scripts/recordmcount.h

   1 /*
   2  * recordmcount.h
   3  *
   4  * This code was taken out of recordmcount.c written by
   5  * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
   6  *
   7  * The original code had the same algorithms for both 32bit
   8  * and 64bit ELF files, but the code was duplicated to support
   9  * the difference in structures that were used. This
  10  * file creates a macro of everything that is different between
  11  * the 64 and 32 bit code, such that by including this header
  12  * twice we can create both sets of functions by including this
  13  * header once with RECORD_MCOUNT_64 undefined, and again with
  14  * it defined.
  15  *
  16  * This conversion to macros was done by:
  17  * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
  18  *
  19  * Licensed under the GNU General Public License, version 2 (GPLv2).
  20  */
  21 #undef append_func
  22 #undef is_fake_mcount
  23 #undef fn_is_fake_mcount
  24 #undef MIPS_is_fake_mcount
  25 #undef mcount_adjust
  26 #undef sift_rel_mcount
  27 #undef nop_mcount
  28 #undef find_secsym_ndx
  29 #undef __has_rel_mcount
  30 #undef has_rel_mcount
  31 #undef tot_relsize
  32 #undef get_mcountsym
  33 #undef get_sym_str_and_relp
  34 #undef do_func
  35 #undef Elf_Addr
  36 #undef Elf_Ehdr
  37 #undef Elf_Shdr
  38 #undef Elf_Rel
  39 #undef Elf_Rela
  40 #undef Elf_Sym
  41 #undef ELF_R_SYM
  42 #undef Elf_r_sym
  43 #undef ELF_R_INFO
  44 #undef Elf_r_info
  45 #undef ELF_ST_BIND
  46 #undef fn_ELF_R_SYM
  47 #undef fn_ELF_R_INFO
  48 #undef uint_t
  49 #undef _w
  50 #undef _align
  51 #undef _size
  52
  53 #ifdef RECORD_MCOUNT_64
  54 # define append_func            append64
  55 # define sift_rel_mcount        sift64_rel_mcount
  56 # define nop_mcount             nop_mcount_64
  57 # define find_secsym_ndx        find64_secsym_ndx
  58 # define __has_rel_mcount       __has64_rel_mcount
  59 # define has_rel_mcount         has64_rel_mcount
  60 # define tot_relsize            tot64_relsize
  61 # define get_sym_str_and_relp   get_sym_str_and_relp_64
  62 # define do_func                do64
  63 # define get_mcountsym          get_mcountsym_64
  64 # define is_fake_mcount         is_fake_mcount64
  65 # define fn_is_fake_mcount      fn_is_fake_mcount64
  66 # define MIPS_is_fake_mcount    MIPS64_is_fake_mcount
  67 # define mcount_adjust          mcount_adjust_64
  68 # define Elf_Addr               Elf64_Addr
  69 # define Elf_Ehdr               Elf64_Ehdr
  70 # define Elf_Shdr               Elf64_Shdr
  71 # define Elf_Rel                Elf64_Rel
  72 # define Elf_Rela               Elf64_Rela
  73 # define Elf_Sym                Elf64_Sym
  74 # define ELF_R_SYM              ELF64_R_SYM
  75 # define Elf_r_sym              Elf64_r_sym
  76 # define ELF_R_INFO             ELF64_R_INFO
  77 # define Elf_r_info             Elf64_r_info
  78 # define ELF_ST_BIND            ELF64_ST_BIND
  79 # define fn_ELF_R_SYM           fn_ELF64_R_SYM
  80 # define fn_ELF_R_INFO          fn_ELF64_R_INFO
  81 # define uint_t                 uint64_t
  82 # define _w                     w8
  83 # define _align                 7u
  84 # define _size                  8
  85 #else
  86 # define append_func            append32
  87 # define sift_rel_mcount        sift32_rel_mcount
  88 # define nop_mcount             nop_mcount_32
  89 # define find_secsym_ndx        find32_secsym_ndx
  90 # define __has_rel_mcount       __has32_rel_mcount
  91 # define has_rel_mcount         has32_rel_mcount
  92 # define tot_relsize            tot32_relsize
  93 # define get_sym_str_and_relp   get_sym_str_and_relp_32
  94 # define do_func                do32
  95 # define get_mcountsym          get_mcountsym_32
  96 # define is_fake_mcount         is_fake_mcount32
  97 # define fn_is_fake_mcount      fn_is_fake_mcount32
  98 # define MIPS_is_fake_mcount    MIPS32_is_fake_mcount
  99 # define mcount_adjust          mcount_adjust_32
 100 # define Elf_Addr               Elf32_Addr
 101 # define Elf_Ehdr               Elf32_Ehdr
 102 # define Elf_Shdr               Elf32_Shdr
 103 # define Elf_Rel                Elf32_Rel
 104 # define Elf_Rela               Elf32_Rela
 105 # define Elf_Sym                Elf32_Sym
 106 # define ELF_R_SYM              ELF32_R_SYM
 107 # define Elf_r_sym              Elf32_r_sym
 108 # define ELF_R_INFO             ELF32_R_INFO
 109 # define Elf_r_info             Elf32_r_info
 110 # define ELF_ST_BIND            ELF32_ST_BIND
 111 # define fn_ELF_R_SYM           fn_ELF32_R_SYM
 112 # define fn_ELF_R_INFO          fn_ELF32_R_INFO
 113 # define uint_t                 uint32_t
 114 # define _w                     w
 115 # define _align                 3u
 116 # define _size                  4
 117 #endif
 118
 119 /* Functions and pointers that do_file() may override for specific e_machine. */
 120 static int fn_is_fake_mcount(Elf_Rel const *rp)
 121 {
 122         return 0;
 123 }
 124 static int (*is_fake_mcount)(Elf_Rel const *rp) = fn_is_fake_mcount;
 125
 126 static uint_t fn_ELF_R_SYM(Elf_Rel const *rp)
 127 {
 128         return ELF_R_SYM(_w(rp->r_info));
 129 }
 130 static uint_t (*Elf_r_sym)(Elf_Rel const *rp) = fn_ELF_R_SYM;
 131
 132 static void fn_ELF_R_INFO(Elf_Rel *const rp, unsigned sym, unsigned type)
 133 {
 134         rp->r_info = _w(ELF_R_INFO(sym, type));
 135 }
 136 static void (*Elf_r_info)(Elf_Rel *const rp, unsigned sym, unsigned type) = fn_ELF_R_INFO;
 137
 138 static int mcount_adjust = 0;
 139
 140 /*
 141  * MIPS mcount long call has 2 _mcount symbols, only the position of the 1st
 142  * _mcount symbol is needed for dynamic function tracer, with it, to disable
 143  * tracing(ftrace_make_nop), the instruction in the position is replaced with
 144  * the "b label" instruction, to enable tracing(ftrace_make_call), replace the
 145  * instruction back. So, here, we set the 2nd one as fake and filter it.
 146  *
 147  * c:   3c030000        lui     v1,0x0          <-->    b       label
 148  *              c: R_MIPS_HI16  _mcount
 149  *              c: R_MIPS_NONE  *ABS*
 150  *              c: R_MIPS_NONE  *ABS*
 151  * 10:  64630000        daddiu  v1,v1,0
 152  *              10: R_MIPS_LO16 _mcount
 153  *              10: R_MIPS_NONE *ABS*
 154  *              10: R_MIPS_NONE *ABS*
 155  * 14:  03e0082d        move    at,ra
 156  * 18:  0060f809        jalr    v1
 157  * label:
 158  */
 159 #define MIPS_FAKEMCOUNT_OFFSET  4
 160
 161 static int MIPS_is_fake_mcount(Elf_Rel const *rp)
 162 {
 163         static Elf_Addr old_r_offset;
 164         Elf_Addr current_r_offset = _w(rp->r_offset);
 165         int is_fake;
 166
 167         is_fake = old_r_offset &&
 168                 (current_r_offset - old_r_offset == MIPS_FAKEMCOUNT_OFFSET);
 169         old_r_offset = current_r_offset;
 170
 171         return is_fake;
 172 }
 173
 174 /* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */
 175 static void append_func(Elf_Ehdr *const ehdr,
 176                         Elf_Shdr *const shstr,
 177                         uint_t const *const mloc0,
 178                         uint_t const *const mlocp,
 179                         Elf_Rel const *const mrel0,
 180                         Elf_Rel const *const mrelp,
 181                         unsigned int const rel_entsize,
 182                         unsigned int const symsec_sh_link)
 183 {
 184         /* Begin constructing output file */
 185         Elf_Shdr mcsec;
 186         char const *mc_name = (sizeof(Elf_Rela) == rel_entsize)
 187                 ? ".rela__mcount_loc"
 188                 :  ".rel__mcount_loc";
 189         unsigned const old_shnum = w2(ehdr->e_shnum);
 190         uint_t const old_shoff = _w(ehdr->e_shoff);
 191         uint_t const old_shstr_sh_size   = _w(shstr->sh_size);
 192         uint_t const old_shstr_sh_offset = _w(shstr->sh_offset);
 193         uint_t t = 1 + strlen(mc_name) + _w(shstr->sh_size);
 194         uint_t new_e_shoff;
 195
 196         shstr->sh_size = _w(t);
 197         shstr->sh_offset = _w(sb.st_size);
 198         t += sb.st_size;
 199         t += (_align & -t);  /* word-byte align */
 200         new_e_shoff = t;
 201
 202         /* body for new shstrtab */
 203         ulseek(fd_map, sb.st_size, SEEK_SET);
 204         uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size);
 205         uwrite(fd_map, mc_name, 1 + strlen(mc_name));
 206
 207         /* old(modified) Elf_Shdr table, word-byte aligned */
 208         ulseek(fd_map, t, SEEK_SET);
 209         t += sizeof(Elf_Shdr) * old_shnum;
 210         uwrite(fd_map, old_shoff + (void *)ehdr,
 211                sizeof(Elf_Shdr) * old_shnum);
 212
 213         /* new sections __mcount_loc and .rel__mcount_loc */
 214         t += 2*sizeof(mcsec);
 215         mcsec.sh_name = w((sizeof(Elf_Rela) == rel_entsize) + strlen(".rel")
 216                 + old_shstr_sh_size);
 217         mcsec.sh_type = w(SHT_PROGBITS);
 218         mcsec.sh_flags = _w(SHF_ALLOC);
 219         mcsec.sh_addr = 0;
 220         mcsec.sh_offset = _w(t);
 221         mcsec.sh_size = _w((void *)mlocp - (void *)mloc0);
 222         mcsec.sh_link = 0;
 223         mcsec.sh_info = 0;
 224         mcsec.sh_addralign = _w(_size);
 225         mcsec.sh_entsize = _w(_size);
 226         uwrite(fd_map, &mcsec, sizeof(mcsec));
 227
 228         mcsec.sh_name = w(old_shstr_sh_size);
 229         mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize)
 230                 ? w(SHT_RELA)
 231                 : w(SHT_REL);
 232         mcsec.sh_flags = 0;
 233         mcsec.sh_addr = 0;
 234         mcsec.sh_offset = _w((void *)mlocp - (void *)mloc0 + t);
 235         mcsec.sh_size   = _w((void *)mrelp - (void *)mrel0);
 236         mcsec.sh_link = w(symsec_sh_link);
 237         mcsec.sh_info = w(old_shnum);
 238         mcsec.sh_addralign = _w(_size);
 239         mcsec.sh_entsize = _w(rel_entsize);
 240         uwrite(fd_map, &mcsec, sizeof(mcsec));
 241
 242         uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0);
 243         uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0);
 244
 245         ehdr->e_shoff = _w(new_e_shoff);
 246         ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum));  /* {.rel,}__mcount_loc */
 247         ulseek(fd_map, 0, SEEK_SET);
 248         uwrite(fd_map, ehdr, sizeof(*ehdr));
 249 }
 250
 251 static unsigned get_mcountsym(Elf_Sym const *const sym0,
 252                               Elf_Rel const *relp,
 253                               char const *const str0)
 254 {
 255         unsigned mcountsym = 0;
 256
 257         Elf_Sym const *const symp =
 258                 &sym0[Elf_r_sym(relp)];
 259         char const *symname = &str0[w(symp->st_name)];
 260         char const *mcount = gpfx == '_' ? "_mcount" : "mcount";
 261
 262         if (symname[0] == '.')
 263                 ++symname;  /* ppc64 hack */
 264         if (strcmp(mcount, symname) == 0 ||
 265             (altmcount && strcmp(altmcount, symname) == 0))
 266                 mcountsym = Elf_r_sym(relp);
 267
 268         return mcountsym;
 269 }
 270
 271 static void get_sym_str_and_relp(Elf_Shdr const *const relhdr,
 272                                  Elf_Ehdr const *const ehdr,
 273                                  Elf_Sym const **sym0,
 274                                  char const **str0,
 275                                  Elf_Rel const **relp)
 276 {
 277         Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
 278                 + (void *)ehdr);
 279         unsigned const symsec_sh_link = w(relhdr->sh_link);
 280         Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];
 281         Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
 282         Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)
 283                 + (void *)ehdr);
 284
 285         *sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)
 286                                   + (void *)ehdr);
 287
 288         *str0 = (char const *)(_w(strsec->sh_offset)
 289                                + (void *)ehdr);
 290
 291         *relp = rel0;
 292 }
 293
 294 /*
 295  * Look at the relocations in order to find the calls to mcount.
 296  * Accumulate the section offsets that are found, and their relocation info,
 297  * onto the end of the existing arrays.
 298  */
 299 static uint_t *sift_rel_mcount(uint_t *mlocp,
 300                                unsigned const offbase,
 301                                Elf_Rel **const mrelpp,
 302                                Elf_Shdr const *const relhdr,
 303                                Elf_Ehdr const *const ehdr,
 304                                unsigned const recsym,
 305                                uint_t const recval,
 306                                unsigned const reltype)
 307 {
 308         uint_t *const mloc0 = mlocp;
 309         Elf_Rel *mrelp = *mrelpp;
 310         Elf_Sym const *sym0;
 311         char const *str0;
 312         Elf_Rel const *relp;
 313         unsigned rel_entsize = _w(relhdr->sh_entsize);
 314         unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
 315         unsigned mcountsym = 0;
 316         unsigned t;
 317
 318         get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
 319
 320         for (t = nrel; t; --t) {
 321                 if (!mcountsym)
 322                         mcountsym = get_mcountsym(sym0, relp, str0);
 323
 324                 if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {
 325                         uint_t const addend =
 326                                 _w(_w(relp->r_offset) - recval + mcount_adjust);
 327                         mrelp->r_offset = _w(offbase
 328                                 + ((void *)mlocp - (void *)mloc0));
 329                         Elf_r_info(mrelp, recsym, reltype);
 330                         if (rel_entsize == sizeof(Elf_Rela)) {
 331                                 ((Elf_Rela *)mrelp)->r_addend = addend;
 332                                 *mlocp++ = 0;
 333                         } else
 334                                 *mlocp++ = addend;
 335
 336                         mrelp = (Elf_Rel *)(rel_entsize + (void *)mrelp);
 337                 }
 338                 relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
 339         }
 340         *mrelpp = mrelp;
 341         return mlocp;
 342 }
 343
 344 /*
 345  * Read the relocation table again, but this time its called on sections
 346  * that are not going to be traced. The mcount calls here will be converted
 347  * into nops.
 348  */
 349 static void nop_mcount(Elf_Shdr const *const relhdr,
 350                        Elf_Ehdr const *const ehdr,
 351                        const char *const txtname)
 352 {
 353         Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
 354                 + (void *)ehdr);
 355         Elf_Sym const *sym0;
 356         char const *str0;
 357         Elf_Rel const *relp;
 358         Elf_Shdr const *const shdr = &shdr0[w(relhdr->sh_info)];
 359         unsigned rel_entsize = _w(relhdr->sh_entsize);
 360         unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
 361         unsigned mcountsym = 0;
 362         unsigned t;
 363         int once = 0;
 364
 365         get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
 366
 367         for (t = nrel; t; --t) {
 368                 int ret = -1;
 369
 370                 if (!mcountsym)
 371                         mcountsym = get_mcountsym(sym0, relp, str0);
 372
 373                 if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {
 374                         if (make_nop)
 375                                 ret = make_nop((void *)ehdr, shdr->sh_offset + relp->r_offset);
 376                         if (warn_on_notrace_sect && !once) {
 377                                 printf("Section %s has mcount callers being ignored\n",
 378                                        txtname);
 379                                 once = 1;
 380                                 /* just warn? */
 381                                 if (!make_nop)
 382                                         return;
 383                         }
 384                 }
 385
 386                 /*
 387                  * If we successfully removed the mcount, mark the relocation
 388                  * as a nop (don't do anything with it).
 389                  */
 390                 if (!ret) {
 391                         Elf_Rel rel;
 392                         rel = *(Elf_Rel *)relp;
 393                         Elf_r_info(&rel, Elf_r_sym(relp), rel_type_nop);
 394                         ulseek(fd_map, (void *)relp - (void *)ehdr, SEEK_SET);
 395                         uwrite(fd_map, &rel, sizeof(rel));
 396                 }
 397                 relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
 398         }
 399 }
 400
 401
 402 /*
 403  * Find a symbol in the given section, to be used as the base for relocating
 404  * the table of offsets of calls to mcount.  A local or global symbol suffices,
 405  * but avoid a Weak symbol because it may be overridden; the change in value
 406  * would invalidate the relocations of the offsets of the calls to mcount.
 407  * Often the found symbol will be the unnamed local symbol generated by
 408  * GNU 'as' for the start of each section.  For example:
 409  *    Num:    Value  Size Type    Bind   Vis      Ndx Name
 410  *      2: 00000000     0 SECTION LOCAL  DEFAULT    1
 411  */
 412 static unsigned find_secsym_ndx(unsigned const txtndx,
 413                                 char const *const txtname,
 414                                 uint_t *const recvalp,
 415                                 Elf_Shdr const *const symhdr,
 416                                 Elf_Ehdr const *const ehdr)
 417 {
 418         Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symhdr->sh_offset)
 419                 + (void *)ehdr);
 420         unsigned const nsym = _w(symhdr->sh_size) / _w(symhdr->sh_entsize);
 421         Elf_Sym const *symp;
 422         unsigned t;
 423
 424         for (symp = sym0, t = nsym; t; --t, ++symp) {
 425                 unsigned int const st_bind = ELF_ST_BIND(symp->st_info);
 426
 427                 if (txtndx == w2(symp->st_shndx)
 428                         /* avoid STB_WEAK */
 429                     && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) {
 430                         *recvalp = _w(symp->st_value);
 431                         return symp - sym0;
 432                 }
 433         }
 434         fprintf(stderr, "Cannot find symbol for section %d: %s.\n",
 435                 txtndx, txtname);
 436         fail_file();
 437 }
 438
 439
 440 /* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */
 441 static char const *
 442 __has_rel_mcount(Elf_Shdr const *const relhdr,  /* is SHT_REL or SHT_RELA */
 443                  Elf_Shdr const *const shdr0,
 444                  char const *const shstrtab,
 445                  char const *const fname)
 446 {
 447         /* .sh_info depends on .sh_type == SHT_REL[,A] */
 448         Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)];
 449         char const *const txtname = &shstrtab[w(txthdr->sh_name)];
 450
 451         if (strcmp("__mcount_loc", txtname) == 0) {
 452                 fprintf(stderr, "warning: __mcount_loc already exists: %s\n",
 453                         fname);
 454                 succeed_file();
 455         }
 456         if (w(txthdr->sh_type) != SHT_PROGBITS ||
 457             !(w(txthdr->sh_flags) & SHF_EXECINSTR))
 458                 return NULL;
 459         return txtname;
 460 }
 461
 462 static char const *has_rel_mcount(Elf_Shdr const *const relhdr,
 463                                   Elf_Shdr const *const shdr0,
 464                                   char const *const shstrtab,
 465                                   char const *const fname)
 466 {
 467         if (w(relhdr->sh_type) != SHT_REL && w(relhdr->sh_type) != SHT_RELA)
 468                 return NULL;
 469         return __has_rel_mcount(relhdr, shdr0, shstrtab, fname);
 470 }
 471
 472
 473 static unsigned tot_relsize(Elf_Shdr const *const shdr0,
 474                             unsigned nhdr,
 475                             const char *const shstrtab,
 476                             const char *const fname)
 477 {
 478         unsigned totrelsz = 0;
 479         Elf_Shdr const *shdrp = shdr0;
 480         char const *txtname;
 481
 482         for (; nhdr; --nhdr, ++shdrp) {
 483                 txtname = has_rel_mcount(shdrp, shdr0, shstrtab, fname);
 484                 if (txtname && is_mcounted_section_name(txtname))
 485                         totrelsz += _w(shdrp->sh_size);
 486         }
 487         return totrelsz;
 488 }
 489
 490
 491 /* Overall supervision for Elf32 ET_REL file. */
 492 static void
 493 do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
 494 {
 495         Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
 496                 + (void *)ehdr);
 497         unsigned const nhdr = w2(ehdr->e_shnum);
 498         Elf_Shdr *const shstr = &shdr0[w2(ehdr->e_shstrndx)];
 499         char const *const shstrtab = (char const *)(_w(shstr->sh_offset)
 500                 + (void *)ehdr);
 501
 502         Elf_Shdr const *relhdr;
 503         unsigned k;
 504
 505         /* Upper bound on space: assume all relevant relocs are for mcount. */
 506         unsigned const totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname);
 507         Elf_Rel *const mrel0 = umalloc(totrelsz);
 508         Elf_Rel *      mrelp = mrel0;
 509
 510         /* 2*sizeof(address) <= sizeof(Elf_Rel) */
 511         uint_t *const mloc0 = umalloc(totrelsz>>1);
 512         uint_t *      mlocp = mloc0;
 513
 514         unsigned rel_entsize = 0;
 515         unsigned symsec_sh_link = 0;
 516
 517         for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) {
 518                 char const *const txtname = has_rel_mcount(relhdr, shdr0,
 519                         shstrtab, fname);
 520                 if (txtname && is_mcounted_section_name(txtname)) {
 521                         uint_t recval = 0;
 522                         unsigned const recsym = find_secsym_ndx(
 523                                 w(relhdr->sh_info), txtname, &recval,
 524                                 &shdr0[symsec_sh_link = w(relhdr->sh_link)],
 525                                 ehdr);
 526
 527                         rel_entsize = _w(relhdr->sh_entsize);
 528                         mlocp = sift_rel_mcount(mlocp,
 529                                 (void *)mlocp - (void *)mloc0, &mrelp,
 530                                 relhdr, ehdr, recsym, recval, reltype);
 531                 } else if (txtname && (warn_on_notrace_sect || make_nop)) {
 532                         /*
 533                          * This section is ignored by ftrace, but still
 534                          * has mcount calls. Convert them to nops now.
 535                          */
 536                         nop_mcount(relhdr, ehdr, txtname);
 537                 }
 538         }
 539         if (mloc0 != mlocp) {
 540                 append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
 541                             rel_entsize, symsec_sh_link);
 542         }
 543         free(mrel0);
 544         free(mloc0);
 545 }