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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
4e6a05fe | 2 | /* |
4e6a05fe TS |
3 | * |
4 | * Copyright (C) 2001 Rusty Russell. | |
5 | * Copyright (C) 2003, 2004 Ralf Baechle (ralf@linux-mips.org) | |
6 | * Copyright (C) 2005 Thiemo Seufer | |
7 | */ | |
8 | ||
9 | #undef DEBUG | |
10 | ||
9f3b8081 | 11 | #include <linux/extable.h> |
4e6a05fe TS |
12 | #include <linux/moduleloader.h> |
13 | #include <linux/elf.h> | |
27ac792c | 14 | #include <linux/mm.h> |
761845f0 | 15 | #include <linux/numa.h> |
4e6a05fe TS |
16 | #include <linux/vmalloc.h> |
17 | #include <linux/slab.h> | |
18 | #include <linux/fs.h> | |
19 | #include <linux/string.h> | |
20 | #include <linux/kernel.h> | |
1da177e4 | 21 | #include <linux/spinlock.h> |
94bb0c1a DD |
22 | #include <linux/jump_label.h> |
23 | ||
1da177e4 | 24 | |
4e6a05fe TS |
25 | struct mips_hi16 { |
26 | struct mips_hi16 *next; | |
27 | Elf_Addr *addr; | |
28 | Elf_Addr value; | |
29 | }; | |
30 | ||
1da177e4 LT |
31 | static LIST_HEAD(dbe_list); |
32 | static DEFINE_SPINLOCK(dbe_lock); | |
33 | ||
66574cc0 | 34 | #ifdef MODULE_START |
4e6a05fe TS |
35 | void *module_alloc(unsigned long size) |
36 | { | |
d0a21265 | 37 | return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END, |
cb9e3c29 | 38 | GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE, |
d0a21265 | 39 | __builtin_return_address(0)); |
4e6a05fe | 40 | } |
66574cc0 | 41 | #endif |
4e6a05fe | 42 | |
430d0b88 PB |
43 | static int apply_r_mips_none(struct module *me, u32 *location, |
44 | u32 base, Elf_Addr v, bool rela) | |
4e6a05fe TS |
45 | { |
46 | return 0; | |
47 | } | |
48 | ||
430d0b88 PB |
49 | static int apply_r_mips_32(struct module *me, u32 *location, |
50 | u32 base, Elf_Addr v, bool rela) | |
4e6a05fe | 51 | { |
430d0b88 | 52 | *location = base + v; |
4e6a05fe TS |
53 | |
54 | return 0; | |
55 | } | |
56 | ||
430d0b88 PB |
57 | static int apply_r_mips_26(struct module *me, u32 *location, |
58 | u32 base, Elf_Addr v, bool rela) | |
4e6a05fe TS |
59 | { |
60 | if (v % 4) { | |
430d0b88 | 61 | pr_err("module %s: dangerous R_MIPS_26 relocation\n", |
6f9fdeb6 | 62 | me->name); |
4e6a05fe TS |
63 | return -ENOEXEC; |
64 | } | |
65 | ||
66 | if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { | |
55d791f3 | 67 | pr_err("module %s: relocation overflow\n", |
4e6a05fe TS |
68 | me->name); |
69 | return -ENOEXEC; | |
70 | } | |
71 | ||
72 | *location = (*location & ~0x03ffffff) | | |
430d0b88 | 73 | ((base + (v >> 2)) & 0x03ffffff); |
4e6a05fe TS |
74 | |
75 | return 0; | |
76 | } | |
77 | ||
430d0b88 PB |
78 | static int apply_r_mips_hi16(struct module *me, u32 *location, |
79 | u32 base, Elf_Addr v, bool rela) | |
4e6a05fe TS |
80 | { |
81 | struct mips_hi16 *n; | |
82 | ||
430d0b88 PB |
83 | if (rela) { |
84 | *location = (*location & 0xffff0000) | | |
85 | ((((long long) v + 0x8000LL) >> 16) & 0xffff); | |
86 | return 0; | |
87 | } | |
88 | ||
4e6a05fe TS |
89 | /* |
90 | * We cannot relocate this one now because we don't know the value of | |
91 | * the carry we need to add. Save the information, and let LO16 do the | |
92 | * actual relocation. | |
93 | */ | |
94 | n = kmalloc(sizeof *n, GFP_KERNEL); | |
95 | if (!n) | |
96 | return -ENOMEM; | |
97 | ||
98 | n->addr = (Elf_Addr *)location; | |
99 | n->value = v; | |
861667dc RB |
100 | n->next = me->arch.r_mips_hi16_list; |
101 | me->arch.r_mips_hi16_list = n; | |
4e6a05fe TS |
102 | |
103 | return 0; | |
104 | } | |
105 | ||
c54de490 RB |
106 | static void free_relocation_chain(struct mips_hi16 *l) |
107 | { | |
108 | struct mips_hi16 *next; | |
109 | ||
110 | while (l) { | |
111 | next = l->next; | |
112 | kfree(l); | |
113 | l = next; | |
114 | } | |
115 | } | |
116 | ||
430d0b88 PB |
117 | static int apply_r_mips_lo16(struct module *me, u32 *location, |
118 | u32 base, Elf_Addr v, bool rela) | |
4e6a05fe | 119 | { |
430d0b88 | 120 | unsigned long insnlo = base; |
c54de490 | 121 | struct mips_hi16 *l; |
4e6a05fe TS |
122 | Elf_Addr val, vallo; |
123 | ||
430d0b88 PB |
124 | if (rela) { |
125 | *location = (*location & 0xffff0000) | (v & 0xffff); | |
126 | return 0; | |
127 | } | |
128 | ||
70342287 | 129 | /* Sign extend the addend we extract from the lo insn. */ |
4e6a05fe TS |
130 | vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000; |
131 | ||
861667dc | 132 | if (me->arch.r_mips_hi16_list != NULL) { |
861667dc | 133 | l = me->arch.r_mips_hi16_list; |
4e6a05fe | 134 | while (l != NULL) { |
c54de490 | 135 | struct mips_hi16 *next; |
4e6a05fe TS |
136 | unsigned long insn; |
137 | ||
138 | /* | |
139 | * The value for the HI16 had best be the same. | |
140 | */ | |
141 | if (v != l->value) | |
142 | goto out_danger; | |
143 | ||
144 | /* | |
145 | * Do the HI16 relocation. Note that we actually don't | |
146 | * need to know anything about the LO16 itself, except | |
147 | * where to find the low 16 bits of the addend needed | |
148 | * by the LO16. | |
149 | */ | |
150 | insn = *l->addr; | |
151 | val = ((insn & 0xffff) << 16) + vallo; | |
152 | val += v; | |
153 | ||
154 | /* | |
155 | * Account for the sign extension that will happen in | |
156 | * the low bits. | |
157 | */ | |
158 | val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff; | |
159 | ||
160 | insn = (insn & ~0xffff) | val; | |
161 | *l->addr = insn; | |
162 | ||
163 | next = l->next; | |
164 | kfree(l); | |
165 | l = next; | |
166 | } | |
167 | ||
861667dc | 168 | me->arch.r_mips_hi16_list = NULL; |
4e6a05fe TS |
169 | } |
170 | ||
171 | /* | |
70342287 | 172 | * Ok, we're done with the HI16 relocs. Now deal with the LO16. |
4e6a05fe TS |
173 | */ |
174 | val = v + vallo; | |
175 | insnlo = (insnlo & ~0xffff) | (val & 0xffff); | |
176 | *location = insnlo; | |
177 | ||
178 | return 0; | |
179 | ||
180 | out_danger: | |
c54de490 RB |
181 | free_relocation_chain(l); |
182 | me->arch.r_mips_hi16_list = NULL; | |
d3cac35c | 183 | |
430d0b88 | 184 | pr_err("module %s: dangerous R_MIPS_LO16 relocation\n", me->name); |
4e6a05fe TS |
185 | |
186 | return -ENOEXEC; | |
187 | } | |
188 | ||
430d0b88 PB |
189 | static int apply_r_mips_pc(struct module *me, u32 *location, u32 base, |
190 | Elf_Addr v, unsigned int bits) | |
5d3c7925 PB |
191 | { |
192 | unsigned long mask = GENMASK(bits - 1, 0); | |
193 | unsigned long se_bits; | |
194 | long offset; | |
195 | ||
196 | if (v % 4) { | |
430d0b88 | 197 | pr_err("module %s: dangerous R_MIPS_PC%u relocation\n", |
5d3c7925 PB |
198 | me->name, bits); |
199 | return -ENOEXEC; | |
200 | } | |
201 | ||
430d0b88 PB |
202 | /* retrieve & sign extend implicit addend if any */ |
203 | offset = base & mask; | |
5d3c7925 PB |
204 | offset |= (offset & BIT(bits - 1)) ? ~mask : 0; |
205 | ||
206 | offset += ((long)v - (long)location) >> 2; | |
207 | ||
208 | /* check the sign bit onwards are identical - ie. we didn't overflow */ | |
209 | se_bits = (offset & BIT(bits - 1)) ? ~0ul : 0; | |
210 | if ((offset & ~mask) != (se_bits & ~mask)) { | |
211 | pr_err("module %s: relocation overflow\n", me->name); | |
212 | return -ENOEXEC; | |
213 | } | |
214 | ||
215 | *location = (*location & ~mask) | (offset & mask); | |
216 | ||
217 | return 0; | |
218 | } | |
219 | ||
430d0b88 PB |
220 | static int apply_r_mips_pc16(struct module *me, u32 *location, |
221 | u32 base, Elf_Addr v, bool rela) | |
5d3c7925 | 222 | { |
430d0b88 | 223 | return apply_r_mips_pc(me, location, base, v, 16); |
5d3c7925 PB |
224 | } |
225 | ||
430d0b88 PB |
226 | static int apply_r_mips_pc21(struct module *me, u32 *location, |
227 | u32 base, Elf_Addr v, bool rela) | |
5d3c7925 | 228 | { |
430d0b88 | 229 | return apply_r_mips_pc(me, location, base, v, 21); |
5d3c7925 PB |
230 | } |
231 | ||
430d0b88 PB |
232 | static int apply_r_mips_pc26(struct module *me, u32 *location, |
233 | u32 base, Elf_Addr v, bool rela) | |
5d3c7925 | 234 | { |
430d0b88 | 235 | return apply_r_mips_pc(me, location, base, v, 26); |
5d3c7925 PB |
236 | } |
237 | ||
430d0b88 PB |
238 | static int apply_r_mips_64(struct module *me, u32 *location, |
239 | u32 base, Elf_Addr v, bool rela) | |
5d3c7925 | 240 | { |
430d0b88 PB |
241 | if (WARN_ON(!rela)) |
242 | return -EINVAL; | |
243 | ||
244 | *(Elf_Addr *)location = v; | |
245 | ||
246 | return 0; | |
5d3c7925 PB |
247 | } |
248 | ||
430d0b88 PB |
249 | static int apply_r_mips_higher(struct module *me, u32 *location, |
250 | u32 base, Elf_Addr v, bool rela) | |
5d3c7925 | 251 | { |
430d0b88 PB |
252 | if (WARN_ON(!rela)) |
253 | return -EINVAL; | |
254 | ||
255 | *location = (*location & 0xffff0000) | | |
256 | ((((long long)v + 0x80008000LL) >> 32) & 0xffff); | |
257 | ||
258 | return 0; | |
5d3c7925 PB |
259 | } |
260 | ||
430d0b88 PB |
261 | static int apply_r_mips_highest(struct module *me, u32 *location, |
262 | u32 base, Elf_Addr v, bool rela) | |
5d3c7925 | 263 | { |
430d0b88 PB |
264 | if (WARN_ON(!rela)) |
265 | return -EINVAL; | |
266 | ||
267 | *location = (*location & 0xffff0000) | | |
268 | ((((long long)v + 0x800080008000LL) >> 48) & 0xffff); | |
269 | ||
270 | return 0; | |
5d3c7925 PB |
271 | } |
272 | ||
430d0b88 PB |
273 | /** |
274 | * reloc_handler() - Apply a particular relocation to a module | |
275 | * @me: the module to apply the reloc to | |
276 | * @location: the address at which the reloc is to be applied | |
277 | * @base: the existing value at location for REL-style; 0 for RELA-style | |
278 | * @v: the value of the reloc, with addend for RELA-style | |
279 | * | |
280 | * Each implemented reloc_handler function applies a particular type of | |
281 | * relocation to the module @me. Relocs that may be found in either REL or RELA | |
282 | * variants can be handled by making use of the @base & @v parameters which are | |
283 | * set to values which abstract the difference away from the particular reloc | |
284 | * implementations. | |
285 | * | |
286 | * Return: 0 upon success, else -ERRNO | |
287 | */ | |
288 | typedef int (*reloc_handler)(struct module *me, u32 *location, | |
289 | u32 base, Elf_Addr v, bool rela); | |
290 | ||
291 | /* The handlers for known reloc types */ | |
292 | static reloc_handler reloc_handlers[] = { | |
4e6a05fe | 293 | [R_MIPS_NONE] = apply_r_mips_none, |
430d0b88 PB |
294 | [R_MIPS_32] = apply_r_mips_32, |
295 | [R_MIPS_26] = apply_r_mips_26, | |
296 | [R_MIPS_HI16] = apply_r_mips_hi16, | |
297 | [R_MIPS_LO16] = apply_r_mips_lo16, | |
298 | [R_MIPS_PC16] = apply_r_mips_pc16, | |
299 | [R_MIPS_64] = apply_r_mips_64, | |
300 | [R_MIPS_HIGHER] = apply_r_mips_higher, | |
301 | [R_MIPS_HIGHEST] = apply_r_mips_highest, | |
302 | [R_MIPS_PC21_S2] = apply_r_mips_pc21, | |
303 | [R_MIPS_PC26_S2] = apply_r_mips_pc26, | |
4e6a05fe TS |
304 | }; |
305 | ||
430d0b88 PB |
306 | static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab, |
307 | unsigned int symindex, unsigned int relsec, | |
308 | struct module *me, bool rela) | |
4e6a05fe | 309 | { |
430d0b88 PB |
310 | union { |
311 | Elf_Mips_Rel *rel; | |
312 | Elf_Mips_Rela *rela; | |
313 | } r; | |
314 | reloc_handler handler; | |
4e6a05fe | 315 | Elf_Sym *sym; |
430d0b88 | 316 | u32 *location, base; |
04211a57 | 317 | unsigned int i, type; |
4e6a05fe | 318 | Elf_Addr v; |
351b0940 | 319 | int err = 0; |
430d0b88 | 320 | size_t reloc_sz; |
4e6a05fe TS |
321 | |
322 | pr_debug("Applying relocate section %u to %u\n", relsec, | |
323 | sechdrs[relsec].sh_info); | |
324 | ||
430d0b88 PB |
325 | r.rel = (void *)sechdrs[relsec].sh_addr; |
326 | reloc_sz = rela ? sizeof(*r.rela) : sizeof(*r.rel); | |
861667dc | 327 | me->arch.r_mips_hi16_list = NULL; |
430d0b88 | 328 | for (i = 0; i < sechdrs[relsec].sh_size / reloc_sz; i++) { |
4e6a05fe TS |
329 | /* This is where to make the change */ |
330 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | |
430d0b88 | 331 | + r.rel->r_offset; |
4e6a05fe TS |
332 | /* This is the symbol it is referring to */ |
333 | sym = (Elf_Sym *)sechdrs[symindex].sh_addr | |
430d0b88 | 334 | + ELF_MIPS_R_SYM(*r.rel); |
ba837d38 | 335 | if (sym->st_value >= -MAX_ERRNO) { |
f3bf07b9 AN |
336 | /* Ignore unresolved weak symbol */ |
337 | if (ELF_ST_BIND(sym->st_info) == STB_WEAK) | |
338 | continue; | |
55d791f3 SH |
339 | pr_warn("%s: Unknown symbol %s\n", |
340 | me->name, strtab + sym->st_name); | |
351b0940 PB |
341 | err = -ENOENT; |
342 | goto out; | |
4e6a05fe TS |
343 | } |
344 | ||
430d0b88 PB |
345 | type = ELF_MIPS_R_TYPE(*r.rel); |
346 | if (type < ARRAY_SIZE(reloc_handlers)) | |
347 | handler = reloc_handlers[type]; | |
04211a57 PB |
348 | else |
349 | handler = NULL; | |
4e6a05fe | 350 | |
04211a57 PB |
351 | if (!handler) { |
352 | pr_err("%s: Unknown relocation type %u\n", | |
353 | me->name, type); | |
351b0940 PB |
354 | err = -EINVAL; |
355 | goto out; | |
04211a57 PB |
356 | } |
357 | ||
430d0b88 PB |
358 | if (rela) { |
359 | v = sym->st_value + r.rela->r_addend; | |
360 | base = 0; | |
361 | r.rela = &r.rela[1]; | |
362 | } else { | |
363 | v = sym->st_value; | |
364 | base = *location; | |
365 | r.rel = &r.rel[1]; | |
366 | } | |
367 | ||
368 | err = handler(me, location, base, v, rela); | |
351b0940 PB |
369 | if (err) |
370 | goto out; | |
4e6a05fe TS |
371 | } |
372 | ||
351b0940 | 373 | out: |
c54de490 | 374 | /* |
351b0940 | 375 | * Normally the hi16 list should be deallocated at this point. A |
c54de490 | 376 | * malformed binary however could contain a series of R_MIPS_HI16 |
351b0940 PB |
377 | * relocations not followed by a R_MIPS_LO16 relocation, or if we hit |
378 | * an error processing a reloc we might have gotten here before | |
379 | * reaching the R_MIPS_LO16. In either case, free up the list and | |
380 | * return an error. | |
c54de490 RB |
381 | */ |
382 | if (me->arch.r_mips_hi16_list) { | |
383 | free_relocation_chain(me->arch.r_mips_hi16_list); | |
384 | me->arch.r_mips_hi16_list = NULL; | |
351b0940 | 385 | err = err ?: -ENOEXEC; |
c54de490 RB |
386 | } |
387 | ||
351b0940 | 388 | return err; |
4e6a05fe TS |
389 | } |
390 | ||
430d0b88 PB |
391 | int apply_relocate(Elf_Shdr *sechdrs, const char *strtab, |
392 | unsigned int symindex, unsigned int relsec, | |
393 | struct module *me) | |
394 | { | |
395 | return __apply_relocate(sechdrs, strtab, symindex, relsec, me, false); | |
396 | } | |
397 | ||
398 | #ifdef CONFIG_MODULES_USE_ELF_RELA | |
399 | int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, | |
400 | unsigned int symindex, unsigned int relsec, | |
401 | struct module *me) | |
402 | { | |
403 | return __apply_relocate(sechdrs, strtab, symindex, relsec, me, true); | |
4e6a05fe | 404 | } |
430d0b88 | 405 | #endif /* CONFIG_MODULES_USE_ELF_RELA */ |
4e6a05fe | 406 | |
1da177e4 LT |
407 | /* Given an address, look for it in the module exception tables. */ |
408 | const struct exception_table_entry *search_module_dbetables(unsigned long addr) | |
409 | { | |
410 | unsigned long flags; | |
411 | const struct exception_table_entry *e = NULL; | |
412 | struct mod_arch_specific *dbe; | |
413 | ||
414 | spin_lock_irqsave(&dbe_lock, flags); | |
415 | list_for_each_entry(dbe, &dbe_list, dbe_list) { | |
a94c33dd TM |
416 | e = search_extable(dbe->dbe_start, |
417 | dbe->dbe_end - dbe->dbe_start, addr); | |
1da177e4 LT |
418 | if (e) |
419 | break; | |
420 | } | |
421 | spin_unlock_irqrestore(&dbe_lock, flags); | |
422 | ||
423 | /* Now, if we found one, we are running inside it now, hence | |
70342287 | 424 | we cannot unload the module, hence no refcnt needed. */ |
1da177e4 LT |
425 | return e; |
426 | } | |
427 | ||
3a4fa0a2 | 428 | /* Put in dbe list if necessary. */ |
1da177e4 LT |
429 | int module_finalize(const Elf_Ehdr *hdr, |
430 | const Elf_Shdr *sechdrs, | |
431 | struct module *me) | |
432 | { | |
433 | const Elf_Shdr *s; | |
434 | char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; | |
435 | ||
94bb0c1a DD |
436 | /* Make jump label nops. */ |
437 | jump_label_apply_nops(me); | |
438 | ||
1da177e4 LT |
439 | INIT_LIST_HEAD(&me->arch.dbe_list); |
440 | for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { | |
441 | if (strcmp("__dbe_table", secstrings + s->sh_name) != 0) | |
442 | continue; | |
443 | me->arch.dbe_start = (void *)s->sh_addr; | |
444 | me->arch.dbe_end = (void *)s->sh_addr + s->sh_size; | |
445 | spin_lock_irq(&dbe_lock); | |
446 | list_add(&me->arch.dbe_list, &dbe_list); | |
447 | spin_unlock_irq(&dbe_lock); | |
448 | } | |
449 | return 0; | |
450 | } | |
451 | ||
452 | void module_arch_cleanup(struct module *mod) | |
453 | { | |
454 | spin_lock_irq(&dbe_lock); | |
455 | list_del(&mod->arch.dbe_list); | |
456 | spin_unlock_irq(&dbe_lock); | |
457 | } |