diff options
Diffstat (limited to 'arch/mips/kernel/module-elf32.c')
-rw-r--r-- | arch/mips/kernel/module-elf32.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/arch/mips/kernel/module-elf32.c b/arch/mips/kernel/module-elf32.c new file mode 100644 index 000000000000..ffd216d6d6dc --- /dev/null +++ b/arch/mips/kernel/module-elf32.c | |||
@@ -0,0 +1,250 @@ | |||
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 | */ | ||
19 | |||
20 | #undef DEBUG | ||
21 | |||
22 | #include <linux/moduleloader.h> | ||
23 | #include <linux/elf.h> | ||
24 | #include <linux/vmalloc.h> | ||
25 | #include <linux/slab.h> | ||
26 | #include <linux/fs.h> | ||
27 | #include <linux/string.h> | ||
28 | #include <linux/kernel.h> | ||
29 | |||
30 | struct mips_hi16 { | ||
31 | struct mips_hi16 *next; | ||
32 | Elf32_Addr *addr; | ||
33 | Elf32_Addr value; | ||
34 | }; | ||
35 | |||
36 | static struct mips_hi16 *mips_hi16_list; | ||
37 | |||
38 | void *module_alloc(unsigned long size) | ||
39 | { | ||
40 | if (size == 0) | ||
41 | return NULL; | ||
42 | return vmalloc(size); | ||
43 | } | ||
44 | |||
45 | |||
46 | /* Free memory returned from module_alloc */ | ||
47 | void module_free(struct module *mod, void *module_region) | ||
48 | { | ||
49 | vfree(module_region); | ||
50 | /* FIXME: If module_region == mod->init_region, trim exception | ||
51 | table entries. */ | ||
52 | } | ||
53 | |||
54 | int module_frob_arch_sections(Elf_Ehdr *hdr, | ||
55 | Elf_Shdr *sechdrs, | ||
56 | char *secstrings, | ||
57 | struct module *mod) | ||
58 | { | ||
59 | return 0; | ||
60 | } | ||
61 | |||
62 | static int apply_r_mips_none(struct module *me, uint32_t *location, | ||
63 | Elf32_Addr v) | ||
64 | { | ||
65 | return 0; | ||
66 | } | ||
67 | |||
68 | static int apply_r_mips_32(struct module *me, uint32_t *location, | ||
69 | Elf32_Addr v) | ||
70 | { | ||
71 | *location += v; | ||
72 | |||
73 | return 0; | ||
74 | } | ||
75 | |||
76 | static int apply_r_mips_26(struct module *me, uint32_t *location, | ||
77 | Elf32_Addr v) | ||
78 | { | ||
79 | if (v % 4) { | ||
80 | printk(KERN_ERR "module %s: dangerous relocation\n", me->name); | ||
81 | return -ENOEXEC; | ||
82 | } | ||
83 | |||
84 | if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { | ||
85 | printk(KERN_ERR | ||
86 | "module %s: relocation overflow\n", | ||
87 | me->name); | ||
88 | return -ENOEXEC; | ||
89 | } | ||
90 | |||
91 | *location = (*location & ~0x03ffffff) | | ||
92 | ((*location + (v >> 2)) & 0x03ffffff); | ||
93 | |||
94 | return 0; | ||
95 | } | ||
96 | |||
97 | static int apply_r_mips_hi16(struct module *me, uint32_t *location, | ||
98 | Elf32_Addr v) | ||
99 | { | ||
100 | struct mips_hi16 *n; | ||
101 | |||
102 | /* | ||
103 | * We cannot relocate this one now because we don't know the value of | ||
104 | * the carry we need to add. Save the information, and let LO16 do the | ||
105 | * actual relocation. | ||
106 | */ | ||
107 | n = kmalloc(sizeof *n, GFP_KERNEL); | ||
108 | if (!n) | ||
109 | return -ENOMEM; | ||
110 | |||
111 | n->addr = location; | ||
112 | n->value = v; | ||
113 | n->next = mips_hi16_list; | ||
114 | mips_hi16_list = n; | ||
115 | |||
116 | return 0; | ||
117 | } | ||
118 | |||
119 | static int apply_r_mips_lo16(struct module *me, uint32_t *location, | ||
120 | Elf32_Addr v) | ||
121 | { | ||
122 | unsigned long insnlo = *location; | ||
123 | Elf32_Addr val, vallo; | ||
124 | |||
125 | /* Sign extend the addend we extract from the lo insn. */ | ||
126 | vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000; | ||
127 | |||
128 | if (mips_hi16_list != NULL) { | ||
129 | struct mips_hi16 *l; | ||
130 | |||
131 | l = mips_hi16_list; | ||
132 | while (l != NULL) { | ||
133 | struct mips_hi16 *next; | ||
134 | unsigned long insn; | ||
135 | |||
136 | /* | ||
137 | * The value for the HI16 had best be the same. | ||
138 | */ | ||
139 | if (v != l->value) | ||
140 | goto out_danger; | ||
141 | |||
142 | /* | ||
143 | * Do the HI16 relocation. Note that we actually don't | ||
144 | * need to know anything about the LO16 itself, except | ||
145 | * where to find the low 16 bits of the addend needed | ||
146 | * by the LO16. | ||
147 | */ | ||
148 | insn = *l->addr; | ||
149 | val = ((insn & 0xffff) << 16) + vallo; | ||
150 | val += v; | ||
151 | |||
152 | /* | ||
153 | * Account for the sign extension that will happen in | ||
154 | * the low bits. | ||
155 | */ | ||
156 | val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff; | ||
157 | |||
158 | insn = (insn & ~0xffff) | val; | ||
159 | *l->addr = insn; | ||
160 | |||
161 | next = l->next; | ||
162 | kfree(l); | ||
163 | l = next; | ||
164 | } | ||
165 | |||
166 | mips_hi16_list = NULL; | ||
167 | } | ||
168 | |||
169 | /* | ||
170 | * Ok, we're done with the HI16 relocs. Now deal with the LO16. | ||
171 | */ | ||
172 | val = v + vallo; | ||
173 | insnlo = (insnlo & ~0xffff) | (val & 0xffff); | ||
174 | *location = insnlo; | ||
175 | |||
176 | return 0; | ||
177 | |||
178 | out_danger: | ||
179 | printk(KERN_ERR "module %s: dangerous " "relocation\n", me->name); | ||
180 | |||
181 | return -ENOEXEC; | ||
182 | } | ||
183 | |||
184 | static int (*reloc_handlers[]) (struct module *me, uint32_t *location, | ||
185 | Elf32_Addr v) = { | ||
186 | [R_MIPS_NONE] = apply_r_mips_none, | ||
187 | [R_MIPS_32] = apply_r_mips_32, | ||
188 | [R_MIPS_26] = apply_r_mips_26, | ||
189 | [R_MIPS_HI16] = apply_r_mips_hi16, | ||
190 | [R_MIPS_LO16] = apply_r_mips_lo16 | ||
191 | }; | ||
192 | |||
193 | int apply_relocate(Elf32_Shdr *sechdrs, | ||
194 | const char *strtab, | ||
195 | unsigned int symindex, | ||
196 | unsigned int relsec, | ||
197 | struct module *me) | ||
198 | { | ||
199 | Elf32_Rel *rel = (void *) sechdrs[relsec].sh_addr; | ||
200 | Elf32_Sym *sym; | ||
201 | uint32_t *location; | ||
202 | unsigned int i; | ||
203 | Elf32_Addr v; | ||
204 | int res; | ||
205 | |||
206 | pr_debug("Applying relocate section %u to %u\n", relsec, | ||
207 | sechdrs[relsec].sh_info); | ||
208 | |||
209 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { | ||
210 | Elf32_Word r_info = rel[i].r_info; | ||
211 | |||
212 | /* This is where to make the change */ | ||
213 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | ||
214 | + rel[i].r_offset; | ||
215 | /* This is the symbol it is referring to */ | ||
216 | sym = (Elf32_Sym *)sechdrs[symindex].sh_addr | ||
217 | + ELF32_R_SYM(r_info); | ||
218 | if (!sym->st_value) { | ||
219 | printk(KERN_WARNING "%s: Unknown symbol %s\n", | ||
220 | me->name, strtab + sym->st_name); | ||
221 | return -ENOENT; | ||
222 | } | ||
223 | |||
224 | v = sym->st_value; | ||
225 | |||
226 | res = reloc_handlers[ELF32_R_TYPE(r_info)](me, location, v); | ||
227 | if (res) | ||
228 | return res; | ||
229 | } | ||
230 | |||
231 | return 0; | ||
232 | } | ||
233 | |||
234 | int apply_relocate_add(Elf32_Shdr *sechdrs, | ||
235 | const char *strtab, | ||
236 | unsigned int symindex, | ||
237 | unsigned int relsec, | ||
238 | struct module *me) | ||
239 | { | ||
240 | /* | ||
241 | * Current binutils always generate .rela relocations. Keep smiling | ||
242 | * if it's empty, abort otherwise. | ||
243 | */ | ||
244 | if (!sechdrs[relsec].sh_size) | ||
245 | return 0; | ||
246 | |||
247 | printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n", | ||
248 | me->name); | ||
249 | return -ENOEXEC; | ||
250 | } | ||