d1731e39b496cc436a79fbb0631f181e166580e7
[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/slab.h>
20 #include <linux/fs.h>
21 #include <linux/string.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
106                 offset = ELF32_R_SYM(rel->r_info);
107                 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
108                         printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n",
109                                 module->name, relindex, i);
110                         return -ENOEXEC;
111                 }
112
113                 sym = ((Elf32_Sym *)symsec->sh_addr) + offset;
114
115                 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
116                         printk(KERN_ERR "%s: out of bounds relocation, "
117                                 "section %d reloc %d offset %d size %d\n",
118                                 module->name, relindex, i, rel->r_offset,
119                                 dstsec->sh_size);
120                         return -ENOEXEC;
121                 }
122
123                 loc = dstsec->sh_addr + rel->r_offset;
124
125                 switch (ELF32_R_TYPE(rel->r_info)) {
126                 case R_ARM_NONE:
127                         /* ignore */
128                         break;
129
130                 case R_ARM_ABS32:
131                         *(u32 *)loc += sym->st_value;
132                         break;
133
134                 case R_ARM_PC24:
135                 case R_ARM_CALL:
136                 case R_ARM_JUMP24:
137                         offset = (*(u32 *)loc & 0x00ffffff) << 2;
138                         if (offset & 0x02000000)
139                                 offset -= 0x04000000;
140
141                         offset += sym->st_value - loc;
142                         if (offset & 3 ||
143                             offset <= (s32)0xfe000000 ||
144                             offset >= (s32)0x02000000) {
145                                 printk(KERN_ERR
146                                        "%s: relocation out of range, section "
147                                        "%d reloc %d sym '%s'\n", module->name,
148                                        relindex, i, strtab + sym->st_name);
149                                 return -ENOEXEC;
150                         }
151
152                         offset >>= 2;
153
154                         *(u32 *)loc &= 0xff000000;
155                         *(u32 *)loc |= offset & 0x00ffffff;
156                         break;
157
158                case R_ARM_V4BX:
159                        /* Preserve Rm and the condition code. Alter
160                         * other bits to re-code instruction as
161                         * MOV PC,Rm.
162                         */
163                        *(u32 *)loc &= 0xf000000f;
164                        *(u32 *)loc |= 0x01a0f000;
165                        break;
166
167                 case R_ARM_PREL31:
168                         offset = *(u32 *)loc + sym->st_value - loc;
169                         *(u32 *)loc = offset & 0x7fffffff;
170                         break;
171
172                 default:
173                         printk(KERN_ERR "%s: unknown relocation: %u\n",
174                                module->name, ELF32_R_TYPE(rel->r_info));
175                         return -ENOEXEC;
176                 }
177         }
178         return 0;
179 }
180
181 int
182 apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
183                    unsigned int symindex, unsigned int relsec, struct module *module)
184 {
185         printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
186                module->name);
187         return -ENOEXEC;
188 }
189
190 #ifdef CONFIG_ARM_UNWIND
191 static void register_unwind_tables(struct module *mod)
192 {
193         if (mod->arch.unw_sec_init && mod->arch.sec_init_text)
194                 mod->arch.unwind_init =
195                         unwind_table_add(mod->arch.unw_sec_init->sh_addr,
196                                          mod->arch.unw_sec_init->sh_size,
197                                          mod->arch.sec_init_text->sh_addr,
198                                          mod->arch.sec_init_text->sh_size);
199         if (mod->arch.unw_sec_devinit && mod->arch.sec_devinit_text)
200                 mod->arch.unwind_devinit =
201                         unwind_table_add(mod->arch.unw_sec_devinit->sh_addr,
202                                          mod->arch.unw_sec_devinit->sh_size,
203                                          mod->arch.sec_devinit_text->sh_addr,
204                                          mod->arch.sec_devinit_text->sh_size);
205         if (mod->arch.unw_sec_core && mod->arch.sec_core_text)
206                 mod->arch.unwind_core =
207                         unwind_table_add(mod->arch.unw_sec_core->sh_addr,
208                                          mod->arch.unw_sec_core->sh_size,
209                                          mod->arch.sec_core_text->sh_addr,
210                                          mod->arch.sec_core_text->sh_size);
211 }
212
213 static void unregister_unwind_tables(struct module *mod)
214 {
215         unwind_table_del(mod->arch.unwind_init);
216         unwind_table_del(mod->arch.unwind_devinit);
217         unwind_table_del(mod->arch.unwind_core);
218 }
219 #else
220 static inline void register_unwind_tables(struct module *mod) { }
221 static inline void unregister_unwind_tables(struct module *mod) { }
222 #endif
223
224 int
225 module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
226                 struct module *module)
227 {
228         register_unwind_tables(module);
229         return 0;
230 }
231
232 void
233 module_arch_cleanup(struct module *mod)
234 {
235         unregister_unwind_tables(mod);
236 }