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-rw-r--r--arch/avr32/kernel/module.c324
1 files changed, 324 insertions, 0 deletions
diff --git a/arch/avr32/kernel/module.c b/arch/avr32/kernel/module.c
new file mode 100644
index 000000000000..dfc32f2817b6
--- /dev/null
+++ b/arch/avr32/kernel/module.c
@@ -0,0 +1,324 @@
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
15#include <linux/moduleloader.h>
16#include <linux/module.h>
17#include <linux/kernel.h>
18#include <linux/elf.h>
19#include <linux/vmalloc.h>
20
21void *module_alloc(unsigned long size)
22{
23 if (size == 0)
24 return NULL;
25 return vmalloc(size);
26}
27
28void module_free(struct module *mod, void *module_region)
29{
30 vfree(mod->arch.syminfo);
31 mod->arch.syminfo = NULL;
32
33 vfree(module_region);
34 /* FIXME: if module_region == mod->init_region, trim exception
35 * table entries. */
36}
37
38static inline int check_rela(Elf32_Rela *rela, struct module *module,
39 char *strings, Elf32_Sym *symbols)
40{
41 struct mod_arch_syminfo *info;
42
43 info = module->arch.syminfo + ELF32_R_SYM(rela->r_info);
44 switch (ELF32_R_TYPE(rela->r_info)) {
45 case R_AVR32_GOT32:
46 case R_AVR32_GOT16:
47 case R_AVR32_GOT8:
48 case R_AVR32_GOT21S:
49 case R_AVR32_GOT18SW: /* mcall */
50 case R_AVR32_GOT16S: /* ld.w */
51 if (rela->r_addend != 0) {
52 printk(KERN_ERR
53 "GOT relocation against %s at offset %u with addend\n",
54 strings + symbols[ELF32_R_SYM(rela->r_info)].st_name,
55 rela->r_offset);
56 return -ENOEXEC;
57 }
58 if (info->got_offset == -1UL) {
59 info->got_offset = module->arch.got_size;
60 module->arch.got_size += sizeof(void *);
61 }
62 pr_debug("GOT[%3lu] %s\n", info->got_offset,
63 strings + symbols[ELF32_R_SYM(rela->r_info)].st_name);
64 break;
65 }
66
67 return 0;
68}
69
70int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
71 char *secstrings, struct module *module)
72{
73 Elf32_Shdr *symtab;
74 Elf32_Sym *symbols;
75 Elf32_Rela *rela;
76 char *strings;
77 int nrela, i, j;
78 int ret;
79
80 /* Find the symbol table */
81 symtab = NULL;
82 for (i = 0; i < hdr->e_shnum; i++)
83 switch (sechdrs[i].sh_type) {
84 case SHT_SYMTAB:
85 symtab = &sechdrs[i];
86 break;
87 }
88 if (!symtab) {
89 printk(KERN_ERR "module %s: no symbol table\n", module->name);
90 return -ENOEXEC;
91 }
92
93 /* Allocate room for one syminfo structure per symbol. */
94 module->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);
95 module->arch.syminfo = vmalloc(module->arch.nsyms
96 * sizeof(struct mod_arch_syminfo));
97 if (!module->arch.syminfo)
98 return -ENOMEM;
99
100 symbols = (void *)hdr + symtab->sh_offset;
101 strings = (void *)hdr + sechdrs[symtab->sh_link].sh_offset;
102 for (i = 0; i < module->arch.nsyms; i++) {
103 if (symbols[i].st_shndx == SHN_UNDEF &&
104 strcmp(strings + symbols[i].st_name,
105 "_GLOBAL_OFFSET_TABLE_") == 0)
106 /* "Define" it as absolute. */
107 symbols[i].st_shndx = SHN_ABS;
108 module->arch.syminfo[i].got_offset = -1UL;
109 module->arch.syminfo[i].got_initialized = 0;
110 }
111
112 /* Allocate GOT entries for symbols that need it. */
113 module->arch.got_size = 0;
114 for (i = 0; i < hdr->e_shnum; i++) {
115 if (sechdrs[i].sh_type != SHT_RELA)
116 continue;
117 nrela = sechdrs[i].sh_size / sizeof(Elf32_Rela);
118 rela = (void *)hdr + sechdrs[i].sh_offset;
119 for (j = 0; j < nrela; j++) {
120 ret = check_rela(rela + j, module,
121 strings, symbols);
122 if (ret)
123 goto out_free_syminfo;
124 }
125 }
126
127 /*
128 * Increase core size to make room for GOT and set start
129 * offset for GOT.
130 */
131 module->core_size = ALIGN(module->core_size, 4);
132 module->arch.got_offset = module->core_size;
133 module->core_size += module->arch.got_size;
134
135 return 0;
136
137out_free_syminfo:
138 vfree(module->arch.syminfo);
139 module->arch.syminfo = NULL;
140
141 return ret;
142}
143
144static inline int reloc_overflow(struct module *module, const char *reloc_name,
145 Elf32_Addr relocation)
146{
147 printk(KERN_ERR "module %s: Value %lx does not fit relocation %s\n",
148 module->name, (unsigned long)relocation, reloc_name);
149 return -ENOEXEC;
150}
151
152#define get_u16(loc) (*((uint16_t *)loc))
153#define put_u16(loc, val) (*((uint16_t *)loc) = (val))
154
155int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
156 unsigned int symindex, unsigned int relindex,
157 struct module *module)
158{
159 Elf32_Shdr *symsec = sechdrs + symindex;
160 Elf32_Shdr *relsec = sechdrs + relindex;
161 Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
162 Elf32_Rela *rel = (void *)relsec->sh_addr;
163 unsigned int i;
164 int ret = 0;
165
166 for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rela); i++, rel++) {
167 struct mod_arch_syminfo *info;
168 Elf32_Sym *sym;
169 Elf32_Addr relocation;
170 uint32_t *location;
171 uint32_t value;
172
173 location = (void *)dstsec->sh_addr + rel->r_offset;
174 sym = (Elf32_Sym *)symsec->sh_addr + ELF32_R_SYM(rel->r_info);
175 relocation = sym->st_value + rel->r_addend;
176
177 info = module->arch.syminfo + ELF32_R_SYM(rel->r_info);
178
179 /* Initialize GOT entry if necessary */
180 switch (ELF32_R_TYPE(rel->r_info)) {
181 case R_AVR32_GOT32:
182 case R_AVR32_GOT16:
183 case R_AVR32_GOT8:
184 case R_AVR32_GOT21S:
185 case R_AVR32_GOT18SW:
186 case R_AVR32_GOT16S:
187 if (!info->got_initialized) {
188 Elf32_Addr *gotent;
189
190 gotent = (module->module_core
191 + module->arch.got_offset
192 + info->got_offset);
193 *gotent = relocation;
194 info->got_initialized = 1;
195 }
196
197 relocation = info->got_offset;
198 break;
199 }
200
201 switch (ELF32_R_TYPE(rel->r_info)) {
202 case R_AVR32_32:
203 case R_AVR32_32_CPENT:
204 *location = relocation;
205 break;
206 case R_AVR32_22H_PCREL:
207 relocation -= (Elf32_Addr)location;
208 if ((relocation & 0xffe00001) != 0
209 && (relocation & 0xffc00001) != 0xffc00000)
210 return reloc_overflow(module,
211 "R_AVR32_22H_PCREL",
212 relocation);
213 relocation >>= 1;
214
215 value = *location;
216 value = ((value & 0xe1ef0000)
217 | (relocation & 0xffff)
218 | ((relocation & 0x10000) << 4)
219 | ((relocation & 0x1e0000) << 8));
220 *location = value;
221 break;
222 case R_AVR32_11H_PCREL:
223 relocation -= (Elf32_Addr)location;
224 if ((relocation & 0xfffffc01) != 0
225 && (relocation & 0xfffff801) != 0xfffff800)
226 return reloc_overflow(module,
227 "R_AVR32_11H_PCREL",
228 relocation);
229 value = get_u16(location);
230 value = ((value & 0xf00c)
231 | ((relocation & 0x1fe) << 3)
232 | ((relocation & 0x600) >> 9));
233 put_u16(location, value);
234 break;
235 case R_AVR32_9H_PCREL:
236 relocation -= (Elf32_Addr)location;
237 if ((relocation & 0xffffff01) != 0
238 && (relocation & 0xfffffe01) != 0xfffffe00)
239 return reloc_overflow(module,
240 "R_AVR32_9H_PCREL",
241 relocation);
242 value = get_u16(location);
243 value = ((value & 0xf00f)
244 | ((relocation & 0x1fe) << 3));
245 put_u16(location, value);
246 break;
247 case R_AVR32_9UW_PCREL:
248 relocation -= ((Elf32_Addr)location) & 0xfffffffc;
249 if ((relocation & 0xfffffc03) != 0)
250 return reloc_overflow(module,
251 "R_AVR32_9UW_PCREL",
252 relocation);
253 value = get_u16(location);
254 value = ((value & 0xf80f)
255 | ((relocation & 0x1fc) << 2));
256 put_u16(location, value);
257 break;
258 case R_AVR32_GOTPC:
259 /*
260 * R6 = PC - (PC - GOT)
261 *
262 * At this point, relocation contains the
263 * value of PC. Just subtract the value of
264 * GOT, and we're done.
265 */
266 pr_debug("GOTPC: PC=0x%lx, got_offset=0x%lx, core=0x%p\n",
267 relocation, module->arch.got_offset,
268 module->module_core);
269 relocation -= ((unsigned long)module->module_core
270 + module->arch.got_offset);
271 *location = relocation;
272 break;
273 case R_AVR32_GOT18SW:
274 if ((relocation & 0xfffe0003) != 0
275 && (relocation & 0xfffc0003) != 0xffff0000)
276 return reloc_overflow(module, "R_AVR32_GOT18SW",
277 relocation);
278 relocation >>= 2;
279 /* fall through */
280 case R_AVR32_GOT16S:
281 if ((relocation & 0xffff8000) != 0
282 && (relocation & 0xffff0000) != 0xffff0000)
283 return reloc_overflow(module, "R_AVR32_GOT16S",
284 relocation);
285 pr_debug("GOT reloc @ 0x%lx -> %lu\n",
286 rel->r_offset, relocation);
287 value = *location;
288 value = ((value & 0xffff0000)
289 | (relocation & 0xffff));
290 *location = value;
291 break;
292
293 default:
294 printk(KERN_ERR "module %s: Unknown relocation: %u\n",
295 module->name, ELF32_R_TYPE(rel->r_info));
296 return -ENOEXEC;
297 }
298 }
299
300 return ret;
301}
302
303int apply_relocate(Elf32_Shdr *sechdrs, const char *strtab,
304 unsigned int symindex, unsigned int relindex,
305 struct module *module)
306{
307 printk(KERN_ERR "module %s: REL relocations are not supported\n",
308 module->name);
309 return -ENOEXEC;
310}
311
312int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
313 struct module *module)
314{
315 vfree(module->arch.syminfo);
316 module->arch.syminfo = NULL;
317
318 return 0;
319}
320
321void module_arch_cleanup(struct module *module)
322{
323
324}
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