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 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 } 305