| 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 + ~PMD_MASK) & PMD_MASK) |
| 37 | #endif |
| 38 | |
| 39 | #ifdef CONFIG_MMU |
| 40 | void *module_alloc(unsigned long size) |
| 41 | { |
| 42 | return size == 0 ? NULL : __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, |
| 43 | GFP_KERNEL, PAGE_KERNEL_EXEC, -1, |
| 44 | __builtin_return_address(0)); |
| 45 | } |
| 46 | #endif |
| 47 | |
| 48 | int |
| 49 | apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, |
| 50 | unsigned int relindex, struct module *module) |
| 51 | { |
| 52 | Elf32_Shdr *symsec = sechdrs + symindex; |
| 53 | Elf32_Shdr *relsec = sechdrs + relindex; |
| 54 | Elf32_Shdr *dstsec = sechdrs + relsec->sh_info; |
| 55 | Elf32_Rel *rel = (void *)relsec->sh_addr; |
| 56 | unsigned int i; |
| 57 | |
| 58 | for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) { |
| 59 | unsigned long loc; |
| 60 | Elf32_Sym *sym; |
| 61 | const char *symname; |
| 62 | s32 offset; |
| 63 | #ifdef CONFIG_THUMB2_KERNEL |
| 64 | u32 upper, lower, sign, j1, j2; |
| 65 | #endif |
| 66 | |
| 67 | offset = ELF32_R_SYM(rel->r_info); |
| 68 | if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) { |
| 69 | pr_err("%s: section %u reloc %u: bad relocation sym offset\n", |
| 70 | module->name, relindex, i); |
| 71 | return -ENOEXEC; |
| 72 | } |
| 73 | |
| 74 | sym = ((Elf32_Sym *)symsec->sh_addr) + offset; |
| 75 | symname = strtab + sym->st_name; |
| 76 | |
| 77 | if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) { |
| 78 | pr_err("%s: section %u reloc %u sym '%s': out of bounds relocation, offset %d size %u\n", |
| 79 | module->name, relindex, i, symname, |
| 80 | rel->r_offset, dstsec->sh_size); |
| 81 | return -ENOEXEC; |
| 82 | } |
| 83 | |
| 84 | loc = dstsec->sh_addr + rel->r_offset; |
| 85 | |
| 86 | switch (ELF32_R_TYPE(rel->r_info)) { |
| 87 | case R_ARM_NONE: |
| 88 | /* ignore */ |
| 89 | break; |
| 90 | |
| 91 | case R_ARM_ABS32: |
| 92 | *(u32 *)loc += sym->st_value; |
| 93 | break; |
| 94 | |
| 95 | case R_ARM_PC24: |
| 96 | case R_ARM_CALL: |
| 97 | case R_ARM_JUMP24: |
| 98 | offset = (*(u32 *)loc & 0x00ffffff) << 2; |
| 99 | if (offset & 0x02000000) |
| 100 | offset -= 0x04000000; |
| 101 | |
| 102 | offset += sym->st_value - loc; |
| 103 | if (offset & 3 || |
| 104 | offset <= (s32)0xfe000000 || |
| 105 | offset >= (s32)0x02000000) { |
| 106 | pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n", |
| 107 | module->name, relindex, i, symname, |
| 108 | ELF32_R_TYPE(rel->r_info), loc, |
| 109 | sym->st_value); |
| 110 | return -ENOEXEC; |
| 111 | } |
| 112 | |
| 113 | offset >>= 2; |
| 114 | |
| 115 | *(u32 *)loc &= 0xff000000; |
| 116 | *(u32 *)loc |= offset & 0x00ffffff; |
| 117 | break; |
| 118 | |
| 119 | case R_ARM_V4BX: |
| 120 | /* Preserve Rm and the condition code. Alter |
| 121 | * other bits to re-code instruction as |
| 122 | * MOV PC,Rm. |
| 123 | */ |
| 124 | *(u32 *)loc &= 0xf000000f; |
| 125 | *(u32 *)loc |= 0x01a0f000; |
| 126 | break; |
| 127 | |
| 128 | case R_ARM_PREL31: |
| 129 | offset = *(u32 *)loc + sym->st_value - loc; |
| 130 | *(u32 *)loc = offset & 0x7fffffff; |
| 131 | break; |
| 132 | |
| 133 | case R_ARM_MOVW_ABS_NC: |
| 134 | case R_ARM_MOVT_ABS: |
| 135 | offset = *(u32 *)loc; |
| 136 | offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff); |
| 137 | offset = (offset ^ 0x8000) - 0x8000; |
| 138 | |
| 139 | offset += sym->st_value; |
| 140 | if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS) |
| 141 | offset >>= 16; |
| 142 | |
| 143 | *(u32 *)loc &= 0xfff0f000; |
| 144 | *(u32 *)loc |= ((offset & 0xf000) << 4) | |
| 145 | (offset & 0x0fff); |
| 146 | break; |
| 147 | |
| 148 | #ifdef CONFIG_THUMB2_KERNEL |
| 149 | case R_ARM_THM_CALL: |
| 150 | case R_ARM_THM_JUMP24: |
| 151 | upper = *(u16 *)loc; |
| 152 | lower = *(u16 *)(loc + 2); |
| 153 | |
| 154 | /* |
| 155 | * 25 bit signed address range (Thumb-2 BL and B.W |
| 156 | * instructions): |
| 157 | * S:I1:I2:imm10:imm11:0 |
| 158 | * where: |
| 159 | * S = upper[10] = offset[24] |
| 160 | * I1 = ~(J1 ^ S) = offset[23] |
| 161 | * I2 = ~(J2 ^ S) = offset[22] |
| 162 | * imm10 = upper[9:0] = offset[21:12] |
| 163 | * imm11 = lower[10:0] = offset[11:1] |
| 164 | * J1 = lower[13] |
| 165 | * J2 = lower[11] |
| 166 | */ |
| 167 | sign = (upper >> 10) & 1; |
| 168 | j1 = (lower >> 13) & 1; |
| 169 | j2 = (lower >> 11) & 1; |
| 170 | offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) | |
| 171 | ((~(j2 ^ sign) & 1) << 22) | |
| 172 | ((upper & 0x03ff) << 12) | |
| 173 | ((lower & 0x07ff) << 1); |
| 174 | if (offset & 0x01000000) |
| 175 | offset -= 0x02000000; |
| 176 | offset += sym->st_value - loc; |
| 177 | |
| 178 | /* |
| 179 | * For function symbols, only Thumb addresses are |
| 180 | * allowed (no interworking). |
| 181 | * |
| 182 | * For non-function symbols, the destination |
| 183 | * has no specific ARM/Thumb disposition, so |
| 184 | * the branch is resolved under the assumption |
| 185 | * that interworking is not required. |
| 186 | */ |
| 187 | if ((ELF32_ST_TYPE(sym->st_info) == STT_FUNC && |
| 188 | !(offset & 1)) || |
| 189 | offset <= (s32)0xff000000 || |
| 190 | offset >= (s32)0x01000000) { |
| 191 | pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n", |
| 192 | module->name, relindex, i, symname, |
| 193 | ELF32_R_TYPE(rel->r_info), loc, |
| 194 | sym->st_value); |
| 195 | return -ENOEXEC; |
| 196 | } |
| 197 | |
| 198 | sign = (offset >> 24) & 1; |
| 199 | j1 = sign ^ (~(offset >> 23) & 1); |
| 200 | j2 = sign ^ (~(offset >> 22) & 1); |
| 201 | *(u16 *)loc = (u16)((upper & 0xf800) | (sign << 10) | |
| 202 | ((offset >> 12) & 0x03ff)); |
| 203 | *(u16 *)(loc + 2) = (u16)((lower & 0xd000) | |
| 204 | (j1 << 13) | (j2 << 11) | |
| 205 | ((offset >> 1) & 0x07ff)); |
| 206 | break; |
| 207 | |
| 208 | case R_ARM_THM_MOVW_ABS_NC: |
| 209 | case R_ARM_THM_MOVT_ABS: |
| 210 | upper = *(u16 *)loc; |
| 211 | lower = *(u16 *)(loc + 2); |
| 212 | |
| 213 | /* |
| 214 | * MOVT/MOVW instructions encoding in Thumb-2: |
| 215 | * |
| 216 | * i = upper[10] |
| 217 | * imm4 = upper[3:0] |
| 218 | * imm3 = lower[14:12] |
| 219 | * imm8 = lower[7:0] |
| 220 | * |
| 221 | * imm16 = imm4:i:imm3:imm8 |
| 222 | */ |
| 223 | offset = ((upper & 0x000f) << 12) | |
| 224 | ((upper & 0x0400) << 1) | |
| 225 | ((lower & 0x7000) >> 4) | (lower & 0x00ff); |
| 226 | offset = (offset ^ 0x8000) - 0x8000; |
| 227 | offset += sym->st_value; |
| 228 | |
| 229 | if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS) |
| 230 | offset >>= 16; |
| 231 | |
| 232 | *(u16 *)loc = (u16)((upper & 0xfbf0) | |
| 233 | ((offset & 0xf000) >> 12) | |
| 234 | ((offset & 0x0800) >> 1)); |
| 235 | *(u16 *)(loc + 2) = (u16)((lower & 0x8f00) | |
| 236 | ((offset & 0x0700) << 4) | |
| 237 | (offset & 0x00ff)); |
| 238 | break; |
| 239 | #endif |
| 240 | |
| 241 | default: |
| 242 | printk(KERN_ERR "%s: unknown relocation: %u\n", |
| 243 | module->name, ELF32_R_TYPE(rel->r_info)); |
| 244 | return -ENOEXEC; |
| 245 | } |
| 246 | } |
| 247 | return 0; |
| 248 | } |
| 249 | |
| 250 | struct mod_unwind_map { |
| 251 | const Elf_Shdr *unw_sec; |
| 252 | const Elf_Shdr *txt_sec; |
| 253 | }; |
| 254 | |
| 255 | static const Elf_Shdr *find_mod_section(const Elf32_Ehdr *hdr, |
| 256 | const Elf_Shdr *sechdrs, const char *name) |
| 257 | { |
| 258 | const Elf_Shdr *s, *se; |
| 259 | const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; |
| 260 | |
| 261 | for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) |
| 262 | if (strcmp(name, secstrs + s->sh_name) == 0) |
| 263 | return s; |
| 264 | |
| 265 | return NULL; |
| 266 | } |
| 267 | |
| 268 | extern void fixup_pv_table(const void *, unsigned long); |
| 269 | extern void fixup_smp(const void *, unsigned long); |
| 270 | |
| 271 | int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, |
| 272 | struct module *mod) |
| 273 | { |
| 274 | const Elf_Shdr *s = NULL; |
| 275 | #ifdef CONFIG_ARM_UNWIND |
| 276 | const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; |
| 277 | const Elf_Shdr *sechdrs_end = sechdrs + hdr->e_shnum; |
| 278 | struct mod_unwind_map maps[ARM_SEC_MAX]; |
| 279 | int i; |
| 280 | |
| 281 | memset(maps, 0, sizeof(maps)); |
| 282 | |
| 283 | for (s = sechdrs; s < sechdrs_end; s++) { |
| 284 | const char *secname = secstrs + s->sh_name; |
| 285 | |
| 286 | if (!(s->sh_flags & SHF_ALLOC)) |
| 287 | continue; |
| 288 | |
| 289 | if (strcmp(".ARM.exidx.init.text", secname) == 0) |
| 290 | maps[ARM_SEC_INIT].unw_sec = s; |
| 291 | else if (strcmp(".ARM.exidx.devinit.text", secname) == 0) |
| 292 | maps[ARM_SEC_DEVINIT].unw_sec = s; |
| 293 | else if (strcmp(".ARM.exidx", secname) == 0) |
| 294 | maps[ARM_SEC_CORE].unw_sec = s; |
| 295 | else if (strcmp(".ARM.exidx.exit.text", secname) == 0) |
| 296 | maps[ARM_SEC_EXIT].unw_sec = s; |
| 297 | else if (strcmp(".ARM.exidx.devexit.text", secname) == 0) |
| 298 | maps[ARM_SEC_DEVEXIT].unw_sec = s; |
| 299 | else if (strcmp(".init.text", secname) == 0) |
| 300 | maps[ARM_SEC_INIT].txt_sec = s; |
| 301 | else if (strcmp(".devinit.text", secname) == 0) |
| 302 | maps[ARM_SEC_DEVINIT].txt_sec = s; |
| 303 | else if (strcmp(".text", secname) == 0) |
| 304 | maps[ARM_SEC_CORE].txt_sec = s; |
| 305 | else if (strcmp(".exit.text", secname) == 0) |
| 306 | maps[ARM_SEC_EXIT].txt_sec = s; |
| 307 | else if (strcmp(".devexit.text", secname) == 0) |
| 308 | maps[ARM_SEC_DEVEXIT].txt_sec = s; |
| 309 | } |
| 310 | |
| 311 | for (i = 0; i < ARM_SEC_MAX; i++) |
| 312 | if (maps[i].unw_sec && maps[i].txt_sec) |
| 313 | mod->arch.unwind[i] = |
| 314 | unwind_table_add(maps[i].unw_sec->sh_addr, |
| 315 | maps[i].unw_sec->sh_size, |
| 316 | maps[i].txt_sec->sh_addr, |
| 317 | maps[i].txt_sec->sh_size); |
| 318 | #endif |
| 319 | #ifdef CONFIG_ARM_PATCH_PHYS_VIRT |
| 320 | s = find_mod_section(hdr, sechdrs, ".pv_table"); |
| 321 | if (s) |
| 322 | fixup_pv_table((void *)s->sh_addr, s->sh_size); |
| 323 | #endif |
| 324 | s = find_mod_section(hdr, sechdrs, ".alt.smp.init"); |
| 325 | if (s && !is_smp()) |
| 326 | #ifdef CONFIG_SMP_ON_UP |
| 327 | fixup_smp((void *)s->sh_addr, s->sh_size); |
| 328 | #else |
| 329 | return -EINVAL; |
| 330 | #endif |
| 331 | return 0; |
| 332 | } |
| 333 | |
| 334 | void |
| 335 | module_arch_cleanup(struct module *mod) |
| 336 | { |
| 337 | #ifdef CONFIG_ARM_UNWIND |
| 338 | int i; |
| 339 | |
| 340 | for (i = 0; i < ARM_SEC_MAX; i++) |
| 341 | if (mod->arch.unwind[i]) |
| 342 | unwind_table_del(mod->arch.unwind[i]); |
| 343 | #endif |
| 344 | } |