scripts/recordmcount.c

   1 /*
   2  * recordmcount.c: construct a table of the locations of calls to 'mcount'
   3  * so that ftrace can find them quickly.
   4  * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
   5  * Licensed under the GNU General Public License, version 2 (GPLv2).
   6  *
   7  * Restructured to fit Linux format, as well as other updates:
   8  *  Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
   9  */
  10
  11 /*
  12  * Strategy: alter the .o file in-place.
  13  *
  14  * Append a new STRTAB that has the new section names, followed by a new array
  15  * ElfXX_Shdr[] that has the new section headers, followed by the section
  16  * contents for __mcount_loc and its relocations.  The old shstrtab strings,
  17  * and the old ElfXX_Shdr[] array, remain as "garbage" (commonly, a couple
  18  * kilobytes.)  Subsequent processing by /bin/ld (or the kernel module loader)
  19  * will ignore the garbage regions, because they are not designated by the
  20  * new .e_shoff nor the new ElfXX_Shdr[].  [In order to remove the garbage,
  21  * then use "ld -r" to create a new file that omits the garbage.]
  22  */
  23
  24 #include <sys/types.h>
  25 #include <sys/mman.h>
  26 #include <sys/stat.h>
  27 #include <getopt.h>
  28 #include <elf.h>
  29 #include <fcntl.h>
  30 #include <setjmp.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <unistd.h>
  35
  36 /*
  37  * glibc synced up and added the metag number but didn't add the relocations.
  38  * Work around this in a crude manner for now.
  39  */
  40 #ifndef EM_METAG
  41 #define EM_METAG      174
  42 #endif
  43 #ifndef R_METAG_ADDR32
  44 #define R_METAG_ADDR32                   2
  45 #endif
  46 #ifndef R_METAG_NONE
  47 #define R_METAG_NONE                     3
  48 #endif
  49
  50 #ifndef EM_AARCH64
  51 #define EM_AARCH64      183
  52 #define R_AARCH64_NONE          0
  53 #define R_AARCH64_ABS64 257
  54 #endif
  55
  56 #define R_ARM_PC24              1
  57 #define R_ARM_THM_CALL          10
  58 #define R_ARM_CALL              28
  59
  60 static int fd_map;      /* File descriptor for file being modified. */
  61 static int mmap_failed; /* Boolean flag. */
  62 static char gpfx;       /* prefix for global symbol name (sometimes '_') */
  63 static struct stat sb;  /* Remember .st_size, etc. */
  64 static jmp_buf jmpenv;  /* setjmp/longjmp per-file error escape */
  65 static const char *altmcount;   /* alternate mcount symbol name */
  66 static int warn_on_notrace_sect; /* warn when section has mcount not being recorded */
  67 static void *file_map;  /* pointer of the mapped file */
  68 static void *file_end;  /* pointer to the end of the mapped file */
  69 static int file_updated; /* flag to state file was changed */
  70 static void *file_ptr;  /* current file pointer location */
  71 static void *file_append; /* added to the end of the file */
  72 static size_t file_append_size; /* how much is added to end of file */
  73
  74 /* setjmp() return values */
  75 enum {
  76         SJ_SETJMP = 0,  /* hardwired first return */
  77         SJ_FAIL,
  78         SJ_SUCCEED
  79 };
  80
  81 /* Per-file resource cleanup when multiple files. */
  82 static void
  83 cleanup(void)
  84 {
  85         if (!mmap_failed)
  86                 munmap(file_map, sb.st_size);
  87         else
  88                 free(file_map);
  89         file_map = NULL;
  90         free(file_append);
  91         file_append = NULL;
  92         file_append_size = 0;
  93         file_updated = 0;
  94 }
  95
  96 static void __attribute__((noreturn))
  97 fail_file(void)
  98 {
  99         cleanup();
 100         longjmp(jmpenv, SJ_FAIL);
 101 }
 102
 103 static void __attribute__((noreturn))
 104 succeed_file(void)
 105 {
 106         cleanup();
 107         longjmp(jmpenv, SJ_SUCCEED);
 108 }
 109
 110 /* ulseek, uread, ...:  Check return value for errors. */
 111
 112 static off_t
 113 ulseek(int const fd, off_t const offset, int const whence)
 114 {
 115         switch (whence) {
 116         case SEEK_SET:
 117                 file_ptr = file_map + offset;
 118                 break;
 119         case SEEK_CUR:
 120                 file_ptr += offset;
 121                 break;
 122         case SEEK_END:
 123                 file_ptr = file_map + (sb.st_size - offset);
 124                 break;
 125         }
 126         if (file_ptr < file_map) {
 127                 fprintf(stderr, "lseek: seek before file\n");
 128                 fail_file();
 129         }
 130         return file_ptr - file_map;
 131 }
 132
 133 static size_t
 134 uread(int const fd, void *const buf, size_t const count)
 135 {
 136         size_t const n = read(fd, buf, count);
 137         if (n != count) {
 138                 perror("read");
 139                 fail_file();
 140         }
 141         return n;
 142 }
 143
 144 static size_t
 145 uwrite(int const fd, void const *const buf, size_t const count)
 146 {
 147         size_t cnt = count;
 148         off_t idx = 0;
 149
 150         file_updated = 1;
 151
 152         if (file_ptr + count >= file_end) {
 153                 off_t aoffset = (file_ptr + count) - file_end;
 154
 155                 if (aoffset > file_append_size) {
 156                         file_append = realloc(file_append, aoffset);
 157                         file_append_size = aoffset;
 158                 }
 159                 if (!file_append) {
 160                         perror("write");
 161                         fail_file();
 162                 }
 163                 if (file_ptr < file_end) {
 164                         cnt = file_end - file_ptr;
 165                 } else {
 166                         cnt = 0;
 167                         idx = aoffset - count;
 168                 }
 169         }
 170
 171         if (cnt)
 172                 memcpy(file_ptr, buf, cnt);
 173
 174         if (cnt < count)
 175                 memcpy(file_append + idx, buf + cnt, count - cnt);
 176
 177         file_ptr += count;
 178         return count;
 179 }
 180
 181 static void *
 182 umalloc(size_t size)
 183 {
 184         void *const addr = malloc(size);
 185         if (addr == 0) {
 186                 fprintf(stderr, "malloc failed: %zu bytes\n", size);
 187                 fail_file();
 188         }
 189         return addr;
 190 }
 191
 192 static unsigned char ideal_nop5_x86_64[5] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 };
 193 static unsigned char ideal_nop5_x86_32[5] = { 0x3e, 0x8d, 0x74, 0x26, 0x00 };
 194 static unsigned char *ideal_nop;
 195
 196 static char rel_type_nop;
 197
 198 static int (*make_nop)(void *map, size_t const offset);
 199
 200 static int make_nop_x86(void *map, size_t const offset)
 201 {
 202         uint32_t *ptr;
 203         unsigned char *op;
 204
 205         /* Confirm we have 0xe8 0x0 0x0 0x0 0x0 */
 206         ptr = map + offset;
 207         if (*ptr != 0)
 208                 return -1;
 209
 210         op = map + offset - 1;
 211         if (*op != 0xe8)
 212                 return -1;
 213
 214         /* convert to nop */
 215         ulseek(fd_map, offset - 1, SEEK_SET);
 216         uwrite(fd_map, ideal_nop, 5);
 217         return 0;
 218 }
 219
 220 static unsigned char ideal_nop4_arm_le[4] = { 0x00, 0x00, 0xa0, 0xe1 }; /* mov r0, r0 */
 221 static unsigned char ideal_nop4_arm_be[4] = { 0xe1, 0xa0, 0x00, 0x00 }; /* mov r0, r0 */
 222 static unsigned char *ideal_nop4_arm;
 223
 224 static unsigned char bl_mcount_arm_le[4] = { 0xfe, 0xff, 0xff, 0xeb }; /* bl */
 225 static unsigned char bl_mcount_arm_be[4] = { 0xeb, 0xff, 0xff, 0xfe }; /* bl */
 226 static unsigned char *bl_mcount_arm;
 227
 228 static unsigned char push_arm_le[4] = { 0x04, 0xe0, 0x2d, 0xe5 }; /* push {lr} */
 229 static unsigned char push_arm_be[4] = { 0xe5, 0x2d, 0xe0, 0x04 }; /* push {lr} */
 230 static unsigned char *push_arm;
 231
 232 static unsigned char ideal_nop2_thumb_le[2] = { 0x00, 0xbf }; /* nop */
 233 static unsigned char ideal_nop2_thumb_be[2] = { 0xbf, 0x00 }; /* nop */
 234 static unsigned char *ideal_nop2_thumb;
 235
 236 static unsigned char push_bl_mcount_thumb_le[6] = { 0x00, 0xb5, 0xff, 0xf7, 0xfe, 0xff }; /* push {lr}, bl */
 237 static unsigned char push_bl_mcount_thumb_be[6] = { 0xb5, 0x00, 0xf7, 0xff, 0xff, 0xfe }; /* push {lr}, bl */
 238 static unsigned char *push_bl_mcount_thumb;
 239
 240 static int make_nop_arm(void *map, size_t const offset)
 241 {
 242         char *ptr;
 243         int cnt = 1;
 244         int nop_size;
 245         size_t off = offset;
 246
 247         ptr = map + offset;
 248         if (memcmp(ptr, bl_mcount_arm, 4) == 0) {
 249                 if (memcmp(ptr - 4, push_arm, 4) == 0) {
 250                         off -= 4;
 251                         cnt = 2;
 252                 }
 253                 ideal_nop = ideal_nop4_arm;
 254                 nop_size = 4;
 255         } else if (memcmp(ptr - 2, push_bl_mcount_thumb, 6) == 0) {
 256                 cnt = 3;
 257                 nop_size = 2;
 258                 off -= 2;
 259                 ideal_nop = ideal_nop2_thumb;
 260         } else
 261                 return -1;
 262
 263         /* Convert to nop */
 264         ulseek(fd_map, off, SEEK_SET);
 265
 266         do {
 267                 uwrite(fd_map, ideal_nop, nop_size);
 268         } while (--cnt > 0);
 269
 270         return 0;
 271 }
 272
 273 static unsigned char ideal_nop4_arm64[4] = {0x1f, 0x20, 0x03, 0xd5};
 274 static int make_nop_arm64(void *map, size_t const offset)
 275 {
 276         uint32_t *ptr;
 277
 278         ptr = map + offset;
 279         /* bl <_mcount> is 0x94000000 before relocation */
 280         if (*ptr != 0x94000000)
 281                 return -1;
 282
 283         /* Convert to nop */
 284         ulseek(fd_map, offset, SEEK_SET);
 285         uwrite(fd_map, ideal_nop, 4);
 286         return 0;
 287 }
 288
 289 /*
 290  * Get the whole file as a programming convenience in order to avoid
 291  * malloc+lseek+read+free of many pieces.  If successful, then mmap
 292  * avoids copying unused pieces; else just read the whole file.
 293  * Open for both read and write; new info will be appended to the file.
 294  * Use MAP_PRIVATE so that a few changes to the in-memory ElfXX_Ehdr
 295  * do not propagate to the file until an explicit overwrite at the last.
 296  * This preserves most aspects of consistency (all except .st_size)
 297  * for simultaneous readers of the file while we are appending to it.
 298  * However, multiple writers still are bad.  We choose not to use
 299  * locking because it is expensive and the use case of kernel build
 300  * makes multiple writers unlikely.
 301  */
 302 static void *mmap_file(char const *fname)
 303 {
 304         fd_map = open(fname, O_RDONLY);
 305         if (fd_map < 0 || fstat(fd_map, &sb) < 0) {
 306                 perror(fname);
 307                 fail_file();
 308         }
 309         if (!S_ISREG(sb.st_mode)) {
 310                 fprintf(stderr, "not a regular file: %s\n", fname);
 311                 fail_file();
 312         }
 313         file_map = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
 314                         fd_map, 0);
 315         mmap_failed = 0;
 316         if (file_map == MAP_FAILED) {
 317                 mmap_failed = 1;
 318                 file_map = umalloc(sb.st_size);
 319                 uread(fd_map, file_map, sb.st_size);
 320         }
 321         close(fd_map);
 322
 323         file_end = file_map + sb.st_size;
 324
 325         return file_map;
 326 }
 327
 328 static void write_file(const char *fname)
 329 {
 330         char tmp_file[strlen(fname) + 4];
 331         size_t n;
 332
 333         if (!file_updated)
 334                 return;
 335
 336         sprintf(tmp_file, "%s.rc", fname);
 337
 338         /*
 339          * After reading the entire file into memory, delete it
 340          * and write it back, to prevent weird side effects of modifying
 341          * an object file in place.
 342          */
 343         fd_map = open(tmp_file, O_WRONLY | O_TRUNC | O_CREAT, sb.st_mode);
 344         if (fd_map < 0) {
 345                 perror(fname);
 346                 fail_file();
 347         }
 348         n = write(fd_map, file_map, sb.st_size);
 349         if (n != sb.st_size) {
 350                 perror("write");
 351                 fail_file();
 352         }
 353         if (file_append_size) {
 354                 n = write(fd_map, file_append, file_append_size);
 355                 if (n != file_append_size) {
 356                         perror("write");
 357                         fail_file();
 358                 }
 359         }
 360         close(fd_map);
 361         if (rename(tmp_file, fname) < 0) {
 362                 perror(fname);
 363                 fail_file();
 364         }
 365 }
 366
 367 /* w8rev, w8nat, ...: Handle endianness. */
 368
 369 static uint64_t w8rev(uint64_t const x)
 370 {
 371         return   ((0xff & (x >> (0 * 8))) << (7 * 8))
 372                | ((0xff & (x >> (1 * 8))) << (6 * 8))
 373                | ((0xff & (x >> (2 * 8))) << (5 * 8))
 374                | ((0xff & (x >> (3 * 8))) << (4 * 8))
 375                | ((0xff & (x >> (4 * 8))) << (3 * 8))
 376                | ((0xff & (x >> (5 * 8))) << (2 * 8))
 377                | ((0xff & (x >> (6 * 8))) << (1 * 8))
 378                | ((0xff & (x >> (7 * 8))) << (0 * 8));
 379 }
 380
 381 static uint32_t w4rev(uint32_t const x)
 382 {
 383         return   ((0xff & (x >> (0 * 8))) << (3 * 8))
 384                | ((0xff & (x >> (1 * 8))) << (2 * 8))
 385                | ((0xff & (x >> (2 * 8))) << (1 * 8))
 386                | ((0xff & (x >> (3 * 8))) << (0 * 8));
 387 }
 388
 389 static uint32_t w2rev(uint16_t const x)
 390 {
 391         return   ((0xff & (x >> (0 * 8))) << (1 * 8))
 392                | ((0xff & (x >> (1 * 8))) << (0 * 8));
 393 }
 394
 395 static uint64_t w8nat(uint64_t const x)
 396 {
 397         return x;
 398 }
 399
 400 static uint32_t w4nat(uint32_t const x)
 401 {
 402         return x;
 403 }
 404
 405 static uint32_t w2nat(uint16_t const x)
 406 {
 407         return x;
 408 }
 409
 410 static uint64_t (*w8)(uint64_t);
 411 static uint32_t (*w)(uint32_t);
 412 static uint32_t (*w2)(uint16_t);
 413
 414 /* Names of the sections that could contain calls to mcount. */
 415 static int
 416 is_mcounted_section_name(char const *const txtname)
 417 {
 418         return strcmp(".text",           txtname) == 0 ||
 419                 strcmp(".init.text",     txtname) == 0 ||
 420                 strcmp(".ref.text",      txtname) == 0 ||
 421                 strcmp(".sched.text",    txtname) == 0 ||
 422                 strcmp(".spinlock.text", txtname) == 0 ||
 423                 strcmp(".irqentry.text", txtname) == 0 ||
 424                 strcmp(".softirqentry.text", txtname) == 0 ||
 425                 strcmp(".kprobes.text", txtname) == 0 ||
 426                 strcmp(".cpuidle.text", txtname) == 0 ||
 427                 strcmp(".text.unlikely", txtname) == 0;
 428 }
 429
 430 /* 32 bit and 64 bit are very similar */
 431 #include "recordmcount.h"
 432 #define RECORD_MCOUNT_64
 433 #include "recordmcount.h"
 434
 435 static int arm_is_fake_mcount(Elf32_Rel const *rp)
 436 {
 437         switch (ELF32_R_TYPE(w(rp->r_info))) {
 438         case R_ARM_THM_CALL:
 439         case R_ARM_CALL:
 440         case R_ARM_PC24:
 441                 return 0;
 442         }
 443
 444         return 1;
 445 }
 446
 447 /* 64-bit EM_MIPS has weird ELF64_Rela.r_info.
 448  * http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf
 449  * We interpret Table 29 Relocation Operation (Elf64_Rel, Elf64_Rela) [p.40]
 450  * to imply the order of the members; the spec does not say so.
 451  *      typedef unsigned char Elf64_Byte;
 452  * fails on MIPS64 because their <elf.h> already has it!
 453  */
 454
 455 typedef uint8_t myElf64_Byte;           /* Type for a 8-bit quantity.  */
 456
 457 union mips_r_info {
 458         Elf64_Xword r_info;
 459         struct {
 460                 Elf64_Word r_sym;               /* Symbol index.  */
 461                 myElf64_Byte r_ssym;            /* Special symbol.  */
 462                 myElf64_Byte r_type3;           /* Third relocation.  */
 463                 myElf64_Byte r_type2;           /* Second relocation.  */
 464                 myElf64_Byte r_type;            /* First relocation.  */
 465         } r_mips;
 466 };
 467
 468 static uint64_t MIPS64_r_sym(Elf64_Rel const *rp)
 469 {
 470         return w(((union mips_r_info){ .r_info = rp->r_info }).r_mips.r_sym);
 471 }
 472
 473 static void MIPS64_r_info(Elf64_Rel *const rp, unsigned sym, unsigned type)
 474 {
 475         rp->r_info = ((union mips_r_info){
 476                 .r_mips = { .r_sym = w(sym), .r_type = type }
 477         }).r_info;
 478 }
 479
 480 static void
 481 do_file(char const *const fname)
 482 {
 483         Elf32_Ehdr *const ehdr = mmap_file(fname);
 484         unsigned int reltype = 0;
 485
 486         w = w4nat;
 487         w2 = w2nat;
 488         w8 = w8nat;
 489         switch (ehdr->e_ident[EI_DATA]) {
 490                 static unsigned int const endian = 1;
 491         default:
 492                 fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
 493                         ehdr->e_ident[EI_DATA], fname);
 494                 fail_file();
 495                 break;
 496         case ELFDATA2LSB:
 497                 if (*(unsigned char const *)&endian != 1) {
 498                         /* main() is big endian, file.o is little endian. */
 499                         w = w4rev;
 500                         w2 = w2rev;
 501                         w8 = w8rev;
 502                 }
 503                 ideal_nop4_arm = ideal_nop4_arm_le;
 504                 bl_mcount_arm = bl_mcount_arm_le;
 505                 push_arm = push_arm_le;
 506                 ideal_nop2_thumb = ideal_nop2_thumb_le;
 507                 push_bl_mcount_thumb = push_bl_mcount_thumb_le;
 508                 break;
 509         case ELFDATA2MSB:
 510                 if (*(unsigned char const *)&endian != 0) {
 511                         /* main() is little endian, file.o is big endian. */
 512                         w = w4rev;
 513                         w2 = w2rev;
 514                         w8 = w8rev;
 515                 }
 516                 ideal_nop4_arm = ideal_nop4_arm_be;
 517                 bl_mcount_arm = bl_mcount_arm_be;
 518                 push_arm = push_arm_be;
 519                 ideal_nop2_thumb = ideal_nop2_thumb_be;
 520                 push_bl_mcount_thumb = push_bl_mcount_thumb_be;
 521                 break;
 522         }  /* end switch */
 523         if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
 524         ||  w2(ehdr->e_type) != ET_REL
 525         ||  ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
 526                 fprintf(stderr, "unrecognized ET_REL file %s\n", fname);
 527                 fail_file();
 528         }
 529
 530         gpfx = 0;
 531         switch (w2(ehdr->e_machine)) {
 532         default:
 533                 fprintf(stderr, "unrecognized e_machine %d %s\n",
 534                         w2(ehdr->e_machine), fname);
 535                 fail_file();
 536                 break;
 537         case EM_386:
 538                 reltype = R_386_32;
 539                 rel_type_nop = R_386_NONE;
 540                 make_nop = make_nop_x86;
 541                 ideal_nop = ideal_nop5_x86_32;
 542                 mcount_adjust_32 = -1;
 543                 break;
 544         case EM_ARM:     reltype = R_ARM_ABS32;
 545                          altmcount = "__gnu_mcount_nc";
 546                          make_nop = make_nop_arm;
 547                          rel_type_nop = R_ARM_NONE;
 548                          is_fake_mcount32 = arm_is_fake_mcount;
 549                          break;
 550         case EM_AARCH64:
 551                         reltype = R_AARCH64_ABS64;
 552                         make_nop = make_nop_arm64;
 553                         rel_type_nop = R_AARCH64_NONE;
 554                         ideal_nop = ideal_nop4_arm64;
 555                         gpfx = '_';
 556                         break;
 557         case EM_IA_64:   reltype = R_IA64_IMM64;   gpfx = '_'; break;
 558         case EM_METAG:   reltype = R_METAG_ADDR32;
 559                          altmcount = "_mcount_wrapper";
 560                          rel_type_nop = R_METAG_NONE;
 561                          /* We happen to have the same requirement as MIPS */
 562                          is_fake_mcount32 = MIPS32_is_fake_mcount;
 563                          break;
 564         case EM_MIPS:    /* reltype: e_class    */ gpfx = '_'; break;
 565         case EM_PPC:     reltype = R_PPC_ADDR32;   gpfx = '_'; break;
 566         case EM_PPC64:   reltype = R_PPC64_ADDR64; gpfx = '_'; break;
 567         case EM_S390:    /* reltype: e_class    */ gpfx = '_'; break;
 568         case EM_SH:      reltype = R_SH_DIR32;                 break;
 569         case EM_SPARCV9: reltype = R_SPARC_64;     gpfx = '_'; break;
 570         case EM_X86_64:
 571                 make_nop = make_nop_x86;
 572                 ideal_nop = ideal_nop5_x86_64;
 573                 reltype = R_X86_64_64;
 574                 rel_type_nop = R_X86_64_NONE;
 575                 mcount_adjust_64 = -1;
 576                 break;
 577         }  /* end switch */
 578
 579         switch (ehdr->e_ident[EI_CLASS]) {
 580         default:
 581                 fprintf(stderr, "unrecognized ELF class %d %s\n",
 582                         ehdr->e_ident[EI_CLASS], fname);
 583                 fail_file();
 584                 break;
 585         case ELFCLASS32:
 586                 if (w2(ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
 587                 ||  w2(ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
 588                         fprintf(stderr,
 589                                 "unrecognized ET_REL file: %s\n", fname);
 590                         fail_file();
 591                 }
 592                 if (w2(ehdr->e_machine) == EM_MIPS) {
 593                         reltype = R_MIPS_32;
 594                         is_fake_mcount32 = MIPS32_is_fake_mcount;
 595                 }
 596                 do32(ehdr, fname, reltype);
 597                 break;
 598         case ELFCLASS64: {
 599                 Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
 600                 if (w2(ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
 601                 ||  w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
 602                         fprintf(stderr,
 603                                 "unrecognized ET_REL file: %s\n", fname);
 604                         fail_file();
 605                 }
 606                 if (w2(ghdr->e_machine) == EM_S390) {
 607                         reltype = R_390_64;
 608                         mcount_adjust_64 = -14;
 609                 }
 610                 if (w2(ghdr->e_machine) == EM_MIPS) {
 611                         reltype = R_MIPS_64;
 612                         Elf64_r_sym = MIPS64_r_sym;
 613                         Elf64_r_info = MIPS64_r_info;
 614                         is_fake_mcount64 = MIPS64_is_fake_mcount;
 615                 }
 616                 do64(ghdr, fname, reltype);
 617                 break;
 618         }
 619         }  /* end switch */
 620
 621         write_file(fname);
 622         cleanup();
 623 }
 624
 625 int
 626 main(int argc, char *argv[])
 627 {
 628         const char ftrace[] = "/ftrace.o";
 629         int ftrace_size = sizeof(ftrace) - 1;
 630         int n_error = 0;  /* gcc-4.3.0 false positive complaint */
 631         int c;
 632         int i;
 633
 634         while ((c = getopt(argc, argv, "w")) >= 0) {
 635                 switch (c) {
 636                 case 'w':
 637                         warn_on_notrace_sect = 1;
 638                         break;
 639                 default:
 640                         fprintf(stderr, "usage: recordmcount [-w] file.o...\n");
 641                         return 0;
 642                 }
 643         }
 644
 645         if ((argc - optind) < 1) {
 646                 fprintf(stderr, "usage: recordmcount [-w] file.o...\n");
 647                 return 0;
 648         }
 649
 650         /* Process each file in turn, allowing deep failure. */
 651         for (i = optind; i < argc; i++) {
 652                 char *file = argv[i];
 653                 int const sjval = setjmp(jmpenv);
 654                 int len;
 655
 656                 /*
 657                  * The file kernel/trace/ftrace.o references the mcount
 658                  * function but does not call it. Since ftrace.o should
 659                  * not be traced anyway, we just skip it.
 660                  */
 661                 len = strlen(file);
 662                 if (len >= ftrace_size &&
 663                     strcmp(file + (len - ftrace_size), ftrace) == 0)
 664                         continue;
 665
 666                 switch (sjval) {
 667                 default:
 668                         fprintf(stderr, "internal error: %s\n", file);
 669                         exit(1);
 670                         break;
 671                 case SJ_SETJMP:    /* normal sequence */
 672                         /* Avoid problems if early cleanup() */
 673                         fd_map = -1;
 674                         mmap_failed = 1;
 675                         file_map = NULL;
 676                         file_ptr = NULL;
 677                         file_updated = 0;
 678                         do_file(file);
 679                         break;
 680                 case SJ_FAIL:    /* error in do_file or below */
 681                         fprintf(stderr, "%s: failed\n", file);
 682                         ++n_error;
 683                         break;
 684                 case SJ_SUCCEED:    /* premature success */
 685                         /* do nothing */
 686                         break;
 687                 }  /* end switch */
 688         }
 689         return !!n_error;
 690 }