2 * Copyright (c) 2008-2010 Rui Paulo <rpaulo@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 #include <sys/types.h>
30 #include <bootstrap.h>
32 #if defined(__aarch64__) || defined(__amd64__) || defined(__riscv)
33 #define ElfW_Rel Elf64_Rela
34 #define ElfW_Dyn Elf64_Dyn
35 #define ELFW_R_TYPE ELF64_R_TYPE
37 #elif defined(__arm__) || defined(__i386__)
38 #define ElfW_Rel Elf32_Rel
39 #define ElfW_Dyn Elf32_Dyn
40 #define ELFW_R_TYPE ELF32_R_TYPE
42 #error architecture not supported
44 #if defined(__aarch64__)
45 #define RELOC_TYPE_NONE R_AARCH64_NONE
46 #define RELOC_TYPE_RELATIVE R_AARCH64_RELATIVE
47 #elif defined(__amd64__)
48 #define RELOC_TYPE_NONE R_X86_64_NONE
49 #define RELOC_TYPE_RELATIVE R_X86_64_RELATIVE
50 #elif defined(__arm__)
51 #define RELOC_TYPE_NONE R_ARM_NONE
52 #define RELOC_TYPE_RELATIVE R_ARM_RELATIVE
53 #elif defined(__i386__)
54 #define RELOC_TYPE_NONE R_386_NONE
55 #define RELOC_TYPE_RELATIVE R_386_RELATIVE
56 #elif defined(__riscv)
57 #define RELOC_TYPE_NONE R_RISCV_NONE
58 #define RELOC_TYPE_RELATIVE R_RISCV_RELATIVE
61 void self_reloc(Elf_Addr baseaddr, ElfW_Dyn *dynamic);
64 * A simple elf relocator.
67 self_reloc(Elf_Addr baseaddr, ElfW_Dyn *dynamic)
69 Elf_Word relsz, relent;
75 * Find the relocation address, its size and the relocation entry.
79 for (dynp = dynamic; dynp->d_tag != DT_NULL; dynp++) {
80 switch (dynp->d_tag) {
83 rel = (ElfW_Rel *)(dynp->d_un.d_ptr + baseaddr);
87 relsz = dynp->d_un.d_val;
91 relent = dynp->d_un.d_val;
99 * Perform the actual relocation. We rely on the object having been
100 * linked at 0, so that the difference between the load and link
101 * address is the same as the load address.
103 for (; relsz > 0; relsz -= relent) {
104 switch (ELFW_R_TYPE(rel->r_info)) {
105 case RELOC_TYPE_NONE:
106 /* No relocation needs be performed. */
109 case RELOC_TYPE_RELATIVE:
110 newaddr = (Elf_Addr *)(rel->r_offset + baseaddr);
112 /* Addend relative to the base address. */
113 *newaddr = baseaddr + rel->r_addend;
115 /* Address relative to the base address. */
116 *newaddr += baseaddr;
120 /* XXX: do we need other relocations ? */
123 rel = (ElfW_Rel *)(void *)((caddr_t) rel + relent);