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 * Copyright (c) 2023 Jessica Clarke <jrtc27@FreeBSD.org>
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <sys/endian.h>
32
33 #include <err.h>
34 #include <errno.h>
35 #include <gelf.h>
36
37 #include "ef.h"
38
39 /*
40 * Apply relocations to the values obtained from the file. `relbase' is the
41 * target relocation address of the section, and `dataoff/len' is the region
42 * that is to be relocated, and has been copied to *dest
43 */
44 static int
ef_arm_reloc(struct elf_file * ef,const void * reldata,Elf_Type reltype,GElf_Addr relbase,GElf_Addr dataoff,size_t len,void * dest)45 ef_arm_reloc(struct elf_file *ef, const void *reldata, Elf_Type reltype,
46 GElf_Addr relbase, GElf_Addr dataoff, size_t len, void *dest)
47 {
48 char *where;
49 GElf_Addr addr, addend;
50 GElf_Size rtype, symidx;
51 const GElf_Rel *rel;
52 const GElf_Rela *rela;
53
54 switch (reltype) {
55 case ELF_T_REL:
56 rel = (const GElf_Rel *)reldata;
57 where = (char *)dest + (relbase + rel->r_offset - dataoff);
58 addend = 0;
59 rtype = GELF_R_TYPE(rel->r_info);
60 symidx = GELF_R_SYM(rel->r_info);
61 break;
62 case ELF_T_RELA:
63 rela = (const GElf_Rela *)reldata;
64 where = (char *)dest + (relbase + rela->r_offset - dataoff);
65 addend = rela->r_addend;
66 rtype = GELF_R_TYPE(rela->r_info);
67 symidx = GELF_R_SYM(rela->r_info);
68 break;
69 default:
70 return (EINVAL);
71 }
72
73 if (where < (char *)dest || where >= (char *)dest + len)
74 return (0);
75
76 if (reltype == ELF_T_REL)
77 addend = le32dec(where);
78
79 switch (rtype) {
80 case R_ARM_ABS32: /* S + A */
81 addr = EF_SYMADDR(ef, symidx) + addend;
82 le32enc(where, addr);
83 break;
84 case R_ARM_RELATIVE: /* B + A */
85 addr = relbase + addend;
86 le32enc(where, addr);
87 break;
88 default:
89 warnx("unhandled relocation type %d", (int)rtype);
90 }
91 return (0);
92 }
93
94 ELF_RELOC(ELFCLASS32, ELFDATA2LSB, EM_ARM, ef_arm_reloc);
95