1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2003 Jake Burkholder.
5 * Copyright 1996-1998 John D. Polstra.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/endian.h>
31
32#include <err.h>
33#include <errno.h>
34#include <gelf.h>
35
36#include "ef.h"
37
38/*
39 * Apply relocations to the values obtained from the file. `relbase' is the
40 * target relocation address of the section, and `dataoff/len' is the region
41 * that is to be relocated, and has been copied to *dest
42 */
43static int
44ef_amd64_reloc(struct elf_file *ef, const void *reldata, Elf_Type reltype,
45    GElf_Addr relbase, GElf_Addr dataoff, size_t len, void *dest)
46{
47	char *where;
48	GElf_Addr addr, addend;
49	GElf_Size rtype, symidx;
50	const GElf_Rel *rel;
51	const GElf_Rela *rela;
52
53	switch (reltype) {
54	case ELF_T_REL:
55		rel = (const GElf_Rel *)reldata;
56		where = (char *)dest + (relbase + rel->r_offset - dataoff);
57		addend = 0;
58		rtype = GELF_R_TYPE(rel->r_info);
59		symidx = GELF_R_SYM(rel->r_info);
60		break;
61	case ELF_T_RELA:
62		rela = (const GElf_Rela *)reldata;
63		where = (char *)dest + (relbase + rela->r_offset - dataoff);
64		addend = rela->r_addend;
65		rtype = GELF_R_TYPE(rela->r_info);
66		symidx = GELF_R_SYM(rela->r_info);
67		break;
68	default:
69		return (EINVAL);
70	}
71
72	if (where < (char *)dest || where >= (char *)dest + len)
73		return (0);
74
75	if (reltype == ELF_T_REL) {
76		/* Addend is 32 bit on 32 bit relocs */
77		switch (rtype) {
78		case R_X86_64_PC32:
79		case R_X86_64_32S:
80			addend = le32dec(where);
81			break;
82		default:
83			addend = le64dec(where);
84			break;
85		}
86	}
87
88	switch (rtype) {
89	case R_X86_64_NONE:	/* none */
90		break;
91	case R_X86_64_64:	/* S + A */
92		addr = EF_SYMADDR(ef, symidx) + addend;
93		le64enc(where, addr);
94		break;
95	case R_X86_64_32S:	/* S + A sign extend */
96		addr = EF_SYMADDR(ef, symidx) + addend;
97		le32enc(where, addr);
98		break;
99	case R_X86_64_GLOB_DAT:	/* S */
100		addr = EF_SYMADDR(ef, symidx);
101		le64enc(where, addr);
102		break;
103	case R_X86_64_RELATIVE:	/* B + A */
104		addr = relbase + addend;
105		le64enc(where, addr);
106		break;
107	default:
108		warnx("unhandled relocation type %d", (int)rtype);
109	}
110	return (0);
111}
112
113ELF_RELOC(ELFCLASS64, ELFDATA2LSB, EM_X86_64, ef_amd64_reloc);
114