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 #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 sort_relative_table_with_data(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 s390_sort_relative_table(char *extab_image, int image_size)
 265 {
 266         int i;
 267
 268         for (i = 0; i < image_size; i += 16) {
 269                 char *loc = extab_image + i;
 270                 uint64_t handler;
 271
 272                 w(r((uint32_t *)loc) + i, (uint32_t *)loc);
 273                 w(r((uint32_t *)(loc + 4)) + (i + 4), (uint32_t *)(loc + 4));
 274                 /*
 275                  * 0 is a special self-relative handler value, which means that
 276                  * handler should be ignored. It is safe, because it means that
 277                  * handler field points to itself, which should never happen.
 278                  * When creating extable-relative values, keep it as 0, since
 279                  * this should never occur either: it would mean that handler
 280                  * field points to the first extable entry.
 281                  */
 282                 handler = r8((uint64_t *)(loc + 8));
 283                 if (handler)
 284                         handler += i + 8;
 285                 w8(handler, (uint64_t *)(loc + 8));
 286         }
 287
 288         qsort(extab_image, image_size / 16, 16, compare_relative_table);
 289
 290         for (i = 0; i < image_size; i += 16) {
 291                 char *loc = extab_image + i;
 292                 uint64_t handler;
 293
 294                 w(r((uint32_t *)loc) - i, (uint32_t *)loc);
 295                 w(r((uint32_t *)(loc + 4)) - (i + 4), (uint32_t *)(loc + 4));
 296                 handler = r8((uint64_t *)(loc + 8));
 297                 if (handler)
 298                         handler -= i + 8;
 299                 w8(handler, (uint64_t *)(loc + 8));
 300         }
 301 }
 302
 303 static int do_file(char const *const fname, void *addr)
 304 {
 305         int rc = -1;
 306         Elf32_Ehdr *ehdr = addr;
 307         table_sort_t custom_sort = NULL;
 308
 309         switch (ehdr->e_ident[EI_DATA]) {
 310         case ELFDATA2LSB:
 311                 r       = rle;
 312                 r2      = r2le;
 313                 r8      = r8le;
 314                 w       = wle;
 315                 w2      = w2le;
 316                 w8      = w8le;
 317                 break;
 318         case ELFDATA2MSB:
 319                 r       = rbe;
 320                 r2      = r2be;
 321                 r8      = r8be;
 322                 w       = wbe;
 323                 w2      = w2be;
 324                 w8      = w8be;
 325                 break;
 326         default:
 327                 fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
 328                         ehdr->e_ident[EI_DATA], fname);
 329                 return -1;
 330         }
 331
 332         if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 ||
 333             (r2(&ehdr->e_type) != ET_EXEC && r2(&ehdr->e_type) != ET_DYN) ||
 334             ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
 335                 fprintf(stderr, "unrecognized ET_EXEC/ET_DYN file %s\n", fname);
 336                 return -1;
 337         }
 338
 339         switch (r2(&ehdr->e_machine)) {
 340         case EM_386:
 341         case EM_AARCH64:
 342         case EM_RISCV:
 343         case EM_X86_64:
 344                 custom_sort = sort_relative_table_with_data;
 345                 break;
 346         case EM_S390:
 347                 custom_sort = s390_sort_relative_table;
 348                 break;
 349         case EM_PARISC:
 350         case EM_PPC:
 351         case EM_PPC64:
 352                 custom_sort = sort_relative_table;
 353                 break;
 354         case EM_ARCOMPACT:
 355         case EM_ARCV2:
 356         case EM_ARM:
 357         case EM_MICROBLAZE:
 358         case EM_MIPS:
 359         case EM_XTENSA:
 360                 break;
 361         default:
 362                 fprintf(stderr, "unrecognized e_machine %d %s\n",
 363                         r2(&ehdr->e_machine), fname);
 364                 return -1;
 365         }
 366
 367         switch (ehdr->e_ident[EI_CLASS]) {
 368         case ELFCLASS32:
 369                 if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr) ||
 370                     r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
 371                         fprintf(stderr,
 372                                 "unrecognized ET_EXEC/ET_DYN file: %s\n", fname);
 373                         break;
 374                 }
 375                 rc = do_sort_32(ehdr, fname, custom_sort);
 376                 break;
 377         case ELFCLASS64:
 378                 {
 379                 Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
 380                 if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr) ||
 381                     r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
 382                         fprintf(stderr,
 383                                 "unrecognized ET_EXEC/ET_DYN file: %s\n",
 384                                 fname);
 385                         break;
 386                 }
 387                 rc = do_sort_64(ghdr, fname, custom_sort);
 388                 }
 389                 break;
 390         default:
 391                 fprintf(stderr, "unrecognized ELF class %d %s\n",
 392                         ehdr->e_ident[EI_CLASS], fname);
 393                 break;
 394         }
 395
 396         return rc;
 397 }
 398
 399 int main(int argc, char *argv[])
 400 {
 401         int i, n_error = 0;  /* gcc-4.3.0 false positive complaint */
 402         size_t size = 0;
 403         void *addr = NULL;
 404
 405         if (argc < 2) {
 406                 fprintf(stderr, "usage: sorttable vmlinux...\n");
 407                 return 0;
 408         }
 409
 410         /* Process each file in turn, allowing deep failure. */
 411         for (i = 1; i < argc; i++) {
 412                 addr = mmap_file(argv[i], &size);
 413                 if (!addr) {
 414                         ++n_error;
 415                         continue;
 416                 }
 417
 418                 if (do_file(argv[i], addr))
 419                         ++n_error;
 420
 421                 munmap(addr, size);
 422         }
 423
 424         return !!n_error;
 425 }