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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> | |
27ac792c | 25 | #include <linux/mm.h> |
4e6a05fe TS |
26 | #include <linux/vmalloc.h> |
27 | #include <linux/slab.h> | |
28 | #include <linux/fs.h> | |
29 | #include <linux/string.h> | |
30 | #include <linux/kernel.h> | |
1da177e4 LT |
31 | #include <linux/module.h> |
32 | #include <linux/spinlock.h> | |
656be92f | 33 | #include <asm/pgtable.h> /* MODULE_START */ |
1da177e4 | 34 | |
4e6a05fe TS |
35 | struct mips_hi16 { |
36 | struct mips_hi16 *next; | |
37 | Elf_Addr *addr; | |
38 | Elf_Addr value; | |
39 | }; | |
40 | ||
41 | static struct mips_hi16 *mips_hi16_list; | |
42 | ||
1da177e4 LT |
43 | static LIST_HEAD(dbe_list); |
44 | static DEFINE_SPINLOCK(dbe_lock); | |
45 | ||
4e6a05fe TS |
46 | void *module_alloc(unsigned long size) |
47 | { | |
656be92f AN |
48 | #ifdef MODULE_START |
49 | struct vm_struct *area; | |
50 | ||
51 | size = PAGE_ALIGN(size); | |
52 | if (!size) | |
53 | return NULL; | |
54 | ||
55 | area = __get_vm_area(size, VM_ALLOC, MODULE_START, MODULE_END); | |
56 | if (!area) | |
57 | return NULL; | |
58 | ||
59 | return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL); | |
60 | #else | |
4e6a05fe TS |
61 | if (size == 0) |
62 | return NULL; | |
63 | return vmalloc(size); | |
656be92f | 64 | #endif |
4e6a05fe TS |
65 | } |
66 | ||
67 | /* Free memory returned from module_alloc */ | |
68 | void module_free(struct module *mod, void *module_region) | |
69 | { | |
70 | vfree(module_region); | |
71 | /* FIXME: If module_region == mod->init_region, trim exception | |
72 | table entries. */ | |
73 | } | |
74 | ||
75 | int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, | |
76 | char *secstrings, struct module *mod) | |
77 | { | |
78 | return 0; | |
79 | } | |
80 | ||
81 | static int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v) | |
82 | { | |
83 | return 0; | |
84 | } | |
85 | ||
86 | static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v) | |
87 | { | |
88 | *location += v; | |
89 | ||
90 | return 0; | |
91 | } | |
92 | ||
93 | static int apply_r_mips_32_rela(struct module *me, u32 *location, Elf_Addr v) | |
94 | { | |
95 | *location = v; | |
96 | ||
97 | return 0; | |
98 | } | |
99 | ||
100 | static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v) | |
101 | { | |
102 | if (v % 4) { | |
103 | printk(KERN_ERR "module %s: dangerous relocation\n", me->name); | |
104 | return -ENOEXEC; | |
105 | } | |
106 | ||
107 | if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { | |
108 | printk(KERN_ERR | |
109 | "module %s: relocation overflow\n", | |
110 | me->name); | |
111 | return -ENOEXEC; | |
112 | } | |
113 | ||
114 | *location = (*location & ~0x03ffffff) | | |
115 | ((*location + (v >> 2)) & 0x03ffffff); | |
116 | ||
117 | return 0; | |
118 | } | |
119 | ||
120 | static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v) | |
121 | { | |
122 | if (v % 4) { | |
123 | printk(KERN_ERR "module %s: dangerous relocation\n", me->name); | |
124 | return -ENOEXEC; | |
125 | } | |
126 | ||
127 | if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { | |
128 | printk(KERN_ERR | |
129 | "module %s: relocation overflow\n", | |
130 | me->name); | |
131 | return -ENOEXEC; | |
132 | } | |
133 | ||
134 | *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff); | |
135 | ||
136 | return 0; | |
137 | } | |
138 | ||
139 | static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v) | |
140 | { | |
141 | struct mips_hi16 *n; | |
142 | ||
143 | /* | |
144 | * We cannot relocate this one now because we don't know the value of | |
145 | * the carry we need to add. Save the information, and let LO16 do the | |
146 | * actual relocation. | |
147 | */ | |
148 | n = kmalloc(sizeof *n, GFP_KERNEL); | |
149 | if (!n) | |
150 | return -ENOMEM; | |
151 | ||
152 | n->addr = (Elf_Addr *)location; | |
153 | n->value = v; | |
154 | n->next = mips_hi16_list; | |
155 | mips_hi16_list = n; | |
156 | ||
157 | return 0; | |
158 | } | |
159 | ||
160 | static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v) | |
161 | { | |
162 | *location = (*location & 0xffff0000) | | |
163 | ((((long long) v + 0x8000LL) >> 16) & 0xffff); | |
164 | ||
165 | return 0; | |
166 | } | |
167 | ||
168 | static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v) | |
169 | { | |
170 | unsigned long insnlo = *location; | |
171 | Elf_Addr val, vallo; | |
172 | ||
173 | /* Sign extend the addend we extract from the lo insn. */ | |
174 | vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000; | |
175 | ||
176 | if (mips_hi16_list != NULL) { | |
177 | struct mips_hi16 *l; | |
178 | ||
179 | l = mips_hi16_list; | |
180 | while (l != NULL) { | |
181 | struct mips_hi16 *next; | |
182 | unsigned long insn; | |
183 | ||
184 | /* | |
185 | * The value for the HI16 had best be the same. | |
186 | */ | |
187 | if (v != l->value) | |
188 | goto out_danger; | |
189 | ||
190 | /* | |
191 | * Do the HI16 relocation. Note that we actually don't | |
192 | * need to know anything about the LO16 itself, except | |
193 | * where to find the low 16 bits of the addend needed | |
194 | * by the LO16. | |
195 | */ | |
196 | insn = *l->addr; | |
197 | val = ((insn & 0xffff) << 16) + vallo; | |
198 | val += v; | |
199 | ||
200 | /* | |
201 | * Account for the sign extension that will happen in | |
202 | * the low bits. | |
203 | */ | |
204 | val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff; | |
205 | ||
206 | insn = (insn & ~0xffff) | val; | |
207 | *l->addr = insn; | |
208 | ||
209 | next = l->next; | |
210 | kfree(l); | |
211 | l = next; | |
212 | } | |
213 | ||
214 | mips_hi16_list = NULL; | |
215 | } | |
216 | ||
217 | /* | |
218 | * Ok, we're done with the HI16 relocs. Now deal with the LO16. | |
219 | */ | |
220 | val = v + vallo; | |
221 | insnlo = (insnlo & ~0xffff) | (val & 0xffff); | |
222 | *location = insnlo; | |
223 | ||
224 | return 0; | |
225 | ||
226 | out_danger: | |
227 | printk(KERN_ERR "module %s: dangerous " "relocation\n", me->name); | |
228 | ||
229 | return -ENOEXEC; | |
230 | } | |
231 | ||
232 | static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v) | |
233 | { | |
234 | *location = (*location & 0xffff0000) | (v & 0xffff); | |
235 | ||
236 | return 0; | |
237 | } | |
238 | ||
239 | static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v) | |
240 | { | |
241 | *(Elf_Addr *)location = v; | |
242 | ||
243 | return 0; | |
244 | } | |
245 | ||
246 | static int apply_r_mips_higher_rela(struct module *me, u32 *location, | |
247 | Elf_Addr v) | |
248 | { | |
249 | *location = (*location & 0xffff0000) | | |
250 | ((((long long) v + 0x80008000LL) >> 32) & 0xffff); | |
251 | ||
252 | return 0; | |
253 | } | |
254 | ||
255 | static int apply_r_mips_highest_rela(struct module *me, u32 *location, | |
256 | Elf_Addr v) | |
257 | { | |
258 | *location = (*location & 0xffff0000) | | |
259 | ((((long long) v + 0x800080008000LL) >> 48) & 0xffff); | |
260 | ||
261 | return 0; | |
262 | } | |
263 | ||
264 | static int (*reloc_handlers_rel[]) (struct module *me, u32 *location, | |
265 | Elf_Addr v) = { | |
266 | [R_MIPS_NONE] = apply_r_mips_none, | |
267 | [R_MIPS_32] = apply_r_mips_32_rel, | |
268 | [R_MIPS_26] = apply_r_mips_26_rel, | |
269 | [R_MIPS_HI16] = apply_r_mips_hi16_rel, | |
270 | [R_MIPS_LO16] = apply_r_mips_lo16_rel | |
271 | }; | |
272 | ||
273 | static int (*reloc_handlers_rela[]) (struct module *me, u32 *location, | |
274 | Elf_Addr v) = { | |
275 | [R_MIPS_NONE] = apply_r_mips_none, | |
276 | [R_MIPS_32] = apply_r_mips_32_rela, | |
277 | [R_MIPS_26] = apply_r_mips_26_rela, | |
278 | [R_MIPS_HI16] = apply_r_mips_hi16_rela, | |
279 | [R_MIPS_LO16] = apply_r_mips_lo16_rela, | |
280 | [R_MIPS_64] = apply_r_mips_64_rela, | |
281 | [R_MIPS_HIGHER] = apply_r_mips_higher_rela, | |
282 | [R_MIPS_HIGHEST] = apply_r_mips_highest_rela | |
283 | }; | |
284 | ||
285 | int apply_relocate(Elf_Shdr *sechdrs, const char *strtab, | |
286 | unsigned int symindex, unsigned int relsec, | |
287 | struct module *me) | |
288 | { | |
289 | Elf_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr; | |
290 | Elf_Sym *sym; | |
291 | u32 *location; | |
292 | unsigned int i; | |
293 | Elf_Addr v; | |
294 | int res; | |
295 | ||
296 | pr_debug("Applying relocate section %u to %u\n", relsec, | |
297 | sechdrs[relsec].sh_info); | |
298 | ||
299 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { | |
300 | /* This is where to make the change */ | |
301 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | |
302 | + rel[i].r_offset; | |
303 | /* This is the symbol it is referring to */ | |
304 | sym = (Elf_Sym *)sechdrs[symindex].sh_addr | |
305 | + ELF_MIPS_R_SYM(rel[i]); | |
306 | if (!sym->st_value) { | |
f3bf07b9 AN |
307 | /* Ignore unresolved weak symbol */ |
308 | if (ELF_ST_BIND(sym->st_info) == STB_WEAK) | |
309 | continue; | |
4e6a05fe TS |
310 | printk(KERN_WARNING "%s: Unknown symbol %s\n", |
311 | me->name, strtab + sym->st_name); | |
312 | return -ENOENT; | |
313 | } | |
314 | ||
315 | v = sym->st_value; | |
316 | ||
317 | res = reloc_handlers_rel[ELF_MIPS_R_TYPE(rel[i])](me, location, v); | |
318 | if (res) | |
319 | return res; | |
320 | } | |
321 | ||
322 | return 0; | |
323 | } | |
324 | ||
325 | int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, | |
326 | unsigned int symindex, unsigned int relsec, | |
327 | struct module *me) | |
328 | { | |
329 | Elf_Mips_Rela *rel = (void *) sechdrs[relsec].sh_addr; | |
330 | Elf_Sym *sym; | |
331 | u32 *location; | |
332 | unsigned int i; | |
333 | Elf_Addr v; | |
334 | int res; | |
335 | ||
336 | pr_debug("Applying relocate section %u to %u\n", relsec, | |
337 | sechdrs[relsec].sh_info); | |
338 | ||
339 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { | |
340 | /* This is where to make the change */ | |
341 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | |
342 | + rel[i].r_offset; | |
343 | /* This is the symbol it is referring to */ | |
344 | sym = (Elf_Sym *)sechdrs[symindex].sh_addr | |
345 | + ELF_MIPS_R_SYM(rel[i]); | |
346 | if (!sym->st_value) { | |
f3bf07b9 AN |
347 | /* Ignore unresolved weak symbol */ |
348 | if (ELF_ST_BIND(sym->st_info) == STB_WEAK) | |
349 | continue; | |
4e6a05fe TS |
350 | printk(KERN_WARNING "%s: Unknown symbol %s\n", |
351 | me->name, strtab + sym->st_name); | |
352 | return -ENOENT; | |
353 | } | |
354 | ||
355 | v = sym->st_value + rel[i].r_addend; | |
356 | ||
357 | res = reloc_handlers_rela[ELF_MIPS_R_TYPE(rel[i])](me, location, v); | |
358 | if (res) | |
359 | return res; | |
360 | } | |
361 | ||
362 | return 0; | |
363 | } | |
364 | ||
1da177e4 LT |
365 | /* Given an address, look for it in the module exception tables. */ |
366 | const struct exception_table_entry *search_module_dbetables(unsigned long addr) | |
367 | { | |
368 | unsigned long flags; | |
369 | const struct exception_table_entry *e = NULL; | |
370 | struct mod_arch_specific *dbe; | |
371 | ||
372 | spin_lock_irqsave(&dbe_lock, flags); | |
373 | list_for_each_entry(dbe, &dbe_list, dbe_list) { | |
374 | e = search_extable(dbe->dbe_start, dbe->dbe_end - 1, addr); | |
375 | if (e) | |
376 | break; | |
377 | } | |
378 | spin_unlock_irqrestore(&dbe_lock, flags); | |
379 | ||
380 | /* Now, if we found one, we are running inside it now, hence | |
381 | we cannot unload the module, hence no refcnt needed. */ | |
382 | return e; | |
383 | } | |
384 | ||
3a4fa0a2 | 385 | /* Put in dbe list if necessary. */ |
1da177e4 LT |
386 | int module_finalize(const Elf_Ehdr *hdr, |
387 | const Elf_Shdr *sechdrs, | |
388 | struct module *me) | |
389 | { | |
390 | const Elf_Shdr *s; | |
391 | char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; | |
392 | ||
393 | INIT_LIST_HEAD(&me->arch.dbe_list); | |
394 | for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { | |
395 | if (strcmp("__dbe_table", secstrings + s->sh_name) != 0) | |
396 | continue; | |
397 | me->arch.dbe_start = (void *)s->sh_addr; | |
398 | me->arch.dbe_end = (void *)s->sh_addr + s->sh_size; | |
399 | spin_lock_irq(&dbe_lock); | |
400 | list_add(&me->arch.dbe_list, &dbe_list); | |
401 | spin_unlock_irq(&dbe_lock); | |
402 | } | |
403 | return 0; | |
404 | } | |
405 | ||
406 | void module_arch_cleanup(struct module *mod) | |
407 | { | |
408 | spin_lock_irq(&dbe_lock); | |
409 | list_del(&mod->arch.dbe_list); | |
410 | spin_unlock_irq(&dbe_lock); | |
411 | } |