Merge branch 'for-rmk' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux...
[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                 u32 upper, lower, sign, j1, j2;
106
107                 offset = ELF32_R_SYM(rel->r_info);
108                 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
109                         printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n",
110                                 module->name, relindex, i);
111                         return -ENOEXEC;
112                 }
113
114                 sym = ((Elf32_Sym *)symsec->sh_addr) + offset;
115
116                 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
117                         printk(KERN_ERR "%s: out of bounds relocation, "
118                                 "section %d reloc %d offset %d size %d\n",
119                                 module->name, relindex, i, rel->r_offset,
120                                 dstsec->sh_size);
121                         return -ENOEXEC;
122                 }
123
124                 loc = dstsec->sh_addr + rel->r_offset;
125
126                 switch (ELF32_R_TYPE(rel->r_info)) {
127                 case R_ARM_NONE:
128                         /* ignore */
129                         break;
130
131                 case R_ARM_ABS32:
132                         *(u32 *)loc += sym->st_value;
133                         break;
134
135                 case R_ARM_PC24:
136                 case R_ARM_CALL:
137                 case R_ARM_JUMP24:
138                         offset = (*(u32 *)loc & 0x00ffffff) << 2;
139                         if (offset & 0x02000000)
140                                 offset -= 0x04000000;
141
142                         offset += sym->st_value - loc;
143                         if (offset & 3 ||
144                             offset <= (s32)0xfe000000 ||
145                             offset >= (s32)0x02000000) {
146                                 printk(KERN_ERR
147                                        "%s: relocation out of range, section "
148                                        "%d reloc %d sym '%s'\n", module->name,
149                                        relindex, i, strtab + sym->st_name);
150                                 return -ENOEXEC;
151                         }
152
153                         offset >>= 2;
154
155                         *(u32 *)loc &= 0xff000000;
156                         *(u32 *)loc |= offset & 0x00ffffff;
157                         break;
158
159                case R_ARM_V4BX:
160                        /* Preserve Rm and the condition code. Alter
161                         * other bits to re-code instruction as
162                         * MOV PC,Rm.
163                         */
164                        *(u32 *)loc &= 0xf000000f;
165                        *(u32 *)loc |= 0x01a0f000;
166                        break;
167
168                 case R_ARM_PREL31:
169                         offset = *(u32 *)loc + sym->st_value - loc;
170                         *(u32 *)loc = offset & 0x7fffffff;
171                         break;
172
173                 case R_ARM_MOVW_ABS_NC:
174                 case R_ARM_MOVT_ABS:
175                         offset = *(u32 *)loc;
176                         offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);
177                         offset = (offset ^ 0x8000) - 0x8000;
178
179                         offset += sym->st_value;
180                         if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS)
181                                 offset >>= 16;
182
183                         *(u32 *)loc &= 0xfff0f000;
184                         *(u32 *)loc |= ((offset & 0xf000) << 4) |
185                                         (offset & 0x0fff);
186                         break;
187
188                 case R_ARM_THM_CALL:
189                 case R_ARM_THM_JUMP24:
190                         upper = *(u16 *)loc;
191                         lower = *(u16 *)(loc + 2);
192
193                         /*
194                          * 25 bit signed address range (Thumb-2 BL and B.W
195                          * instructions):
196                          *   S:I1:I2:imm10:imm11:0
197                          * where:
198                          *   S     = upper[10]   = offset[24]
199                          *   I1    = ~(J1 ^ S)   = offset[23]
200                          *   I2    = ~(J2 ^ S)   = offset[22]
201                          *   imm10 = upper[9:0]  = offset[21:12]
202                          *   imm11 = lower[10:0] = offset[11:1]
203                          *   J1    = lower[13]
204                          *   J2    = lower[11]
205                          */
206                         sign = (upper >> 10) & 1;
207                         j1 = (lower >> 13) & 1;
208                         j2 = (lower >> 11) & 1;
209                         offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) |
210                                 ((~(j2 ^ sign) & 1) << 22) |
211                                 ((upper & 0x03ff) << 12) |
212                                 ((lower & 0x07ff) << 1);
213                         if (offset & 0x01000000)
214                                 offset -= 0x02000000;
215                         offset += sym->st_value - loc;
216
217                         /* only Thumb addresses allowed (no interworking) */
218                         if (!(offset & 1) ||
219                             offset <= (s32)0xff000000 ||
220                             offset >= (s32)0x01000000) {
221                                 printk(KERN_ERR
222                                        "%s: relocation out of range, section "
223                                        "%d reloc %d sym '%s'\n", module->name,
224                                        relindex, i, strtab + sym->st_name);
225                                 return -ENOEXEC;
226                         }
227
228                         sign = (offset >> 24) & 1;
229                         j1 = sign ^ (~(offset >> 23) & 1);
230                         j2 = sign ^ (~(offset >> 22) & 1);
231                         *(u16 *)loc = (u16)((upper & 0xf800) | (sign << 10) |
232                                             ((offset >> 12) & 0x03ff));
233                         *(u16 *)(loc + 2) = (u16)((lower & 0xd000) |
234                                                   (j1 << 13) | (j2 << 11) |
235                                                   ((offset >> 1) & 0x07ff));
236                         upper = *(u16 *)loc;
237                         lower = *(u16 *)(loc + 2);
238                         break;
239
240                 default:
241                         printk(KERN_ERR "%s: unknown relocation: %u\n",
242                                module->name, ELF32_R_TYPE(rel->r_info));
243                         return -ENOEXEC;
244                 }
245         }
246         return 0;
247 }
248
249 int
250 apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
251                    unsigned int symindex, unsigned int relsec, struct module *module)
252 {
253         printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
254                module->name);
255         return -ENOEXEC;
256 }
257
258 #ifdef CONFIG_ARM_UNWIND
259 static void register_unwind_tables(struct module *mod)
260 {
261         if (mod->arch.unw_sec_init && mod->arch.sec_init_text)
262                 mod->arch.unwind_init =
263                         unwind_table_add(mod->arch.unw_sec_init->sh_addr,
264                                          mod->arch.unw_sec_init->sh_size,
265                                          mod->arch.sec_init_text->sh_addr,
266                                          mod->arch.sec_init_text->sh_size);
267         if (mod->arch.unw_sec_devinit && mod->arch.sec_devinit_text)
268                 mod->arch.unwind_devinit =
269                         unwind_table_add(mod->arch.unw_sec_devinit->sh_addr,
270                                          mod->arch.unw_sec_devinit->sh_size,
271                                          mod->arch.sec_devinit_text->sh_addr,
272                                          mod->arch.sec_devinit_text->sh_size);
273         if (mod->arch.unw_sec_core && mod->arch.sec_core_text)
274                 mod->arch.unwind_core =
275                         unwind_table_add(mod->arch.unw_sec_core->sh_addr,
276                                          mod->arch.unw_sec_core->sh_size,
277                                          mod->arch.sec_core_text->sh_addr,
278                                          mod->arch.sec_core_text->sh_size);
279 }
280
281 static void unregister_unwind_tables(struct module *mod)
282 {
283         unwind_table_del(mod->arch.unwind_init);
284         unwind_table_del(mod->arch.unwind_devinit);
285         unwind_table_del(mod->arch.unwind_core);
286 }
287 #else
288 static inline void register_unwind_tables(struct module *mod) { }
289 static inline void unregister_unwind_tables(struct module *mod) { }
290 #endif
291
292 int
293 module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
294                 struct module *module)
295 {
296         register_unwind_tables(module);
297         return 0;
298 }
299
300 void
301 module_arch_cleanup(struct module *mod)
302 {
303         unregister_unwind_tables(mod);
304 }