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/smp_plat.h> 26 #include <asm/unwind.h> 27 28 #ifdef CONFIG_XIP_KERNEL 29 /* 30 * The XIP kernel text is mapped in the module area for modules and 31 * some other stuff to work without any indirect relocations. 32 * MODULES_VADDR is redefined here and not in asm/memory.h to avoid 33 * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off. 34 */ 35 #undef MODULES_VADDR 36 #define MODULES_VADDR (((unsigned long)_etext + ~PGDIR_MASK) & PGDIR_MASK) 37 #endif 38 39 #ifdef CONFIG_MMU 40 void *module_alloc(unsigned long size) 41 { 42 return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, 43 GFP_KERNEL, PAGE_KERNEL_EXEC, -1, 44 __builtin_return_address(0)); 45 } 46 #else /* CONFIG_MMU */ 47 void *module_alloc(unsigned long size) 48 { 49 return size == 0 ? NULL : vmalloc(size); 50 } 51 #endif /* !CONFIG_MMU */ 52 53 void module_free(struct module *module, void *region) 54 { 55 vfree(region); 56 } 57 58 int module_frob_arch_sections(Elf_Ehdr *hdr, 59 Elf_Shdr *sechdrs, 60 char *secstrings, 61 struct module *mod) 62 { 63 return 0; 64 } 65 66 int 67 apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, 68 unsigned int relindex, struct module *module) 69 { 70 Elf32_Shdr *symsec = sechdrs + symindex; 71 Elf32_Shdr *relsec = sechdrs + relindex; 72 Elf32_Shdr *dstsec = sechdrs + relsec->sh_info; 73 Elf32_Rel *rel = (void *)relsec->sh_addr; 74 unsigned int i; 75 76 for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) { 77 unsigned long loc; 78 Elf32_Sym *sym; 79 s32 offset; 80 #ifdef CONFIG_THUMB2_KERNEL 81 u32 upper, lower, sign, j1, j2; 82 #endif 83 84 offset = ELF32_R_SYM(rel->r_info); 85 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) { 86 printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n", 87 module->name, relindex, i); 88 return -ENOEXEC; 89 } 90 91 sym = ((Elf32_Sym *)symsec->sh_addr) + offset; 92 93 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) { 94 printk(KERN_ERR "%s: out of bounds relocation, " 95 "section %d reloc %d offset %d size %d\n", 96 module->name, relindex, i, rel->r_offset, 97 dstsec->sh_size); 98 return -ENOEXEC; 99 } 100 101 loc = dstsec->sh_addr + rel->r_offset; 102 103 switch (ELF32_R_TYPE(rel->r_info)) { 104 case R_ARM_NONE: 105 /* ignore */ 106 break; 107 108 case R_ARM_ABS32: 109 *(u32 *)loc += sym->st_value; 110 break; 111 112 case R_ARM_PC24: 113 case R_ARM_CALL: 114 case R_ARM_JUMP24: 115 offset = (*(u32 *)loc & 0x00ffffff) << 2; 116 if (offset & 0x02000000) 117 offset -= 0x04000000; 118 119 offset += sym->st_value - loc; 120 if (offset & 3 || 121 offset <= (s32)0xfe000000 || 122 offset >= (s32)0x02000000) { 123 printk(KERN_ERR 124 "%s: relocation out of range, section " 125 "%d reloc %d sym '%s'\n", module->name, 126 relindex, i, strtab + sym->st_name); 127 return -ENOEXEC; 128 } 129 130 offset >>= 2; 131 132 *(u32 *)loc &= 0xff000000; 133 *(u32 *)loc |= offset & 0x00ffffff; 134 break; 135 136 case R_ARM_V4BX: 137 /* Preserve Rm and the condition code. Alter 138 * other bits to re-code instruction as 139 * MOV PC,Rm. 140 */ 141 *(u32 *)loc &= 0xf000000f; 142 *(u32 *)loc |= 0x01a0f000; 143 break; 144 145 case R_ARM_PREL31: 146 offset = *(u32 *)loc + sym->st_value - loc; 147 *(u32 *)loc = offset & 0x7fffffff; 148 break; 149 150 case R_ARM_MOVW_ABS_NC: 151 case R_ARM_MOVT_ABS: 152 offset = *(u32 *)loc; 153 offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff); 154 offset = (offset ^ 0x8000) - 0x8000; 155 156 offset += sym->st_value; 157 if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS) 158 offset >>= 16; 159 160 *(u32 *)loc &= 0xfff0f000; 161 *(u32 *)loc |= ((offset & 0xf000) << 4) | 162 (offset & 0x0fff); 163 break; 164 165 #ifdef CONFIG_THUMB2_KERNEL 166 case R_ARM_THM_CALL: 167 case R_ARM_THM_JUMP24: 168 upper = *(u16 *)loc; 169 lower = *(u16 *)(loc + 2); 170 171 /* 172 * 25 bit signed address range (Thumb-2 BL and B.W 173 * instructions): 174 * S:I1:I2:imm10:imm11:0 175 * where: 176 * S = upper[10] = offset[24] 177 * I1 = ~(J1 ^ S) = offset[23] 178 * I2 = ~(J2 ^ S) = offset[22] 179 * imm10 = upper[9:0] = offset[21:12] 180 * imm11 = lower[10:0] = offset[11:1] 181 * J1 = lower[13] 182 * J2 = lower[11] 183 */ 184 sign = (upper >> 10) & 1; 185 j1 = (lower >> 13) & 1; 186 j2 = (lower >> 11) & 1; 187 offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) | 188 ((~(j2 ^ sign) & 1) << 22) | 189 ((upper & 0x03ff) << 12) | 190 ((lower & 0x07ff) << 1); 191 if (offset & 0x01000000) 192 offset -= 0x02000000; 193 offset += sym->st_value - loc; 194 195 /* only Thumb addresses allowed (no interworking) */ 196 if (!(offset & 1) || 197 offset <= (s32)0xff000000 || 198 offset >= (s32)0x01000000) { 199 printk(KERN_ERR 200 "%s: relocation out of range, section " 201 "%d reloc %d sym '%s'\n", module->name, 202 relindex, i, strtab + sym->st_name); 203 return -ENOEXEC; 204 } 205 206 sign = (offset >> 24) & 1; 207 j1 = sign ^ (~(offset >> 23) & 1); 208 j2 = sign ^ (~(offset >> 22) & 1); 209 *(u16 *)loc = (u16)((upper & 0xf800) | (sign << 10) | 210 ((offset >> 12) & 0x03ff)); 211 *(u16 *)(loc + 2) = (u16)((lower & 0xd000) | 212 (j1 << 13) | (j2 << 11) | 213 ((offset >> 1) & 0x07ff)); 214 break; 215 216 case R_ARM_THM_MOVW_ABS_NC: 217 case R_ARM_THM_MOVT_ABS: 218 upper = *(u16 *)loc; 219 lower = *(u16 *)(loc + 2); 220 221 /* 222 * MOVT/MOVW instructions encoding in Thumb-2: 223 * 224 * i = upper[10] 225 * imm4 = upper[3:0] 226 * imm3 = lower[14:12] 227 * imm8 = lower[7:0] 228 * 229 * imm16 = imm4:i:imm3:imm8 230 */ 231 offset = ((upper & 0x000f) << 12) | 232 ((upper & 0x0400) << 1) | 233 ((lower & 0x7000) >> 4) | (lower & 0x00ff); 234 offset = (offset ^ 0x8000) - 0x8000; 235 offset += sym->st_value; 236 237 if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS) 238 offset >>= 16; 239 240 *(u16 *)loc = (u16)((upper & 0xfbf0) | 241 ((offset & 0xf000) >> 12) | 242 ((offset & 0x0800) >> 1)); 243 *(u16 *)(loc + 2) = (u16)((lower & 0x8f00) | 244 ((offset & 0x0700) << 4) | 245 (offset & 0x00ff)); 246 break; 247 #endif 248 249 default: 250 printk(KERN_ERR "%s: unknown relocation: %u\n", 251 module->name, ELF32_R_TYPE(rel->r_info)); 252 return -ENOEXEC; 253 } 254 } 255 return 0; 256 } 257 258 int 259 apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, 260 unsigned int symindex, unsigned int relsec, struct module *module) 261 { 262 printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n", 263 module->name); 264 return -ENOEXEC; 265 } 266 267 struct mod_unwind_map { 268 const Elf_Shdr *unw_sec; 269 const Elf_Shdr *txt_sec; 270 }; 271 272 static const Elf_Shdr *find_mod_section(const Elf32_Ehdr *hdr, 273 const Elf_Shdr *sechdrs, const char *name) 274 { 275 const Elf_Shdr *s, *se; 276 const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 277 278 for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) 279 if (strcmp(name, secstrs + s->sh_name) == 0) 280 return s; 281 282 return NULL; 283 } 284 285 extern void fixup_smp(const void *, unsigned long); 286 287 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, 288 struct module *mod) 289 { 290 const Elf_Shdr * __maybe_unused s = NULL; 291 #ifdef CONFIG_ARM_UNWIND 292 const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 293 const Elf_Shdr *sechdrs_end = sechdrs + hdr->e_shnum; 294 struct mod_unwind_map maps[ARM_SEC_MAX]; 295 int i; 296 297 memset(maps, 0, sizeof(maps)); 298 299 for (s = sechdrs; s < sechdrs_end; s++) { 300 const char *secname = secstrs + s->sh_name; 301 302 if (!(s->sh_flags & SHF_ALLOC)) 303 continue; 304 305 if (strcmp(".ARM.exidx.init.text", secname) == 0) 306 maps[ARM_SEC_INIT].unw_sec = s; 307 else if (strcmp(".ARM.exidx.devinit.text", secname) == 0) 308 maps[ARM_SEC_DEVINIT].unw_sec = s; 309 else if (strcmp(".ARM.exidx", secname) == 0) 310 maps[ARM_SEC_CORE].unw_sec = s; 311 else if (strcmp(".ARM.exidx.exit.text", secname) == 0) 312 maps[ARM_SEC_EXIT].unw_sec = s; 313 else if (strcmp(".ARM.exidx.devexit.text", secname) == 0) 314 maps[ARM_SEC_DEVEXIT].unw_sec = s; 315 else if (strcmp(".init.text", secname) == 0) 316 maps[ARM_SEC_INIT].txt_sec = s; 317 else if (strcmp(".devinit.text", secname) == 0) 318 maps[ARM_SEC_DEVINIT].txt_sec = s; 319 else if (strcmp(".text", secname) == 0) 320 maps[ARM_SEC_CORE].txt_sec = s; 321 else if (strcmp(".exit.text", secname) == 0) 322 maps[ARM_SEC_EXIT].txt_sec = s; 323 else if (strcmp(".devexit.text", secname) == 0) 324 maps[ARM_SEC_DEVEXIT].txt_sec = s; 325 } 326 327 for (i = 0; i < ARM_SEC_MAX; i++) 328 if (maps[i].unw_sec && maps[i].txt_sec) 329 mod->arch.unwind[i] = 330 unwind_table_add(maps[i].unw_sec->sh_addr, 331 maps[i].unw_sec->sh_size, 332 maps[i].txt_sec->sh_addr, 333 maps[i].txt_sec->sh_size); 334 #endif 335 s = find_mod_section(hdr, sechdrs, ".alt.smp.init"); 336 if (s && !is_smp()) 337 fixup_smp((void *)s->sh_addr, s->sh_size); 338 return 0; 339 } 340 341 void 342 module_arch_cleanup(struct module *mod) 343 { 344 #ifdef CONFIG_ARM_UNWIND 345 int i; 346 347 for (i = 0; i < ARM_SEC_MAX; i++) 348 if (mod->arch.unwind[i]) 349 unwind_table_del(mod->arch.unwind[i]); 350 #endif 351 } 352