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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 | 48 | #ifdef MODULE_START |
d0a21265 DR |
49 | return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END, |
50 | GFP_KERNEL, PAGE_KERNEL, -1, | |
51 | __builtin_return_address(0)); | |
656be92f | 52 | #else |
4e6a05fe TS |
53 | if (size == 0) |
54 | return NULL; | |
55 | return vmalloc(size); | |
656be92f | 56 | #endif |
4e6a05fe TS |
57 | } |
58 | ||
59 | /* Free memory returned from module_alloc */ | |
60 | void module_free(struct module *mod, void *module_region) | |
61 | { | |
62 | vfree(module_region); | |
4e6a05fe TS |
63 | } |
64 | ||
65 | int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, | |
66 | char *secstrings, struct module *mod) | |
67 | { | |
68 | return 0; | |
69 | } | |
70 | ||
71 | static int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v) | |
72 | { | |
73 | return 0; | |
74 | } | |
75 | ||
76 | static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v) | |
77 | { | |
78 | *location += v; | |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | static int apply_r_mips_32_rela(struct module *me, u32 *location, Elf_Addr v) | |
84 | { | |
85 | *location = v; | |
86 | ||
87 | return 0; | |
88 | } | |
89 | ||
90 | static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v) | |
91 | { | |
92 | if (v % 4) { | |
6f9fdeb6 RB |
93 | pr_err("module %s: dangerous R_MIPS_26 REL relocation\n", |
94 | me->name); | |
4e6a05fe TS |
95 | return -ENOEXEC; |
96 | } | |
97 | ||
98 | if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { | |
99 | printk(KERN_ERR | |
100 | "module %s: relocation overflow\n", | |
101 | me->name); | |
102 | return -ENOEXEC; | |
103 | } | |
104 | ||
105 | *location = (*location & ~0x03ffffff) | | |
106 | ((*location + (v >> 2)) & 0x03ffffff); | |
107 | ||
108 | return 0; | |
109 | } | |
110 | ||
111 | static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v) | |
112 | { | |
113 | if (v % 4) { | |
6f9fdeb6 RB |
114 | pr_err("module %s: dangerous R_MIPS_26 RELArelocation\n", |
115 | me->name); | |
4e6a05fe TS |
116 | return -ENOEXEC; |
117 | } | |
118 | ||
119 | if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { | |
120 | printk(KERN_ERR | |
121 | "module %s: relocation overflow\n", | |
122 | me->name); | |
123 | return -ENOEXEC; | |
124 | } | |
125 | ||
126 | *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff); | |
127 | ||
128 | return 0; | |
129 | } | |
130 | ||
131 | static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v) | |
132 | { | |
133 | struct mips_hi16 *n; | |
134 | ||
135 | /* | |
136 | * We cannot relocate this one now because we don't know the value of | |
137 | * the carry we need to add. Save the information, and let LO16 do the | |
138 | * actual relocation. | |
139 | */ | |
140 | n = kmalloc(sizeof *n, GFP_KERNEL); | |
141 | if (!n) | |
142 | return -ENOMEM; | |
143 | ||
144 | n->addr = (Elf_Addr *)location; | |
145 | n->value = v; | |
146 | n->next = mips_hi16_list; | |
147 | mips_hi16_list = n; | |
148 | ||
149 | return 0; | |
150 | } | |
151 | ||
152 | static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v) | |
153 | { | |
154 | *location = (*location & 0xffff0000) | | |
155 | ((((long long) v + 0x8000LL) >> 16) & 0xffff); | |
156 | ||
157 | return 0; | |
158 | } | |
159 | ||
160 | static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v) | |
161 | { | |
162 | unsigned long insnlo = *location; | |
163 | Elf_Addr val, vallo; | |
164 | ||
165 | /* Sign extend the addend we extract from the lo insn. */ | |
166 | vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000; | |
167 | ||
168 | if (mips_hi16_list != NULL) { | |
169 | struct mips_hi16 *l; | |
170 | ||
171 | l = mips_hi16_list; | |
172 | while (l != NULL) { | |
173 | struct mips_hi16 *next; | |
174 | unsigned long insn; | |
175 | ||
176 | /* | |
177 | * The value for the HI16 had best be the same. | |
178 | */ | |
179 | if (v != l->value) | |
180 | goto out_danger; | |
181 | ||
182 | /* | |
183 | * Do the HI16 relocation. Note that we actually don't | |
184 | * need to know anything about the LO16 itself, except | |
185 | * where to find the low 16 bits of the addend needed | |
186 | * by the LO16. | |
187 | */ | |
188 | insn = *l->addr; | |
189 | val = ((insn & 0xffff) << 16) + vallo; | |
190 | val += v; | |
191 | ||
192 | /* | |
193 | * Account for the sign extension that will happen in | |
194 | * the low bits. | |
195 | */ | |
196 | val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff; | |
197 | ||
198 | insn = (insn & ~0xffff) | val; | |
199 | *l->addr = insn; | |
200 | ||
201 | next = l->next; | |
202 | kfree(l); | |
203 | l = next; | |
204 | } | |
205 | ||
206 | mips_hi16_list = NULL; | |
207 | } | |
208 | ||
209 | /* | |
210 | * Ok, we're done with the HI16 relocs. Now deal with the LO16. | |
211 | */ | |
212 | val = v + vallo; | |
213 | insnlo = (insnlo & ~0xffff) | (val & 0xffff); | |
214 | *location = insnlo; | |
215 | ||
216 | return 0; | |
217 | ||
218 | out_danger: | |
6f9fdeb6 | 219 | pr_err("module %s: dangerous R_MIPS_LO16 REL relocation\n", me->name); |
4e6a05fe TS |
220 | |
221 | return -ENOEXEC; | |
222 | } | |
223 | ||
224 | static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v) | |
225 | { | |
226 | *location = (*location & 0xffff0000) | (v & 0xffff); | |
227 | ||
228 | return 0; | |
229 | } | |
230 | ||
231 | static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v) | |
232 | { | |
233 | *(Elf_Addr *)location = v; | |
234 | ||
235 | return 0; | |
236 | } | |
237 | ||
238 | static int apply_r_mips_higher_rela(struct module *me, u32 *location, | |
239 | Elf_Addr v) | |
240 | { | |
241 | *location = (*location & 0xffff0000) | | |
242 | ((((long long) v + 0x80008000LL) >> 32) & 0xffff); | |
243 | ||
244 | return 0; | |
245 | } | |
246 | ||
247 | static int apply_r_mips_highest_rela(struct module *me, u32 *location, | |
248 | Elf_Addr v) | |
249 | { | |
250 | *location = (*location & 0xffff0000) | | |
251 | ((((long long) v + 0x800080008000LL) >> 48) & 0xffff); | |
252 | ||
253 | return 0; | |
254 | } | |
255 | ||
256 | static int (*reloc_handlers_rel[]) (struct module *me, u32 *location, | |
257 | Elf_Addr v) = { | |
258 | [R_MIPS_NONE] = apply_r_mips_none, | |
259 | [R_MIPS_32] = apply_r_mips_32_rel, | |
260 | [R_MIPS_26] = apply_r_mips_26_rel, | |
261 | [R_MIPS_HI16] = apply_r_mips_hi16_rel, | |
262 | [R_MIPS_LO16] = apply_r_mips_lo16_rel | |
263 | }; | |
264 | ||
265 | static int (*reloc_handlers_rela[]) (struct module *me, u32 *location, | |
266 | Elf_Addr v) = { | |
267 | [R_MIPS_NONE] = apply_r_mips_none, | |
268 | [R_MIPS_32] = apply_r_mips_32_rela, | |
269 | [R_MIPS_26] = apply_r_mips_26_rela, | |
270 | [R_MIPS_HI16] = apply_r_mips_hi16_rela, | |
271 | [R_MIPS_LO16] = apply_r_mips_lo16_rela, | |
272 | [R_MIPS_64] = apply_r_mips_64_rela, | |
273 | [R_MIPS_HIGHER] = apply_r_mips_higher_rela, | |
274 | [R_MIPS_HIGHEST] = apply_r_mips_highest_rela | |
275 | }; | |
276 | ||
277 | int apply_relocate(Elf_Shdr *sechdrs, const char *strtab, | |
278 | unsigned int symindex, unsigned int relsec, | |
279 | struct module *me) | |
280 | { | |
281 | Elf_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr; | |
282 | Elf_Sym *sym; | |
283 | u32 *location; | |
284 | unsigned int i; | |
285 | Elf_Addr v; | |
286 | int res; | |
287 | ||
288 | pr_debug("Applying relocate section %u to %u\n", relsec, | |
289 | sechdrs[relsec].sh_info); | |
290 | ||
291 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { | |
292 | /* This is where to make the change */ | |
293 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | |
294 | + rel[i].r_offset; | |
295 | /* This is the symbol it is referring to */ | |
296 | sym = (Elf_Sym *)sechdrs[symindex].sh_addr | |
297 | + ELF_MIPS_R_SYM(rel[i]); | |
0e66fff8 | 298 | if (IS_ERR_VALUE(sym->st_value)) { |
f3bf07b9 AN |
299 | /* Ignore unresolved weak symbol */ |
300 | if (ELF_ST_BIND(sym->st_info) == STB_WEAK) | |
301 | continue; | |
4e6a05fe TS |
302 | printk(KERN_WARNING "%s: Unknown symbol %s\n", |
303 | me->name, strtab + sym->st_name); | |
304 | return -ENOENT; | |
305 | } | |
306 | ||
307 | v = sym->st_value; | |
308 | ||
309 | res = reloc_handlers_rel[ELF_MIPS_R_TYPE(rel[i])](me, location, v); | |
310 | if (res) | |
311 | return res; | |
312 | } | |
313 | ||
314 | return 0; | |
315 | } | |
316 | ||
317 | int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, | |
318 | unsigned int symindex, unsigned int relsec, | |
319 | struct module *me) | |
320 | { | |
321 | Elf_Mips_Rela *rel = (void *) sechdrs[relsec].sh_addr; | |
322 | Elf_Sym *sym; | |
323 | u32 *location; | |
324 | unsigned int i; | |
325 | Elf_Addr v; | |
326 | int res; | |
327 | ||
328 | pr_debug("Applying relocate section %u to %u\n", relsec, | |
329 | sechdrs[relsec].sh_info); | |
330 | ||
331 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { | |
332 | /* This is where to make the change */ | |
333 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | |
334 | + rel[i].r_offset; | |
335 | /* This is the symbol it is referring to */ | |
336 | sym = (Elf_Sym *)sechdrs[symindex].sh_addr | |
337 | + ELF_MIPS_R_SYM(rel[i]); | |
0e66fff8 | 338 | if (IS_ERR_VALUE(sym->st_value)) { |
f3bf07b9 AN |
339 | /* Ignore unresolved weak symbol */ |
340 | if (ELF_ST_BIND(sym->st_info) == STB_WEAK) | |
341 | continue; | |
4e6a05fe TS |
342 | printk(KERN_WARNING "%s: Unknown symbol %s\n", |
343 | me->name, strtab + sym->st_name); | |
344 | return -ENOENT; | |
345 | } | |
346 | ||
347 | v = sym->st_value + rel[i].r_addend; | |
348 | ||
349 | res = reloc_handlers_rela[ELF_MIPS_R_TYPE(rel[i])](me, location, v); | |
350 | if (res) | |
351 | return res; | |
352 | } | |
353 | ||
354 | return 0; | |
355 | } | |
356 | ||
1da177e4 LT |
357 | /* Given an address, look for it in the module exception tables. */ |
358 | const struct exception_table_entry *search_module_dbetables(unsigned long addr) | |
359 | { | |
360 | unsigned long flags; | |
361 | const struct exception_table_entry *e = NULL; | |
362 | struct mod_arch_specific *dbe; | |
363 | ||
364 | spin_lock_irqsave(&dbe_lock, flags); | |
365 | list_for_each_entry(dbe, &dbe_list, dbe_list) { | |
366 | e = search_extable(dbe->dbe_start, dbe->dbe_end - 1, addr); | |
367 | if (e) | |
368 | break; | |
369 | } | |
370 | spin_unlock_irqrestore(&dbe_lock, flags); | |
371 | ||
372 | /* Now, if we found one, we are running inside it now, hence | |
373 | we cannot unload the module, hence no refcnt needed. */ | |
374 | return e; | |
375 | } | |
376 | ||
3a4fa0a2 | 377 | /* Put in dbe list if necessary. */ |
1da177e4 LT |
378 | int module_finalize(const Elf_Ehdr *hdr, |
379 | const Elf_Shdr *sechdrs, | |
380 | struct module *me) | |
381 | { | |
382 | const Elf_Shdr *s; | |
383 | char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; | |
384 | ||
385 | INIT_LIST_HEAD(&me->arch.dbe_list); | |
386 | for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { | |
387 | if (strcmp("__dbe_table", secstrings + s->sh_name) != 0) | |
388 | continue; | |
389 | me->arch.dbe_start = (void *)s->sh_addr; | |
390 | me->arch.dbe_end = (void *)s->sh_addr + s->sh_size; | |
391 | spin_lock_irq(&dbe_lock); | |
392 | list_add(&me->arch.dbe_list, &dbe_list); | |
393 | spin_unlock_irq(&dbe_lock); | |
394 | } | |
395 | return 0; | |
396 | } | |
397 | ||
398 | void module_arch_cleanup(struct module *mod) | |
399 | { | |
400 | spin_lock_irq(&dbe_lock); | |
401 | list_del(&mod->arch.dbe_list); | |
402 | spin_unlock_irq(&dbe_lock); | |
403 | } |