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