xref: /freebsd/stand/common/reloc_elf.c (revision 4928135658a9d0eaee37003df6137ab363fcb0b4)
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 <sys/link_elf.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 #define	R_X86_64_IRELATIVE	37
119 
120 	switch (rtype) {
121 	case R_X86_64_64:		/* S + A */
122 		addr = symaddr(ef, symidx);
123 		if (addr == 0)
124 			return (ESRCH);
125 		val = addr + addend;
126 		*where = val;
127 		break;
128 	case R_X86_64_RELATIVE:
129 		addr = (Elf_Addr)addend + relbase;
130 		val = addr;
131 		*where = val;
132 		break;
133 	case R_X86_64_IRELATIVE:
134 		/* leave it to kernel */
135 		break;
136 	default:
137 		printf("\nunhandled relocation type %u\n", (u_int)rtype);
138 		return (EFTYPE);
139 	}
140 
141 	return (0);
142 #elif defined(__i386__) && __ELF_WORD_SIZE == 32
143 	Elf_Addr addend, addr, *where, val;
144 	Elf_Size rtype, symidx;
145 	const Elf_Rel *rel;
146 	const Elf_Rela *rela;
147 
148 	switch (reltype) {
149 	case ELF_RELOC_REL:
150 		rel = (const Elf_Rel *)reldata;
151 		where = (Elf_Addr *)((char *)data + relbase + rel->r_offset -
152 		    dataaddr);
153 		addend = 0;
154 		rtype = ELF_R_TYPE(rel->r_info);
155 		symidx = ELF_R_SYM(rel->r_info);
156 		addend = 0;
157 		break;
158 	case ELF_RELOC_RELA:
159 		rela = (const Elf_Rela *)reldata;
160 		where = (Elf_Addr *)((char *)data + relbase + rela->r_offset -
161 		    dataaddr);
162 		addend = rela->r_addend;
163 		rtype = ELF_R_TYPE(rela->r_info);
164 		symidx = ELF_R_SYM(rela->r_info);
165 		break;
166 	default:
167 		return (EINVAL);
168 	}
169 
170 	if ((char *)where < (char *)data || (char *)where >= (char *)data + len)
171 		return (0);
172 
173 	if (reltype == ELF_RELOC_REL)
174 		addend = *where;
175 
176 /* XXX, definitions not available on amd64. */
177 #define R_386_32	1	/* Add symbol value. */
178 #define R_386_GLOB_DAT	6	/* Set GOT entry to data address. */
179 #define R_386_RELATIVE	8	/* Add load address of shared object. */
180 #define	R_386_IRELATIVE	42
181 
182 	switch (rtype) {
183 	case R_386_RELATIVE:
184 		addr = addend + relbase;
185 		*where = addr;
186 		break;
187 	case R_386_32:		/* S + A */
188 		addr = symaddr(ef, symidx);
189 		if (addr == 0)
190 			return (ESRCH);
191 		val = addr + addend;
192 		*where = val;
193 		break;
194 	case R_386_IRELATIVE:
195 		/* leave it to kernel */
196 		break;
197 	default:
198 		printf("\nunhandled relocation type %u\n", (u_int)rtype);
199 		return (EFTYPE);
200 	}
201 
202 	return (0);
203 #elif defined(__powerpc__)
204 	Elf_Size w;
205 	const Elf_Rela *rela;
206 
207 	switch (reltype) {
208 	case ELF_RELOC_RELA:
209 		rela = reldata;
210 		if (relbase + rela->r_offset >= dataaddr &&
211 		    relbase + rela->r_offset < dataaddr + len) {
212 			switch (ELF_R_TYPE(rela->r_info)) {
213 			case R_PPC_RELATIVE:
214 				w = relbase + rela->r_addend;
215 				bcopy(&w, (u_char *)data + (relbase +
216 				      rela->r_offset - dataaddr), sizeof(w));
217 				break;
218 			default:
219 				printf("\nunhandled relocation type %u\n",
220 				       (u_int)ELF_R_TYPE(rela->r_info));
221 				return (EFTYPE);
222 			}
223 		}
224 		break;
225 	}
226 
227 	return (0);
228 #else
229 	return (EOPNOTSUPP);
230 #endif
231 }
232