1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2018 John Baldwin <jhb@FreeBSD.org>
5 *
6 * This software was developed by SRI International and the University of
7 * Cambridge Computer Laboratory (Department of Computer Science and
8 * Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
9 * DARPA SSITH research programme.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD$");
35
36#include <sys/types.h>
37#include <machine/elf.h>
38
39#include <err.h>
40#include <errno.h>
41
42#include "ef.h"
43
44int
45ef_reloc(struct elf_file *ef, const void *reldata, int reltype, Elf_Off relbase,
46    Elf_Off dataoff, size_t len, void *dest)
47{
48	Elf_Addr *where, val;
49	const Elf_Rela *rela;
50	Elf_Addr addend, addr;
51	Elf_Size rtype;
52
53	switch (reltype) {
54	case EF_RELOC_RELA:
55		rela = (const Elf_Rela *)reldata;
56		where = (Elf_Addr *)((char *)dest + relbase + rela->r_offset -
57		    dataoff);
58		addend = rela->r_addend;
59		rtype = ELF_R_TYPE(rela->r_info);
60		break;
61	default:
62		return (EINVAL);
63	}
64
65	if ((char *)where < (char *)dest || (char *)where >= (char *)dest + len)
66		return (0);
67
68	switch (rtype) {
69	case R_RISCV_RELATIVE:	/* B + A */
70		addr = addend + relbase;
71		val = addr;
72		*where = val;
73		break;
74	default:
75		warnx("unhandled relocation type %d", (int)rtype);
76	}
77	return (0);
78}
79