1 /* $NetBSD: self_reloc.c,v 1.1 2017/01/24 11:09:14 nonaka Exp $ */
2
3 /*-
4 * Copyright (c) 2008-2010 Rui Paulo <rpaulo@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/types.h>
30 #include <sys/exec_elf.h>
31
32 #include <efi.h>
33
34 void self_reloc(Elf_Addr, Elf_Dyn *);
35
36 #if defined(__aarch64__)
37 #define USE_RELA
38 #endif
39
40 /*
41 * A simple elf relocator.
42 */
43 void
self_reloc(Elf_Addr baseaddr,Elf_Dyn * dynamic)44 self_reloc(Elf_Addr baseaddr, Elf_Dyn *dynamic)
45 {
46 Elf_Word relsz, relent;
47 Elf_Addr *newaddr;
48 Elf_Rel *rel = NULL;
49 Elf_Dyn *dynp;
50
51 /*
52 * Find the relocation address, its size and the relocation entry.
53 */
54 relsz = 0;
55 relent = 0;
56 for (dynp = dynamic; dynp->d_tag != DT_NULL; dynp++) {
57 switch (dynp->d_tag) {
58 case DT_REL:
59 case DT_RELA:
60 rel = (Elf_Rel *)(dynp->d_un.d_ptr + baseaddr);
61 break;
62 case DT_RELSZ:
63 case DT_RELASZ:
64 relsz = dynp->d_un.d_val;
65 break;
66 case DT_RELENT:
67 case DT_RELAENT:
68 relent = dynp->d_un.d_val;
69 break;
70 default:
71 break;
72 }
73 }
74
75 /*
76 * Perform the actual relocation.
77 */
78 for (; relsz > 0; relsz -= relent) {
79 switch (ELF_R_TYPE(rel->r_info)) {
80 case R_TYPE(NONE):
81 /* No relocation needs be performed. */
82 break;
83
84 case R_TYPE(RELATIVE):
85 /* Address relative to the base address. */
86 newaddr = (Elf_Addr *)(rel->r_offset + baseaddr);
87 *newaddr += baseaddr;
88 #ifdef USE_RELA
89 /* Add the addend when the ABI uses them */
90 *newaddr += ((Elf_Rela *)rel)->r_addend;
91 #endif
92 break;
93 default:
94 /* XXX: do we need other relocations ? */
95 break;
96 }
97 rel = (Elf_Rel *) ((char *) rel + relent);
98 }
99 }
100