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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/numa.h>
27#include <linux/vmalloc.h>
28#include <linux/slab.h>
29#include <linux/fs.h>
30#include <linux/string.h>
31#include <linux/kernel.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 LIST_HEAD(dbe_list);
44static DEFINE_SPINLOCK(dbe_lock);
45
46#ifdef MODULE_START
47void *module_alloc(unsigned long size)
48{
49 return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
50 GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
51 __builtin_return_address(0));
52}
53#endif
54
55int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
56{
57 return 0;
58}
59
60static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v)
61{
62 *location += v;
63
64 return 0;
65}
66
67static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
68{
69 if (v % 4) {
70 pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
71 me->name);
72 return -ENOEXEC;
73 }
74
75 if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
76 printk(KERN_ERR
77 "module %s: relocation overflow\n",
78 me->name);
79 return -ENOEXEC;
80 }
81
82 *location = (*location & ~0x03ffffff) |
83 ((*location + (v >> 2)) & 0x03ffffff);
84
85 return 0;
86}
87
88static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
89{
90 struct mips_hi16 *n;
91
92 /*
93 * We cannot relocate this one now because we don't know the value of
94 * the carry we need to add. Save the information, and let LO16 do the
95 * actual relocation.
96 */
97 n = kmalloc(sizeof *n, GFP_KERNEL);
98 if (!n)
99 return -ENOMEM;
100
101 n->addr = (Elf_Addr *)location;
102 n->value = v;
103 n->next = me->arch.r_mips_hi16_list;
104 me->arch.r_mips_hi16_list = n;
105
106 return 0;
107}
108
109static void free_relocation_chain(struct mips_hi16 *l)
110{
111 struct mips_hi16 *next;
112
113 while (l) {
114 next = l->next;
115 kfree(l);
116 l = next;
117 }
118}
119
120static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
121{
122 unsigned long insnlo = *location;
123 struct mips_hi16 *l;
124 Elf_Addr val, vallo;
125
126 /* Sign extend the addend we extract from the lo insn. */
127 vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
128
129 if (me->arch.r_mips_hi16_list != NULL) {
130 l = me->arch.r_mips_hi16_list;
131 while (l != NULL) {
132 struct mips_hi16 *next;
133 unsigned long insn;
134
135 /*
136 * The value for the HI16 had best be the same.
137 */
138 if (v != l->value)
139 goto out_danger;
140
141 /*
142 * Do the HI16 relocation. Note that we actually don't
143 * need to know anything about the LO16 itself, except
144 * where to find the low 16 bits of the addend needed
145 * by the LO16.
146 */
147 insn = *l->addr;
148 val = ((insn & 0xffff) << 16) + vallo;
149 val += v;
150
151 /*
152 * Account for the sign extension that will happen in
153 * the low bits.
154 */
155 val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
156
157 insn = (insn & ~0xffff) | val;
158 *l->addr = insn;
159
160 next = l->next;
161 kfree(l);
162 l = next;
163 }
164
165 me->arch.r_mips_hi16_list = NULL;
166 }
167
168 /*
169 * Ok, we're done with the HI16 relocs. Now deal with the LO16.
170 */
171 val = v + vallo;
172 insnlo = (insnlo & ~0xffff) | (val & 0xffff);
173 *location = insnlo;
174
175 return 0;
176
177out_danger:
178 free_relocation_chain(l);
179 me->arch.r_mips_hi16_list = NULL;
180
181 pr_err("module %s: dangerous R_MIPS_LO16 REL relocation\n", me->name);
182
183 return -ENOEXEC;
184}
185
186static int (*reloc_handlers_rel[]) (struct module *me, u32 *location,
187 Elf_Addr v) = {
188 [R_MIPS_NONE] = apply_r_mips_none,
189 [R_MIPS_32] = apply_r_mips_32_rel,
190 [R_MIPS_26] = apply_r_mips_26_rel,
191 [R_MIPS_HI16] = apply_r_mips_hi16_rel,
192 [R_MIPS_LO16] = apply_r_mips_lo16_rel
193};
194
195int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
196 unsigned int symindex, unsigned int relsec,
197 struct module *me)
198{
199 Elf_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr;
200 int (*handler)(struct module *me, u32 *location, Elf_Addr v);
201 Elf_Sym *sym;
202 u32 *location;
203 unsigned int i, type;
204 Elf_Addr v;
205 int res;
206
207 pr_debug("Applying relocate section %u to %u\n", relsec,
208 sechdrs[relsec].sh_info);
209
210 me->arch.r_mips_hi16_list = NULL;
211 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
212 /* This is where to make the change */
213 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
214 + rel[i].r_offset;
215 /* This is the symbol it is referring to */
216 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
217 + ELF_MIPS_R_SYM(rel[i]);
218 if (IS_ERR_VALUE(sym->st_value)) {
219 /* Ignore unresolved weak symbol */
220 if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
221 continue;
222 printk(KERN_WARNING "%s: Unknown symbol %s\n",
223 me->name, strtab + sym->st_name);
224 return -ENOENT;
225 }
226
227 type = ELF_MIPS_R_TYPE(rel[i]);
228
229 if (type < ARRAY_SIZE(reloc_handlers_rel))
230 handler = reloc_handlers_rel[type];
231 else
232 handler = NULL;
233
234 if (!handler) {
235 pr_err("%s: Unknown relocation type %u\n",
236 me->name, type);
237 return -EINVAL;
238 }
239
240 v = sym->st_value;
241 res = handler(me, location, v);
242 if (res)
243 return res;
244 }
245
246 /*
247 * Normally the hi16 list should be deallocated at this point. A
248 * malformed binary however could contain a series of R_MIPS_HI16
249 * relocations not followed by a R_MIPS_LO16 relocation. In that
250 * case, free up the list and return an error.
251 */
252 if (me->arch.r_mips_hi16_list) {
253 free_relocation_chain(me->arch.r_mips_hi16_list);
254 me->arch.r_mips_hi16_list = NULL;
255
256 return -ENOEXEC;
257 }
258
259 return 0;
260}
261
262/* Given an address, look for it in the module exception tables. */
263const struct exception_table_entry *search_module_dbetables(unsigned long addr)
264{
265 unsigned long flags;
266 const struct exception_table_entry *e = NULL;
267 struct mod_arch_specific *dbe;
268
269 spin_lock_irqsave(&dbe_lock, flags);
270 list_for_each_entry(dbe, &dbe_list, dbe_list) {
271 e = search_extable(dbe->dbe_start, dbe->dbe_end - 1, addr);
272 if (e)
273 break;
274 }
275 spin_unlock_irqrestore(&dbe_lock, flags);
276
277 /* Now, if we found one, we are running inside it now, hence
278 we cannot unload the module, hence no refcnt needed. */
279 return e;
280}
281
282/* Put in dbe list if necessary. */
283int module_finalize(const Elf_Ehdr *hdr,
284 const Elf_Shdr *sechdrs,
285 struct module *me)
286{
287 const Elf_Shdr *s;
288 char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
289
290 /* Make jump label nops. */
291 jump_label_apply_nops(me);
292
293 INIT_LIST_HEAD(&me->arch.dbe_list);
294 for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
295 if (strcmp("__dbe_table", secstrings + s->sh_name) != 0)
296 continue;
297 me->arch.dbe_start = (void *)s->sh_addr;
298 me->arch.dbe_end = (void *)s->sh_addr + s->sh_size;
299 spin_lock_irq(&dbe_lock);
300 list_add(&me->arch.dbe_list, &dbe_list);
301 spin_unlock_irq(&dbe_lock);
302 }
303 return 0;
304}
305
306void module_arch_cleanup(struct module *mod)
307{
308 spin_lock_irq(&dbe_lock);
309 list_del(&mod->arch.dbe_list);
310 spin_unlock_irq(&dbe_lock);
311}
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/numa.h>
27#include <linux/vmalloc.h>
28#include <linux/slab.h>
29#include <linux/fs.h>
30#include <linux/string.h>
31#include <linux/kernel.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 LIST_HEAD(dbe_list);
44static DEFINE_SPINLOCK(dbe_lock);
45
46#ifdef MODULE_START
47void *module_alloc(unsigned long size)
48{
49 return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
50 GFP_KERNEL, PAGE_KERNEL, NUMA_NO_NODE,
51 __builtin_return_address(0));
52}
53#endif
54
55int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
56{
57 return 0;
58}
59
60static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v)
61{
62 *location += v;
63
64 return 0;
65}
66
67static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
68{
69 if (v % 4) {
70 pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
71 me->name);
72 return -ENOEXEC;
73 }
74
75 if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
76 printk(KERN_ERR
77 "module %s: relocation overflow\n",
78 me->name);
79 return -ENOEXEC;
80 }
81
82 *location = (*location & ~0x03ffffff) |
83 ((*location + (v >> 2)) & 0x03ffffff);
84
85 return 0;
86}
87
88static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
89{
90 struct mips_hi16 *n;
91
92 /*
93 * We cannot relocate this one now because we don't know the value of
94 * the carry we need to add. Save the information, and let LO16 do the
95 * actual relocation.
96 */
97 n = kmalloc(sizeof *n, GFP_KERNEL);
98 if (!n)
99 return -ENOMEM;
100
101 n->addr = (Elf_Addr *)location;
102 n->value = v;
103 n->next = me->arch.r_mips_hi16_list;
104 me->arch.r_mips_hi16_list = n;
105
106 return 0;
107}
108
109static void free_relocation_chain(struct mips_hi16 *l)
110{
111 struct mips_hi16 *next;
112
113 while (l) {
114 next = l->next;
115 kfree(l);
116 l = next;
117 }
118}
119
120static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
121{
122 unsigned long insnlo = *location;
123 struct mips_hi16 *l;
124 Elf_Addr val, vallo;
125
126 /* Sign extend the addend we extract from the lo insn. */
127 vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
128
129 if (me->arch.r_mips_hi16_list != NULL) {
130 l = me->arch.r_mips_hi16_list;
131 while (l != NULL) {
132 struct mips_hi16 *next;
133 unsigned long insn;
134
135 /*
136 * The value for the HI16 had best be the same.
137 */
138 if (v != l->value)
139 goto out_danger;
140
141 /*
142 * Do the HI16 relocation. Note that we actually don't
143 * need to know anything about the LO16 itself, except
144 * where to find the low 16 bits of the addend needed
145 * by the LO16.
146 */
147 insn = *l->addr;
148 val = ((insn & 0xffff) << 16) + vallo;
149 val += v;
150
151 /*
152 * Account for the sign extension that will happen in
153 * the low bits.
154 */
155 val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
156
157 insn = (insn & ~0xffff) | val;
158 *l->addr = insn;
159
160 next = l->next;
161 kfree(l);
162 l = next;
163 }
164
165 me->arch.r_mips_hi16_list = NULL;
166 }
167
168 /*
169 * Ok, we're done with the HI16 relocs. Now deal with the LO16.
170 */
171 val = v + vallo;
172 insnlo = (insnlo & ~0xffff) | (val & 0xffff);
173 *location = insnlo;
174
175 return 0;
176
177out_danger:
178 free_relocation_chain(l);
179 me->arch.r_mips_hi16_list = NULL;
180
181 pr_err("module %s: dangerous R_MIPS_LO16 REL relocation\n", me->name);
182
183 return -ENOEXEC;
184}
185
186static int (*reloc_handlers_rel[]) (struct module *me, u32 *location,
187 Elf_Addr v) = {
188 [R_MIPS_NONE] = apply_r_mips_none,
189 [R_MIPS_32] = apply_r_mips_32_rel,
190 [R_MIPS_26] = apply_r_mips_26_rel,
191 [R_MIPS_HI16] = apply_r_mips_hi16_rel,
192 [R_MIPS_LO16] = apply_r_mips_lo16_rel
193};
194
195int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
196 unsigned int symindex, unsigned int relsec,
197 struct module *me)
198{
199 Elf_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr;
200 Elf_Sym *sym;
201 u32 *location;
202 unsigned int i;
203 Elf_Addr v;
204 int res;
205
206 pr_debug("Applying relocate section %u to %u\n", relsec,
207 sechdrs[relsec].sh_info);
208
209 me->arch.r_mips_hi16_list = NULL;
210 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
211 /* This is where to make the change */
212 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
213 + rel[i].r_offset;
214 /* This is the symbol it is referring to */
215 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
216 + ELF_MIPS_R_SYM(rel[i]);
217 if (IS_ERR_VALUE(sym->st_value)) {
218 /* Ignore unresolved weak symbol */
219 if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
220 continue;
221 printk(KERN_WARNING "%s: Unknown symbol %s\n",
222 me->name, strtab + sym->st_name);
223 return -ENOENT;
224 }
225
226 v = sym->st_value;
227
228 res = reloc_handlers_rel[ELF_MIPS_R_TYPE(rel[i])](me, location, v);
229 if (res)
230 return res;
231 }
232
233 /*
234 * Normally the hi16 list should be deallocated at this point. A
235 * malformed binary however could contain a series of R_MIPS_HI16
236 * relocations not followed by a R_MIPS_LO16 relocation. In that
237 * case, free up the list and return an error.
238 */
239 if (me->arch.r_mips_hi16_list) {
240 free_relocation_chain(me->arch.r_mips_hi16_list);
241 me->arch.r_mips_hi16_list = NULL;
242
243 return -ENOEXEC;
244 }
245
246 return 0;
247}
248
249/* Given an address, look for it in the module exception tables. */
250const struct exception_table_entry *search_module_dbetables(unsigned long addr)
251{
252 unsigned long flags;
253 const struct exception_table_entry *e = NULL;
254 struct mod_arch_specific *dbe;
255
256 spin_lock_irqsave(&dbe_lock, flags);
257 list_for_each_entry(dbe, &dbe_list, dbe_list) {
258 e = search_extable(dbe->dbe_start, dbe->dbe_end - 1, addr);
259 if (e)
260 break;
261 }
262 spin_unlock_irqrestore(&dbe_lock, flags);
263
264 /* Now, if we found one, we are running inside it now, hence
265 we cannot unload the module, hence no refcnt needed. */
266 return e;
267}
268
269/* Put in dbe list if necessary. */
270int module_finalize(const Elf_Ehdr *hdr,
271 const Elf_Shdr *sechdrs,
272 struct module *me)
273{
274 const Elf_Shdr *s;
275 char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
276
277 /* Make jump label nops. */
278 jump_label_apply_nops(me);
279
280 INIT_LIST_HEAD(&me->arch.dbe_list);
281 for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
282 if (strcmp("__dbe_table", secstrings + s->sh_name) != 0)
283 continue;
284 me->arch.dbe_start = (void *)s->sh_addr;
285 me->arch.dbe_end = (void *)s->sh_addr + s->sh_size;
286 spin_lock_irq(&dbe_lock);
287 list_add(&me->arch.dbe_list, &dbe_list);
288 spin_unlock_irq(&dbe_lock);
289 }
290 return 0;
291}
292
293void module_arch_cleanup(struct module *mod)
294{
295 spin_lock_irq(&dbe_lock);
296 list_del(&mod->arch.dbe_list);
297 spin_unlock_irq(&dbe_lock);
298}