scripts/recordmcount.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * recordmcount.h
   4  *
   5  * This code was taken out of recordmcount.c written by
   6  * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
   7  *
   8  * The original code had the same algorithms for both 32bit
   9  * and 64bit ELF files, but the code was duplicated to support
  10  * the difference in structures that were used. This
  11  * file creates a macro of everything that is different between
  12  * the 64 and 32 bit code, such that by including this header
  13  * twice we can create both sets of functions by including this
  14  * header once with RECORD_MCOUNT_64 undefined, and again with
  15  * it defined.
  16  *
  17  * This conversion to macros was done by:
  18  * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
  19  */
  20 #undef append_func
  21 #undef is_fake_mcount
  22 #undef fn_is_fake_mcount
  23 #undef MIPS_is_fake_mcount
  24 #undef mcount_adjust
  25 #undef sift_rel_mcount
  26 #undef nop_mcount
  27 #undef find_secsym_ndx
  28 #undef __has_rel_mcount
  29 #undef has_rel_mcount
  30 #undef tot_relsize
  31 #undef get_mcountsym
  32 #undef get_sym_str_and_relp
  33 #undef do_func
  34 #undef Elf_Addr
  35 #undef Elf_Ehdr
  36 #undef Elf_Shdr
  37 #undef Elf_Rel
  38 #undef Elf_Rela
  39 #undef Elf_Sym
  40 #undef ELF_R_SYM
  41 #undef Elf_r_sym
  42 #undef ELF_R_INFO
  43 #undef Elf_r_info
  44 #undef ELF_ST_BIND
  45 #undef ELF_ST_TYPE
  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 ELF_ST_TYPE            ELF64_ST_TYPE
  80 # define fn_ELF_R_SYM           fn_ELF64_R_SYM
  81 # define fn_ELF_R_INFO          fn_ELF64_R_INFO
  82 # define uint_t                 uint64_t
  83 # define _w                     w8
  84 # define _align                 7u
  85 # define _size                  8
  86 #else
  87 # define append_func            append32
  88 # define sift_rel_mcount        sift32_rel_mcount
  89 # define nop_mcount             nop_mcount_32
  90 # define find_secsym_ndx        find32_secsym_ndx
  91 # define __has_rel_mcount       __has32_rel_mcount
  92 # define has_rel_mcount         has32_rel_mcount
  93 # define tot_relsize            tot32_relsize
  94 # define get_sym_str_and_relp   get_sym_str_and_relp_32
  95 # define do_func                do32
  96 # define get_mcountsym          get_mcountsym_32
  97 # define is_fake_mcount         is_fake_mcount32
  98 # define fn_is_fake_mcount      fn_is_fake_mcount32
  99 # define MIPS_is_fake_mcount    MIPS32_is_fake_mcount
 100 # define mcount_adjust          mcount_adjust_32
 101 # define Elf_Addr               Elf32_Addr
 102 # define Elf_Ehdr               Elf32_Ehdr
 103 # define Elf_Shdr               Elf32_Shdr
 104 # define Elf_Rel                Elf32_Rel
 105 # define Elf_Rela               Elf32_Rela
 106 # define Elf_Sym                Elf32_Sym
 107 # define ELF_R_SYM              ELF32_R_SYM
 108 # define Elf_r_sym              Elf32_r_sym
 109 # define ELF_R_INFO             ELF32_R_INFO
 110 # define Elf_r_info             Elf32_r_info
 111 # define ELF_ST_BIND            ELF32_ST_BIND
 112 # define ELF_ST_TYPE            ELF32_ST_TYPE
 113 # define fn_ELF_R_SYM           fn_ELF32_R_SYM
 114 # define fn_ELF_R_INFO          fn_ELF32_R_INFO
 115 # define uint_t                 uint32_t
 116 # define _w                     w
 117 # define _align                 3u
 118 # define _size                  4
 119 #endif
 120
 121 /* Functions and pointers that do_file() may override for specific e_machine. */
 122 static int fn_is_fake_mcount(Elf_Rel const *rp)
 123 {
 124         return 0;
 125 }
 126 static int (*is_fake_mcount)(Elf_Rel const *rp) = fn_is_fake_mcount;
 127
 128 static uint_t fn_ELF_R_SYM(Elf_Rel const *rp)
 129 {
 130         return ELF_R_SYM(_w(rp->r_info));
 131 }
 132 static uint_t (*Elf_r_sym)(Elf_Rel const *rp) = fn_ELF_R_SYM;
 133
 134 static void fn_ELF_R_INFO(Elf_Rel *const rp, unsigned sym, unsigned type)
 135 {
 136         rp->r_info = _w(ELF_R_INFO(sym, type));
 137 }
 138 static void (*Elf_r_info)(Elf_Rel *const rp, unsigned sym, unsigned type) = fn_ELF_R_INFO;
 139
 140 static int mcount_adjust = 0;
 141
 142 /*
 143  * MIPS mcount long call has 2 _mcount symbols, only the position of the 1st
 144  * _mcount symbol is needed for dynamic function tracer, with it, to disable
 145  * tracing(ftrace_make_nop), the instruction in the position is replaced with
 146  * the "b label" instruction, to enable tracing(ftrace_make_call), replace the
 147  * instruction back. So, here, we set the 2nd one as fake and filter it.
 148  *
 149  * c:   3c030000        lui     v1,0x0          <-->    b       label
 150  *              c: R_MIPS_HI16  _mcount
 151  *              c: R_MIPS_NONE  *ABS*
 152  *              c: R_MIPS_NONE  *ABS*
 153  * 10:  64630000        daddiu  v1,v1,0
 154  *              10: R_MIPS_LO16 _mcount
 155  *              10: R_MIPS_NONE *ABS*
 156  *              10: R_MIPS_NONE *ABS*
 157  * 14:  03e0082d        move    at,ra
 158  * 18:  0060f809        jalr    v1
 159  * label:
 160  */
 161 #define MIPS_FAKEMCOUNT_OFFSET  4
 162
 163 static int MIPS_is_fake_mcount(Elf_Rel const *rp)
 164 {
 165         static Elf_Addr old_r_offset = ~(Elf_Addr)0;
 166         Elf_Addr current_r_offset = _w(rp->r_offset);
 167         int is_fake;
 168
 169         is_fake = (old_r_offset != ~(Elf_Addr)0) &&
 170                 (current_r_offset - old_r_offset == MIPS_FAKEMCOUNT_OFFSET);
 171         old_r_offset = current_r_offset;
 172
 173         return is_fake;
 174 }
 175
 176 /* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */
 177 static void append_func(Elf_Ehdr *const ehdr,
 178                         Elf_Shdr *const shstr,
 179                         uint_t const *const mloc0,
 180                         uint_t const *const mlocp,
 181                         Elf_Rel const *const mrel0,
 182                         Elf_Rel const *const mrelp,
 183                         unsigned int const rel_entsize,
 184                         unsigned int const symsec_sh_link)
 185 {
 186         /* Begin constructing output file */
 187         Elf_Shdr mcsec;
 188         char const *mc_name = (sizeof(Elf_Rela) == rel_entsize)
 189                 ? ".rela__mcount_loc"
 190                 :  ".rel__mcount_loc";
 191         unsigned const old_shnum = w2(ehdr->e_shnum);
 192         uint_t const old_shoff = _w(ehdr->e_shoff);
 193         uint_t const old_shstr_sh_size   = _w(shstr->sh_size);
 194         uint_t const old_shstr_sh_offset = _w(shstr->sh_offset);
 195         uint_t t = 1 + strlen(mc_name) + _w(shstr->sh_size);
 196         uint_t new_e_shoff;
 197
 198         shstr->sh_size = _w(t);
 199         shstr->sh_offset = _w(sb.st_size);
 200         t += sb.st_size;
 201         t += (_align & -t);  /* word-byte align */
 202         new_e_shoff = t;
 203
 204         /* body for new shstrtab */
 205         ulseek(fd_map, sb.st_size, SEEK_SET);
 206         uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size);
 207         uwrite(fd_map, mc_name, 1 + strlen(mc_name));
 208
 209         /* old(modified) Elf_Shdr table, word-byte aligned */
 210         ulseek(fd_map, t, SEEK_SET);
 211         t += sizeof(Elf_Shdr) * old_shnum;
 212         uwrite(fd_map, old_shoff + (void *)ehdr,
 213                sizeof(Elf_Shdr) * old_shnum);
 214
 215         /* new sections __mcount_loc and .rel__mcount_loc */
 216         t += 2*sizeof(mcsec);
 217         mcsec.sh_name = w((sizeof(Elf_Rela) == rel_entsize) + strlen(".rel")
 218                 + old_shstr_sh_size);
 219         mcsec.sh_type = w(SHT_PROGBITS);
 220         mcsec.sh_flags = _w(SHF_ALLOC);
 221         mcsec.sh_addr = 0;
 222         mcsec.sh_offset = _w(t);
 223         mcsec.sh_size = _w((void *)mlocp - (void *)mloc0);
 224         mcsec.sh_link = 0;
 225         mcsec.sh_info = 0;
 226         mcsec.sh_addralign = _w(_size);
 227         mcsec.sh_entsize = _w(_size);
 228         uwrite(fd_map, &mcsec, sizeof(mcsec));
 229
 230         mcsec.sh_name = w(old_shstr_sh_size);
 231         mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize)
 232                 ? w(SHT_RELA)
 233                 : w(SHT_REL);
 234         mcsec.sh_flags = 0;
 235         mcsec.sh_addr = 0;
 236         mcsec.sh_offset = _w((void *)mlocp - (void *)mloc0 + t);
 237         mcsec.sh_size   = _w((void *)mrelp - (void *)mrel0);
 238         mcsec.sh_link = w(symsec_sh_link);
 239         mcsec.sh_info = w(old_shnum);
 240         mcsec.sh_addralign = _w(_size);
 241         mcsec.sh_entsize = _w(rel_entsize);
 242         uwrite(fd_map, &mcsec, sizeof(mcsec));
 243
 244         uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0);
 245         uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0);
 246
 247         ehdr->e_shoff = _w(new_e_shoff);
 248         ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum));  /* {.rel,}__mcount_loc */
 249         ulseek(fd_map, 0, SEEK_SET);
 250         uwrite(fd_map, ehdr, sizeof(*ehdr));
 251 }
 252
 253 static unsigned get_mcountsym(Elf_Sym const *const sym0,
 254                               Elf_Rel const *relp,
 255                               char const *const str0)
 256 {
 257         unsigned mcountsym = 0;
 258
 259         Elf_Sym const *const symp =
 260                 &sym0[Elf_r_sym(relp)];
 261         char const *symname = &str0[w(symp->st_name)];
 262         char const *mcount = gpfx == '_' ? "_mcount" : "mcount";
 263         char const *fentry = "__fentry__";
 264
 265         if (symname[0] == '.')
 266                 ++symname;  /* ppc64 hack */
 267         if (strcmp(mcount, symname) == 0 ||
 268             (altmcount && strcmp(altmcount, symname) == 0) ||
 269             (strcmp(fentry, symname) == 0))
 270                 mcountsym = Elf_r_sym(relp);
 271
 272         return mcountsym;
 273 }
 274
 275 static void get_sym_str_and_relp(Elf_Shdr const *const relhdr,
 276                                  Elf_Ehdr const *const ehdr,
 277                                  Elf_Sym const **sym0,
 278                                  char const **str0,
 279                                  Elf_Rel const **relp)
 280 {
 281         Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
 282                 + (void *)ehdr);
 283         unsigned const symsec_sh_link = w(relhdr->sh_link);
 284         Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];
 285         Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
 286         Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)
 287                 + (void *)ehdr);
 288
 289         *sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)
 290                                   + (void *)ehdr);
 291
 292         *str0 = (char const *)(_w(strsec->sh_offset)
 293                                + (void *)ehdr);
 294
 295         *relp = rel0;
 296 }
 297
 298 /*
 299  * Look at the relocations in order to find the calls to mcount.
 300  * Accumulate the section offsets that are found, and their relocation info,
 301  * onto the end of the existing arrays.
 302  */
 303 static uint_t *sift_rel_mcount(uint_t *mlocp,
 304                                unsigned const offbase,
 305                                Elf_Rel **const mrelpp,
 306                                Elf_Shdr const *const relhdr,
 307                                Elf_Ehdr const *const ehdr,
 308                                unsigned const recsym,
 309                                uint_t const recval,
 310                                unsigned const reltype)
 311 {
 312         uint_t *const mloc0 = mlocp;
 313         Elf_Rel *mrelp = *mrelpp;
 314         Elf_Sym const *sym0;
 315         char const *str0;
 316         Elf_Rel const *relp;
 317         unsigned rel_entsize = _w(relhdr->sh_entsize);
 318         unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
 319         unsigned mcountsym = 0;
 320         unsigned t;
 321
 322         get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
 323
 324         for (t = nrel; t; --t) {
 325                 if (!mcountsym)
 326                         mcountsym = get_mcountsym(sym0, relp, str0);
 327
 328                 if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {
 329                         uint_t const addend =
 330                                 _w(_w(relp->r_offset) - recval + mcount_adjust);
 331                         mrelp->r_offset = _w(offbase
 332                                 + ((void *)mlocp - (void *)mloc0));
 333                         Elf_r_info(mrelp, recsym, reltype);
 334                         if (rel_entsize == sizeof(Elf_Rela)) {
 335                                 ((Elf_Rela *)mrelp)->r_addend = addend;
 336                                 *mlocp++ = 0;
 337                         } else
 338                                 *mlocp++ = addend;
 339
 340                         mrelp = (Elf_Rel *)(rel_entsize + (void *)mrelp);
 341                 }
 342                 relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
 343         }
 344         *mrelpp = mrelp;
 345         return mlocp;
 346 }
 347
 348 /*
 349  * Read the relocation table again, but this time its called on sections
 350  * that are not going to be traced. The mcount calls here will be converted
 351  * into nops.
 352  */
 353 static void nop_mcount(Elf_Shdr const *const relhdr,
 354                        Elf_Ehdr const *const ehdr,
 355                        const char *const txtname)
 356 {
 357         Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
 358                 + (void *)ehdr);
 359         Elf_Sym const *sym0;
 360         char const *str0;
 361         Elf_Rel const *relp;
 362         Elf_Shdr const *const shdr = &shdr0[w(relhdr->sh_info)];
 363         unsigned rel_entsize = _w(relhdr->sh_entsize);
 364         unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
 365         unsigned mcountsym = 0;
 366         unsigned t;
 367         int once = 0;
 368
 369         get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
 370
 371         for (t = nrel; t; --t) {
 372                 int ret = -1;
 373
 374                 if (!mcountsym)
 375                         mcountsym = get_mcountsym(sym0, relp, str0);
 376
 377                 if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {
 378                         if (make_nop)
 379                                 ret = make_nop((void *)ehdr, _w(shdr->sh_offset) + _w(relp->r_offset));
 380                         if (warn_on_notrace_sect && !once) {
 381                                 printf("Section %s has mcount callers being ignored\n",
 382                                        txtname);
 383                                 once = 1;
 384                                 /* just warn? */
 385                                 if (!make_nop)
 386                                         return;
 387                         }
 388                 }
 389
 390                 /*
 391                  * If we successfully removed the mcount, mark the relocation
 392                  * as a nop (don't do anything with it).
 393                  */
 394                 if (!ret) {
 395                         Elf_Rel rel;
 396                         rel = *(Elf_Rel *)relp;
 397                         Elf_r_info(&rel, Elf_r_sym(relp), rel_type_nop);
 398                         ulseek(fd_map, (void *)relp - (void *)ehdr, SEEK_SET);
 399                         uwrite(fd_map, &rel, sizeof(rel));
 400                 }
 401                 relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
 402         }
 403 }
 404
 405
 406 /*
 407  * Find a symbol in the given section, to be used as the base for relocating
 408  * the table of offsets of calls to mcount.  A local or global symbol suffices,
 409  * but avoid a Weak symbol because it may be overridden; the change in value
 410  * would invalidate the relocations of the offsets of the calls to mcount.
 411  * Often the found symbol will be the unnamed local symbol generated by
 412  * GNU 'as' for the start of each section.  For example:
 413  *    Num:    Value  Size Type    Bind   Vis      Ndx Name
 414  *      2: 00000000     0 SECTION LOCAL  DEFAULT    1
 415  */
 416 static unsigned find_secsym_ndx(unsigned const txtndx,
 417                                 char const *const txtname,
 418                                 uint_t *const recvalp,
 419                                 Elf_Shdr const *const symhdr,
 420                                 Elf_Ehdr const *const ehdr)
 421 {
 422         Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symhdr->sh_offset)
 423                 + (void *)ehdr);
 424         unsigned const nsym = _w(symhdr->sh_size) / _w(symhdr->sh_entsize);
 425         Elf_Sym const *symp;
 426         unsigned t;
 427
 428         for (symp = sym0, t = nsym; t; --t, ++symp) {
 429                 unsigned int const st_bind = ELF_ST_BIND(symp->st_info);
 430
 431                 if (txtndx == w2(symp->st_shndx)
 432                         /* avoid STB_WEAK */
 433                     && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) {
 434                         /* function symbols on ARM have quirks, avoid them */
 435                         if (w2(ehdr->e_machine) == EM_ARM
 436                             && ELF_ST_TYPE(symp->st_info) == STT_FUNC)
 437                                 continue;
 438
 439                         *recvalp = _w(symp->st_value);
 440                         return symp - sym0;
 441                 }
 442         }
 443         fprintf(stderr, "Cannot find symbol for section %u: %s.\n",
 444                 txtndx, txtname);
 445         fail_file();
 446 }
 447
 448
 449 /* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */
 450 static char const *
 451 __has_rel_mcount(Elf_Shdr const *const relhdr,  /* is SHT_REL or SHT_RELA */
 452                  Elf_Shdr const *const shdr0,
 453                  char const *const shstrtab,
 454                  char const *const fname)
 455 {
 456         /* .sh_info depends on .sh_type == SHT_REL[,A] */
 457         Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)];
 458         char const *const txtname = &shstrtab[w(txthdr->sh_name)];
 459
 460         if (strcmp("__mcount_loc", txtname) == 0) {
 461                 fprintf(stderr, "warning: __mcount_loc already exists: %s\n",
 462                         fname);
 463                 succeed_file();
 464         }
 465         if (w(txthdr->sh_type) != SHT_PROGBITS ||
 466             !(_w(txthdr->sh_flags) & SHF_EXECINSTR))
 467                 return NULL;
 468         return txtname;
 469 }
 470
 471 static char const *has_rel_mcount(Elf_Shdr const *const relhdr,
 472                                   Elf_Shdr const *const shdr0,
 473                                   char const *const shstrtab,
 474                                   char const *const fname)
 475 {
 476         if (w(relhdr->sh_type) != SHT_REL && w(relhdr->sh_type) != SHT_RELA)
 477                 return NULL;
 478         return __has_rel_mcount(relhdr, shdr0, shstrtab, fname);
 479 }
 480
 481
 482 static unsigned tot_relsize(Elf_Shdr const *const shdr0,
 483                             unsigned nhdr,
 484                             const char *const shstrtab,
 485                             const char *const fname)
 486 {
 487         unsigned totrelsz = 0;
 488         Elf_Shdr const *shdrp = shdr0;
 489         char const *txtname;
 490
 491         for (; nhdr; --nhdr, ++shdrp) {
 492                 txtname = has_rel_mcount(shdrp, shdr0, shstrtab, fname);
 493                 if (txtname && is_mcounted_section_name(txtname))
 494                         totrelsz += _w(shdrp->sh_size);
 495         }
 496         return totrelsz;
 497 }
 498
 499
 500 /* Overall supervision for Elf32 ET_REL file. */
 501 static void
 502 do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
 503 {
 504         Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
 505                 + (void *)ehdr);
 506         unsigned const nhdr = w2(ehdr->e_shnum);
 507         Elf_Shdr *const shstr = &shdr0[w2(ehdr->e_shstrndx)];
 508         char const *const shstrtab = (char const *)(_w(shstr->sh_offset)
 509                 + (void *)ehdr);
 510
 511         Elf_Shdr const *relhdr;
 512         unsigned k;
 513
 514         /* Upper bound on space: assume all relevant relocs are for mcount. */
 515         unsigned const totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname);
 516         Elf_Rel *const mrel0 = umalloc(totrelsz);
 517         Elf_Rel *      mrelp = mrel0;
 518
 519         /* 2*sizeof(address) <= sizeof(Elf_Rel) */
 520         uint_t *const mloc0 = umalloc(totrelsz>>1);
 521         uint_t *      mlocp = mloc0;
 522
 523         unsigned rel_entsize = 0;
 524         unsigned symsec_sh_link = 0;
 525
 526         for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) {
 527                 char const *const txtname = has_rel_mcount(relhdr, shdr0,
 528                         shstrtab, fname);
 529                 if (txtname && is_mcounted_section_name(txtname)) {
 530                         uint_t recval = 0;
 531                         unsigned const recsym = find_secsym_ndx(
 532                                 w(relhdr->sh_info), txtname, &recval,
 533                                 &shdr0[symsec_sh_link = w(relhdr->sh_link)],
 534                                 ehdr);
 535
 536                         rel_entsize = _w(relhdr->sh_entsize);
 537                         mlocp = sift_rel_mcount(mlocp,
 538                                 (void *)mlocp - (void *)mloc0, &mrelp,
 539                                 relhdr, ehdr, recsym, recval, reltype);
 540                 } else if (txtname && (warn_on_notrace_sect || make_nop)) {
 541                         /*
 542                          * This section is ignored by ftrace, but still
 543                          * has mcount calls. Convert them to nops now.
 544                          */
 545                         nop_mcount(relhdr, ehdr, txtname);
 546                 }
 547         }
 548         if (mloc0 != mlocp) {
 549                 append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
 550                             rel_entsize, symsec_sh_link);
 551         }
 552         free(mrel0);
 553         free(mloc0);
 554 }