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/types.h>
31 #include <machine/elf.h>
32
33 #include <stand.h>
34
35 #include <sys/link_elf.h>
36
37 #include "bootstrap.h"
38
39 #define COPYOUT(s,d,l) archsw.arch_copyout((vm_offset_t)(s), d, l)
40
41 /*
42 * Apply a single intra-module relocation to the data. `relbase' is the
43 * target relocation base for the section (i.e. it corresponds to where
44 * r_offset == 0). `dataaddr' is the relocated address corresponding to
45 * the start of the data, and `len' is the number of bytes.
46 */
47 int
__elfN(reloc)48 __elfN(reloc)(struct elf_file *ef, symaddr_fn *symaddr, const void *reldata,
49 int reltype, Elf_Addr relbase, Elf_Addr dataaddr, void *data, size_t len)
50 {
51 #if (defined(__aarch64__) || defined(__amd64__) || defined(__i386__)) && \
52 __ELF_WORD_SIZE == 64
53 Elf64_Addr *where, val;
54 Elf_Addr addend, addr;
55 Elf_Size rtype;
56 #if defined(__amd64__) || defined(__i386__)
57 Elf_Size symidx;
58 #endif
59 const Elf_Rel *rel;
60 const Elf_Rela *rela;
61
62 switch (reltype) {
63 case ELF_RELOC_REL:
64 rel = (const Elf_Rel *)reldata;
65 where = (Elf_Addr *)((char *)data + relbase + rel->r_offset -
66 dataaddr);
67 addend = 0;
68 rtype = ELF_R_TYPE(rel->r_info);
69 #if defined(__amd64__) || defined(__i386__)
70 symidx = ELF_R_SYM(rel->r_info);
71 #endif
72 addend = 0;
73 break;
74 case ELF_RELOC_RELA:
75 rela = (const Elf_Rela *)reldata;
76 where = (Elf_Addr *)((char *)data + relbase + rela->r_offset -
77 dataaddr);
78 addend = rela->r_addend;
79 rtype = ELF_R_TYPE(rela->r_info);
80 #if defined(__amd64__) || defined(__i386__)
81 symidx = ELF_R_SYM(rela->r_info);
82 #endif
83 break;
84 default:
85 return (EINVAL);
86 }
87
88 if ((char *)where < (char *)data || (char *)where >= (char *)data + len)
89 return (0);
90
91 if (reltype == ELF_RELOC_REL)
92 addend = *where;
93
94 #if defined(__aarch64__)
95 #define RELOC_RELATIVE R_AARCH64_RELATIVE
96 #define RELOC_IRELATIVE R_AARCH64_IRELATIVE
97 #elif defined(__amd64__) || defined(__i386__)
98 /* XXX, definitions not available on i386. */
99 #define R_X86_64_64 1
100 #define R_X86_64_RELATIVE 8
101 #define R_X86_64_IRELATIVE 37
102
103 #define RELOC_RELATIVE R_X86_64_RELATIVE
104 #define RELOC_IRELATIVE R_X86_64_IRELATIVE
105 #endif
106
107 switch (rtype) {
108 case RELOC_RELATIVE:
109 addr = (Elf_Addr)addend + relbase;
110 val = addr;
111 memcpy(where, &val, sizeof(val));
112 break;
113 case RELOC_IRELATIVE:
114 /* leave it to kernel */
115 break;
116 #if defined(__amd64__) || defined(__i386__)
117 case R_X86_64_64: /* S + A */
118 addr = symaddr(ef, symidx);
119 if (addr == 0)
120 return (ESRCH);
121 val = addr + addend;
122 *where = val;
123 break;
124 #endif
125 default:
126 printf("\nunhandled relocation type %u\n", (u_int)rtype);
127 return (EFTYPE);
128 }
129
130 return (0);
131 #elif defined(__i386__) && __ELF_WORD_SIZE == 32
132 Elf_Addr addend, addr, *where, val;
133 Elf_Size rtype, symidx;
134 const Elf_Rel *rel;
135 const Elf_Rela *rela;
136
137 switch (reltype) {
138 case ELF_RELOC_REL:
139 rel = (const Elf_Rel *)reldata;
140 where = (Elf_Addr *)((char *)data + relbase + rel->r_offset -
141 dataaddr);
142 addend = 0;
143 rtype = ELF_R_TYPE(rel->r_info);
144 symidx = ELF_R_SYM(rel->r_info);
145 addend = 0;
146 break;
147 case ELF_RELOC_RELA:
148 rela = (const Elf_Rela *)reldata;
149 where = (Elf_Addr *)((char *)data + relbase + rela->r_offset -
150 dataaddr);
151 addend = rela->r_addend;
152 rtype = ELF_R_TYPE(rela->r_info);
153 symidx = ELF_R_SYM(rela->r_info);
154 break;
155 default:
156 return (EINVAL);
157 }
158
159 if ((char *)where < (char *)data || (char *)where >= (char *)data + len)
160 return (0);
161
162 if (reltype == ELF_RELOC_REL)
163 addend = *where;
164
165 /* XXX, definitions not available on amd64. */
166 #define R_386_32 1 /* Add symbol value. */
167 #define R_386_GLOB_DAT 6 /* Set GOT entry to data address. */
168 #define R_386_RELATIVE 8 /* Add load address of shared object. */
169 #define R_386_IRELATIVE 42
170
171 switch (rtype) {
172 case R_386_RELATIVE:
173 addr = addend + relbase;
174 *where = addr;
175 break;
176 case R_386_32: /* S + A */
177 addr = symaddr(ef, symidx);
178 if (addr == 0)
179 return (ESRCH);
180 val = addr + addend;
181 *where = val;
182 break;
183 case R_386_IRELATIVE:
184 /* leave it to kernel */
185 break;
186 default:
187 printf("\nunhandled relocation type %u\n", (u_int)rtype);
188 return (EFTYPE);
189 }
190
191 return (0);
192 #elif defined(__powerpc__) || defined(__riscv)
193 Elf_Size w;
194 const Elf_Rela *rela;
195
196 switch (reltype) {
197 case ELF_RELOC_RELA:
198 rela = reldata;
199 if (relbase + rela->r_offset >= dataaddr &&
200 relbase + rela->r_offset < dataaddr + len) {
201 switch (ELF_R_TYPE(rela->r_info)) {
202 #if defined(__powerpc__)
203 case R_PPC_RELATIVE:
204 #elif defined(__riscv)
205 case R_RISCV_RELATIVE:
206 #endif
207 w = relbase + rela->r_addend;
208 bcopy(&w, (u_char *)data + (relbase +
209 rela->r_offset - dataaddr), sizeof(w));
210 break;
211 default:
212 printf("\nunhandled relocation type %u\n",
213 (u_int)ELF_R_TYPE(rela->r_info));
214 return (EFTYPE);
215 }
216 }
217 break;
218 }
219
220 return (0);
221 #else
222 return (EOPNOTSUPP);
223 #endif
224 }
225