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