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 case R_ARM_MOVW_ABS_NC: 173 case R_ARM_MOVT_ABS: 174 offset = *(u32 *)loc; 175 offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff); 176 offset = (offset ^ 0x8000) - 0x8000; 177 178 offset += sym->st_value; 179 if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS) 180 offset >>= 16; 181 182 *(u32 *)loc &= 0xfff0f000; 183 *(u32 *)loc |= ((offset & 0xf000) << 4) | 184 (offset & 0x0fff); 185 break; 186 187 default: 188 printk(KERN_ERR "%s: unknown relocation: %u\n", 189 module->name, ELF32_R_TYPE(rel->r_info)); 190 return -ENOEXEC; 191 } 192 } 193 return 0; 194 } 195 196 int 197 apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, 198 unsigned int symindex, unsigned int relsec, struct module *module) 199 { 200 printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n", 201 module->name); 202 return -ENOEXEC; 203 } 204 205 #ifdef CONFIG_ARM_UNWIND 206 static void register_unwind_tables(struct module *mod) 207 { 208 if (mod->arch.unw_sec_init && mod->arch.sec_init_text) 209 mod->arch.unwind_init = 210 unwind_table_add(mod->arch.unw_sec_init->sh_addr, 211 mod->arch.unw_sec_init->sh_size, 212 mod->arch.sec_init_text->sh_addr, 213 mod->arch.sec_init_text->sh_size); 214 if (mod->arch.unw_sec_devinit && mod->arch.sec_devinit_text) 215 mod->arch.unwind_devinit = 216 unwind_table_add(mod->arch.unw_sec_devinit->sh_addr, 217 mod->arch.unw_sec_devinit->sh_size, 218 mod->arch.sec_devinit_text->sh_addr, 219 mod->arch.sec_devinit_text->sh_size); 220 if (mod->arch.unw_sec_core && mod->arch.sec_core_text) 221 mod->arch.unwind_core = 222 unwind_table_add(mod->arch.unw_sec_core->sh_addr, 223 mod->arch.unw_sec_core->sh_size, 224 mod->arch.sec_core_text->sh_addr, 225 mod->arch.sec_core_text->sh_size); 226 } 227 228 static void unregister_unwind_tables(struct module *mod) 229 { 230 unwind_table_del(mod->arch.unwind_init); 231 unwind_table_del(mod->arch.unwind_devinit); 232 unwind_table_del(mod->arch.unwind_core); 233 } 234 #else 235 static inline void register_unwind_tables(struct module *mod) { } 236 static inline void unregister_unwind_tables(struct module *mod) { } 237 #endif 238 239 int 240 module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, 241 struct module *module) 242 { 243 register_unwind_tables(module); 244 return 0; 245 } 246 247 void 248 module_arch_cleanup(struct module *mod) 249 { 250 unregister_unwind_tables(mod); 251 } 252