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v3.1
 
  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>
 25#include <linux/mm.h>
 
 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>
 31#include <linux/module.h>
 32#include <linux/spinlock.h>
 33#include <linux/jump_label.h>
 34
 35#include <asm/pgtable.h>	/* MODULE_START */
 36
 37struct mips_hi16 {
 38	struct mips_hi16 *next;
 39	Elf_Addr *addr;
 40	Elf_Addr value;
 41};
 42
 43static struct mips_hi16 *mips_hi16_list;
 44
 45static LIST_HEAD(dbe_list);
 46static DEFINE_SPINLOCK(dbe_lock);
 47
 48#ifdef MODULE_START
 49void *module_alloc(unsigned long size)
 50{
 51	return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
 52				GFP_KERNEL, PAGE_KERNEL, -1,
 53				__builtin_return_address(0));
 54}
 55#endif
 56
 57static int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
 58{
 59	return 0;
 60}
 61
 62static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v)
 63{
 64	*location += v;
 65
 66	return 0;
 67}
 68
 69static int apply_r_mips_32_rela(struct module *me, u32 *location, Elf_Addr v)
 
 70{
 71	*location = v;
 72
 73	return 0;
 74}
 75
 76static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 
 77{
 78	if (v % 4) {
 79		pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
 80		       me->name);
 81		return -ENOEXEC;
 82	}
 83
 84	if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 85		printk(KERN_ERR
 86		       "module %s: relocation overflow\n",
 87		       me->name);
 88		return -ENOEXEC;
 89	}
 90
 91	*location = (*location & ~0x03ffffff) |
 92	            ((*location + (v >> 2)) & 0x03ffffff);
 93
 94	return 0;
 95}
 96
 97static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 
 98{
 99	if (v % 4) {
100		pr_err("module %s: dangerous R_MIPS_26 RELArelocation\n",
101		       me->name);
102		return -ENOEXEC;
103	}
104
105	if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
106		printk(KERN_ERR
107		       "module %s: relocation overflow\n",
108		       me->name);
109		return -ENOEXEC;
110	}
111
112	*location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
113
114	return 0;
115}
116
117static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
118{
119	struct mips_hi16 *n;
120
121	/*
122	 * We cannot relocate this one now because we don't know the value of
123	 * the carry we need to add.  Save the information, and let LO16 do the
124	 * actual relocation.
125	 */
126	n = kmalloc(sizeof *n, GFP_KERNEL);
127	if (!n)
128		return -ENOMEM;
129
130	n->addr = (Elf_Addr *)location;
131	n->value = v;
132	n->next = mips_hi16_list;
133	mips_hi16_list = n;
134
135	return 0;
136}
137
138static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v)
139{
140	*location = (*location & 0xffff0000) |
141	            ((((long long) v + 0x8000LL) >> 16) & 0xffff);
142
143	return 0;
 
 
 
 
144}
145
146static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
 
147{
148	unsigned long insnlo = *location;
 
149	Elf_Addr val, vallo;
150
151	/* Sign extend the addend we extract from the lo insn.  */
152	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
 
 
153
154	if (mips_hi16_list != NULL) {
155		struct mips_hi16 *l;
156
157		l = mips_hi16_list;
 
158		while (l != NULL) {
159			struct mips_hi16 *next;
160			unsigned long insn;
161
162			/*
163			 * The value for the HI16 had best be the same.
164			 */
165			if (v != l->value)
166				goto out_danger;
167
168			/*
169			 * Do the HI16 relocation.  Note that we actually don't
170			 * need to know anything about the LO16 itself, except
171			 * where to find the low 16 bits of the addend needed
172			 * by the LO16.
173			 */
174			insn = *l->addr;
175			val = ((insn & 0xffff) << 16) + vallo;
176			val += v;
177
178			/*
179			 * Account for the sign extension that will happen in
180			 * the low bits.
181			 */
182			val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
183
184			insn = (insn & ~0xffff) | val;
185			*l->addr = insn;
186
187			next = l->next;
188			kfree(l);
189			l = next;
190		}
191
192		mips_hi16_list = NULL;
193	}
194
195	/*
196	 * Ok, we're done with the HI16 relocs.  Now deal with the LO16.
197	 */
198	val = v + vallo;
199	insnlo = (insnlo & ~0xffff) | (val & 0xffff);
200	*location = insnlo;
201
202	return 0;
203
204out_danger:
205	pr_err("module %s: dangerous R_MIPS_LO16 REL relocation\n", me->name);
 
 
 
206
207	return -ENOEXEC;
208}
209
210static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v)
 
211{
212	*location = (*location & 0xffff0000) | (v & 0xffff);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
213
214	return 0;
215}
216
217static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v)
 
 
 
 
 
 
 
218{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
219	*(Elf_Addr *)location = v;
220
221	return 0;
222}
223
224static int apply_r_mips_higher_rela(struct module *me, u32 *location,
225				    Elf_Addr v)
226{
 
 
 
227	*location = (*location & 0xffff0000) |
228	            ((((long long) v + 0x80008000LL) >> 32) & 0xffff);
229
230	return 0;
231}
232
233static int apply_r_mips_highest_rela(struct module *me, u32 *location,
234				     Elf_Addr v)
235{
 
 
 
236	*location = (*location & 0xffff0000) |
237	            ((((long long) v + 0x800080008000LL) >> 48) & 0xffff);
238
239	return 0;
240}
241
242static int (*reloc_handlers_rel[]) (struct module *me, u32 *location,
243				Elf_Addr v) = {
244	[R_MIPS_NONE]		= apply_r_mips_none,
245	[R_MIPS_32]		= apply_r_mips_32_rel,
246	[R_MIPS_26]		= apply_r_mips_26_rel,
247	[R_MIPS_HI16]		= apply_r_mips_hi16_rel,
248	[R_MIPS_LO16]		= apply_r_mips_lo16_rel
249};
 
 
 
 
 
 
 
 
 
250
251static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
252				Elf_Addr v) = {
253	[R_MIPS_NONE]		= apply_r_mips_none,
254	[R_MIPS_32]		= apply_r_mips_32_rela,
255	[R_MIPS_26]		= apply_r_mips_26_rela,
256	[R_MIPS_HI16]		= apply_r_mips_hi16_rela,
257	[R_MIPS_LO16]		= apply_r_mips_lo16_rela,
258	[R_MIPS_64]		= apply_r_mips_64_rela,
259	[R_MIPS_HIGHER]		= apply_r_mips_higher_rela,
260	[R_MIPS_HIGHEST]	= apply_r_mips_highest_rela
 
 
 
261};
262
263int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
264		   unsigned int symindex, unsigned int relsec,
265		   struct module *me)
266{
267	Elf_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr;
 
 
 
 
268	Elf_Sym *sym;
269	u32 *location;
270	unsigned int i;
271	Elf_Addr v;
272	int res;
 
273
274	pr_debug("Applying relocate section %u to %u\n", relsec,
275	       sechdrs[relsec].sh_info);
276
277	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 
 
 
278		/* This is where to make the change */
279		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
280			+ rel[i].r_offset;
281		/* This is the symbol it is referring to */
282		sym = (Elf_Sym *)sechdrs[symindex].sh_addr
283			+ ELF_MIPS_R_SYM(rel[i]);
284		if (IS_ERR_VALUE(sym->st_value)) {
285			/* Ignore unresolved weak symbol */
286			if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
287				continue;
288			printk(KERN_WARNING "%s: Unknown symbol %s\n",
289			       me->name, strtab + sym->st_name);
290			return -ENOENT;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
291		}
292
293		v = sym->st_value;
 
 
 
 
 
 
 
 
294
295		res = reloc_handlers_rel[ELF_MIPS_R_TYPE(rel[i])](me, location, v);
296		if (res)
297			return res;
298	}
299
300	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
301}
302
 
303int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
304		       unsigned int symindex, unsigned int relsec,
305		       struct module *me)
306{
307	Elf_Mips_Rela *rel = (void *) sechdrs[relsec].sh_addr;
308	Elf_Sym *sym;
309	u32 *location;
310	unsigned int i;
311	Elf_Addr v;
312	int res;
313
314	pr_debug("Applying relocate section %u to %u\n", relsec,
315	       sechdrs[relsec].sh_info);
316
317	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
318		/* This is where to make the change */
319		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
320			+ rel[i].r_offset;
321		/* This is the symbol it is referring to */
322		sym = (Elf_Sym *)sechdrs[symindex].sh_addr
323			+ ELF_MIPS_R_SYM(rel[i]);
324		if (IS_ERR_VALUE(sym->st_value)) {
325			/* Ignore unresolved weak symbol */
326			if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
327				continue;
328			printk(KERN_WARNING "%s: Unknown symbol %s\n",
329			       me->name, strtab + sym->st_name);
330			return -ENOENT;
331		}
332
333		v = sym->st_value + rel[i].r_addend;
334
335		res = reloc_handlers_rela[ELF_MIPS_R_TYPE(rel[i])](me, location, v);
336		if (res)
337			return res;
338	}
339
340	return 0;
341}
 
342
343/* Given an address, look for it in the module exception tables. */
344const struct exception_table_entry *search_module_dbetables(unsigned long addr)
345{
346	unsigned long flags;
347	const struct exception_table_entry *e = NULL;
348	struct mod_arch_specific *dbe;
349
350	spin_lock_irqsave(&dbe_lock, flags);
351	list_for_each_entry(dbe, &dbe_list, dbe_list) {
352		e = search_extable(dbe->dbe_start, dbe->dbe_end - 1, addr);
 
353		if (e)
354			break;
355	}
356	spin_unlock_irqrestore(&dbe_lock, flags);
357
358	/* Now, if we found one, we are running inside it now, hence
359           we cannot unload the module, hence no refcnt needed. */
360	return e;
361}
362
363/* Put in dbe list if necessary. */
364int module_finalize(const Elf_Ehdr *hdr,
365		    const Elf_Shdr *sechdrs,
366		    struct module *me)
367{
368	const Elf_Shdr *s;
369	char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
370
371	/* Make jump label nops. */
372	jump_label_apply_nops(me);
373
374	INIT_LIST_HEAD(&me->arch.dbe_list);
375	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
376		if (strcmp("__dbe_table", secstrings + s->sh_name) != 0)
377			continue;
378		me->arch.dbe_start = (void *)s->sh_addr;
379		me->arch.dbe_end = (void *)s->sh_addr + s->sh_size;
380		spin_lock_irq(&dbe_lock);
381		list_add(&me->arch.dbe_list, &dbe_list);
382		spin_unlock_irq(&dbe_lock);
383	}
384	return 0;
385}
386
387void module_arch_cleanup(struct module *mod)
388{
389	spin_lock_irq(&dbe_lock);
390	list_del(&mod->arch.dbe_list);
391	spin_unlock_irq(&dbe_lock);
392}
v5.9
  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}