1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * sorttable.c: Sort the kernel's table 4 * 5 * Added ORC unwind tables sort support and other updates: 6 * Copyright (C) 1999-2019 Alibaba Group Holding Limited. by: 7 * Shile Zhang <shile.zhang@linux.alibaba.com> 8 * 9 * Copyright 2011 - 2012 Cavium, Inc. 10 * 11 * Based on code taken from recortmcount.c which is: 12 * 13 * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved. 14 * 15 * Restructured to fit Linux format, as well as other updates: 16 * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc. 17 */ 18 19 /* 20 * Strategy: alter the vmlinux file in-place. 21 */ 22 23 #include <sys/types.h> 24 #include <sys/mman.h> 25 #include <sys/stat.h> 26 #include <getopt.h> 27 #include <elf.h> 28 #include <fcntl.h> 29 #include <stdio.h> 30 #include <stdlib.h> 31 #include <string.h> 32 #include <unistd.h> 33 #include <errno.h> 34 #include <pthread.h> 35 36 #include <tools/be_byteshift.h> 37 #include <tools/le_byteshift.h> 38 39 #ifndef EM_ARCOMPACT 40 #define EM_ARCOMPACT 93 41 #endif 42 43 #ifndef EM_XTENSA 44 #define EM_XTENSA 94 45 #endif 46 47 #ifndef EM_AARCH64 48 #define EM_AARCH64 183 49 #endif 50 51 #ifndef EM_MICROBLAZE 52 #define EM_MICROBLAZE 189 53 #endif 54 55 #ifndef EM_ARCV2 56 #define EM_ARCV2 195 57 #endif 58 59 #ifndef EM_RISCV 60 #define EM_RISCV 243 61 #endif 62 63 static uint32_t (*r)(const uint32_t *); 64 static uint16_t (*r2)(const uint16_t *); 65 static uint64_t (*r8)(const uint64_t *); 66 static void (*w)(uint32_t, uint32_t *); 67 static void (*w2)(uint16_t, uint16_t *); 68 static void (*w8)(uint64_t, uint64_t *); 69 typedef void (*table_sort_t)(char *, int); 70 71 /* 72 * Get the whole file as a programming convenience in order to avoid 73 * malloc+lseek+read+free of many pieces. If successful, then mmap 74 * avoids copying unused pieces; else just read the whole file. 75 * Open for both read and write. 76 */ 77 static void *mmap_file(char const *fname, size_t *size) 78 { 79 int fd; 80 struct stat sb; 81 void *addr = NULL; 82 83 fd = open(fname, O_RDWR); 84 if (fd < 0) { 85 perror(fname); 86 return NULL; 87 } 88 if (fstat(fd, &sb) < 0) { 89 perror(fname); 90 goto out; 91 } 92 if (!S_ISREG(sb.st_mode)) { 93 fprintf(stderr, "not a regular file: %s\n", fname); 94 goto out; 95 } 96 97 addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); 98 if (addr == MAP_FAILED) { 99 fprintf(stderr, "Could not mmap file: %s\n", fname); 100 goto out; 101 } 102 103 *size = sb.st_size; 104 105 out: 106 close(fd); 107 return addr; 108 } 109 110 static uint32_t rbe(const uint32_t *x) 111 { 112 return get_unaligned_be32(x); 113 } 114 115 static uint16_t r2be(const uint16_t *x) 116 { 117 return get_unaligned_be16(x); 118 } 119 120 static uint64_t r8be(const uint64_t *x) 121 { 122 return get_unaligned_be64(x); 123 } 124 125 static uint32_t rle(const uint32_t *x) 126 { 127 return get_unaligned_le32(x); 128 } 129 130 static uint16_t r2le(const uint16_t *x) 131 { 132 return get_unaligned_le16(x); 133 } 134 135 static uint64_t r8le(const uint64_t *x) 136 { 137 return get_unaligned_le64(x); 138 } 139 140 static void wbe(uint32_t val, uint32_t *x) 141 { 142 put_unaligned_be32(val, x); 143 } 144 145 static void w2be(uint16_t val, uint16_t *x) 146 { 147 put_unaligned_be16(val, x); 148 } 149 150 static void w8be(uint64_t val, uint64_t *x) 151 { 152 put_unaligned_be64(val, x); 153 } 154 155 static void wle(uint32_t val, uint32_t *x) 156 { 157 put_unaligned_le32(val, x); 158 } 159 160 static void w2le(uint16_t val, uint16_t *x) 161 { 162 put_unaligned_le16(val, x); 163 } 164 165 static void w8le(uint64_t val, uint64_t *x) 166 { 167 put_unaligned_le64(val, x); 168 } 169 170 /* 171 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of 172 * the way to -256..-1, to avoid conflicting with real section 173 * indices. 174 */ 175 #define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1)) 176 177 static inline int is_shndx_special(unsigned int i) 178 { 179 return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE; 180 } 181 182 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */ 183 static inline unsigned int get_secindex(unsigned int shndx, 184 unsigned int sym_offs, 185 const Elf32_Word *symtab_shndx_start) 186 { 187 if (is_shndx_special(shndx)) 188 return SPECIAL(shndx); 189 if (shndx != SHN_XINDEX) 190 return shndx; 191 return r(&symtab_shndx_start[sym_offs]); 192 } 193 194 /* 32 bit and 64 bit are very similar */ 195 #include "sorttable.h" 196 #define SORTTABLE_64 197 #include "sorttable.h" 198 199 static int compare_relative_table(const void *a, const void *b) 200 { 201 int32_t av = (int32_t)r(a); 202 int32_t bv = (int32_t)r(b); 203 204 if (av < bv) 205 return -1; 206 if (av > bv) 207 return 1; 208 return 0; 209 } 210 211 static void sort_relative_table(char *extab_image, int image_size) 212 { 213 int i = 0; 214 215 /* 216 * Do the same thing the runtime sort does, first normalize to 217 * being relative to the start of the section. 218 */ 219 while (i < image_size) { 220 uint32_t *loc = (uint32_t *)(extab_image + i); 221 w(r(loc) + i, loc); 222 i += 4; 223 } 224 225 qsort(extab_image, image_size / 8, 8, compare_relative_table); 226 227 /* Now denormalize. */ 228 i = 0; 229 while (i < image_size) { 230 uint32_t *loc = (uint32_t *)(extab_image + i); 231 w(r(loc) - i, loc); 232 i += 4; 233 } 234 } 235 236 static void arm64_sort_relative_table(char *extab_image, int image_size) 237 { 238 int i = 0; 239 240 while (i < image_size) { 241 uint32_t *loc = (uint32_t *)(extab_image + i); 242 243 w(r(loc) + i, loc); 244 w(r(loc + 1) + i + 4, loc + 1); 245 /* Don't touch the fixup type or data */ 246 247 i += sizeof(uint32_t) * 3; 248 } 249 250 qsort(extab_image, image_size / 12, 12, compare_relative_table); 251 252 i = 0; 253 while (i < image_size) { 254 uint32_t *loc = (uint32_t *)(extab_image + i); 255 256 w(r(loc) - i, loc); 257 w(r(loc + 1) - (i + 4), loc + 1); 258 /* Don't touch the fixup type or data */ 259 260 i += sizeof(uint32_t) * 3; 261 } 262 } 263 264 static void x86_sort_relative_table(char *extab_image, int image_size) 265 { 266 int i = 0; 267 268 while (i < image_size) { 269 uint32_t *loc = (uint32_t *)(extab_image + i); 270 271 w(r(loc) + i, loc); 272 w(r(loc + 1) + i + 4, loc + 1); 273 /* Don't touch the fixup type */ 274 275 i += sizeof(uint32_t) * 3; 276 } 277 278 qsort(extab_image, image_size / 12, 12, compare_relative_table); 279 280 i = 0; 281 while (i < image_size) { 282 uint32_t *loc = (uint32_t *)(extab_image + i); 283 284 w(r(loc) - i, loc); 285 w(r(loc + 1) - (i + 4), loc + 1); 286 /* Don't touch the fixup type */ 287 288 i += sizeof(uint32_t) * 3; 289 } 290 } 291 292 static void s390_sort_relative_table(char *extab_image, int image_size) 293 { 294 int i; 295 296 for (i = 0; i < image_size; i += 16) { 297 char *loc = extab_image + i; 298 uint64_t handler; 299 300 w(r((uint32_t *)loc) + i, (uint32_t *)loc); 301 w(r((uint32_t *)(loc + 4)) + (i + 4), (uint32_t *)(loc + 4)); 302 /* 303 * 0 is a special self-relative handler value, which means that 304 * handler should be ignored. It is safe, because it means that 305 * handler field points to itself, which should never happen. 306 * When creating extable-relative values, keep it as 0, since 307 * this should never occur either: it would mean that handler 308 * field points to the first extable entry. 309 */ 310 handler = r8((uint64_t *)(loc + 8)); 311 if (handler) 312 handler += i + 8; 313 w8(handler, (uint64_t *)(loc + 8)); 314 } 315 316 qsort(extab_image, image_size / 16, 16, compare_relative_table); 317 318 for (i = 0; i < image_size; i += 16) { 319 char *loc = extab_image + i; 320 uint64_t handler; 321 322 w(r((uint32_t *)loc) - i, (uint32_t *)loc); 323 w(r((uint32_t *)(loc + 4)) - (i + 4), (uint32_t *)(loc + 4)); 324 handler = r8((uint64_t *)(loc + 8)); 325 if (handler) 326 handler -= i + 8; 327 w8(handler, (uint64_t *)(loc + 8)); 328 } 329 } 330 331 static int do_file(char const *const fname, void *addr) 332 { 333 int rc = -1; 334 Elf32_Ehdr *ehdr = addr; 335 table_sort_t custom_sort = NULL; 336 337 switch (ehdr->e_ident[EI_DATA]) { 338 case ELFDATA2LSB: 339 r = rle; 340 r2 = r2le; 341 r8 = r8le; 342 w = wle; 343 w2 = w2le; 344 w8 = w8le; 345 break; 346 case ELFDATA2MSB: 347 r = rbe; 348 r2 = r2be; 349 r8 = r8be; 350 w = wbe; 351 w2 = w2be; 352 w8 = w8be; 353 break; 354 default: 355 fprintf(stderr, "unrecognized ELF data encoding %d: %s\n", 356 ehdr->e_ident[EI_DATA], fname); 357 return -1; 358 } 359 360 if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 || 361 (r2(&ehdr->e_type) != ET_EXEC && r2(&ehdr->e_type) != ET_DYN) || 362 ehdr->e_ident[EI_VERSION] != EV_CURRENT) { 363 fprintf(stderr, "unrecognized ET_EXEC/ET_DYN file %s\n", fname); 364 return -1; 365 } 366 367 switch (r2(&ehdr->e_machine)) { 368 case EM_386: 369 case EM_X86_64: 370 custom_sort = x86_sort_relative_table; 371 break; 372 case EM_S390: 373 custom_sort = s390_sort_relative_table; 374 break; 375 case EM_AARCH64: 376 custom_sort = arm64_sort_relative_table; 377 break; 378 case EM_PARISC: 379 case EM_PPC: 380 case EM_PPC64: 381 custom_sort = sort_relative_table; 382 break; 383 case EM_ARCOMPACT: 384 case EM_ARCV2: 385 case EM_ARM: 386 case EM_MICROBLAZE: 387 case EM_MIPS: 388 case EM_RISCV: 389 case EM_XTENSA: 390 break; 391 default: 392 fprintf(stderr, "unrecognized e_machine %d %s\n", 393 r2(&ehdr->e_machine), fname); 394 return -1; 395 } 396 397 switch (ehdr->e_ident[EI_CLASS]) { 398 case ELFCLASS32: 399 if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr) || 400 r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) { 401 fprintf(stderr, 402 "unrecognized ET_EXEC/ET_DYN file: %s\n", fname); 403 break; 404 } 405 rc = do_sort_32(ehdr, fname, custom_sort); 406 break; 407 case ELFCLASS64: 408 { 409 Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr; 410 if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr) || 411 r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) { 412 fprintf(stderr, 413 "unrecognized ET_EXEC/ET_DYN file: %s\n", 414 fname); 415 break; 416 } 417 rc = do_sort_64(ghdr, fname, custom_sort); 418 } 419 break; 420 default: 421 fprintf(stderr, "unrecognized ELF class %d %s\n", 422 ehdr->e_ident[EI_CLASS], fname); 423 break; 424 } 425 426 return rc; 427 } 428 429 int main(int argc, char *argv[]) 430 { 431 int i, n_error = 0; /* gcc-4.3.0 false positive complaint */ 432 size_t size = 0; 433 void *addr = NULL; 434 435 if (argc < 2) { 436 fprintf(stderr, "usage: sorttable vmlinux...\n"); 437 return 0; 438 } 439 440 /* Process each file in turn, allowing deep failure. */ 441 for (i = 1; i < argc; i++) { 442 addr = mmap_file(argv[i], &size); 443 if (!addr) { 444 ++n_error; 445 continue; 446 } 447 448 if (do_file(argv[i], addr)) 449 ++n_error; 450 451 munmap(addr, size); 452 } 453 454 return !!n_error; 455 } 456