scripts/sorttable.c

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