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5f97f7f9 HS |
1 | /* |
2 | * AVR32-specific kernel module loader | |
3 | * | |
4 | * Copyright (C) 2005-2006 Atmel Corporation | |
5 | * | |
6 | * GOT initialization parts are based on the s390 version | |
7 | * Copyright (C) 2002, 2003 IBM Deutschland Entwicklung GmbH, | |
8 | * IBM Corporation | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | */ | |
14 | ||
623b0355 | 15 | #include <linux/bug.h> |
5f97f7f9 | 16 | #include <linux/elf.h> |
623b0355 HS |
17 | #include <linux/kernel.h> |
18 | #include <linux/module.h> | |
19 | #include <linux/moduleloader.h> | |
5f97f7f9 HS |
20 | #include <linux/vmalloc.h> |
21 | ||
22 | void *module_alloc(unsigned long size) | |
23 | { | |
24 | if (size == 0) | |
25 | return NULL; | |
26 | return vmalloc(size); | |
27 | } | |
28 | ||
29 | void module_free(struct module *mod, void *module_region) | |
30 | { | |
31 | vfree(mod->arch.syminfo); | |
32 | mod->arch.syminfo = NULL; | |
33 | ||
34 | vfree(module_region); | |
5f97f7f9 HS |
35 | } |
36 | ||
37 | static inline int check_rela(Elf32_Rela *rela, struct module *module, | |
38 | char *strings, Elf32_Sym *symbols) | |
39 | { | |
40 | struct mod_arch_syminfo *info; | |
41 | ||
42 | info = module->arch.syminfo + ELF32_R_SYM(rela->r_info); | |
43 | switch (ELF32_R_TYPE(rela->r_info)) { | |
44 | case R_AVR32_GOT32: | |
45 | case R_AVR32_GOT16: | |
46 | case R_AVR32_GOT8: | |
47 | case R_AVR32_GOT21S: | |
48 | case R_AVR32_GOT18SW: /* mcall */ | |
49 | case R_AVR32_GOT16S: /* ld.w */ | |
50 | if (rela->r_addend != 0) { | |
51 | printk(KERN_ERR | |
52 | "GOT relocation against %s at offset %u with addend\n", | |
53 | strings + symbols[ELF32_R_SYM(rela->r_info)].st_name, | |
54 | rela->r_offset); | |
55 | return -ENOEXEC; | |
56 | } | |
57 | if (info->got_offset == -1UL) { | |
58 | info->got_offset = module->arch.got_size; | |
59 | module->arch.got_size += sizeof(void *); | |
60 | } | |
61 | pr_debug("GOT[%3lu] %s\n", info->got_offset, | |
62 | strings + symbols[ELF32_R_SYM(rela->r_info)].st_name); | |
63 | break; | |
64 | } | |
65 | ||
66 | return 0; | |
67 | } | |
68 | ||
69 | int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, | |
70 | char *secstrings, struct module *module) | |
71 | { | |
72 | Elf32_Shdr *symtab; | |
73 | Elf32_Sym *symbols; | |
74 | Elf32_Rela *rela; | |
75 | char *strings; | |
76 | int nrela, i, j; | |
77 | int ret; | |
78 | ||
79 | /* Find the symbol table */ | |
80 | symtab = NULL; | |
81 | for (i = 0; i < hdr->e_shnum; i++) | |
82 | switch (sechdrs[i].sh_type) { | |
83 | case SHT_SYMTAB: | |
84 | symtab = &sechdrs[i]; | |
85 | break; | |
86 | } | |
87 | if (!symtab) { | |
88 | printk(KERN_ERR "module %s: no symbol table\n", module->name); | |
89 | return -ENOEXEC; | |
90 | } | |
91 | ||
92 | /* Allocate room for one syminfo structure per symbol. */ | |
93 | module->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym); | |
94 | module->arch.syminfo = vmalloc(module->arch.nsyms | |
95 | * sizeof(struct mod_arch_syminfo)); | |
96 | if (!module->arch.syminfo) | |
97 | return -ENOMEM; | |
98 | ||
99 | symbols = (void *)hdr + symtab->sh_offset; | |
100 | strings = (void *)hdr + sechdrs[symtab->sh_link].sh_offset; | |
101 | for (i = 0; i < module->arch.nsyms; i++) { | |
102 | if (symbols[i].st_shndx == SHN_UNDEF && | |
103 | strcmp(strings + symbols[i].st_name, | |
104 | "_GLOBAL_OFFSET_TABLE_") == 0) | |
105 | /* "Define" it as absolute. */ | |
106 | symbols[i].st_shndx = SHN_ABS; | |
107 | module->arch.syminfo[i].got_offset = -1UL; | |
108 | module->arch.syminfo[i].got_initialized = 0; | |
109 | } | |
110 | ||
111 | /* Allocate GOT entries for symbols that need it. */ | |
112 | module->arch.got_size = 0; | |
113 | for (i = 0; i < hdr->e_shnum; i++) { | |
114 | if (sechdrs[i].sh_type != SHT_RELA) | |
115 | continue; | |
116 | nrela = sechdrs[i].sh_size / sizeof(Elf32_Rela); | |
117 | rela = (void *)hdr + sechdrs[i].sh_offset; | |
118 | for (j = 0; j < nrela; j++) { | |
119 | ret = check_rela(rela + j, module, | |
120 | strings, symbols); | |
121 | if (ret) | |
122 | goto out_free_syminfo; | |
123 | } | |
124 | } | |
125 | ||
126 | /* | |
127 | * Increase core size to make room for GOT and set start | |
128 | * offset for GOT. | |
129 | */ | |
130 | module->core_size = ALIGN(module->core_size, 4); | |
131 | module->arch.got_offset = module->core_size; | |
132 | module->core_size += module->arch.got_size; | |
133 | ||
134 | return 0; | |
135 | ||
136 | out_free_syminfo: | |
137 | vfree(module->arch.syminfo); | |
138 | module->arch.syminfo = NULL; | |
139 | ||
140 | return ret; | |
141 | } | |
142 | ||
143 | static inline int reloc_overflow(struct module *module, const char *reloc_name, | |
144 | Elf32_Addr relocation) | |
145 | { | |
146 | printk(KERN_ERR "module %s: Value %lx does not fit relocation %s\n", | |
147 | module->name, (unsigned long)relocation, reloc_name); | |
148 | return -ENOEXEC; | |
149 | } | |
150 | ||
151 | #define get_u16(loc) (*((uint16_t *)loc)) | |
152 | #define put_u16(loc, val) (*((uint16_t *)loc) = (val)) | |
153 | ||
154 | int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, | |
155 | unsigned int symindex, unsigned int relindex, | |
156 | struct module *module) | |
157 | { | |
158 | Elf32_Shdr *symsec = sechdrs + symindex; | |
159 | Elf32_Shdr *relsec = sechdrs + relindex; | |
160 | Elf32_Shdr *dstsec = sechdrs + relsec->sh_info; | |
161 | Elf32_Rela *rel = (void *)relsec->sh_addr; | |
162 | unsigned int i; | |
163 | int ret = 0; | |
164 | ||
165 | for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rela); i++, rel++) { | |
166 | struct mod_arch_syminfo *info; | |
167 | Elf32_Sym *sym; | |
168 | Elf32_Addr relocation; | |
169 | uint32_t *location; | |
170 | uint32_t value; | |
171 | ||
172 | location = (void *)dstsec->sh_addr + rel->r_offset; | |
173 | sym = (Elf32_Sym *)symsec->sh_addr + ELF32_R_SYM(rel->r_info); | |
174 | relocation = sym->st_value + rel->r_addend; | |
175 | ||
176 | info = module->arch.syminfo + ELF32_R_SYM(rel->r_info); | |
177 | ||
178 | /* Initialize GOT entry if necessary */ | |
179 | switch (ELF32_R_TYPE(rel->r_info)) { | |
180 | case R_AVR32_GOT32: | |
181 | case R_AVR32_GOT16: | |
182 | case R_AVR32_GOT8: | |
183 | case R_AVR32_GOT21S: | |
184 | case R_AVR32_GOT18SW: | |
185 | case R_AVR32_GOT16S: | |
186 | if (!info->got_initialized) { | |
187 | Elf32_Addr *gotent; | |
188 | ||
189 | gotent = (module->module_core | |
190 | + module->arch.got_offset | |
191 | + info->got_offset); | |
192 | *gotent = relocation; | |
193 | info->got_initialized = 1; | |
194 | } | |
195 | ||
196 | relocation = info->got_offset; | |
197 | break; | |
198 | } | |
199 | ||
200 | switch (ELF32_R_TYPE(rel->r_info)) { | |
201 | case R_AVR32_32: | |
202 | case R_AVR32_32_CPENT: | |
203 | *location = relocation; | |
204 | break; | |
205 | case R_AVR32_22H_PCREL: | |
206 | relocation -= (Elf32_Addr)location; | |
207 | if ((relocation & 0xffe00001) != 0 | |
208 | && (relocation & 0xffc00001) != 0xffc00000) | |
209 | return reloc_overflow(module, | |
210 | "R_AVR32_22H_PCREL", | |
211 | relocation); | |
212 | relocation >>= 1; | |
213 | ||
214 | value = *location; | |
215 | value = ((value & 0xe1ef0000) | |
216 | | (relocation & 0xffff) | |
217 | | ((relocation & 0x10000) << 4) | |
218 | | ((relocation & 0x1e0000) << 8)); | |
219 | *location = value; | |
220 | break; | |
221 | case R_AVR32_11H_PCREL: | |
222 | relocation -= (Elf32_Addr)location; | |
223 | if ((relocation & 0xfffffc01) != 0 | |
224 | && (relocation & 0xfffff801) != 0xfffff800) | |
225 | return reloc_overflow(module, | |
226 | "R_AVR32_11H_PCREL", | |
227 | relocation); | |
228 | value = get_u16(location); | |
229 | value = ((value & 0xf00c) | |
230 | | ((relocation & 0x1fe) << 3) | |
231 | | ((relocation & 0x600) >> 9)); | |
232 | put_u16(location, value); | |
233 | break; | |
234 | case R_AVR32_9H_PCREL: | |
235 | relocation -= (Elf32_Addr)location; | |
236 | if ((relocation & 0xffffff01) != 0 | |
237 | && (relocation & 0xfffffe01) != 0xfffffe00) | |
238 | return reloc_overflow(module, | |
239 | "R_AVR32_9H_PCREL", | |
240 | relocation); | |
241 | value = get_u16(location); | |
242 | value = ((value & 0xf00f) | |
243 | | ((relocation & 0x1fe) << 3)); | |
244 | put_u16(location, value); | |
245 | break; | |
246 | case R_AVR32_9UW_PCREL: | |
247 | relocation -= ((Elf32_Addr)location) & 0xfffffffc; | |
248 | if ((relocation & 0xfffffc03) != 0) | |
249 | return reloc_overflow(module, | |
250 | "R_AVR32_9UW_PCREL", | |
251 | relocation); | |
252 | value = get_u16(location); | |
253 | value = ((value & 0xf80f) | |
254 | | ((relocation & 0x1fc) << 2)); | |
255 | put_u16(location, value); | |
256 | break; | |
257 | case R_AVR32_GOTPC: | |
258 | /* | |
259 | * R6 = PC - (PC - GOT) | |
260 | * | |
261 | * At this point, relocation contains the | |
262 | * value of PC. Just subtract the value of | |
263 | * GOT, and we're done. | |
264 | */ | |
6ea850b5 | 265 | pr_debug("GOTPC: PC=0x%x, got_offset=0x%lx, core=0x%p\n", |
5f97f7f9 HS |
266 | relocation, module->arch.got_offset, |
267 | module->module_core); | |
268 | relocation -= ((unsigned long)module->module_core | |
269 | + module->arch.got_offset); | |
270 | *location = relocation; | |
271 | break; | |
272 | case R_AVR32_GOT18SW: | |
273 | if ((relocation & 0xfffe0003) != 0 | |
274 | && (relocation & 0xfffc0003) != 0xffff0000) | |
275 | return reloc_overflow(module, "R_AVR32_GOT18SW", | |
276 | relocation); | |
277 | relocation >>= 2; | |
278 | /* fall through */ | |
279 | case R_AVR32_GOT16S: | |
280 | if ((relocation & 0xffff8000) != 0 | |
281 | && (relocation & 0xffff0000) != 0xffff0000) | |
282 | return reloc_overflow(module, "R_AVR32_GOT16S", | |
283 | relocation); | |
6ea850b5 | 284 | pr_debug("GOT reloc @ 0x%x -> %u\n", |
5f97f7f9 HS |
285 | rel->r_offset, relocation); |
286 | value = *location; | |
287 | value = ((value & 0xffff0000) | |
288 | | (relocation & 0xffff)); | |
289 | *location = value; | |
290 | break; | |
291 | ||
292 | default: | |
293 | printk(KERN_ERR "module %s: Unknown relocation: %u\n", | |
294 | module->name, ELF32_R_TYPE(rel->r_info)); | |
295 | return -ENOEXEC; | |
296 | } | |
297 | } | |
298 | ||
299 | return ret; | |
300 | } | |
301 | ||
302 | int apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, | |
303 | unsigned int symindex, unsigned int relindex, | |
304 | struct module *module) | |
305 | { | |
306 | printk(KERN_ERR "module %s: REL relocations are not supported\n", | |
307 | module->name); | |
308 | return -ENOEXEC; | |
309 | } | |
310 | ||
311 | int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, | |
312 | struct module *module) | |
313 | { | |
314 | vfree(module->arch.syminfo); | |
315 | module->arch.syminfo = NULL; | |
316 | ||
5336377d | 317 | return 0; |
5f97f7f9 HS |
318 | } |
319 | ||
320 | void module_arch_cleanup(struct module *module) | |
321 | { | |
5f97f7f9 | 322 | } |