Merge branch 'devel-stable' into devel
[sfrench/cifs-2.6.git] / arch / arm / kernel / module.c
1 /*
2  *  linux/arch/arm/kernel/module.c
3  *
4  *  Copyright (C) 2002 Russell King.
5  *  Modified for nommu by Hyok S. Choi
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * Module allocation method suggested by Andi Kleen.
12  */
13 #include <linux/module.h>
14 #include <linux/moduleloader.h>
15 #include <linux/kernel.h>
16 #include <linux/mm.h>
17 #include <linux/elf.h>
18 #include <linux/vmalloc.h>
19 #include <linux/fs.h>
20 #include <linux/string.h>
21 #include <linux/gfp.h>
22
23 #include <asm/pgtable.h>
24 #include <asm/sections.h>
25 #include <asm/unwind.h>
26
27 #ifdef CONFIG_XIP_KERNEL
28 /*
29  * The XIP kernel text is mapped in the module area for modules and
30  * some other stuff to work without any indirect relocations.
31  * MODULES_VADDR is redefined here and not in asm/memory.h to avoid
32  * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
33  */
34 #undef MODULES_VADDR
35 #define MODULES_VADDR   (((unsigned long)_etext + ~PGDIR_MASK) & PGDIR_MASK)
36 #endif
37
38 #ifdef CONFIG_MMU
39 void *module_alloc(unsigned long size)
40 {
41         struct vm_struct *area;
42
43         size = PAGE_ALIGN(size);
44         if (!size)
45                 return NULL;
46
47         area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END);
48         if (!area)
49                 return NULL;
50
51         return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC);
52 }
53 #else /* CONFIG_MMU */
54 void *module_alloc(unsigned long size)
55 {
56         return size == 0 ? NULL : vmalloc(size);
57 }
58 #endif /* !CONFIG_MMU */
59
60 void module_free(struct module *module, void *region)
61 {
62         vfree(region);
63 }
64
65 int module_frob_arch_sections(Elf_Ehdr *hdr,
66                               Elf_Shdr *sechdrs,
67                               char *secstrings,
68                               struct module *mod)
69 {
70 #ifdef CONFIG_ARM_UNWIND
71         Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;
72
73         for (s = sechdrs; s < sechdrs_end; s++) {
74                 if (strcmp(".ARM.exidx.init.text", secstrings + s->sh_name) == 0)
75                         mod->arch.unw_sec_init = s;
76                 else if (strcmp(".ARM.exidx.devinit.text", secstrings + s->sh_name) == 0)
77                         mod->arch.unw_sec_devinit = s;
78                 else if (strcmp(".ARM.exidx", secstrings + s->sh_name) == 0)
79                         mod->arch.unw_sec_core = s;
80                 else if (strcmp(".init.text", secstrings + s->sh_name) == 0)
81                         mod->arch.sec_init_text = s;
82                 else if (strcmp(".devinit.text", secstrings + s->sh_name) == 0)
83                         mod->arch.sec_devinit_text = s;
84                 else if (strcmp(".text", secstrings + s->sh_name) == 0)
85                         mod->arch.sec_core_text = s;
86         }
87 #endif
88         return 0;
89 }
90
91 int
92 apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
93                unsigned int relindex, struct module *module)
94 {
95         Elf32_Shdr *symsec = sechdrs + symindex;
96         Elf32_Shdr *relsec = sechdrs + relindex;
97         Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
98         Elf32_Rel *rel = (void *)relsec->sh_addr;
99         unsigned int i;
100
101         for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) {
102                 unsigned long loc;
103                 Elf32_Sym *sym;
104                 s32 offset;
105 #ifdef CONFIG_THUMB2_KERNEL
106                 u32 upper, lower, sign, j1, j2;
107 #endif
108
109                 offset = ELF32_R_SYM(rel->r_info);
110                 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
111                         printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n",
112                                 module->name, relindex, i);
113                         return -ENOEXEC;
114                 }
115
116                 sym = ((Elf32_Sym *)symsec->sh_addr) + offset;
117
118                 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
119                         printk(KERN_ERR "%s: out of bounds relocation, "
120                                 "section %d reloc %d offset %d size %d\n",
121                                 module->name, relindex, i, rel->r_offset,
122                                 dstsec->sh_size);
123                         return -ENOEXEC;
124                 }
125
126                 loc = dstsec->sh_addr + rel->r_offset;
127
128                 switch (ELF32_R_TYPE(rel->r_info)) {
129                 case R_ARM_NONE:
130                         /* ignore */
131                         break;
132
133                 case R_ARM_ABS32:
134                         *(u32 *)loc += sym->st_value;
135                         break;
136
137                 case R_ARM_PC24:
138                 case R_ARM_CALL:
139                 case R_ARM_JUMP24:
140                         offset = (*(u32 *)loc & 0x00ffffff) << 2;
141                         if (offset & 0x02000000)
142                                 offset -= 0x04000000;
143
144                         offset += sym->st_value - loc;
145                         if (offset & 3 ||
146                             offset <= (s32)0xfe000000 ||
147                             offset >= (s32)0x02000000) {
148                                 printk(KERN_ERR
149                                        "%s: relocation out of range, section "
150                                        "%d reloc %d sym '%s'\n", module->name,
151                                        relindex, i, strtab + sym->st_name);
152                                 return -ENOEXEC;
153                         }
154
155                         offset >>= 2;
156
157                         *(u32 *)loc &= 0xff000000;
158                         *(u32 *)loc |= offset & 0x00ffffff;
159                         break;
160
161                case R_ARM_V4BX:
162                        /* Preserve Rm and the condition code. Alter
163                         * other bits to re-code instruction as
164                         * MOV PC,Rm.
165                         */
166                        *(u32 *)loc &= 0xf000000f;
167                        *(u32 *)loc |= 0x01a0f000;
168                        break;
169
170                 case R_ARM_PREL31:
171                         offset = *(u32 *)loc + sym->st_value - loc;
172                         *(u32 *)loc = offset & 0x7fffffff;
173                         break;
174
175                 case R_ARM_MOVW_ABS_NC:
176                 case R_ARM_MOVT_ABS:
177                         offset = *(u32 *)loc;
178                         offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);
179                         offset = (offset ^ 0x8000) - 0x8000;
180
181                         offset += sym->st_value;
182                         if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS)
183                                 offset >>= 16;
184
185                         *(u32 *)loc &= 0xfff0f000;
186                         *(u32 *)loc |= ((offset & 0xf000) << 4) |
187                                         (offset & 0x0fff);
188                         break;
189
190 #ifdef CONFIG_THUMB2_KERNEL
191                 case R_ARM_THM_CALL:
192                 case R_ARM_THM_JUMP24:
193                         upper = *(u16 *)loc;
194                         lower = *(u16 *)(loc + 2);
195
196                         /*
197                          * 25 bit signed address range (Thumb-2 BL and B.W
198                          * instructions):
199                          *   S:I1:I2:imm10:imm11:0
200                          * where:
201                          *   S     = upper[10]   = offset[24]
202                          *   I1    = ~(J1 ^ S)   = offset[23]
203                          *   I2    = ~(J2 ^ S)   = offset[22]
204                          *   imm10 = upper[9:0]  = offset[21:12]
205                          *   imm11 = lower[10:0] = offset[11:1]
206                          *   J1    = lower[13]
207                          *   J2    = lower[11]
208                          */
209                         sign = (upper >> 10) & 1;
210                         j1 = (lower >> 13) & 1;
211                         j2 = (lower >> 11) & 1;
212                         offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) |
213                                 ((~(j2 ^ sign) & 1) << 22) |
214                                 ((upper & 0x03ff) << 12) |
215                                 ((lower & 0x07ff) << 1);
216                         if (offset & 0x01000000)
217                                 offset -= 0x02000000;
218                         offset += sym->st_value - loc;
219
220                         /* only Thumb addresses allowed (no interworking) */
221                         if (!(offset & 1) ||
222                             offset <= (s32)0xff000000 ||
223                             offset >= (s32)0x01000000) {
224                                 printk(KERN_ERR
225                                        "%s: relocation out of range, section "
226                                        "%d reloc %d sym '%s'\n", module->name,
227                                        relindex, i, strtab + sym->st_name);
228                                 return -ENOEXEC;
229                         }
230
231                         sign = (offset >> 24) & 1;
232                         j1 = sign ^ (~(offset >> 23) & 1);
233                         j2 = sign ^ (~(offset >> 22) & 1);
234                         *(u16 *)loc = (u16)((upper & 0xf800) | (sign << 10) |
235                                             ((offset >> 12) & 0x03ff));
236                         *(u16 *)(loc + 2) = (u16)((lower & 0xd000) |
237                                                   (j1 << 13) | (j2 << 11) |
238                                                   ((offset >> 1) & 0x07ff));
239                         break;
240
241                 case R_ARM_THM_MOVW_ABS_NC:
242                 case R_ARM_THM_MOVT_ABS:
243                         upper = *(u16 *)loc;
244                         lower = *(u16 *)(loc + 2);
245
246                         /*
247                          * MOVT/MOVW instructions encoding in Thumb-2:
248                          *
249                          * i    = upper[10]
250                          * imm4 = upper[3:0]
251                          * imm3 = lower[14:12]
252                          * imm8 = lower[7:0]
253                          *
254                          * imm16 = imm4:i:imm3:imm8
255                          */
256                         offset = ((upper & 0x000f) << 12) |
257                                 ((upper & 0x0400) << 1) |
258                                 ((lower & 0x7000) >> 4) | (lower & 0x00ff);
259                         offset = (offset ^ 0x8000) - 0x8000;
260                         offset += sym->st_value;
261
262                         if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS)
263                                 offset >>= 16;
264
265                         *(u16 *)loc = (u16)((upper & 0xfbf0) |
266                                             ((offset & 0xf000) >> 12) |
267                                             ((offset & 0x0800) >> 1));
268                         *(u16 *)(loc + 2) = (u16)((lower & 0x8f00) |
269                                                   ((offset & 0x0700) << 4) |
270                                                   (offset & 0x00ff));
271                         break;
272 #endif
273
274                 default:
275                         printk(KERN_ERR "%s: unknown relocation: %u\n",
276                                module->name, ELF32_R_TYPE(rel->r_info));
277                         return -ENOEXEC;
278                 }
279         }
280         return 0;
281 }
282
283 int
284 apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
285                    unsigned int symindex, unsigned int relsec, struct module *module)
286 {
287         printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
288                module->name);
289         return -ENOEXEC;
290 }
291
292 #ifdef CONFIG_ARM_UNWIND
293 static void register_unwind_tables(struct module *mod)
294 {
295         if (mod->arch.unw_sec_init && mod->arch.sec_init_text)
296                 mod->arch.unwind_init =
297                         unwind_table_add(mod->arch.unw_sec_init->sh_addr,
298                                          mod->arch.unw_sec_init->sh_size,
299                                          mod->arch.sec_init_text->sh_addr,
300                                          mod->arch.sec_init_text->sh_size);
301         if (mod->arch.unw_sec_devinit && mod->arch.sec_devinit_text)
302                 mod->arch.unwind_devinit =
303                         unwind_table_add(mod->arch.unw_sec_devinit->sh_addr,
304                                          mod->arch.unw_sec_devinit->sh_size,
305                                          mod->arch.sec_devinit_text->sh_addr,
306                                          mod->arch.sec_devinit_text->sh_size);
307         if (mod->arch.unw_sec_core && mod->arch.sec_core_text)
308                 mod->arch.unwind_core =
309                         unwind_table_add(mod->arch.unw_sec_core->sh_addr,
310                                          mod->arch.unw_sec_core->sh_size,
311                                          mod->arch.sec_core_text->sh_addr,
312                                          mod->arch.sec_core_text->sh_size);
313 }
314
315 static void unregister_unwind_tables(struct module *mod)
316 {
317         unwind_table_del(mod->arch.unwind_init);
318         unwind_table_del(mod->arch.unwind_devinit);
319         unwind_table_del(mod->arch.unwind_core);
320 }
321 #else
322 static inline void register_unwind_tables(struct module *mod) { }
323 static inline void unregister_unwind_tables(struct module *mod) { }
324 #endif
325
326 int
327 module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
328                 struct module *module)
329 {
330         register_unwind_tables(module);
331         return 0;
332 }
333
334 void
335 module_arch_cleanup(struct module *mod)
336 {
337         unregister_unwind_tables(mod);
338 }