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4e6a05fe TS |
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 | #undef DEBUG | |
22 | ||
23 | #include <linux/moduleloader.h> | |
24 | #include <linux/elf.h> | |
25 | #include <linux/vmalloc.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/fs.h> | |
28 | #include <linux/string.h> | |
29 | #include <linux/kernel.h> | |
1da177e4 LT |
30 | #include <linux/module.h> |
31 | #include <linux/spinlock.h> | |
32 | ||
4e6a05fe TS |
33 | struct mips_hi16 { |
34 | struct mips_hi16 *next; | |
35 | Elf_Addr *addr; | |
36 | Elf_Addr value; | |
37 | }; | |
38 | ||
39 | static struct mips_hi16 *mips_hi16_list; | |
40 | ||
1da177e4 LT |
41 | static LIST_HEAD(dbe_list); |
42 | static DEFINE_SPINLOCK(dbe_lock); | |
43 | ||
4e6a05fe TS |
44 | void *module_alloc(unsigned long size) |
45 | { | |
46 | if (size == 0) | |
47 | return NULL; | |
48 | return vmalloc(size); | |
49 | } | |
50 | ||
51 | /* Free memory returned from module_alloc */ | |
52 | void module_free(struct module *mod, void *module_region) | |
53 | { | |
54 | vfree(module_region); | |
55 | /* FIXME: If module_region == mod->init_region, trim exception | |
56 | table entries. */ | |
57 | } | |
58 | ||
59 | int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, | |
60 | char *secstrings, struct module *mod) | |
61 | { | |
62 | return 0; | |
63 | } | |
64 | ||
65 | static int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v) | |
66 | { | |
67 | return 0; | |
68 | } | |
69 | ||
70 | static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v) | |
71 | { | |
72 | *location += v; | |
73 | ||
74 | return 0; | |
75 | } | |
76 | ||
77 | static int apply_r_mips_32_rela(struct module *me, u32 *location, Elf_Addr v) | |
78 | { | |
79 | *location = v; | |
80 | ||
81 | return 0; | |
82 | } | |
83 | ||
84 | static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v) | |
85 | { | |
86 | if (v % 4) { | |
87 | printk(KERN_ERR "module %s: dangerous relocation\n", me->name); | |
88 | return -ENOEXEC; | |
89 | } | |
90 | ||
91 | if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { | |
92 | printk(KERN_ERR | |
93 | "module %s: relocation overflow\n", | |
94 | me->name); | |
95 | return -ENOEXEC; | |
96 | } | |
97 | ||
98 | *location = (*location & ~0x03ffffff) | | |
99 | ((*location + (v >> 2)) & 0x03ffffff); | |
100 | ||
101 | return 0; | |
102 | } | |
103 | ||
104 | static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v) | |
105 | { | |
106 | if (v % 4) { | |
107 | printk(KERN_ERR "module %s: dangerous relocation\n", me->name); | |
108 | return -ENOEXEC; | |
109 | } | |
110 | ||
111 | if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { | |
112 | printk(KERN_ERR | |
113 | "module %s: relocation overflow\n", | |
114 | me->name); | |
115 | return -ENOEXEC; | |
116 | } | |
117 | ||
118 | *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff); | |
119 | ||
120 | return 0; | |
121 | } | |
122 | ||
123 | static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v) | |
124 | { | |
125 | struct mips_hi16 *n; | |
126 | ||
127 | /* | |
128 | * We cannot relocate this one now because we don't know the value of | |
129 | * the carry we need to add. Save the information, and let LO16 do the | |
130 | * actual relocation. | |
131 | */ | |
132 | n = kmalloc(sizeof *n, GFP_KERNEL); | |
133 | if (!n) | |
134 | return -ENOMEM; | |
135 | ||
136 | n->addr = (Elf_Addr *)location; | |
137 | n->value = v; | |
138 | n->next = mips_hi16_list; | |
139 | mips_hi16_list = n; | |
140 | ||
141 | return 0; | |
142 | } | |
143 | ||
144 | static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v) | |
145 | { | |
146 | *location = (*location & 0xffff0000) | | |
147 | ((((long long) v + 0x8000LL) >> 16) & 0xffff); | |
148 | ||
149 | return 0; | |
150 | } | |
151 | ||
152 | static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v) | |
153 | { | |
154 | unsigned long insnlo = *location; | |
155 | Elf_Addr val, vallo; | |
156 | ||
157 | /* Sign extend the addend we extract from the lo insn. */ | |
158 | vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000; | |
159 | ||
160 | if (mips_hi16_list != NULL) { | |
161 | struct mips_hi16 *l; | |
162 | ||
163 | l = mips_hi16_list; | |
164 | while (l != NULL) { | |
165 | struct mips_hi16 *next; | |
166 | unsigned long insn; | |
167 | ||
168 | /* | |
169 | * The value for the HI16 had best be the same. | |
170 | */ | |
171 | if (v != l->value) | |
172 | goto out_danger; | |
173 | ||
174 | /* | |
175 | * Do the HI16 relocation. Note that we actually don't | |
176 | * need to know anything about the LO16 itself, except | |
177 | * where to find the low 16 bits of the addend needed | |
178 | * by the LO16. | |
179 | */ | |
180 | insn = *l->addr; | |
181 | val = ((insn & 0xffff) << 16) + vallo; | |
182 | val += v; | |
183 | ||
184 | /* | |
185 | * Account for the sign extension that will happen in | |
186 | * the low bits. | |
187 | */ | |
188 | val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff; | |
189 | ||
190 | insn = (insn & ~0xffff) | val; | |
191 | *l->addr = insn; | |
192 | ||
193 | next = l->next; | |
194 | kfree(l); | |
195 | l = next; | |
196 | } | |
197 | ||
198 | mips_hi16_list = NULL; | |
199 | } | |
200 | ||
201 | /* | |
202 | * Ok, we're done with the HI16 relocs. Now deal with the LO16. | |
203 | */ | |
204 | val = v + vallo; | |
205 | insnlo = (insnlo & ~0xffff) | (val & 0xffff); | |
206 | *location = insnlo; | |
207 | ||
208 | return 0; | |
209 | ||
210 | out_danger: | |
211 | printk(KERN_ERR "module %s: dangerous " "relocation\n", me->name); | |
212 | ||
213 | return -ENOEXEC; | |
214 | } | |
215 | ||
216 | static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v) | |
217 | { | |
218 | *location = (*location & 0xffff0000) | (v & 0xffff); | |
219 | ||
220 | return 0; | |
221 | } | |
222 | ||
223 | static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v) | |
224 | { | |
225 | *(Elf_Addr *)location = v; | |
226 | ||
227 | return 0; | |
228 | } | |
229 | ||
230 | static int apply_r_mips_higher_rela(struct module *me, u32 *location, | |
231 | Elf_Addr v) | |
232 | { | |
233 | *location = (*location & 0xffff0000) | | |
234 | ((((long long) v + 0x80008000LL) >> 32) & 0xffff); | |
235 | ||
236 | return 0; | |
237 | } | |
238 | ||
239 | static int apply_r_mips_highest_rela(struct module *me, u32 *location, | |
240 | Elf_Addr v) | |
241 | { | |
242 | *location = (*location & 0xffff0000) | | |
243 | ((((long long) v + 0x800080008000LL) >> 48) & 0xffff); | |
244 | ||
245 | return 0; | |
246 | } | |
247 | ||
248 | static int (*reloc_handlers_rel[]) (struct module *me, u32 *location, | |
249 | Elf_Addr v) = { | |
250 | [R_MIPS_NONE] = apply_r_mips_none, | |
251 | [R_MIPS_32] = apply_r_mips_32_rel, | |
252 | [R_MIPS_26] = apply_r_mips_26_rel, | |
253 | [R_MIPS_HI16] = apply_r_mips_hi16_rel, | |
254 | [R_MIPS_LO16] = apply_r_mips_lo16_rel | |
255 | }; | |
256 | ||
257 | static int (*reloc_handlers_rela[]) (struct module *me, u32 *location, | |
258 | Elf_Addr v) = { | |
259 | [R_MIPS_NONE] = apply_r_mips_none, | |
260 | [R_MIPS_32] = apply_r_mips_32_rela, | |
261 | [R_MIPS_26] = apply_r_mips_26_rela, | |
262 | [R_MIPS_HI16] = apply_r_mips_hi16_rela, | |
263 | [R_MIPS_LO16] = apply_r_mips_lo16_rela, | |
264 | [R_MIPS_64] = apply_r_mips_64_rela, | |
265 | [R_MIPS_HIGHER] = apply_r_mips_higher_rela, | |
266 | [R_MIPS_HIGHEST] = apply_r_mips_highest_rela | |
267 | }; | |
268 | ||
269 | int apply_relocate(Elf_Shdr *sechdrs, const char *strtab, | |
270 | unsigned int symindex, unsigned int relsec, | |
271 | struct module *me) | |
272 | { | |
273 | Elf_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr; | |
274 | Elf_Sym *sym; | |
275 | u32 *location; | |
276 | unsigned int i; | |
277 | Elf_Addr v; | |
278 | int res; | |
279 | ||
280 | pr_debug("Applying relocate section %u to %u\n", relsec, | |
281 | sechdrs[relsec].sh_info); | |
282 | ||
283 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { | |
284 | /* This is where to make the change */ | |
285 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | |
286 | + rel[i].r_offset; | |
287 | /* This is the symbol it is referring to */ | |
288 | sym = (Elf_Sym *)sechdrs[symindex].sh_addr | |
289 | + ELF_MIPS_R_SYM(rel[i]); | |
290 | if (!sym->st_value) { | |
f3bf07b9 AN |
291 | /* Ignore unresolved weak symbol */ |
292 | if (ELF_ST_BIND(sym->st_info) == STB_WEAK) | |
293 | continue; | |
4e6a05fe TS |
294 | printk(KERN_WARNING "%s: Unknown symbol %s\n", |
295 | me->name, strtab + sym->st_name); | |
296 | return -ENOENT; | |
297 | } | |
298 | ||
299 | v = sym->st_value; | |
300 | ||
301 | res = reloc_handlers_rel[ELF_MIPS_R_TYPE(rel[i])](me, location, v); | |
302 | if (res) | |
303 | return res; | |
304 | } | |
305 | ||
306 | return 0; | |
307 | } | |
308 | ||
309 | int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, | |
310 | unsigned int symindex, unsigned int relsec, | |
311 | struct module *me) | |
312 | { | |
313 | Elf_Mips_Rela *rel = (void *) sechdrs[relsec].sh_addr; | |
314 | Elf_Sym *sym; | |
315 | u32 *location; | |
316 | unsigned int i; | |
317 | Elf_Addr v; | |
318 | int res; | |
319 | ||
320 | pr_debug("Applying relocate section %u to %u\n", relsec, | |
321 | sechdrs[relsec].sh_info); | |
322 | ||
323 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { | |
324 | /* This is where to make the change */ | |
325 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | |
326 | + rel[i].r_offset; | |
327 | /* This is the symbol it is referring to */ | |
328 | sym = (Elf_Sym *)sechdrs[symindex].sh_addr | |
329 | + ELF_MIPS_R_SYM(rel[i]); | |
330 | if (!sym->st_value) { | |
f3bf07b9 AN |
331 | /* Ignore unresolved weak symbol */ |
332 | if (ELF_ST_BIND(sym->st_info) == STB_WEAK) | |
333 | continue; | |
4e6a05fe TS |
334 | printk(KERN_WARNING "%s: Unknown symbol %s\n", |
335 | me->name, strtab + sym->st_name); | |
336 | return -ENOENT; | |
337 | } | |
338 | ||
339 | v = sym->st_value + rel[i].r_addend; | |
340 | ||
341 | res = reloc_handlers_rela[ELF_MIPS_R_TYPE(rel[i])](me, location, v); | |
342 | if (res) | |
343 | return res; | |
344 | } | |
345 | ||
346 | return 0; | |
347 | } | |
348 | ||
1da177e4 LT |
349 | /* Given an address, look for it in the module exception tables. */ |
350 | const struct exception_table_entry *search_module_dbetables(unsigned long addr) | |
351 | { | |
352 | unsigned long flags; | |
353 | const struct exception_table_entry *e = NULL; | |
354 | struct mod_arch_specific *dbe; | |
355 | ||
356 | spin_lock_irqsave(&dbe_lock, flags); | |
357 | list_for_each_entry(dbe, &dbe_list, dbe_list) { | |
358 | e = search_extable(dbe->dbe_start, dbe->dbe_end - 1, addr); | |
359 | if (e) | |
360 | break; | |
361 | } | |
362 | spin_unlock_irqrestore(&dbe_lock, flags); | |
363 | ||
364 | /* Now, if we found one, we are running inside it now, hence | |
365 | we cannot unload the module, hence no refcnt needed. */ | |
366 | return e; | |
367 | } | |
368 | ||
369 | /* Put in dbe list if neccessary. */ | |
370 | int module_finalize(const Elf_Ehdr *hdr, | |
371 | const Elf_Shdr *sechdrs, | |
372 | struct module *me) | |
373 | { | |
374 | const Elf_Shdr *s; | |
375 | char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; | |
376 | ||
377 | INIT_LIST_HEAD(&me->arch.dbe_list); | |
378 | for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { | |
379 | if (strcmp("__dbe_table", secstrings + s->sh_name) != 0) | |
380 | continue; | |
381 | me->arch.dbe_start = (void *)s->sh_addr; | |
382 | me->arch.dbe_end = (void *)s->sh_addr + s->sh_size; | |
383 | spin_lock_irq(&dbe_lock); | |
384 | list_add(&me->arch.dbe_list, &dbe_list); | |
385 | spin_unlock_irq(&dbe_lock); | |
386 | } | |
387 | return 0; | |
388 | } | |
389 | ||
390 | void module_arch_cleanup(struct module *mod) | |
391 | { | |
392 | spin_lock_irq(&dbe_lock); | |
393 | list_del(&mod->arch.dbe_list); | |
394 | spin_unlock_irq(&dbe_lock); | |
395 | } |