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 */
43 int
ef_reloc(struct elf_file * ef,const void * reldata,int reltype,Elf_Off relbase,Elf_Off dataoff,size_t len,void * _dest)44 ef_reloc(struct elf_file *ef, const void *reldata, int reltype, Elf_Off relbase,
45 Elf_Off dataoff, size_t len, void *_dest)
46 {
47 Elf_Addr *where, addr, addend;
48 Elf_Size rtype, symidx;
49 const Elf_Rel *rel;
50 const Elf_Rela *rela;
51 char *dest = _dest;
52
53 switch (reltype) {
54 case EF_RELOC_REL:
55 rel = (const Elf_Rel *)reldata;
56 where = (Elf_Addr *)(dest + relbase + rel->r_offset - dataoff);
57 addend = 0;
58 rtype = ELF_R_TYPE(rel->r_info);
59 symidx = ELF_R_SYM(rel->r_info);
60 break;
61 case EF_RELOC_RELA:
62 rela = (const Elf_Rela *)reldata;
63 where = (Elf_Addr *)(dest + relbase + rela->r_offset - dataoff);
64 addend = rela->r_addend;
65 rtype = ELF_R_TYPE(rela->r_info);
66 symidx = ELF_R_SYM(rela->r_info);
67 break;
68 default:
69 return (EINVAL);
70 }
71
72 if ((char *)where < (char *)dest || (char *)where >= (char *)dest + len)
73 return (0);
74
75 if (reltype == EF_RELOC_REL)
76 addend = *where;
77
78 switch (rtype) {
79 case R_386_RELATIVE: /* A + B */
80 addr = (Elf_Addr)addend + relbase;
81 *where = addr;
82 break;
83 case R_386_32: /* S + A - P */
84 addr = EF_SYMADDR(ef, symidx);
85 addr += addend;
86 *where = addr;
87 break;
88 case R_386_GLOB_DAT: /* S */
89 addr = EF_SYMADDR(ef, symidx);
90 *where = addr;
91 break;
92 default:
93 warnx("unhandled relocation type %d", (int)rtype);
94 }
95 return (0);
96 }
97