1 /*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
15 *
16 * Copyright (C) 2001 Rusty Russell.
17 * Copyright (C) 2003, 2004 Ralf Baechle (ralf@linux-mips.org)
18 * Copyright (C) 2005 Thiemo Seufer
19 */
20
21 #include <linux/elf.h>
22 #include <linux/err.h>
23 #include <linux/errno.h>
24 #include <linux/moduleloader.h>
25
26 extern int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v);
27
apply_r_mips_32_rela(struct module * me,u32 * location,Elf_Addr v)28 static int apply_r_mips_32_rela(struct module *me, u32 *location, Elf_Addr v)
29 {
30 *location = v;
31
32 return 0;
33 }
34
apply_r_mips_26_rela(struct module * me,u32 * location,Elf_Addr v)35 static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
36 {
37 if (v % 4) {
38 pr_err("module %s: dangerous R_MIPS_26 RELArelocation\n",
39 me->name);
40 return -ENOEXEC;
41 }
42
43 if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
44 printk(KERN_ERR
45 "module %s: relocation overflow\n",
46 me->name);
47 return -ENOEXEC;
48 }
49
50 *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
51
52 return 0;
53 }
54
apply_r_mips_hi16_rela(struct module * me,u32 * location,Elf_Addr v)55 static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v)
56 {
57 *location = (*location & 0xffff0000) |
58 ((((long long) v + 0x8000LL) >> 16) & 0xffff);
59
60 return 0;
61 }
62
apply_r_mips_lo16_rela(struct module * me,u32 * location,Elf_Addr v)63 static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v)
64 {
65 *location = (*location & 0xffff0000) | (v & 0xffff);
66
67 return 0;
68 }
69
apply_r_mips_64_rela(struct module * me,u32 * location,Elf_Addr v)70 static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v)
71 {
72 *(Elf_Addr *)location = v;
73
74 return 0;
75 }
76
apply_r_mips_higher_rela(struct module * me,u32 * location,Elf_Addr v)77 static int apply_r_mips_higher_rela(struct module *me, u32 *location,
78 Elf_Addr v)
79 {
80 *location = (*location & 0xffff0000) |
81 ((((long long) v + 0x80008000LL) >> 32) & 0xffff);
82
83 return 0;
84 }
85
apply_r_mips_highest_rela(struct module * me,u32 * location,Elf_Addr v)86 static int apply_r_mips_highest_rela(struct module *me, u32 *location,
87 Elf_Addr v)
88 {
89 *location = (*location & 0xffff0000) |
90 ((((long long) v + 0x800080008000LL) >> 48) & 0xffff);
91
92 return 0;
93 }
94
95 static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
96 Elf_Addr v) = {
97 [R_MIPS_NONE] = apply_r_mips_none,
98 [R_MIPS_32] = apply_r_mips_32_rela,
99 [R_MIPS_26] = apply_r_mips_26_rela,
100 [R_MIPS_HI16] = apply_r_mips_hi16_rela,
101 [R_MIPS_LO16] = apply_r_mips_lo16_rela,
102 [R_MIPS_64] = apply_r_mips_64_rela,
103 [R_MIPS_HIGHER] = apply_r_mips_higher_rela,
104 [R_MIPS_HIGHEST] = apply_r_mips_highest_rela
105 };
106
apply_relocate_add(Elf_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)107 int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
108 unsigned int symindex, unsigned int relsec,
109 struct module *me)
110 {
111 Elf_Mips_Rela *rel = (void *) sechdrs[relsec].sh_addr;
112 Elf_Sym *sym;
113 u32 *location;
114 unsigned int i;
115 Elf_Addr v;
116 int res;
117
118 pr_debug("Applying relocate section %u to %u\n", relsec,
119 sechdrs[relsec].sh_info);
120
121 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
122 /* This is where to make the change */
123 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
124 + rel[i].r_offset;
125 /* This is the symbol it is referring to */
126 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
127 + ELF_MIPS_R_SYM(rel[i]);
128 if (IS_ERR_VALUE(sym->st_value)) {
129 /* Ignore unresolved weak symbol */
130 if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
131 continue;
132 printk(KERN_WARNING "%s: Unknown symbol %s\n",
133 me->name, strtab + sym->st_name);
134 return -ENOENT;
135 }
136
137 v = sym->st_value + rel[i].r_addend;
138
139 res = reloc_handlers_rela[ELF_MIPS_R_TYPE(rel[i])](me, location, v);
140 if (res)
141 return res;
142 }
143
144 return 0;
145 }
146