xref: /illumos-gate/usr/src/boot/common/reloc_elf.c (revision ed093b41a93e8563e6e1e5dae0768dda2a7bcc27)
1 /*-
2  * Copyright (c) 2003 Jake Burkholder.
3  * Copyright 1996-1998 John D. Polstra.
4  * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
5  * Copyright (c) 1998 Peter Wemm <peter@freebsd.org>
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/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/types.h>
34 #include <machine/elf.h>
35 
36 #include <stand.h>
37 
38 #define FREEBSD_ELF
39 #include <link.h>
40 
41 #include "bootstrap.h"
42 
43 #define COPYOUT(s,d,l)	archsw.arch_copyout((vm_offset_t)(s), d, l)
44 
45 /*
46  * Apply a single intra-module relocation to the data. `relbase' is the
47  * target relocation base for the section (i.e. it corresponds to where
48  * r_offset == 0). `dataaddr' is the relocated address corresponding to
49  * the start of the data, and `len' is the number of bytes.
50  */
51 int
52 __elfN(reloc)(struct elf_file *ef, symaddr_fn *symaddr, const void *reldata,
53     int reltype, Elf_Addr relbase, Elf_Addr dataaddr, void *data, size_t len)
54 {
55 #ifdef __sparc__
56 	Elf_Size w;
57 	const Elf_Rela *a;
58 
59 	switch (reltype) {
60 	case ELF_RELOC_RELA:
61 		a = reldata;
62 		 if (relbase + a->r_offset >= dataaddr &&
63 		     relbase + a->r_offset < dataaddr + len) {
64 			switch (ELF_R_TYPE(a->r_info)) {
65 			case R_SPARC_RELATIVE:
66 				w = relbase + a->r_addend;
67 				bcopy(&w, (u_char *)data + (relbase +
68 				    a->r_offset - dataaddr), sizeof(w));
69 				break;
70 			default:
71 				printf("\nunhandled relocation type %u\n",
72 				    (u_int)ELF_R_TYPE(a->r_info));
73 				return (EFTYPE);
74 			}
75 		}
76 		break;
77 	}
78 
79 	return (0);
80 #elif (defined(__i386__) || defined(__amd64__)) && __ELF_WORD_SIZE == 64
81 	Elf64_Addr *where, val;
82 	Elf_Addr addend, addr;
83 	Elf_Size rtype, symidx;
84 	const Elf_Rel *rel;
85 	const Elf_Rela *rela;
86 
87 	switch (reltype) {
88 	case ELF_RELOC_REL:
89 		rel = (const Elf_Rel *)reldata;
90 		where = (Elf_Addr *)((char *)data + relbase + rel->r_offset -
91 		    dataaddr);
92 		addend = 0;
93 		rtype = ELF_R_TYPE(rel->r_info);
94 		symidx = ELF_R_SYM(rel->r_info);
95 		addend = 0;
96 		break;
97 	case ELF_RELOC_RELA:
98 		rela = (const Elf_Rela *)reldata;
99 		where = (Elf_Addr *)((char *)data + relbase + rela->r_offset -
100 		    dataaddr);
101 		addend = rela->r_addend;
102 		rtype = ELF_R_TYPE(rela->r_info);
103 		symidx = ELF_R_SYM(rela->r_info);
104 		break;
105 	default:
106 		return (EINVAL);
107 	}
108 
109 	if ((char *)where < (char *)data || (char *)where >= (char *)data + len)
110 		return (0);
111 
112 	if (reltype == ELF_RELOC_REL)
113 		addend = *where;
114 
115 /* XXX, definitions not available on i386. */
116 #define	R_X86_64_64		1
117 #define	R_X86_64_RELATIVE	8
118 
119 	switch (rtype) {
120 	case R_X86_64_64:		/* S + A */
121 		addr = symaddr(ef, symidx);
122 		if (addr == 0)
123 			return (ESRCH);
124 		val = addr + addend;
125 		*where = val;
126 		break;
127 	case R_X86_64_RELATIVE:
128 		addr = (Elf_Addr)addend + relbase;
129 		val = addr;
130 		*where = val;
131 		break;
132 	default:
133 		printf("\nunhandled relocation type %u\n", (u_int)rtype);
134 		return (EFTYPE);
135 	}
136 
137 	return (0);
138 #elif defined(__i386__) && __ELF_WORD_SIZE == 32
139 	Elf_Addr addend, addr, *where, val;
140 	Elf_Size rtype, symidx;
141 	const Elf_Rel *rel;
142 	const Elf_Rela *rela;
143 
144 	switch (reltype) {
145 	case ELF_RELOC_REL:
146 		rel = (const Elf_Rel *)reldata;
147 		where = (Elf_Addr *)((char *)data + relbase + rel->r_offset -
148 		    dataaddr);
149 		addend = 0;
150 		rtype = ELF_R_TYPE(rel->r_info);
151 		symidx = ELF_R_SYM(rel->r_info);
152 		addend = 0;
153 		break;
154 	case ELF_RELOC_RELA:
155 		rela = (const Elf_Rela *)reldata;
156 		where = (Elf_Addr *)((char *)data + relbase + rela->r_offset -
157 		    dataaddr);
158 		addend = rela->r_addend;
159 		rtype = ELF_R_TYPE(rela->r_info);
160 		symidx = ELF_R_SYM(rela->r_info);
161 		break;
162 	default:
163 		return (EINVAL);
164 	}
165 
166 	if ((char *)where < (char *)data || (char *)where >= (char *)data + len)
167 		return (0);
168 
169 	if (reltype == ELF_RELOC_REL)
170 		addend = *where;
171 
172 /* XXX, definitions not available on amd64. */
173 #define R_386_32	1	/* Add symbol value. */
174 #define R_386_GLOB_DAT	6	/* Set GOT entry to data address. */
175 #define R_386_RELATIVE	8	/* Add load address of shared object. */
176 
177 	switch (rtype) {
178 	case R_386_RELATIVE:
179 		addr = addend + relbase;
180 		*where = addr;
181 		break;
182 	case R_386_32:		/* S + A */
183 		addr = symaddr(ef, symidx);
184 		if (addr == 0)
185 			return (ESRCH);
186 		val = addr + addend;
187 		*where = val;
188 		break;
189 	default:
190 		printf("\nunhandled relocation type %u\n", (u_int)rtype);
191 		return (EFTYPE);
192 	}
193 
194 	return (0);
195 #elif defined(__powerpc__)
196 	Elf_Size w;
197 	const Elf_Rela *rela;
198 
199 	switch (reltype) {
200 	case ELF_RELOC_RELA:
201 		rela = reldata;
202 		if (relbase + rela->r_offset >= dataaddr &&
203 		    relbase + rela->r_offset < dataaddr + len) {
204 			switch (ELF_R_TYPE(rela->r_info)) {
205 			case R_PPC_RELATIVE:
206 				w = relbase + rela->r_addend;
207 				bcopy(&w, (u_char *)data + (relbase +
208 				      rela->r_offset - dataaddr), sizeof(w));
209 				break;
210 			default:
211 				printf("\nunhandled relocation type %u\n",
212 				       (u_int)ELF_R_TYPE(rela->r_info));
213 				return (EFTYPE);
214 			}
215 		}
216 		break;
217 	}
218 
219 	return (0);
220 #else
221 	(void)ef;
222 	(void)symaddr;
223 	(void)reldata;
224 	(void)reltype;
225 	(void)relbase;
226 	(void)dataaddr;
227 	(void)data;
228 	(void)len;
229 	return (EOPNOTSUPP);
230 #endif
231 }
232