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 ELF_ST_TYPE
  47 #undef fn_ELF_R_SYM
  48 #undef fn_ELF_R_INFO
  49 #undef uint_t
  50 #undef _w
  51 #undef _align
  52 #undef _size
  53
  54 #ifdef RECORD_MCOUNT_64
  55 # define append_func            append64
  56 # define sift_rel_mcount        sift64_rel_mcount
  57 # define nop_mcount             nop_mcount_64
  58 # define find_secsym_ndx        find64_secsym_ndx
  59 # define __has_rel_mcount       __has64_rel_mcount
  60 # define has_rel_mcount         has64_rel_mcount
  61 # define tot_relsize            tot64_relsize
  62 # define get_sym_str_and_relp   get_sym_str_and_relp_64
  63 # define do_func                do64
  64 # define get_mcountsym          get_mcountsym_64
  65 # define is_fake_mcount         is_fake_mcount64
  66 # define fn_is_fake_mcount      fn_is_fake_mcount64
  67 # define MIPS_is_fake_mcount    MIPS64_is_fake_mcount
  68 # define mcount_adjust          mcount_adjust_64
  69 # define Elf_Addr               Elf64_Addr
  70 # define Elf_Ehdr               Elf64_Ehdr
  71 # define Elf_Shdr               Elf64_Shdr
  72 # define Elf_Rel                Elf64_Rel
  73 # define Elf_Rela               Elf64_Rela
  74 # define Elf_Sym                Elf64_Sym
  75 # define ELF_R_SYM              ELF64_R_SYM
  76 # define Elf_r_sym              Elf64_r_sym
  77 # define ELF_R_INFO             ELF64_R_INFO
  78 # define Elf_r_info             Elf64_r_info
  79 # define ELF_ST_BIND            ELF64_ST_BIND
  80 # define ELF_ST_TYPE            ELF64_ST_TYPE
  81 # define fn_ELF_R_SYM           fn_ELF64_R_SYM
  82 # define fn_ELF_R_INFO          fn_ELF64_R_INFO
  83 # define uint_t                 uint64_t
  84 # define _w                     w8
  85 # define _align                 7u
  86 # define _size                  8
  87 #else
  88 # define append_func            append32
  89 # define sift_rel_mcount        sift32_rel_mcount
  90 # define nop_mcount             nop_mcount_32
  91 # define find_secsym_ndx        find32_secsym_ndx
  92 # define __has_rel_mcount       __has32_rel_mcount
  93 # define has_rel_mcount         has32_rel_mcount
  94 # define tot_relsize            tot32_relsize
  95 # define get_sym_str_and_relp   get_sym_str_and_relp_32
  96 # define do_func                do32
  97 # define get_mcountsym          get_mcountsym_32
  98 # define is_fake_mcount         is_fake_mcount32
  99 # define fn_is_fake_mcount      fn_is_fake_mcount32
 100 # define MIPS_is_fake_mcount    MIPS32_is_fake_mcount
 101 # define mcount_adjust          mcount_adjust_32
 102 # define Elf_Addr               Elf32_Addr
 103 # define Elf_Ehdr               Elf32_Ehdr
 104 # define Elf_Shdr               Elf32_Shdr
 105 # define Elf_Rel                Elf32_Rel
 106 # define Elf_Rela               Elf32_Rela
 107 # define Elf_Sym                Elf32_Sym
 108 # define ELF_R_SYM              ELF32_R_SYM
 109 # define Elf_r_sym              Elf32_r_sym
 110 # define ELF_R_INFO             ELF32_R_INFO
 111 # define Elf_r_info             Elf32_r_info
 112 # define ELF_ST_BIND            ELF32_ST_BIND
 113 # define ELF_ST_TYPE            ELF32_ST_TYPE
 114 # define fn_ELF_R_SYM           fn_ELF32_R_SYM
 115 # define fn_ELF_R_INFO          fn_ELF32_R_INFO
 116 # define uint_t                 uint32_t
 117 # define _w                     w
 118 # define _align                 3u
 119 # define _size                  4
 120 #endif
 121
 122 /* Functions and pointers that do_file() may override for specific e_machine. */
 123 static int fn_is_fake_mcount(Elf_Rel const *rp)
 124 {
 125         return 0;
 126 }
 127 static int (*is_fake_mcount)(Elf_Rel const *rp) = fn_is_fake_mcount;
 128
 129 static uint_t fn_ELF_R_SYM(Elf_Rel const *rp)
 130 {
 131         return ELF_R_SYM(_w(rp->r_info));
 132 }
 133 static uint_t (*Elf_r_sym)(Elf_Rel const *rp) = fn_ELF_R_SYM;
 134
 135 static void fn_ELF_R_INFO(Elf_Rel *const rp, unsigned sym, unsigned type)
 136 {
 137         rp->r_info = _w(ELF_R_INFO(sym, type));
 138 }
 139 static void (*Elf_r_info)(Elf_Rel *const rp, unsigned sym, unsigned type) = fn_ELF_R_INFO;
 140
 141 static int mcount_adjust = 0;
 142
 143 /*
 144  * MIPS mcount long call has 2 _mcount symbols, only the position of the 1st
 145  * _mcount symbol is needed for dynamic function tracer, with it, to disable
 146  * tracing(ftrace_make_nop), the instruction in the position is replaced with
 147  * the "b label" instruction, to enable tracing(ftrace_make_call), replace the
 148  * instruction back. So, here, we set the 2nd one as fake and filter it.
 149  *
 150  * c:   3c030000        lui     v1,0x0          <-->    b       label
 151  *              c: R_MIPS_HI16  _mcount
 152  *              c: R_MIPS_NONE  *ABS*
 153  *              c: R_MIPS_NONE  *ABS*
 154  * 10:  64630000        daddiu  v1,v1,0
 155  *              10: R_MIPS_LO16 _mcount
 156  *              10: R_MIPS_NONE *ABS*
 157  *              10: R_MIPS_NONE *ABS*
 158  * 14:  03e0082d        move    at,ra
 159  * 18:  0060f809        jalr    v1
 160  * label:
 161  */
 162 #define MIPS_FAKEMCOUNT_OFFSET  4
 163
 164 static int MIPS_is_fake_mcount(Elf_Rel const *rp)
 165 {
 166         static Elf_Addr old_r_offset;
 167         Elf_Addr current_r_offset = _w(rp->r_offset);
 168         int is_fake;
 169
 170         is_fake = old_r_offset &&
 171                 (current_r_offset - old_r_offset == MIPS_FAKEMCOUNT_OFFSET);
 172         old_r_offset = current_r_offset;
 173
 174         return is_fake;
 175 }
 176
 177 /* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */
 178 static void append_func(Elf_Ehdr *const ehdr,
 179                         Elf_Shdr *const shstr,
 180                         uint_t const *const mloc0,
 181                         uint_t const *const mlocp,
 182                         Elf_Rel const *const mrel0,
 183                         Elf_Rel const *const mrelp,
 184                         unsigned int const rel_entsize,
 185                         unsigned int const symsec_sh_link)
 186 {
 187         /* Begin constructing output file */
 188         Elf_Shdr mcsec;
 189         char const *mc_name = (sizeof(Elf_Rela) == rel_entsize)
 190                 ? ".rela__mcount_loc"
 191                 :  ".rel__mcount_loc";
 192         unsigned const old_shnum = w2(ehdr->e_shnum);
 193         uint_t const old_shoff = _w(ehdr->e_shoff);
 194         uint_t const old_shstr_sh_size   = _w(shstr->sh_size);
 195         uint_t const old_shstr_sh_offset = _w(shstr->sh_offset);
 196         uint_t t = 1 + strlen(mc_name) + _w(shstr->sh_size);
 197         uint_t new_e_shoff;
 198
 199         shstr->sh_size = _w(t);
 200         shstr->sh_offset = _w(sb.st_size);
 201         t += sb.st_size;
 202         t += (_align & -t);  /* word-byte align */
 203         new_e_shoff = t;
 204
 205         /* body for new shstrtab */
 206         ulseek(fd_map, sb.st_size, SEEK_SET);
 207         uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size);
 208         uwrite(fd_map, mc_name, 1 + strlen(mc_name));
 209
 210         /* old(modified) Elf_Shdr table, word-byte aligned */
 211         ulseek(fd_map, t, SEEK_SET);
 212         t += sizeof(Elf_Shdr) * old_shnum;
 213         uwrite(fd_map, old_shoff + (void *)ehdr,
 214                sizeof(Elf_Shdr) * old_shnum);
 215
 216         /* new sections __mcount_loc and .rel__mcount_loc */
 217         t += 2*sizeof(mcsec);
 218         mcsec.sh_name = w((sizeof(Elf_Rela) == rel_entsize) + strlen(".rel")
 219                 + old_shstr_sh_size);
 220         mcsec.sh_type = w(SHT_PROGBITS);
 221         mcsec.sh_flags = _w(SHF_ALLOC);
 222         mcsec.sh_addr = 0;
 223         mcsec.sh_offset = _w(t);
 224         mcsec.sh_size = _w((void *)mlocp - (void *)mloc0);
 225         mcsec.sh_link = 0;
 226         mcsec.sh_info = 0;
 227         mcsec.sh_addralign = _w(_size);
 228         mcsec.sh_entsize = _w(_size);
 229         uwrite(fd_map, &mcsec, sizeof(mcsec));
 230
 231         mcsec.sh_name = w(old_shstr_sh_size);
 232         mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize)
 233                 ? w(SHT_RELA)
 234                 : w(SHT_REL);
 235         mcsec.sh_flags = 0;
 236         mcsec.sh_addr = 0;
 237         mcsec.sh_offset = _w((void *)mlocp - (void *)mloc0 + t);
 238         mcsec.sh_size   = _w((void *)mrelp - (void *)mrel0);
 239         mcsec.sh_link = w(symsec_sh_link);
 240         mcsec.sh_info = w(old_shnum);
 241         mcsec.sh_addralign = _w(_size);
 242         mcsec.sh_entsize = _w(rel_entsize);
 243         uwrite(fd_map, &mcsec, sizeof(mcsec));
 244
 245         uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0);
 246         uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0);
 247
 248         ehdr->e_shoff = _w(new_e_shoff);
 249         ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum));  /* {.rel,}__mcount_loc */
 250         ulseek(fd_map, 0, SEEK_SET);
 251         uwrite(fd_map, ehdr, sizeof(*ehdr));
 252 }
 253
 254 static unsigned get_mcountsym(Elf_Sym const *const sym0,
 255                               Elf_Rel const *relp,
 256                               char const *const str0)
 257 {
 258         unsigned mcountsym = 0;
 259
 260         Elf_Sym const *const symp =
 261                 &sym0[Elf_r_sym(relp)];
 262         char const *symname = &str0[w(symp->st_name)];
 263         char const *mcount = gpfx == '_' ? "_mcount" : "mcount";
 264         char const *fentry = "__fentry__";
 265
 266         if (symname[0] == '.')
 267                 ++symname;  /* ppc64 hack */
 268         if (strcmp(mcount, symname) == 0 ||
 269             (altmcount && strcmp(altmcount, symname) == 0) ||
 270             (strcmp(fentry, symname) == 0))
 271                 mcountsym = Elf_r_sym(relp);
 272
 273         return mcountsym;
 274 }
 275
 276 static void get_sym_str_and_relp(Elf_Shdr const *const relhdr,
 277                                  Elf_Ehdr const *const ehdr,
 278                                  Elf_Sym const **sym0,
 279                                  char const **str0,
 280                                  Elf_Rel const **relp)
 281 {
 282         Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
 283                 + (void *)ehdr);
 284         unsigned const symsec_sh_link = w(relhdr->sh_link);
 285         Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];
 286         Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
 287         Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)
 288                 + (void *)ehdr);
 289
 290         *sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)
 291                                   + (void *)ehdr);
 292
 293         *str0 = (char const *)(_w(strsec->sh_offset)
 294                                + (void *)ehdr);
 295
 296         *relp = rel0;
 297 }
 298
 299 /*
 300  * Look at the relocations in order to find the calls to mcount.
 301  * Accumulate the section offsets that are found, and their relocation info,
 302  * onto the end of the existing arrays.
 303  */
 304 static uint_t *sift_rel_mcount(uint_t *mlocp,
 305                                unsigned const offbase,
 306                                Elf_Rel **const mrelpp,
 307                                Elf_Shdr const *const relhdr,
 308                                Elf_Ehdr const *const ehdr,
 309                                unsigned const recsym,
 310                                uint_t const recval,
 311                                unsigned const reltype)
 312 {
 313         uint_t *const mloc0 = mlocp;
 314         Elf_Rel *mrelp = *mrelpp;
 315         Elf_Sym const *sym0;
 316         char const *str0;
 317         Elf_Rel const *relp;
 318         unsigned rel_entsize = _w(relhdr->sh_entsize);
 319         unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
 320         unsigned mcountsym = 0;
 321         unsigned t;
 322
 323         get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
 324
 325         for (t = nrel; t; --t) {
 326                 if (!mcountsym)
 327                         mcountsym = get_mcountsym(sym0, relp, str0);
 328
 329                 if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {
 330                         uint_t const addend =
 331                                 _w(_w(relp->r_offset) - recval + mcount_adjust);
 332                         mrelp->r_offset = _w(offbase
 333                                 + ((void *)mlocp - (void *)mloc0));
 334                         Elf_r_info(mrelp, recsym, reltype);
 335                         if (rel_entsize == sizeof(Elf_Rela)) {
 336                                 ((Elf_Rela *)mrelp)->r_addend = addend;
 337                                 *mlocp++ = 0;
 338                         } else
 339                                 *mlocp++ = addend;
 340
 341                         mrelp = (Elf_Rel *)(rel_entsize + (void *)mrelp);
 342                 }
 343                 relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
 344         }
 345         *mrelpp = mrelp;
 346         return mlocp;
 347 }
 348
 349 /*
 350  * Read the relocation table again, but this time its called on sections
 351  * that are not going to be traced. The mcount calls here will be converted
 352  * into nops.
 353  */
 354 static void nop_mcount(Elf_Shdr const *const relhdr,
 355                        Elf_Ehdr const *const ehdr,
 356                        const char *const txtname)
 357 {
 358         Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
 359                 + (void *)ehdr);
 360         Elf_Sym const *sym0;
 361         char const *str0;
 362         Elf_Rel const *relp;
 363         Elf_Shdr const *const shdr = &shdr0[w(relhdr->sh_info)];
 364         unsigned rel_entsize = _w(relhdr->sh_entsize);
 365         unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
 366         unsigned mcountsym = 0;
 367         unsigned t;
 368         int once = 0;
 369
 370         get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
 371
 372         for (t = nrel; t; --t) {
 373                 int ret = -1;
 374
 375                 if (!mcountsym)
 376                         mcountsym = get_mcountsym(sym0, relp, str0);
 377
 378                 if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {
 379                         if (make_nop)
 380                                 ret = make_nop((void *)ehdr, shdr->sh_offset + relp->r_offset);
 381                         if (warn_on_notrace_sect && !once) {
 382                                 printf("Section %s has mcount callers being ignored\n",
 383                                        txtname);
 384                                 once = 1;
 385                                 /* just warn? */
 386                                 if (!make_nop)
 387                                         return;
 388                         }
 389                 }
 390
 391                 /*
 392                  * If we successfully removed the mcount, mark the relocation
 393                  * as a nop (don't do anything with it).
 394                  */
 395                 if (!ret) {
 396                         Elf_Rel rel;
 397                         rel = *(Elf_Rel *)relp;
 398                         Elf_r_info(&rel, Elf_r_sym(relp), rel_type_nop);
 399                         ulseek(fd_map, (void *)relp - (void *)ehdr, SEEK_SET);
 400                         uwrite(fd_map, &rel, sizeof(rel));
 401                 }
 402                 relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
 403         }
 404 }
 405
 406
 407 /*
 408  * Find a symbol in the given section, to be used as the base for relocating
 409  * the table of offsets of calls to mcount.  A local or global symbol suffices,
 410  * but avoid a Weak symbol because it may be overridden; the change in value
 411  * would invalidate the relocations of the offsets of the calls to mcount.
 412  * Often the found symbol will be the unnamed local symbol generated by
 413  * GNU 'as' for the start of each section.  For example:
 414  *    Num:    Value  Size Type    Bind   Vis      Ndx Name
 415  *      2: 00000000     0 SECTION LOCAL  DEFAULT    1
 416  */
 417 static unsigned find_secsym_ndx(unsigned const txtndx,
 418                                 char const *const txtname,
 419                                 uint_t *const recvalp,
 420                                 Elf_Shdr const *const symhdr,
 421                                 Elf_Ehdr const *const ehdr)
 422 {
 423         Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symhdr->sh_offset)
 424                 + (void *)ehdr);
 425         unsigned const nsym = _w(symhdr->sh_size) / _w(symhdr->sh_entsize);
 426         Elf_Sym const *symp;
 427         unsigned t;
 428
 429         for (symp = sym0, t = nsym; t; --t, ++symp) {
 430                 unsigned int const st_bind = ELF_ST_BIND(symp->st_info);
 431
 432                 if (txtndx == w2(symp->st_shndx)
 433                         /* avoid STB_WEAK */
 434                     && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) {
 435                         /* function symbols on ARM have quirks, avoid them */
 436                         if (w2(ehdr->e_machine) == EM_ARM
 437                             && ELF_ST_TYPE(symp->st_info) == STT_FUNC)
 438                                 continue;
 439
 440                         *recvalp = _w(symp->st_value);
 441                         return symp - sym0;
 442                 }
 443         }
 444         fprintf(stderr, "Cannot find symbol for section %d: %s.\n",
 445                 txtndx, txtname);
 446         fail_file();
 447 }
 448
 449
 450 /* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */
 451 static char const *
 452 __has_rel_mcount(Elf_Shdr const *const relhdr,  /* is SHT_REL or SHT_RELA */
 453                  Elf_Shdr const *const shdr0,
 454                  char const *const shstrtab,
 455                  char const *const fname)
 456 {
 457         /* .sh_info depends on .sh_type == SHT_REL[,A] */
 458         Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)];
 459         char const *const txtname = &shstrtab[w(txthdr->sh_name)];
 460
 461         if (strcmp("__mcount_loc", txtname) == 0) {
 462                 fprintf(stderr, "warning: __mcount_loc already exists: %s\n",
 463                         fname);
 464                 succeed_file();
 465         }
 466         if (w(txthdr->sh_type) != SHT_PROGBITS ||
 467             !(_w(txthdr->sh_flags) & SHF_EXECINSTR))
 468                 return NULL;
 469         return txtname;
 470 }
 471
 472 static char const *has_rel_mcount(Elf_Shdr const *const relhdr,
 473                                   Elf_Shdr const *const shdr0,
 474                                   char const *const shstrtab,
 475                                   char const *const fname)
 476 {
 477         if (w(relhdr->sh_type) != SHT_REL && w(relhdr->sh_type) != SHT_RELA)
 478                 return NULL;
 479         return __has_rel_mcount(relhdr, shdr0, shstrtab, fname);
 480 }
 481
 482
 483 static unsigned tot_relsize(Elf_Shdr const *const shdr0,
 484                             unsigned nhdr,
 485                             const char *const shstrtab,
 486                             const char *const fname)
 487 {
 488         unsigned totrelsz = 0;
 489         Elf_Shdr const *shdrp = shdr0;
 490         char const *txtname;
 491
 492         for (; nhdr; --nhdr, ++shdrp) {
 493                 txtname = has_rel_mcount(shdrp, shdr0, shstrtab, fname);
 494                 if (txtname && is_mcounted_section_name(txtname))
 495                         totrelsz += _w(shdrp->sh_size);
 496         }
 497         return totrelsz;
 498 }
 499
 500
 501 /* Overall supervision for Elf32 ET_REL file. */
 502 static void
 503 do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
 504 {
 505         Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
 506                 + (void *)ehdr);
 507         unsigned const nhdr = w2(ehdr->e_shnum);
 508         Elf_Shdr *const shstr = &shdr0[w2(ehdr->e_shstrndx)];
 509         char const *const shstrtab = (char const *)(_w(shstr->sh_offset)
 510                 + (void *)ehdr);
 511
 512         Elf_Shdr const *relhdr;
 513         unsigned k;
 514
 515         /* Upper bound on space: assume all relevant relocs are for mcount. */
 516         unsigned const totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname);
 517         Elf_Rel *const mrel0 = umalloc(totrelsz);
 518         Elf_Rel *      mrelp = mrel0;
 519
 520         /* 2*sizeof(address) <= sizeof(Elf_Rel) */
 521         uint_t *const mloc0 = umalloc(totrelsz>>1);
 522         uint_t *      mlocp = mloc0;
 523
 524         unsigned rel_entsize = 0;
 525         unsigned symsec_sh_link = 0;
 526
 527         for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) {
 528                 char const *const txtname = has_rel_mcount(relhdr, shdr0,
 529                         shstrtab, fname);
 530                 if (txtname && is_mcounted_section_name(txtname)) {
 531                         uint_t recval = 0;
 532                         unsigned const recsym = find_secsym_ndx(
 533                                 w(relhdr->sh_info), txtname, &recval,
 534                                 &shdr0[symsec_sh_link = w(relhdr->sh_link)],
 535                                 ehdr);
 536
 537                         rel_entsize = _w(relhdr->sh_entsize);
 538                         mlocp = sift_rel_mcount(mlocp,
 539                                 (void *)mlocp - (void *)mloc0, &mrelp,
 540                                 relhdr, ehdr, recsym, recval, reltype);
 541                 } else if (txtname && (warn_on_notrace_sect || make_nop)) {
 542                         /*
 543                          * This section is ignored by ftrace, but still
 544                          * has mcount calls. Convert them to nops now.
 545                          */
 546                         nop_mcount(relhdr, ehdr, txtname);
 547                 }
 548         }
 549         if (mloc0 != mlocp) {
 550                 append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
 551                             rel_entsize, symsec_sh_link);
 552         }
 553         free(mrel0);
 554         free(mloc0);
 555 }