1/*-
2 * Copyright (c) 2003 Jake Burkholder.
3 * Copyright 1996-1998 John D. Polstra.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 */
29
30#include <sys/types.h>
31#include <machine/elf.h>
32
33#include <err.h>
34#include <errno.h>
35
36#include "ef.h"
37
38/*
39 * Apply relocations to the values we got from the file. `relbase' is the
40 * target relocation address of the section, and `dataoff' is the target
41 * relocation address of the data in `dest'.
42 */
43int
44ef_reloc(struct elf_file *ef, const void *reldata, int reltype, Elf_Off relbase,
45    Elf_Off dataoff, size_t len, void *dest)
46{
47	Elf64_Addr *where, val;
48	Elf32_Addr *where32, val32;
49	Elf_Addr addend, addr;
50	Elf_Size rtype, symidx;
51	const Elf_Rel *rel;
52	const Elf_Rela *rela;
53
54	switch (reltype) {
55	case EF_RELOC_REL:
56		rel = (const Elf_Rel *)reldata;
57		where = (Elf_Addr *)(dest + relbase + rel->r_offset - dataoff);
58		addend = 0;
59		rtype = ELF_R_TYPE(rel->r_info);
60		symidx = ELF_R_SYM(rel->r_info);
61		break;
62	case EF_RELOC_RELA:
63		rela = (const Elf_Rela *)reldata;
64		where = (Elf_Addr *)(dest + relbase + rela->r_offset - dataoff);
65		addend = rela->r_addend;
66		rtype = ELF_R_TYPE(rela->r_info);
67		symidx = ELF_R_SYM(rela->r_info);
68		break;
69	default:
70		return (EINVAL);
71	}
72
73	if ((char *)where < (char *)dest || (char *)where >= (char *)dest + len)
74		return (0);
75
76	if (reltype == EF_RELOC_REL) {
77		/* Addend is 32 bit on 32 bit relocs */
78		switch (rtype) {
79		case R_X86_64_PC32:
80		case R_X86_64_32S:
81			addend = *(Elf32_Addr *)where;
82			break;
83		default:
84			addend = *where;
85			break;
86		}
87	}
88
89	switch (rtype) {
90	case R_X86_64_NONE:	/* none */
91		break;
92	case R_X86_64_64:	/* S + A */
93		addr = EF_SYMADDR(ef, symidx);
94		val = addr + addend;
95		*where = val;
96		break;
97	case R_X86_64_32S:	/* S + A sign extend */
98		addr = EF_SYMADDR(ef, symidx);
99		val32 = (Elf32_Addr)(addr + addend);
100		where32 = (Elf32_Addr *)where;
101		*where32 = val32;
102		break;
103	case R_X86_64_GLOB_DAT:	/* S */
104		addr = EF_SYMADDR(ef, symidx);
105		*where = addr;
106		break;
107	case R_X86_64_RELATIVE:	/* B + A */
108		addr = (Elf_Addr)addend + relbase;
109		val = addr;
110		*where = val;
111		break;
112	default:
113		warnx("unhandled relocation type %d", (int)rtype);
114	}
115	return (0);
116}
117