diff options
Diffstat (limited to 'arch/mips/kernel/module-elf64.c')
-rw-r--r-- | arch/mips/kernel/module-elf64.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/arch/mips/kernel/module-elf64.c b/arch/mips/kernel/module-elf64.c new file mode 100644 index 000000000000..e804792ee1ee --- /dev/null +++ b/arch/mips/kernel/module-elf64.c | |||
@@ -0,0 +1,274 @@ | |||
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 | */ | ||
19 | |||
20 | #undef DEBUG | ||
21 | |||
22 | #include <linux/moduleloader.h> | ||
23 | #include <linux/elf.h> | ||
24 | #include <linux/vmalloc.h> | ||
25 | #include <linux/slab.h> | ||
26 | #include <linux/fs.h> | ||
27 | #include <linux/string.h> | ||
28 | #include <linux/kernel.h> | ||
29 | |||
30 | struct mips_hi16 { | ||
31 | struct mips_hi16 *next; | ||
32 | Elf32_Addr *addr; | ||
33 | Elf64_Addr value; | ||
34 | }; | ||
35 | |||
36 | static struct mips_hi16 *mips_hi16_list; | ||
37 | |||
38 | void *module_alloc(unsigned long size) | ||
39 | { | ||
40 | if (size == 0) | ||
41 | return NULL; | ||
42 | return vmalloc(size); | ||
43 | } | ||
44 | |||
45 | |||
46 | /* Free memory returned from module_alloc */ | ||
47 | void module_free(struct module *mod, void *module_region) | ||
48 | { | ||
49 | vfree(module_region); | ||
50 | /* FIXME: If module_region == mod->init_region, trim exception | ||
51 | table entries. */ | ||
52 | } | ||
53 | |||
54 | int module_frob_arch_sections(Elf_Ehdr *hdr, | ||
55 | Elf_Shdr *sechdrs, | ||
56 | char *secstrings, | ||
57 | struct module *mod) | ||
58 | { | ||
59 | return 0; | ||
60 | } | ||
61 | |||
62 | int apply_relocate(Elf64_Shdr *sechdrs, | ||
63 | const char *strtab, | ||
64 | unsigned int symindex, | ||
65 | unsigned int relsec, | ||
66 | struct module *me) | ||
67 | { | ||
68 | /* | ||
69 | * We don't want to deal with REL relocations - RELA is so much saner. | ||
70 | */ | ||
71 | if (!sechdrs[relsec].sh_size) | ||
72 | return 0; | ||
73 | |||
74 | printk(KERN_ERR "module %s: REL relocation unsupported\n", | ||
75 | me->name); | ||
76 | return -ENOEXEC; | ||
77 | } | ||
78 | |||
79 | static int apply_r_mips_none(struct module *me, uint32_t *location, | ||
80 | Elf64_Addr v) | ||
81 | { | ||
82 | return 0; | ||
83 | } | ||
84 | |||
85 | static int apply_r_mips_32(struct module *me, uint32_t *location, | ||
86 | Elf64_Addr v) | ||
87 | { | ||
88 | *location = v; | ||
89 | |||
90 | return 0; | ||
91 | } | ||
92 | |||
93 | static int apply_r_mips_26(struct module *me, uint32_t *location, | ||
94 | Elf64_Addr v) | ||
95 | { | ||
96 | if (v % 4) { | ||
97 | printk(KERN_ERR "module %s: dangerous relocation\n", me->name); | ||
98 | return -ENOEXEC; | ||
99 | } | ||
100 | |||
101 | if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { | ||
102 | printk(KERN_ERR | ||
103 | "module %s: relocation overflow\n", | ||
104 | me->name); | ||
105 | return -ENOEXEC; | ||
106 | } | ||
107 | |||
108 | *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff); | ||
109 | |||
110 | return 0; | ||
111 | } | ||
112 | |||
113 | static int apply_r_mips_hi16(struct module *me, uint32_t *location, | ||
114 | Elf64_Addr v) | ||
115 | { | ||
116 | struct mips_hi16 *n; | ||
117 | |||
118 | /* | ||
119 | * We cannot relocate this one now because we don't know the value of | ||
120 | * the carry we need to add. Save the information, and let LO16 do the | ||
121 | * actual relocation. | ||
122 | */ | ||
123 | n = kmalloc(sizeof *n, GFP_KERNEL); | ||
124 | if (!n) | ||
125 | return -ENOMEM; | ||
126 | |||
127 | n->addr = location; | ||
128 | n->value = v; | ||
129 | n->next = mips_hi16_list; | ||
130 | mips_hi16_list = n; | ||
131 | |||
132 | return 0; | ||
133 | } | ||
134 | |||
135 | static int apply_r_mips_lo16(struct module *me, uint32_t *location, | ||
136 | Elf64_Addr v) | ||
137 | { | ||
138 | unsigned long insnlo = *location; | ||
139 | Elf32_Addr val, vallo; | ||
140 | |||
141 | /* Sign extend the addend we extract from the lo insn. */ | ||
142 | vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000; | ||
143 | |||
144 | if (mips_hi16_list != NULL) { | ||
145 | struct mips_hi16 *l; | ||
146 | |||
147 | l = mips_hi16_list; | ||
148 | while (l != NULL) { | ||
149 | struct mips_hi16 *next; | ||
150 | unsigned long insn; | ||
151 | |||
152 | /* | ||
153 | * The value for the HI16 had best be the same. | ||
154 | */ | ||
155 | if (v != l->value) | ||
156 | goto out_danger; | ||
157 | |||
158 | /* | ||
159 | * Do the HI16 relocation. Note that we actually don't | ||
160 | * need to know anything about the LO16 itself, except | ||
161 | * where to find the low 16 bits of the addend needed | ||
162 | * by the LO16. | ||
163 | */ | ||
164 | insn = *l->addr; | ||
165 | val = ((insn & 0xffff) << 16) + vallo; | ||
166 | val += v; | ||
167 | |||
168 | /* | ||
169 | * Account for the sign extension that will happen in | ||
170 | * the low bits. | ||
171 | */ | ||
172 | val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff; | ||
173 | |||
174 | insn = (insn & ~0xffff) | val; | ||
175 | *l->addr = insn; | ||
176 | |||
177 | next = l->next; | ||
178 | kfree(l); | ||
179 | l = next; | ||
180 | } | ||
181 | |||
182 | mips_hi16_list = NULL; | ||
183 | } | ||
184 | |||
185 | /* | ||
186 | * Ok, we're done with the HI16 relocs. Now deal with the LO16. | ||
187 | */ | ||
188 | insnlo = (insnlo & ~0xffff) | (v & 0xffff); | ||
189 | *location = insnlo; | ||
190 | |||
191 | return 0; | ||
192 | |||
193 | out_danger: | ||
194 | printk(KERN_ERR "module %s: dangerous " "relocation\n", me->name); | ||
195 | |||
196 | return -ENOEXEC; | ||
197 | } | ||
198 | |||
199 | static int apply_r_mips_64(struct module *me, uint32_t *location, | ||
200 | Elf64_Addr v) | ||
201 | { | ||
202 | *(uint64_t *) location = v; | ||
203 | |||
204 | return 0; | ||
205 | } | ||
206 | |||
207 | |||
208 | static int apply_r_mips_higher(struct module *me, uint32_t *location, | ||
209 | Elf64_Addr v) | ||
210 | { | ||
211 | *location = (*location & 0xffff0000) | | ||
212 | ((((long long) v + 0x80008000LL) >> 32) & 0xffff); | ||
213 | |||
214 | return 0; | ||
215 | } | ||
216 | |||
217 | static int apply_r_mips_highest(struct module *me, uint32_t *location, | ||
218 | Elf64_Addr v) | ||
219 | { | ||
220 | *location = (*location & 0xffff0000) | | ||
221 | ((((long long) v + 0x800080008000LL) >> 48) & 0xffff); | ||
222 | |||
223 | return 0; | ||
224 | } | ||
225 | |||
226 | static int (*reloc_handlers[]) (struct module *me, uint32_t *location, | ||
227 | Elf64_Addr v) = { | ||
228 | [R_MIPS_NONE] = apply_r_mips_none, | ||
229 | [R_MIPS_32] = apply_r_mips_32, | ||
230 | [R_MIPS_26] = apply_r_mips_26, | ||
231 | [R_MIPS_HI16] = apply_r_mips_hi16, | ||
232 | [R_MIPS_LO16] = apply_r_mips_lo16, | ||
233 | [R_MIPS_64] = apply_r_mips_64, | ||
234 | [R_MIPS_HIGHER] = apply_r_mips_higher, | ||
235 | [R_MIPS_HIGHEST] = apply_r_mips_highest | ||
236 | }; | ||
237 | |||
238 | int apply_relocate_add(Elf64_Shdr *sechdrs, | ||
239 | const char *strtab, | ||
240 | unsigned int symindex, | ||
241 | unsigned int relsec, | ||
242 | struct module *me) | ||
243 | { | ||
244 | Elf64_Mips_Rela *rel = (void *) sechdrs[relsec].sh_addr; | ||
245 | Elf64_Sym *sym; | ||
246 | uint32_t *location; | ||
247 | unsigned int i; | ||
248 | Elf64_Addr v; | ||
249 | int res; | ||
250 | |||
251 | pr_debug("Applying relocate section %u to %u\n", relsec, | ||
252 | sechdrs[relsec].sh_info); | ||
253 | |||
254 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { | ||
255 | /* This is where to make the change */ | ||
256 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr | ||
257 | + rel[i].r_offset; | ||
258 | /* This is the symbol it is referring to */ | ||
259 | sym = (Elf64_Sym *)sechdrs[symindex].sh_addr + rel[i].r_sym; | ||
260 | if (!sym->st_value) { | ||
261 | printk(KERN_WARNING "%s: Unknown symbol %s\n", | ||
262 | me->name, strtab + sym->st_name); | ||
263 | return -ENOENT; | ||
264 | } | ||
265 | |||
266 | v = sym->st_value; | ||
267 | |||
268 | res = reloc_handlers[rel[i].r_type](me, location, v); | ||
269 | if (res) | ||
270 | return res; | ||
271 | } | ||
272 | |||
273 | return 0; | ||
274 | } | ||