1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 4 * Copyright (C) 2017 Zihao Yu 5 */ 6 7 #include <linux/elf.h> 8 #include <linux/err.h> 9 #include <linux/errno.h> 10 #include <linux/moduleloader.h> 11 #include <linux/vmalloc.h> 12 #include <linux/sizes.h> 13 #include <linux/pgtable.h> 14 #include <asm/sections.h> 15 16 static int apply_r_riscv_32_rela(struct module *me, u32 *location, Elf_Addr v) 17 { 18 if (v != (u32)v) { 19 pr_err("%s: value %016llx out of range for 32-bit field\n", 20 me->name, (long long)v); 21 return -EINVAL; 22 } 23 *location = v; 24 return 0; 25 } 26 27 static int apply_r_riscv_64_rela(struct module *me, u32 *location, Elf_Addr v) 28 { 29 *(u64 *)location = v; 30 return 0; 31 } 32 33 static int apply_r_riscv_branch_rela(struct module *me, u32 *location, 34 Elf_Addr v) 35 { 36 ptrdiff_t offset = (void *)v - (void *)location; 37 u32 imm12 = (offset & 0x1000) << (31 - 12); 38 u32 imm11 = (offset & 0x800) >> (11 - 7); 39 u32 imm10_5 = (offset & 0x7e0) << (30 - 10); 40 u32 imm4_1 = (offset & 0x1e) << (11 - 4); 41 42 *location = (*location & 0x1fff07f) | imm12 | imm11 | imm10_5 | imm4_1; 43 return 0; 44 } 45 46 static int apply_r_riscv_jal_rela(struct module *me, u32 *location, 47 Elf_Addr v) 48 { 49 ptrdiff_t offset = (void *)v - (void *)location; 50 u32 imm20 = (offset & 0x100000) << (31 - 20); 51 u32 imm19_12 = (offset & 0xff000); 52 u32 imm11 = (offset & 0x800) << (20 - 11); 53 u32 imm10_1 = (offset & 0x7fe) << (30 - 10); 54 55 *location = (*location & 0xfff) | imm20 | imm19_12 | imm11 | imm10_1; 56 return 0; 57 } 58 59 static int apply_r_riscv_rcv_branch_rela(struct module *me, u32 *location, 60 Elf_Addr v) 61 { 62 ptrdiff_t offset = (void *)v - (void *)location; 63 u16 imm8 = (offset & 0x100) << (12 - 8); 64 u16 imm7_6 = (offset & 0xc0) >> (6 - 5); 65 u16 imm5 = (offset & 0x20) >> (5 - 2); 66 u16 imm4_3 = (offset & 0x18) << (12 - 5); 67 u16 imm2_1 = (offset & 0x6) << (12 - 10); 68 69 *(u16 *)location = (*(u16 *)location & 0xe383) | 70 imm8 | imm7_6 | imm5 | imm4_3 | imm2_1; 71 return 0; 72 } 73 74 static int apply_r_riscv_rvc_jump_rela(struct module *me, u32 *location, 75 Elf_Addr v) 76 { 77 ptrdiff_t offset = (void *)v - (void *)location; 78 u16 imm11 = (offset & 0x800) << (12 - 11); 79 u16 imm10 = (offset & 0x400) >> (10 - 8); 80 u16 imm9_8 = (offset & 0x300) << (12 - 11); 81 u16 imm7 = (offset & 0x80) >> (7 - 6); 82 u16 imm6 = (offset & 0x40) << (12 - 11); 83 u16 imm5 = (offset & 0x20) >> (5 - 2); 84 u16 imm4 = (offset & 0x10) << (12 - 5); 85 u16 imm3_1 = (offset & 0xe) << (12 - 10); 86 87 *(u16 *)location = (*(u16 *)location & 0xe003) | 88 imm11 | imm10 | imm9_8 | imm7 | imm6 | imm5 | imm4 | imm3_1; 89 return 0; 90 } 91 92 static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location, 93 Elf_Addr v) 94 { 95 ptrdiff_t offset = (void *)v - (void *)location; 96 s32 hi20; 97 98 if (offset != (s32)offset) { 99 pr_err( 100 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n", 101 me->name, (long long)v, location); 102 return -EINVAL; 103 } 104 105 hi20 = (offset + 0x800) & 0xfffff000; 106 *location = (*location & 0xfff) | hi20; 107 return 0; 108 } 109 110 static int apply_r_riscv_pcrel_lo12_i_rela(struct module *me, u32 *location, 111 Elf_Addr v) 112 { 113 /* 114 * v is the lo12 value to fill. It is calculated before calling this 115 * handler. 116 */ 117 *location = (*location & 0xfffff) | ((v & 0xfff) << 20); 118 return 0; 119 } 120 121 static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location, 122 Elf_Addr v) 123 { 124 /* 125 * v is the lo12 value to fill. It is calculated before calling this 126 * handler. 127 */ 128 u32 imm11_5 = (v & 0xfe0) << (31 - 11); 129 u32 imm4_0 = (v & 0x1f) << (11 - 4); 130 131 *location = (*location & 0x1fff07f) | imm11_5 | imm4_0; 132 return 0; 133 } 134 135 static int apply_r_riscv_hi20_rela(struct module *me, u32 *location, 136 Elf_Addr v) 137 { 138 s32 hi20; 139 140 if (IS_ENABLED(CONFIG_CMODEL_MEDLOW)) { 141 pr_err( 142 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n", 143 me->name, (long long)v, location); 144 return -EINVAL; 145 } 146 147 hi20 = ((s32)v + 0x800) & 0xfffff000; 148 *location = (*location & 0xfff) | hi20; 149 return 0; 150 } 151 152 static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location, 153 Elf_Addr v) 154 { 155 /* Skip medlow checking because of filtering by HI20 already */ 156 s32 hi20 = ((s32)v + 0x800) & 0xfffff000; 157 s32 lo12 = ((s32)v - hi20); 158 *location = (*location & 0xfffff) | ((lo12 & 0xfff) << 20); 159 return 0; 160 } 161 162 static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location, 163 Elf_Addr v) 164 { 165 /* Skip medlow checking because of filtering by HI20 already */ 166 s32 hi20 = ((s32)v + 0x800) & 0xfffff000; 167 s32 lo12 = ((s32)v - hi20); 168 u32 imm11_5 = (lo12 & 0xfe0) << (31 - 11); 169 u32 imm4_0 = (lo12 & 0x1f) << (11 - 4); 170 *location = (*location & 0x1fff07f) | imm11_5 | imm4_0; 171 return 0; 172 } 173 174 static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location, 175 Elf_Addr v) 176 { 177 ptrdiff_t offset = (void *)v - (void *)location; 178 s32 hi20; 179 180 /* Always emit the got entry */ 181 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) { 182 offset = module_emit_got_entry(me, v); 183 offset = (void *)offset - (void *)location; 184 } else { 185 pr_err( 186 "%s: can not generate the GOT entry for symbol = %016llx from PC = %p\n", 187 me->name, (long long)v, location); 188 return -EINVAL; 189 } 190 191 hi20 = (offset + 0x800) & 0xfffff000; 192 *location = (*location & 0xfff) | hi20; 193 return 0; 194 } 195 196 static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location, 197 Elf_Addr v) 198 { 199 ptrdiff_t offset = (void *)v - (void *)location; 200 s32 fill_v = offset; 201 u32 hi20, lo12; 202 203 if (offset != fill_v) { 204 /* Only emit the plt entry if offset over 32-bit range */ 205 if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) { 206 offset = module_emit_plt_entry(me, v); 207 offset = (void *)offset - (void *)location; 208 } else { 209 pr_err( 210 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n", 211 me->name, (long long)v, location); 212 return -EINVAL; 213 } 214 } 215 216 hi20 = (offset + 0x800) & 0xfffff000; 217 lo12 = (offset - hi20) & 0xfff; 218 *location = (*location & 0xfff) | hi20; 219 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20); 220 return 0; 221 } 222 223 static int apply_r_riscv_call_rela(struct module *me, u32 *location, 224 Elf_Addr v) 225 { 226 ptrdiff_t offset = (void *)v - (void *)location; 227 s32 fill_v = offset; 228 u32 hi20, lo12; 229 230 if (offset != fill_v) { 231 pr_err( 232 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n", 233 me->name, (long long)v, location); 234 return -EINVAL; 235 } 236 237 hi20 = (offset + 0x800) & 0xfffff000; 238 lo12 = (offset - hi20) & 0xfff; 239 *location = (*location & 0xfff) | hi20; 240 *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20); 241 return 0; 242 } 243 244 static int apply_r_riscv_relax_rela(struct module *me, u32 *location, 245 Elf_Addr v) 246 { 247 return 0; 248 } 249 250 static int apply_r_riscv_align_rela(struct module *me, u32 *location, 251 Elf_Addr v) 252 { 253 pr_err( 254 "%s: The unexpected relocation type 'R_RISCV_ALIGN' from PC = %p\n", 255 me->name, location); 256 return -EINVAL; 257 } 258 259 static int apply_r_riscv_add32_rela(struct module *me, u32 *location, 260 Elf_Addr v) 261 { 262 *(u32 *)location += (u32)v; 263 return 0; 264 } 265 266 static int apply_r_riscv_add64_rela(struct module *me, u32 *location, 267 Elf_Addr v) 268 { 269 *(u64 *)location += (u64)v; 270 return 0; 271 } 272 273 static int apply_r_riscv_sub32_rela(struct module *me, u32 *location, 274 Elf_Addr v) 275 { 276 *(u32 *)location -= (u32)v; 277 return 0; 278 } 279 280 static int apply_r_riscv_sub64_rela(struct module *me, u32 *location, 281 Elf_Addr v) 282 { 283 *(u64 *)location -= (u64)v; 284 return 0; 285 } 286 287 static int (*reloc_handlers_rela[]) (struct module *me, u32 *location, 288 Elf_Addr v) = { 289 [R_RISCV_32] = apply_r_riscv_32_rela, 290 [R_RISCV_64] = apply_r_riscv_64_rela, 291 [R_RISCV_BRANCH] = apply_r_riscv_branch_rela, 292 [R_RISCV_JAL] = apply_r_riscv_jal_rela, 293 [R_RISCV_RVC_BRANCH] = apply_r_riscv_rcv_branch_rela, 294 [R_RISCV_RVC_JUMP] = apply_r_riscv_rvc_jump_rela, 295 [R_RISCV_PCREL_HI20] = apply_r_riscv_pcrel_hi20_rela, 296 [R_RISCV_PCREL_LO12_I] = apply_r_riscv_pcrel_lo12_i_rela, 297 [R_RISCV_PCREL_LO12_S] = apply_r_riscv_pcrel_lo12_s_rela, 298 [R_RISCV_HI20] = apply_r_riscv_hi20_rela, 299 [R_RISCV_LO12_I] = apply_r_riscv_lo12_i_rela, 300 [R_RISCV_LO12_S] = apply_r_riscv_lo12_s_rela, 301 [R_RISCV_GOT_HI20] = apply_r_riscv_got_hi20_rela, 302 [R_RISCV_CALL_PLT] = apply_r_riscv_call_plt_rela, 303 [R_RISCV_CALL] = apply_r_riscv_call_rela, 304 [R_RISCV_RELAX] = apply_r_riscv_relax_rela, 305 [R_RISCV_ALIGN] = apply_r_riscv_align_rela, 306 [R_RISCV_ADD32] = apply_r_riscv_add32_rela, 307 [R_RISCV_ADD64] = apply_r_riscv_add64_rela, 308 [R_RISCV_SUB32] = apply_r_riscv_sub32_rela, 309 [R_RISCV_SUB64] = apply_r_riscv_sub64_rela, 310 }; 311 312 int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, 313 unsigned int symindex, unsigned int relsec, 314 struct module *me) 315 { 316 Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr; 317 int (*handler)(struct module *me, u32 *location, Elf_Addr v); 318 Elf_Sym *sym; 319 u32 *location; 320 unsigned int i, type; 321 Elf_Addr v; 322 int res; 323 324 pr_debug("Applying relocate section %u to %u\n", relsec, 325 sechdrs[relsec].sh_info); 326 327 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { 328 /* This is where to make the change */ 329 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr 330 + rel[i].r_offset; 331 /* This is the symbol it is referring to */ 332 sym = (Elf_Sym *)sechdrs[symindex].sh_addr 333 + ELF_RISCV_R_SYM(rel[i].r_info); 334 if (IS_ERR_VALUE(sym->st_value)) { 335 /* Ignore unresolved weak symbol */ 336 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) 337 continue; 338 pr_warn("%s: Unknown symbol %s\n", 339 me->name, strtab + sym->st_name); 340 return -ENOENT; 341 } 342 343 type = ELF_RISCV_R_TYPE(rel[i].r_info); 344 345 if (type < ARRAY_SIZE(reloc_handlers_rela)) 346 handler = reloc_handlers_rela[type]; 347 else 348 handler = NULL; 349 350 if (!handler) { 351 pr_err("%s: Unknown relocation type %u\n", 352 me->name, type); 353 return -EINVAL; 354 } 355 356 v = sym->st_value + rel[i].r_addend; 357 358 if (type == R_RISCV_PCREL_LO12_I || type == R_RISCV_PCREL_LO12_S) { 359 unsigned int j; 360 361 for (j = 0; j < sechdrs[relsec].sh_size / sizeof(*rel); j++) { 362 unsigned long hi20_loc = 363 sechdrs[sechdrs[relsec].sh_info].sh_addr 364 + rel[j].r_offset; 365 u32 hi20_type = ELF_RISCV_R_TYPE(rel[j].r_info); 366 367 /* Find the corresponding HI20 relocation entry */ 368 if (hi20_loc == sym->st_value 369 && (hi20_type == R_RISCV_PCREL_HI20 370 || hi20_type == R_RISCV_GOT_HI20)) { 371 s32 hi20, lo12; 372 Elf_Sym *hi20_sym = 373 (Elf_Sym *)sechdrs[symindex].sh_addr 374 + ELF_RISCV_R_SYM(rel[j].r_info); 375 unsigned long hi20_sym_val = 376 hi20_sym->st_value 377 + rel[j].r_addend; 378 379 /* Calculate lo12 */ 380 size_t offset = hi20_sym_val - hi20_loc; 381 if (IS_ENABLED(CONFIG_MODULE_SECTIONS) 382 && hi20_type == R_RISCV_GOT_HI20) { 383 offset = module_emit_got_entry( 384 me, hi20_sym_val); 385 offset = offset - hi20_loc; 386 } 387 hi20 = (offset + 0x800) & 0xfffff000; 388 lo12 = offset - hi20; 389 v = lo12; 390 391 break; 392 } 393 } 394 if (j == sechdrs[relsec].sh_size / sizeof(*rel)) { 395 pr_err( 396 "%s: Can not find HI20 relocation information\n", 397 me->name); 398 return -EINVAL; 399 } 400 } 401 402 res = handler(me, location, v); 403 if (res) 404 return res; 405 } 406 407 return 0; 408 } 409 410 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT) 411 void *module_alloc(unsigned long size) 412 { 413 return __vmalloc_node_range(size, 1, MODULES_VADDR, 414 MODULES_END, GFP_KERNEL, 415 PAGE_KERNEL, 0, NUMA_NO_NODE, 416 __builtin_return_address(0)); 417 } 418 #endif 419