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 return 0; 71 } 72 73 int 74 apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, 75 unsigned int relindex, struct module *module) 76 { 77 Elf32_Shdr *symsec = sechdrs + symindex; 78 Elf32_Shdr *relsec = sechdrs + relindex; 79 Elf32_Shdr *dstsec = sechdrs + relsec->sh_info; 80 Elf32_Rel *rel = (void *)relsec->sh_addr; 81 unsigned int i; 82 83 for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) { 84 unsigned long loc; 85 Elf32_Sym *sym; 86 s32 offset; 87 #ifdef CONFIG_THUMB2_KERNEL 88 u32 upper, lower, sign, j1, j2; 89 #endif 90 91 offset = ELF32_R_SYM(rel->r_info); 92 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) { 93 printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n", 94 module->name, relindex, i); 95 return -ENOEXEC; 96 } 97 98 sym = ((Elf32_Sym *)symsec->sh_addr) + offset; 99 100 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) { 101 printk(KERN_ERR "%s: out of bounds relocation, " 102 "section %d reloc %d offset %d size %d\n", 103 module->name, relindex, i, rel->r_offset, 104 dstsec->sh_size); 105 return -ENOEXEC; 106 } 107 108 loc = dstsec->sh_addr + rel->r_offset; 109 110 switch (ELF32_R_TYPE(rel->r_info)) { 111 case R_ARM_NONE: 112 /* ignore */ 113 break; 114 115 case R_ARM_ABS32: 116 *(u32 *)loc += sym->st_value; 117 break; 118 119 case R_ARM_PC24: 120 case R_ARM_CALL: 121 case R_ARM_JUMP24: 122 offset = (*(u32 *)loc & 0x00ffffff) << 2; 123 if (offset & 0x02000000) 124 offset -= 0x04000000; 125 126 offset += sym->st_value - loc; 127 if (offset & 3 || 128 offset <= (s32)0xfe000000 || 129 offset >= (s32)0x02000000) { 130 printk(KERN_ERR 131 "%s: relocation out of range, section " 132 "%d reloc %d sym '%s'\n", module->name, 133 relindex, i, strtab + sym->st_name); 134 return -ENOEXEC; 135 } 136 137 offset >>= 2; 138 139 *(u32 *)loc &= 0xff000000; 140 *(u32 *)loc |= offset & 0x00ffffff; 141 break; 142 143 case R_ARM_V4BX: 144 /* Preserve Rm and the condition code. Alter 145 * other bits to re-code instruction as 146 * MOV PC,Rm. 147 */ 148 *(u32 *)loc &= 0xf000000f; 149 *(u32 *)loc |= 0x01a0f000; 150 break; 151 152 case R_ARM_PREL31: 153 offset = *(u32 *)loc + sym->st_value - loc; 154 *(u32 *)loc = offset & 0x7fffffff; 155 break; 156 157 case R_ARM_MOVW_ABS_NC: 158 case R_ARM_MOVT_ABS: 159 offset = *(u32 *)loc; 160 offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff); 161 offset = (offset ^ 0x8000) - 0x8000; 162 163 offset += sym->st_value; 164 if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS) 165 offset >>= 16; 166 167 *(u32 *)loc &= 0xfff0f000; 168 *(u32 *)loc |= ((offset & 0xf000) << 4) | 169 (offset & 0x0fff); 170 break; 171 172 #ifdef CONFIG_THUMB2_KERNEL 173 case R_ARM_THM_CALL: 174 case R_ARM_THM_JUMP24: 175 upper = *(u16 *)loc; 176 lower = *(u16 *)(loc + 2); 177 178 /* 179 * 25 bit signed address range (Thumb-2 BL and B.W 180 * instructions): 181 * S:I1:I2:imm10:imm11:0 182 * where: 183 * S = upper[10] = offset[24] 184 * I1 = ~(J1 ^ S) = offset[23] 185 * I2 = ~(J2 ^ S) = offset[22] 186 * imm10 = upper[9:0] = offset[21:12] 187 * imm11 = lower[10:0] = offset[11:1] 188 * J1 = lower[13] 189 * J2 = lower[11] 190 */ 191 sign = (upper >> 10) & 1; 192 j1 = (lower >> 13) & 1; 193 j2 = (lower >> 11) & 1; 194 offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) | 195 ((~(j2 ^ sign) & 1) << 22) | 196 ((upper & 0x03ff) << 12) | 197 ((lower & 0x07ff) << 1); 198 if (offset & 0x01000000) 199 offset -= 0x02000000; 200 offset += sym->st_value - loc; 201 202 /* only Thumb addresses allowed (no interworking) */ 203 if (!(offset & 1) || 204 offset <= (s32)0xff000000 || 205 offset >= (s32)0x01000000) { 206 printk(KERN_ERR 207 "%s: relocation out of range, section " 208 "%d reloc %d sym '%s'\n", module->name, 209 relindex, i, strtab + sym->st_name); 210 return -ENOEXEC; 211 } 212 213 sign = (offset >> 24) & 1; 214 j1 = sign ^ (~(offset >> 23) & 1); 215 j2 = sign ^ (~(offset >> 22) & 1); 216 *(u16 *)loc = (u16)((upper & 0xf800) | (sign << 10) | 217 ((offset >> 12) & 0x03ff)); 218 *(u16 *)(loc + 2) = (u16)((lower & 0xd000) | 219 (j1 << 13) | (j2 << 11) | 220 ((offset >> 1) & 0x07ff)); 221 break; 222 223 case R_ARM_THM_MOVW_ABS_NC: 224 case R_ARM_THM_MOVT_ABS: 225 upper = *(u16 *)loc; 226 lower = *(u16 *)(loc + 2); 227 228 /* 229 * MOVT/MOVW instructions encoding in Thumb-2: 230 * 231 * i = upper[10] 232 * imm4 = upper[3:0] 233 * imm3 = lower[14:12] 234 * imm8 = lower[7:0] 235 * 236 * imm16 = imm4:i:imm3:imm8 237 */ 238 offset = ((upper & 0x000f) << 12) | 239 ((upper & 0x0400) << 1) | 240 ((lower & 0x7000) >> 4) | (lower & 0x00ff); 241 offset = (offset ^ 0x8000) - 0x8000; 242 offset += sym->st_value; 243 244 if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS) 245 offset >>= 16; 246 247 *(u16 *)loc = (u16)((upper & 0xfbf0) | 248 ((offset & 0xf000) >> 12) | 249 ((offset & 0x0800) >> 1)); 250 *(u16 *)(loc + 2) = (u16)((lower & 0x8f00) | 251 ((offset & 0x0700) << 4) | 252 (offset & 0x00ff)); 253 break; 254 #endif 255 256 default: 257 printk(KERN_ERR "%s: unknown relocation: %u\n", 258 module->name, ELF32_R_TYPE(rel->r_info)); 259 return -ENOEXEC; 260 } 261 } 262 return 0; 263 } 264 265 int 266 apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, 267 unsigned int symindex, unsigned int relsec, struct module *module) 268 { 269 printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n", 270 module->name); 271 return -ENOEXEC; 272 } 273 274 struct mod_unwind_map { 275 const Elf_Shdr *unw_sec; 276 const Elf_Shdr *txt_sec; 277 }; 278 279 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, 280 struct module *mod) 281 { 282 #ifdef CONFIG_ARM_UNWIND 283 const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 284 const Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum; 285 struct mod_unwind_map maps[ARM_SEC_MAX]; 286 int i; 287 288 memset(maps, 0, sizeof(maps)); 289 290 for (s = sechdrs; s < sechdrs_end; s++) { 291 const char *secname = secstrs + s->sh_name; 292 293 if (!(s->sh_flags & SHF_ALLOC)) 294 continue; 295 296 if (strcmp(".ARM.exidx.init.text", secname) == 0) 297 maps[ARM_SEC_INIT].unw_sec = s; 298 else if (strcmp(".ARM.exidx.devinit.text", secname) == 0) 299 maps[ARM_SEC_DEVINIT].unw_sec = s; 300 else if (strcmp(".ARM.exidx", secname) == 0) 301 maps[ARM_SEC_CORE].unw_sec = s; 302 else if (strcmp(".ARM.exidx.exit.text", secname) == 0) 303 maps[ARM_SEC_EXIT].unw_sec = s; 304 else if (strcmp(".ARM.exidx.devexit.text", secname) == 0) 305 maps[ARM_SEC_DEVEXIT].unw_sec = s; 306 else if (strcmp(".init.text", secname) == 0) 307 maps[ARM_SEC_INIT].txt_sec = s; 308 else if (strcmp(".devinit.text", secname) == 0) 309 maps[ARM_SEC_DEVINIT].txt_sec = s; 310 else if (strcmp(".text", secname) == 0) 311 maps[ARM_SEC_CORE].txt_sec = s; 312 else if (strcmp(".exit.text", secname) == 0) 313 maps[ARM_SEC_EXIT].txt_sec = s; 314 else if (strcmp(".devexit.text", secname) == 0) 315 maps[ARM_SEC_DEVEXIT].txt_sec = s; 316 } 317 318 for (i = 0; i < ARM_SEC_MAX; i++) 319 if (maps[i].unw_sec && maps[i].txt_sec) 320 mod->arch.unwind[i] = 321 unwind_table_add(maps[i].unw_sec->sh_addr, 322 maps[i].unw_sec->sh_size, 323 maps[i].txt_sec->sh_addr, 324 maps[i].txt_sec->sh_size); 325 #endif 326 return 0; 327 } 328 329 void 330 module_arch_cleanup(struct module *mod) 331 { 332 #ifdef CONFIG_ARM_UNWIND 333 int i; 334 335 for (i = 0; i < ARM_SEC_MAX; i++) 336 if (mod->arch.unwind[i]) 337 unwind_table_del(mod->arch.unwind[i]); 338 #endif 339 } 340