARM.

This is a last followup of r315974, which fixes userland part
of VFP save/restore problems described in PR 217611.

PR:		217611
MFC after:	2 weeks

2 files changed, 100 insertions, 1 deletions

diff --git a/lib/libc/arm/gen/Makefile.inc b/lib/libc/arm/gen/Makefile.inc
index 95b1bba4c12f..05f3e95889a5 100644
--- a/lib/libc/arm/gen/Makefile.inc
+++ b/lib/libc/arm/gen/Makefile.inc
@@ -5,7 +5,7 @@ SRCS+=	_ctx_start.S _setjmp.S _set_tp.c alloca.S fabs.c \
 	infinity.c ldexp.c makecontext.c \
 	__aeabi_read_tp.S setjmp.S signalcontext.c sigsetjmp.S flt_rounds.c \
 	arm_initfini.c \
-	trivial-getcontextx.c
+	getcontextx.c
 
 .if ${MACHINE_ARCH:Marmv[67]*} && (!defined(CPUTYPE) || ${CPUTYPE:M*soft*} == "")
 SRCS+=	fpgetmask_vfp.c fpgetround_vfp.c fpgetsticky_vfp.c fpsetmask_vfp.c \
diff --git a/lib/libc/arm/gen/getcontextx.c b/lib/libc/arm/gen/getcontextx.c
new file mode 100644
index 000000000000..3092e2818e92
--- /dev/null
+++ b/lib/libc/arm/gen/getcontextx.c
@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2017 Michal Meloun <mmel@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/ucontext.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <machine/sysarch.h>
+
+struct ucontextx {
+	ucontext_t	ucontext;
+	mcontext_vfp_t	mcontext_vfp;
+};
+
+int
+__getcontextx_size(void)
+{
+
+	return (sizeof(struct ucontextx));
+}
+
+int
+__fillcontextx2(char *ctx)
+{
+	struct ucontextx *ucxp;
+	ucontext_t	 *ucp;
+	mcontext_vfp_t	 *mvp;
+	struct arm_get_vfpstate_args vfp_arg;
+
+	ucxp = (struct ucontextx *)ctx;
+	ucp = &ucxp->ucontext;
+	mvp = &ucxp->mcontext_vfp;
+
+	vfp_arg.mc_vfp_size = sizeof(mcontext_vfp_t);
+	vfp_arg.mc_vfp = mvp;
+	if (sysarch(ARM_GET_VFPSTATE, &vfp_arg) == -1)
+			return (-1);
+	ucp->uc_mcontext.mc_vfp_size = sizeof(mcontext_vfp_t);
+	ucp->uc_mcontext.mc_vfp_ptr = mvp;
+	return (0);
+}
+
+int
+__fillcontextx(char *ctx)
+{
+	struct ucontextx *ucxp;
+
+	ucxp = (struct ucontextx *)ctx;
+	if (getcontext(&ucxp->ucontext) == -1)
+		return (-1);
+	__fillcontextx2(ctx);
+	return (0);
+}
+
+__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);
+}