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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 void apply_r_mips_32(u32 *location, u32 base, Elf_Addr v)
44{
45 *location = base + v;
46}
47
48static int apply_r_mips_26(struct module *me, u32 *location, u32 base,
49 Elf_Addr v)
50{
51 if (v % 4) {
52 pr_err("module %s: dangerous R_MIPS_26 relocation\n",
53 me->name);
54 return -ENOEXEC;
55 }
56
57 if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
58 pr_err("module %s: relocation overflow\n",
59 me->name);
60 return -ENOEXEC;
61 }
62
63 *location = (*location & ~0x03ffffff) |
64 ((base + (v >> 2)) & 0x03ffffff);
65
66 return 0;
67}
68
69static int apply_r_mips_hi16(struct module *me, u32 *location, Elf_Addr v,
70 bool rela)
71{
72 struct mips_hi16 *n;
73
74 if (rela) {
75 *location = (*location & 0xffff0000) |
76 ((((long long) v + 0x8000LL) >> 16) & 0xffff);
77 return 0;
78 }
79
80 /*
81 * We cannot relocate this one now because we don't know the value of
82 * the carry we need to add. Save the information, and let LO16 do the
83 * actual relocation.
84 */
85 n = kmalloc(sizeof *n, GFP_KERNEL);
86 if (!n)
87 return -ENOMEM;
88
89 n->addr = (Elf_Addr *)location;
90 n->value = v;
91 n->next = me->arch.r_mips_hi16_list;
92 me->arch.r_mips_hi16_list = n;
93
94 return 0;
95}
96
97static void free_relocation_chain(struct mips_hi16 *l)
98{
99 struct mips_hi16 *next;
100
101 while (l) {
102 next = l->next;
103 kfree(l);
104 l = next;
105 }
106}
107
108static int apply_r_mips_lo16(struct module *me, u32 *location,
109 u32 base, Elf_Addr v, bool rela)
110{
111 unsigned long insnlo = base;
112 struct mips_hi16 *l;
113 Elf_Addr val, vallo;
114
115 if (rela) {
116 *location = (*location & 0xffff0000) | (v & 0xffff);
117 return 0;
118 }
119
120 /* Sign extend the addend we extract from the lo insn. */
121 vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
122
123 if (me->arch.r_mips_hi16_list != NULL) {
124 l = me->arch.r_mips_hi16_list;
125 while (l != NULL) {
126 struct mips_hi16 *next;
127 unsigned long insn;
128
129 /*
130 * The value for the HI16 had best be the same.
131 */
132 if (v != l->value)
133 goto out_danger;
134
135 /*
136 * Do the HI16 relocation. Note that we actually don't
137 * need to know anything about the LO16 itself, except
138 * where to find the low 16 bits of the addend needed
139 * by the LO16.
140 */
141 insn = *l->addr;
142 val = ((insn & 0xffff) << 16) + vallo;
143 val += v;
144
145 /*
146 * Account for the sign extension that will happen in
147 * the low bits.
148 */
149 val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
150
151 insn = (insn & ~0xffff) | val;
152 *l->addr = insn;
153
154 next = l->next;
155 kfree(l);
156 l = next;
157 }
158
159 me->arch.r_mips_hi16_list = NULL;
160 }
161
162 /*
163 * Ok, we're done with the HI16 relocs. Now deal with the LO16.
164 */
165 val = v + vallo;
166 insnlo = (insnlo & ~0xffff) | (val & 0xffff);
167 *location = insnlo;
168
169 return 0;
170
171out_danger:
172 free_relocation_chain(l);
173 me->arch.r_mips_hi16_list = NULL;
174
175 pr_err("module %s: dangerous R_MIPS_LO16 relocation\n", me->name);
176
177 return -ENOEXEC;
178}
179
180static int apply_r_mips_pc(struct module *me, u32 *location, u32 base,
181 Elf_Addr v, unsigned int bits)
182{
183 unsigned long mask = GENMASK(bits - 1, 0);
184 unsigned long se_bits;
185 long offset;
186
187 if (v % 4) {
188 pr_err("module %s: dangerous R_MIPS_PC%u relocation\n",
189 me->name, bits);
190 return -ENOEXEC;
191 }
192
193 /* retrieve & sign extend implicit addend if any */
194 offset = base & mask;
195 offset |= (offset & BIT(bits - 1)) ? ~mask : 0;
196
197 offset += ((long)v - (long)location) >> 2;
198
199 /* check the sign bit onwards are identical - ie. we didn't overflow */
200 se_bits = (offset & BIT(bits - 1)) ? ~0ul : 0;
201 if ((offset & ~mask) != (se_bits & ~mask)) {
202 pr_err("module %s: relocation overflow\n", me->name);
203 return -ENOEXEC;
204 }
205
206 *location = (*location & ~mask) | (offset & mask);
207
208 return 0;
209}
210
211static int apply_r_mips_pc16(struct module *me, u32 *location, u32 base,
212 Elf_Addr v)
213{
214 return apply_r_mips_pc(me, location, base, v, 16);
215}
216
217static int apply_r_mips_pc21(struct module *me, u32 *location, u32 base,
218 Elf_Addr v)
219{
220 return apply_r_mips_pc(me, location, base, v, 21);
221}
222
223static int apply_r_mips_pc26(struct module *me, u32 *location, u32 base,
224 Elf_Addr v)
225{
226 return apply_r_mips_pc(me, location, base, v, 26);
227}
228
229static int apply_r_mips_64(u32 *location, Elf_Addr v, bool rela)
230{
231 if (WARN_ON(!rela))
232 return -EINVAL;
233
234 *(Elf_Addr *)location = v;
235
236 return 0;
237}
238
239static int apply_r_mips_higher(u32 *location, Elf_Addr v, bool rela)
240{
241 if (WARN_ON(!rela))
242 return -EINVAL;
243
244 *location = (*location & 0xffff0000) |
245 ((((long long)v + 0x80008000LL) >> 32) & 0xffff);
246
247 return 0;
248}
249
250static int apply_r_mips_highest(u32 *location, Elf_Addr v, bool rela)
251{
252 if (WARN_ON(!rela))
253 return -EINVAL;
254
255 *location = (*location & 0xffff0000) |
256 ((((long long)v + 0x800080008000LL) >> 48) & 0xffff);
257
258 return 0;
259}
260
261/**
262 * reloc_handler() - Apply a particular relocation to a module
263 * @type: type of the relocation to apply
264 * @me: the module to apply the reloc to
265 * @location: the address at which the reloc is to be applied
266 * @base: the existing value at location for REL-style; 0 for RELA-style
267 * @v: the value of the reloc, with addend for RELA-style
268 * @rela: indication of is this a RELA (true) or REL (false) relocation
269 *
270 * Each implemented relocation function applies a particular type of
271 * relocation to the module @me. Relocs that may be found in either REL or RELA
272 * variants can be handled by making use of the @base & @v parameters which are
273 * set to values which abstract the difference away from the particular reloc
274 * implementations.
275 *
276 * Return: 0 upon success, else -ERRNO
277 */
278static int reloc_handler(u32 type, struct module *me, u32 *location, u32 base,
279 Elf_Addr v, bool rela)
280{
281 switch (type) {
282 case R_MIPS_NONE:
283 break;
284 case R_MIPS_32:
285 apply_r_mips_32(location, base, v);
286 break;
287 case R_MIPS_26:
288 return apply_r_mips_26(me, location, base, v);
289 case R_MIPS_HI16:
290 return apply_r_mips_hi16(me, location, v, rela);
291 case R_MIPS_LO16:
292 return apply_r_mips_lo16(me, location, base, v, rela);
293 case R_MIPS_PC16:
294 return apply_r_mips_pc16(me, location, base, v);
295 case R_MIPS_PC21_S2:
296 return apply_r_mips_pc21(me, location, base, v);
297 case R_MIPS_PC26_S2:
298 return apply_r_mips_pc26(me, location, base, v);
299 case R_MIPS_64:
300 return apply_r_mips_64(location, v, rela);
301 case R_MIPS_HIGHER:
302 return apply_r_mips_higher(location, v, rela);
303 case R_MIPS_HIGHEST:
304 return apply_r_mips_highest(location, v, rela);
305 default:
306 pr_err("%s: Unknown relocation type %u\n", me->name, type);
307 return -EINVAL;
308 }
309
310 return 0;
311}
312
313static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
314 unsigned int symindex, unsigned int relsec,
315 struct module *me, bool rela)
316{
317 union {
318 Elf_Mips_Rel *rel;
319 Elf_Mips_Rela *rela;
320 } r;
321 Elf_Sym *sym;
322 u32 *location, base;
323 unsigned int i, type;
324 Elf_Addr v;
325 int err = 0;
326 size_t reloc_sz;
327
328 pr_debug("Applying relocate section %u to %u\n", relsec,
329 sechdrs[relsec].sh_info);
330
331 r.rel = (void *)sechdrs[relsec].sh_addr;
332 reloc_sz = rela ? sizeof(*r.rela) : sizeof(*r.rel);
333 me->arch.r_mips_hi16_list = NULL;
334 for (i = 0; i < sechdrs[relsec].sh_size / reloc_sz; i++) {
335 /* This is where to make the change */
336 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
337 + r.rel->r_offset;
338 /* This is the symbol it is referring to */
339 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
340 + ELF_MIPS_R_SYM(*r.rel);
341 if (sym->st_value >= -MAX_ERRNO) {
342 /* Ignore unresolved weak symbol */
343 if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
344 continue;
345 pr_warn("%s: Unknown symbol %s\n",
346 me->name, strtab + sym->st_name);
347 err = -ENOENT;
348 goto out;
349 }
350
351 type = ELF_MIPS_R_TYPE(*r.rel);
352
353 if (rela) {
354 v = sym->st_value + r.rela->r_addend;
355 base = 0;
356 r.rela = &r.rela[1];
357 } else {
358 v = sym->st_value;
359 base = *location;
360 r.rel = &r.rel[1];
361 }
362
363 err = reloc_handler(type, me, location, base, v, rela);
364 if (err)
365 goto out;
366 }
367
368out:
369 /*
370 * Normally the hi16 list should be deallocated at this point. A
371 * malformed binary however could contain a series of R_MIPS_HI16
372 * relocations not followed by a R_MIPS_LO16 relocation, or if we hit
373 * an error processing a reloc we might have gotten here before
374 * reaching the R_MIPS_LO16. In either case, free up the list and
375 * return an error.
376 */
377 if (me->arch.r_mips_hi16_list) {
378 free_relocation_chain(me->arch.r_mips_hi16_list);
379 me->arch.r_mips_hi16_list = NULL;
380 err = err ?: -ENOEXEC;
381 }
382
383 return err;
384}
385
386int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
387 unsigned int symindex, unsigned int relsec,
388 struct module *me)
389{
390 return __apply_relocate(sechdrs, strtab, symindex, relsec, me, false);
391}
392
393#ifdef CONFIG_MODULES_USE_ELF_RELA
394int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
395 unsigned int symindex, unsigned int relsec,
396 struct module *me)
397{
398 return __apply_relocate(sechdrs, strtab, symindex, relsec, me, true);
399}
400#endif /* CONFIG_MODULES_USE_ELF_RELA */
401
402/* Given an address, look for it in the module exception tables. */
403const struct exception_table_entry *search_module_dbetables(unsigned long addr)
404{
405 unsigned long flags;
406 const struct exception_table_entry *e = NULL;
407 struct mod_arch_specific *dbe;
408
409 spin_lock_irqsave(&dbe_lock, flags);
410 list_for_each_entry(dbe, &dbe_list, dbe_list) {
411 e = search_extable(dbe->dbe_start,
412 dbe->dbe_end - dbe->dbe_start, addr);
413 if (e)
414 break;
415 }
416 spin_unlock_irqrestore(&dbe_lock, flags);
417
418 /* Now, if we found one, we are running inside it now, hence
419 we cannot unload the module, hence no refcnt needed. */
420 return e;
421}
422
423/* Put in dbe list if necessary. */
424int module_finalize(const Elf_Ehdr *hdr,
425 const Elf_Shdr *sechdrs,
426 struct module *me)
427{
428 const Elf_Shdr *s;
429 char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
430
431 /* Make jump label nops. */
432 jump_label_apply_nops(me);
433
434 INIT_LIST_HEAD(&me->arch.dbe_list);
435 for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
436 if (strcmp("__dbe_table", secstrings + s->sh_name) != 0)
437 continue;
438 me->arch.dbe_start = (void *)s->sh_addr;
439 me->arch.dbe_end = (void *)s->sh_addr + s->sh_size;
440 spin_lock_irq(&dbe_lock);
441 list_add(&me->arch.dbe_list, &dbe_list);
442 spin_unlock_irq(&dbe_lock);
443 }
444 return 0;
445}
446
447void module_arch_cleanup(struct module *mod)
448{
449 spin_lock_irq(&dbe_lock);
450 list_del(&mod->arch.dbe_list);
451 spin_unlock_irq(&dbe_lock);
452}
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#include <asm/pgtable.h> /* MODULE_START */
25
26struct mips_hi16 {
27 struct mips_hi16 *next;
28 Elf_Addr *addr;
29 Elf_Addr value;
30};
31
32static LIST_HEAD(dbe_list);
33static DEFINE_SPINLOCK(dbe_lock);
34
35#ifdef MODULE_START
36void *module_alloc(unsigned long size)
37{
38 return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
39 GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
40 __builtin_return_address(0));
41}
42#endif
43
44static int apply_r_mips_none(struct module *me, u32 *location,
45 u32 base, Elf_Addr v, bool rela)
46{
47 return 0;
48}
49
50static int apply_r_mips_32(struct module *me, u32 *location,
51 u32 base, Elf_Addr v, bool rela)
52{
53 *location = base + v;
54
55 return 0;
56}
57
58static int apply_r_mips_26(struct module *me, u32 *location,
59 u32 base, Elf_Addr v, bool rela)
60{
61 if (v % 4) {
62 pr_err("module %s: dangerous R_MIPS_26 relocation\n",
63 me->name);
64 return -ENOEXEC;
65 }
66
67 if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
68 pr_err("module %s: relocation overflow\n",
69 me->name);
70 return -ENOEXEC;
71 }
72
73 *location = (*location & ~0x03ffffff) |
74 ((base + (v >> 2)) & 0x03ffffff);
75
76 return 0;
77}
78
79static int apply_r_mips_hi16(struct module *me, u32 *location,
80 u32 base, Elf_Addr v, bool rela)
81{
82 struct mips_hi16 *n;
83
84 if (rela) {
85 *location = (*location & 0xffff0000) |
86 ((((long long) v + 0x8000LL) >> 16) & 0xffff);
87 return 0;
88 }
89
90 /*
91 * We cannot relocate this one now because we don't know the value of
92 * the carry we need to add. Save the information, and let LO16 do the
93 * actual relocation.
94 */
95 n = kmalloc(sizeof *n, GFP_KERNEL);
96 if (!n)
97 return -ENOMEM;
98
99 n->addr = (Elf_Addr *)location;
100 n->value = v;
101 n->next = me->arch.r_mips_hi16_list;
102 me->arch.r_mips_hi16_list = n;
103
104 return 0;
105}
106
107static void free_relocation_chain(struct mips_hi16 *l)
108{
109 struct mips_hi16 *next;
110
111 while (l) {
112 next = l->next;
113 kfree(l);
114 l = next;
115 }
116}
117
118static int apply_r_mips_lo16(struct module *me, u32 *location,
119 u32 base, Elf_Addr v, bool rela)
120{
121 unsigned long insnlo = base;
122 struct mips_hi16 *l;
123 Elf_Addr val, vallo;
124
125 if (rela) {
126 *location = (*location & 0xffff0000) | (v & 0xffff);
127 return 0;
128 }
129
130 /* Sign extend the addend we extract from the lo insn. */
131 vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
132
133 if (me->arch.r_mips_hi16_list != NULL) {
134 l = me->arch.r_mips_hi16_list;
135 while (l != NULL) {
136 struct mips_hi16 *next;
137 unsigned long insn;
138
139 /*
140 * The value for the HI16 had best be the same.
141 */
142 if (v != l->value)
143 goto out_danger;
144
145 /*
146 * Do the HI16 relocation. Note that we actually don't
147 * need to know anything about the LO16 itself, except
148 * where to find the low 16 bits of the addend needed
149 * by the LO16.
150 */
151 insn = *l->addr;
152 val = ((insn & 0xffff) << 16) + vallo;
153 val += v;
154
155 /*
156 * Account for the sign extension that will happen in
157 * the low bits.
158 */
159 val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
160
161 insn = (insn & ~0xffff) | val;
162 *l->addr = insn;
163
164 next = l->next;
165 kfree(l);
166 l = next;
167 }
168
169 me->arch.r_mips_hi16_list = NULL;
170 }
171
172 /*
173 * Ok, we're done with the HI16 relocs. Now deal with the LO16.
174 */
175 val = v + vallo;
176 insnlo = (insnlo & ~0xffff) | (val & 0xffff);
177 *location = insnlo;
178
179 return 0;
180
181out_danger:
182 free_relocation_chain(l);
183 me->arch.r_mips_hi16_list = NULL;
184
185 pr_err("module %s: dangerous R_MIPS_LO16 relocation\n", me->name);
186
187 return -ENOEXEC;
188}
189
190static int apply_r_mips_pc(struct module *me, u32 *location, u32 base,
191 Elf_Addr v, unsigned int bits)
192{
193 unsigned long mask = GENMASK(bits - 1, 0);
194 unsigned long se_bits;
195 long offset;
196
197 if (v % 4) {
198 pr_err("module %s: dangerous R_MIPS_PC%u relocation\n",
199 me->name, bits);
200 return -ENOEXEC;
201 }
202
203 /* retrieve & sign extend implicit addend if any */
204 offset = base & mask;
205 offset |= (offset & BIT(bits - 1)) ? ~mask : 0;
206
207 offset += ((long)v - (long)location) >> 2;
208
209 /* check the sign bit onwards are identical - ie. we didn't overflow */
210 se_bits = (offset & BIT(bits - 1)) ? ~0ul : 0;
211 if ((offset & ~mask) != (se_bits & ~mask)) {
212 pr_err("module %s: relocation overflow\n", me->name);
213 return -ENOEXEC;
214 }
215
216 *location = (*location & ~mask) | (offset & mask);
217
218 return 0;
219}
220
221static int apply_r_mips_pc16(struct module *me, u32 *location,
222 u32 base, Elf_Addr v, bool rela)
223{
224 return apply_r_mips_pc(me, location, base, v, 16);
225}
226
227static int apply_r_mips_pc21(struct module *me, u32 *location,
228 u32 base, Elf_Addr v, bool rela)
229{
230 return apply_r_mips_pc(me, location, base, v, 21);
231}
232
233static int apply_r_mips_pc26(struct module *me, u32 *location,
234 u32 base, Elf_Addr v, bool rela)
235{
236 return apply_r_mips_pc(me, location, base, v, 26);
237}
238
239static int apply_r_mips_64(struct module *me, u32 *location,
240 u32 base, Elf_Addr v, bool rela)
241{
242 if (WARN_ON(!rela))
243 return -EINVAL;
244
245 *(Elf_Addr *)location = v;
246
247 return 0;
248}
249
250static int apply_r_mips_higher(struct module *me, u32 *location,
251 u32 base, Elf_Addr v, bool rela)
252{
253 if (WARN_ON(!rela))
254 return -EINVAL;
255
256 *location = (*location & 0xffff0000) |
257 ((((long long)v + 0x80008000LL) >> 32) & 0xffff);
258
259 return 0;
260}
261
262static int apply_r_mips_highest(struct module *me, u32 *location,
263 u32 base, Elf_Addr v, bool rela)
264{
265 if (WARN_ON(!rela))
266 return -EINVAL;
267
268 *location = (*location & 0xffff0000) |
269 ((((long long)v + 0x800080008000LL) >> 48) & 0xffff);
270
271 return 0;
272}
273
274/**
275 * reloc_handler() - Apply a particular relocation to a module
276 * @me: the module to apply the reloc to
277 * @location: the address at which the reloc is to be applied
278 * @base: the existing value at location for REL-style; 0 for RELA-style
279 * @v: the value of the reloc, with addend for RELA-style
280 *
281 * Each implemented reloc_handler function applies a particular type of
282 * relocation to the module @me. Relocs that may be found in either REL or RELA
283 * variants can be handled by making use of the @base & @v parameters which are
284 * set to values which abstract the difference away from the particular reloc
285 * implementations.
286 *
287 * Return: 0 upon success, else -ERRNO
288 */
289typedef int (*reloc_handler)(struct module *me, u32 *location,
290 u32 base, Elf_Addr v, bool rela);
291
292/* The handlers for known reloc types */
293static reloc_handler reloc_handlers[] = {
294 [R_MIPS_NONE] = apply_r_mips_none,
295 [R_MIPS_32] = apply_r_mips_32,
296 [R_MIPS_26] = apply_r_mips_26,
297 [R_MIPS_HI16] = apply_r_mips_hi16,
298 [R_MIPS_LO16] = apply_r_mips_lo16,
299 [R_MIPS_PC16] = apply_r_mips_pc16,
300 [R_MIPS_64] = apply_r_mips_64,
301 [R_MIPS_HIGHER] = apply_r_mips_higher,
302 [R_MIPS_HIGHEST] = apply_r_mips_highest,
303 [R_MIPS_PC21_S2] = apply_r_mips_pc21,
304 [R_MIPS_PC26_S2] = apply_r_mips_pc26,
305};
306
307static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
308 unsigned int symindex, unsigned int relsec,
309 struct module *me, bool rela)
310{
311 union {
312 Elf_Mips_Rel *rel;
313 Elf_Mips_Rela *rela;
314 } r;
315 reloc_handler handler;
316 Elf_Sym *sym;
317 u32 *location, base;
318 unsigned int i, type;
319 Elf_Addr v;
320 int err = 0;
321 size_t reloc_sz;
322
323 pr_debug("Applying relocate section %u to %u\n", relsec,
324 sechdrs[relsec].sh_info);
325
326 r.rel = (void *)sechdrs[relsec].sh_addr;
327 reloc_sz = rela ? sizeof(*r.rela) : sizeof(*r.rel);
328 me->arch.r_mips_hi16_list = NULL;
329 for (i = 0; i < sechdrs[relsec].sh_size / reloc_sz; i++) {
330 /* This is where to make the change */
331 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
332 + r.rel->r_offset;
333 /* This is the symbol it is referring to */
334 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
335 + ELF_MIPS_R_SYM(*r.rel);
336 if (sym->st_value >= -MAX_ERRNO) {
337 /* Ignore unresolved weak symbol */
338 if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
339 continue;
340 pr_warn("%s: Unknown symbol %s\n",
341 me->name, strtab + sym->st_name);
342 err = -ENOENT;
343 goto out;
344 }
345
346 type = ELF_MIPS_R_TYPE(*r.rel);
347 if (type < ARRAY_SIZE(reloc_handlers))
348 handler = reloc_handlers[type];
349 else
350 handler = NULL;
351
352 if (!handler) {
353 pr_err("%s: Unknown relocation type %u\n",
354 me->name, type);
355 err = -EINVAL;
356 goto out;
357 }
358
359 if (rela) {
360 v = sym->st_value + r.rela->r_addend;
361 base = 0;
362 r.rela = &r.rela[1];
363 } else {
364 v = sym->st_value;
365 base = *location;
366 r.rel = &r.rel[1];
367 }
368
369 err = handler(me, location, base, v, rela);
370 if (err)
371 goto out;
372 }
373
374out:
375 /*
376 * Normally the hi16 list should be deallocated at this point. A
377 * malformed binary however could contain a series of R_MIPS_HI16
378 * relocations not followed by a R_MIPS_LO16 relocation, or if we hit
379 * an error processing a reloc we might have gotten here before
380 * reaching the R_MIPS_LO16. In either case, free up the list and
381 * return an error.
382 */
383 if (me->arch.r_mips_hi16_list) {
384 free_relocation_chain(me->arch.r_mips_hi16_list);
385 me->arch.r_mips_hi16_list = NULL;
386 err = err ?: -ENOEXEC;
387 }
388
389 return err;
390}
391
392int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
393 unsigned int symindex, unsigned int relsec,
394 struct module *me)
395{
396 return __apply_relocate(sechdrs, strtab, symindex, relsec, me, false);
397}
398
399#ifdef CONFIG_MODULES_USE_ELF_RELA
400int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
401 unsigned int symindex, unsigned int relsec,
402 struct module *me)
403{
404 return __apply_relocate(sechdrs, strtab, symindex, relsec, me, true);
405}
406#endif /* CONFIG_MODULES_USE_ELF_RELA */
407
408/* Given an address, look for it in the module exception tables. */
409const struct exception_table_entry *search_module_dbetables(unsigned long addr)
410{
411 unsigned long flags;
412 const struct exception_table_entry *e = NULL;
413 struct mod_arch_specific *dbe;
414
415 spin_lock_irqsave(&dbe_lock, flags);
416 list_for_each_entry(dbe, &dbe_list, dbe_list) {
417 e = search_extable(dbe->dbe_start,
418 dbe->dbe_end - dbe->dbe_start, addr);
419 if (e)
420 break;
421 }
422 spin_unlock_irqrestore(&dbe_lock, flags);
423
424 /* Now, if we found one, we are running inside it now, hence
425 we cannot unload the module, hence no refcnt needed. */
426 return e;
427}
428
429/* Put in dbe list if necessary. */
430int module_finalize(const Elf_Ehdr *hdr,
431 const Elf_Shdr *sechdrs,
432 struct module *me)
433{
434 const Elf_Shdr *s;
435 char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
436
437 /* Make jump label nops. */
438 jump_label_apply_nops(me);
439
440 INIT_LIST_HEAD(&me->arch.dbe_list);
441 for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
442 if (strcmp("__dbe_table", secstrings + s->sh_name) != 0)
443 continue;
444 me->arch.dbe_start = (void *)s->sh_addr;
445 me->arch.dbe_end = (void *)s->sh_addr + s->sh_size;
446 spin_lock_irq(&dbe_lock);
447 list_add(&me->arch.dbe_list, &dbe_list);
448 spin_unlock_irq(&dbe_lock);
449 }
450 return 0;
451}
452
453void module_arch_cleanup(struct module *mod)
454{
455 spin_lock_irq(&dbe_lock);
456 list_del(&mod->arch.dbe_list);
457 spin_unlock_irq(&dbe_lock);
458}