From 1bcac4ba99c1634ae0b1433262b3d81e120150b3 Mon Sep 17 00:00:00 2001
From: John Baldwin <jhb@FreeBSD.org>
Date: Mon, 8 Oct 2018 19:15:58 +0000
Subject: [PATCH] Add support for relocations in RISC-V kernel modules to
 kldxref.

Reviewed by:	br, markj
Approved by:	re (gjb)
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D17415
---
 usr.sbin/kldxref/ef_riscv.c | 78 +++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 usr.sbin/kldxref/ef_riscv.c

diff --git a/usr.sbin/kldxref/ef_riscv.c b/usr.sbin/kldxref/ef_riscv.c
new file mode 100644
index 000000000000..e0caae3bd286
--- /dev/null
+++ b/usr.sbin/kldxref/ef_riscv.c
@@ -0,0 +1,78 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2018 John Baldwin <jhb@FreeBSD.org>
+ *
+ * This software was developed by SRI International and the University of
+ * Cambridge Computer Laboratory (Department of Computer Science and
+ * Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
+ * DARPA SSITH research programme.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <machine/elf.h>
+
+#include <err.h>
+#include <errno.h>
+
+#include "ef.h"
+
+int
+ef_reloc(struct elf_file *ef, const void *reldata, int reltype, Elf_Off relbase,
+    Elf_Off dataoff, size_t len, void *dest)
+{
+	Elf_Addr *where, val;
+	const Elf_Rela *rela;
+	Elf_Addr addend, addr;
+	Elf_Size rtype;
+
+	switch (reltype) {
+	case EF_RELOC_RELA:
+		rela = (const Elf_Rela *)reldata;
+		where = (Elf_Addr *)((char *)dest + relbase + rela->r_offset -
+		    dataoff);
+		addend = rela->r_addend;
+		rtype = ELF_R_TYPE(rela->r_info);
+		break;
+	default:
+		return (EINVAL);
+	}
+
+	if ((char *)where < (char *)dest || (char *)where >= (char *)dest + len)
+		return (0);
+
+	switch (rtype) {
+	case R_RISCV_RELATIVE:	/* B + A */
+		addr = addend + relbase;
+		val = addr;
+		*where = val;
+		break;
+	default:
+		warnx("unhandled relocation type %d", (int)rtype);
+	}
+	return (0);
+}