History

ftrace: Remove duplicate code for 64 and 32 bit in recordmcount.c

The elf reader for recordmcount.c had duplicate functions for both 32 bit and 64 bit elf handling. This was due to the need of using the 32 and 64 bit elf structures. This patch consolidates the two by using macros to define the 32 and 64 bit names in a recordmcount.h file, and then by just defining a RECORD_MCOUNT_64 macro and including recordmcount.h twice we create the funtions for both the 32 bit version as well as the 64 bit version using one code source.

Steven Rostedt committed 16 years ago

Commit c28d5071 parent 72441cb2 files · +370 −544Browse files

Unified · Split

2 files
  1. scripts/recordmcount.c +4 −544
  2. scripts/recordmcount.h +366 −0
scripts/recordmcount.c+4−544
@@ -212,550 +212,10 @@ is_mcounted_section_name(char const *const txtname) · 211 unmodified lines
212212 0 == strcmp(".text.unlikely", txtname);
213213 }
214214
215−/* Append the new shstrtab, Elf32_Shdr[], __mcount_loc and its relocations. */
216−static void append32(Elf32_Ehdr *const ehdr,
217− Elf32_Shdr *const shstr,
218− uint32_t const *const mloc0,
219− uint32_t const *const mlocp,
220− Elf32_Rel const *const mrel0,
221− Elf32_Rel const *const mrelp,
222− unsigned int const rel_entsize,
223− unsigned int const symsec_sh_link)
224−{
225− /* Begin constructing output file */
226− Elf32_Shdr mcsec;
227− char const *mc_name = (sizeof(Elf32_Rela) == rel_entsize)
228− ? ".rela__mcount_loc"
229− : ".rel__mcount_loc";
230− unsigned const old_shnum = w2(ehdr->e_shnum);
231− uint32_t const old_shoff = w(ehdr->e_shoff);
232− uint32_t const old_shstr_sh_size = w(shstr->sh_size);
233− uint32_t const old_shstr_sh_offset = w(shstr->sh_offset);
234− uint32_t t = 1 + strlen(mc_name) + w(shstr->sh_size);
235− uint32_t new_e_shoff;
236−
237− shstr->sh_size = w(t);
238− shstr->sh_offset = w(sb.st_size);
239− t += sb.st_size;
240− t += (3u & -t); /* 4-byte align */
241− new_e_shoff = t;
242−
243− /* body for new shstrtab */
244− ulseek(fd_map, sb.st_size, SEEK_SET);
245− uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size);
246− uwrite(fd_map, mc_name, 1 + strlen(mc_name));
247−
248− /* old(modified) Elf32_Shdr table, 4-byte aligned */
249− ulseek(fd_map, t, SEEK_SET);
250− t += sizeof(Elf32_Shdr) * old_shnum;
251− uwrite(fd_map, old_shoff + (void *)ehdr,
252− sizeof(Elf32_Shdr) * old_shnum);
253−
254− /* new sections __mcount_loc and .rel__mcount_loc */
255− t += 2*sizeof(mcsec);
256− mcsec.sh_name = w((sizeof(Elf32_Rela) == rel_entsize) + strlen(".rel")
257− + old_shstr_sh_size);
258− mcsec.sh_type = w(SHT_PROGBITS);
259− mcsec.sh_flags = w(SHF_ALLOC);
260− mcsec.sh_addr = 0;
261− mcsec.sh_offset = w(t);
262− mcsec.sh_size = w((void *)mlocp - (void *)mloc0);
263− mcsec.sh_link = 0;
264− mcsec.sh_info = 0;
265− mcsec.sh_addralign = w(4);
266− mcsec.sh_entsize = w(4);
267− uwrite(fd_map, &mcsec, sizeof(mcsec));
268−
269− mcsec.sh_name = w(old_shstr_sh_size);
270− mcsec.sh_type = (sizeof(Elf32_Rela) == rel_entsize)
271− ? w(SHT_RELA)
272− : w(SHT_REL);
273− mcsec.sh_flags = 0;
274− mcsec.sh_addr = 0;
275− mcsec.sh_offset = w((void *)mlocp - (void *)mloc0 + t);
276− mcsec.sh_size = w((void *)mrelp - (void *)mrel0);
277− mcsec.sh_link = w(symsec_sh_link);
278− mcsec.sh_info = w(old_shnum);
279− mcsec.sh_addralign = w(4);
280− mcsec.sh_entsize = w(rel_entsize);
281− uwrite(fd_map, &mcsec, sizeof(mcsec));
282−
283− uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0);
284− uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0);
285−
286− ehdr->e_shoff = w(new_e_shoff);
287− ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum)); /* {.rel,}__mcount_loc */
288− ulseek(fd_map, 0, SEEK_SET);
289− uwrite(fd_map, ehdr, sizeof(*ehdr));
290−}
291−
292−/*
293− * append64 and append32 (and other analogous pairs) could be templated
294− * using C++, but the complexity is high. (For an example, look at p_elf.h
295− * in the source for UPX, http://upx.sourceforge.net) So: remember to make
296− * the corresponding change in the routine for the other size.
297− */
298−static void append64(Elf64_Ehdr *const ehdr,
299− Elf64_Shdr *const shstr,
300− uint64_t const *const mloc0,
301− uint64_t const *const mlocp,
302− Elf64_Rel const *const mrel0,
303− Elf64_Rel const *const mrelp,
304− unsigned int const rel_entsize,
305− unsigned int const symsec_sh_link)
306−{
307− /* Begin constructing output file */
308− Elf64_Shdr mcsec;
309− char const *mc_name = (sizeof(Elf64_Rela) == rel_entsize)
310− ? ".rela__mcount_loc"
311− : ".rel__mcount_loc";
312− unsigned const old_shnum = w2(ehdr->e_shnum);
313− uint64_t const old_shoff = w8(ehdr->e_shoff);
314− uint64_t const old_shstr_sh_size = w8(shstr->sh_size);
315− uint64_t const old_shstr_sh_offset = w8(shstr->sh_offset);
316− uint64_t t = 1 + strlen(mc_name) + w8(shstr->sh_size);
317− uint64_t new_e_shoff;
318−
319− shstr->sh_size = w8(t);
320− shstr->sh_offset = w8(sb.st_size);
321− t += sb.st_size;
322− t += (7u & -t); /* 8-byte align */
323− new_e_shoff = t;
324−
325− /* body for new shstrtab */
326− ulseek(fd_map, sb.st_size, SEEK_SET);
327− uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size);
328− uwrite(fd_map, mc_name, 1 + strlen(mc_name));
329−
330− /* old(modified) Elf64_Shdr table, 8-byte aligned */
331− ulseek(fd_map, t, SEEK_SET);
332− t += sizeof(Elf64_Shdr) * old_shnum;
333− uwrite(fd_map, old_shoff + (void *)ehdr,
334− sizeof(Elf64_Shdr) * old_shnum);
335−
336− /* new sections __mcount_loc and .rel__mcount_loc */
337− t += 2*sizeof(mcsec);
338− mcsec.sh_name = w((sizeof(Elf64_Rela) == rel_entsize) + strlen(".rel")
339− + old_shstr_sh_size);
340− mcsec.sh_type = w(SHT_PROGBITS);
341− mcsec.sh_flags = w8(SHF_ALLOC);
342− mcsec.sh_addr = 0;
343− mcsec.sh_offset = w8(t);
344− mcsec.sh_size = w8((void *)mlocp - (void *)mloc0);
345− mcsec.sh_link = 0;
346− mcsec.sh_info = 0;
347− mcsec.sh_addralign = w8(8);
348− mcsec.sh_entsize = w8(8);
349− uwrite(fd_map, &mcsec, sizeof(mcsec));
350−
351− mcsec.sh_name = w(old_shstr_sh_size);
352− mcsec.sh_type = (sizeof(Elf64_Rela) == rel_entsize)
353− ? w(SHT_RELA)
354− : w(SHT_REL);
355− mcsec.sh_flags = 0;
356− mcsec.sh_addr = 0;
357− mcsec.sh_offset = w8((void *)mlocp - (void *)mloc0 + t);
358− mcsec.sh_size = w8((void *)mrelp - (void *)mrel0);
359− mcsec.sh_link = w(symsec_sh_link);
360− mcsec.sh_info = w(old_shnum);
361− mcsec.sh_addralign = w8(8);
362− mcsec.sh_entsize = w8(rel_entsize);
363− uwrite(fd_map, &mcsec, sizeof(mcsec));
364−
365− uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0);
366− uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0);
367−
368− ehdr->e_shoff = w8(new_e_shoff);
369− ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum)); /* {.rel,}__mcount_loc */
370− ulseek(fd_map, 0, SEEK_SET);
371− uwrite(fd_map, ehdr, sizeof(*ehdr));
372−}
373−
374−/*
375− * Look at the relocations in order to find the calls to mcount.
376− * Accumulate the section offsets that are found, and their relocation info,
377− * onto the end of the existing arrays.
378− */
379−static uint32_t *sift32_rel_mcount(uint32_t *mlocp,
380− unsigned const offbase,
381− Elf32_Rel **const mrelpp,
382− Elf32_Shdr const *const relhdr,
383− Elf32_Ehdr const *const ehdr,
384− unsigned const recsym,
385− uint32_t const recval,
386− unsigned const reltype)
387−{
388− uint32_t *const mloc0 = mlocp;
389− Elf32_Rel *mrelp = *mrelpp;
390− Elf32_Shdr *const shdr0 = (Elf32_Shdr *)(w(ehdr->e_shoff)
391− + (void *)ehdr);
392− unsigned const symsec_sh_link = w(relhdr->sh_link);
393− Elf32_Shdr const *const symsec = &shdr0[symsec_sh_link];
394− Elf32_Sym const *const sym0 = (Elf32_Sym const *)(w(symsec->sh_offset)
395− + (void *)ehdr);
396−
397− Elf32_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
398− char const *const str0 = (char const *)(w(strsec->sh_offset)
399− + (void *)ehdr);
400−
401− Elf32_Rel const *const rel0 = (Elf32_Rel const *)(w(relhdr->sh_offset)
402− + (void *)ehdr);
403− unsigned rel_entsize = w(relhdr->sh_entsize);
404− unsigned const nrel = w(relhdr->sh_size) / rel_entsize;
405− Elf32_Rel const *relp = rel0;
406−
407− unsigned mcountsym = 0;
408− unsigned t;
409−
410− for (t = nrel; t; --t) {
411− if (!mcountsym) {
412− Elf32_Sym const *const symp =
413− &sym0[ELF32_R_SYM(w(relp->r_info))];
414−
415− if (0 == strcmp((('_' == gpfx) ? "_mcount" : "mcount"),
416− &str0[w(symp->st_name)]))
417− mcountsym = ELF32_R_SYM(w(relp->r_info));
418− }
419− if (mcountsym == ELF32_R_SYM(w(relp->r_info))) {
420− uint32_t const addend = w(w(relp->r_offset) - recval);
421− mrelp->r_offset = w(offbase
422− + ((void *)mlocp - (void *)mloc0));
423− mrelp->r_info = w(ELF32_R_INFO(recsym, reltype));
424− if (sizeof(Elf32_Rela) == rel_entsize) {
425− ((Elf32_Rela *)mrelp)->r_addend = addend;
426− *mlocp++ = 0;
427− } else
428− *mlocp++ = addend;
429−
430− mrelp = (Elf32_Rel *)(rel_entsize + (void *)mrelp);
431− }
432− relp = (Elf32_Rel const *)(rel_entsize + (void *)relp);
433− }
434− *mrelpp = mrelp;
435− return mlocp;
436−}
437−
438−static uint64_t *sift64_rel_mcount(uint64_t *mlocp,
439− unsigned const offbase,
440− Elf64_Rel **const mrelpp,
441− Elf64_Shdr const *const relhdr,
442− Elf64_Ehdr const *const ehdr,
443− unsigned const recsym,
444− uint64_t const recval,
445− unsigned const reltype)
446−{
447− uint64_t *const mloc0 = mlocp;
448− Elf64_Rel *mrelp = *mrelpp;
449− Elf64_Shdr *const shdr0 = (Elf64_Shdr *)(w8(ehdr->e_shoff)
450− + (void *)ehdr);
451− unsigned const symsec_sh_link = w(relhdr->sh_link);
452− Elf64_Shdr const *const symsec = &shdr0[symsec_sh_link];
453− Elf64_Sym const *const sym0 = (Elf64_Sym const *)(w8(symsec->sh_offset)
454− + (void *)ehdr);
455−
456− Elf64_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
457− char const *const str0 = (char const *)(w8(strsec->sh_offset)
458− + (void *)ehdr);
459−
460− Elf64_Rel const *const rel0 = (Elf64_Rel const *)(w8(relhdr->sh_offset)
461− + (void *)ehdr);
462− unsigned rel_entsize = w8(relhdr->sh_entsize);
463− unsigned const nrel = w8(relhdr->sh_size) / rel_entsize;
464− Elf64_Rel const *relp = rel0;
465−
466− unsigned mcountsym = 0;
467− unsigned t;
468−
469− for (t = nrel; 0 != t; --t) {
470− if (!mcountsym) {
471− Elf64_Sym const *const symp =
472− &sym0[ELF64_R_SYM(w8(relp->r_info))];
473− char const *symname = &str0[w(symp->st_name)];
474−
475− if ('.' == symname[0])
476− ++symname; /* ppc64 hack */
477− if (0 == strcmp((('_' == gpfx) ? "_mcount" : "mcount"),
478− symname))
479− mcountsym = ELF64_R_SYM(w8(relp->r_info));
480− }
481−
482− if (mcountsym == ELF64_R_SYM(w8(relp->r_info))) {
483− uint64_t const addend = w8(w8(relp->r_offset) - recval);
484−
485− mrelp->r_offset = w8(offbase
486− + ((void *)mlocp - (void *)mloc0));
487− mrelp->r_info = w8(ELF64_R_INFO(recsym, reltype));
488− if (sizeof(Elf64_Rela) == rel_entsize) {
489− ((Elf64_Rela *)mrelp)->r_addend = addend;
490− *mlocp++ = 0;
491− } else
492− *mlocp++ = addend;
493−
494− mrelp = (Elf64_Rel *)(rel_entsize + (void *)mrelp);
495− }
496− relp = (Elf64_Rel const *)(rel_entsize + (void *)relp);
497− }
498− *mrelpp = mrelp;
499−
500− return mlocp;
501−}
502−
503−/*
504− * Find a symbol in the given section, to be used as the base for relocating
505− * the table of offsets of calls to mcount. A local or global symbol suffices,
506− * but avoid a Weak symbol because it may be overridden; the change in value
507− * would invalidate the relocations of the offsets of the calls to mcount.
508− * Often the found symbol will be the unnamed local symbol generated by
509− * GNU 'as' for the start of each section. For example:
510− * Num: Value Size Type Bind Vis Ndx Name
511− * 2: 00000000 0 SECTION LOCAL DEFAULT 1
512− */
513−static unsigned find32_secsym_ndx(unsigned const txtndx,
514− char const *const txtname,
515− uint32_t *const recvalp,
516− Elf32_Shdr const *const symhdr,
517− Elf32_Ehdr const *const ehdr)
518−{
519− Elf32_Sym const *const sym0 = (Elf32_Sym const *)(w(symhdr->sh_offset)
520− + (void *)ehdr);
521− unsigned const nsym = w(symhdr->sh_size) / w(symhdr->sh_entsize);
522− Elf32_Sym const *symp;
523− unsigned t;
524−
525− for (symp = sym0, t = nsym; t; --t, ++symp) {
526− unsigned int const st_bind = ELF32_ST_BIND(symp->st_info);
527−
528− if (txtndx == w2(symp->st_shndx)
529− /* avoid STB_WEAK */
530− && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) {
531− *recvalp = w(symp->st_value);
532− return symp - sym0;
533− }
534− }
535− fprintf(stderr, "Cannot find symbol for section %d: %s.\n",
536− txtndx, txtname);
537− fail_file();
538−}
539−
540−static unsigned find64_secsym_ndx(unsigned const txtndx,
541− char const *const txtname,
542− uint64_t *const recvalp,
543− Elf64_Shdr const *const symhdr,
544− Elf64_Ehdr const *const ehdr)
545−{
546− Elf64_Sym const *const sym0 = (Elf64_Sym const *)(w8(symhdr->sh_offset)
547− + (void *)ehdr);
548− unsigned const nsym = w8(symhdr->sh_size) / w8(symhdr->sh_entsize);
549− Elf64_Sym const *symp;
550− unsigned t;
551−
552− for (symp = sym0, t = nsym; t; --t, ++symp) {
553− unsigned int const st_bind = ELF64_ST_BIND(symp->st_info);
554−
555− if (txtndx == w2(symp->st_shndx)
556− /* avoid STB_WEAK */
557− && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) {
558− *recvalp = w8(symp->st_value);
559− return symp - sym0;
560− }
561− }
562− fprintf(stderr, "Cannot find symbol for section %d: %s.\n",
563− txtndx, txtname);
564− fail_file();
565−}
566−
567−/*
568− * Evade ISO C restriction: no declaration after statement in
569− * has32_rel_mcount.
570− */
571−static char const *
572−__has32_rel_mcount(Elf32_Shdr const *const relhdr, /* is SHT_REL or SHT_RELA */
573− Elf32_Shdr const *const shdr0,
574− char const *const shstrtab,
575− char const *const fname)
576−{
577− /* .sh_info depends on .sh_type == SHT_REL[,A] */
578− Elf32_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)];
579− char const *const txtname = &shstrtab[w(txthdr->sh_name)];
580−
581− if (0 == strcmp("__mcount_loc", txtname)) {
582− fprintf(stderr, "warning: __mcount_loc already exists: %s\n",
583− fname);
584− succeed_file();
585− }
586− if (SHT_PROGBITS != w(txthdr->sh_type) ||
587− !is_mcounted_section_name(txtname))
588− return NULL;
589− return txtname;
590−}
591−
592−static char const *has32_rel_mcount(Elf32_Shdr const *const relhdr,
593− Elf32_Shdr const *const shdr0,
594− char const *const shstrtab,
595− char const *const fname)
596−{
597− if (SHT_REL != w(relhdr->sh_type) && SHT_RELA != w(relhdr->sh_type))
598− return NULL;
599− return __has32_rel_mcount(relhdr, shdr0, shstrtab, fname);
600−}
601−
602−static char const *__has64_rel_mcount(Elf64_Shdr const *const relhdr,
603− Elf64_Shdr const *const shdr0,
604− char const *const shstrtab,
605− char const *const fname)
606−{
607− /* .sh_info depends on .sh_type == SHT_REL[,A] */
608− Elf64_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)];
609− char const *const txtname = &shstrtab[w(txthdr->sh_name)];
610−
611− if (0 == strcmp("__mcount_loc", txtname)) {
612− fprintf(stderr, "warning: __mcount_loc already exists: %s\n",
613− fname);
614− succeed_file();
615− }
616− if (SHT_PROGBITS != w(txthdr->sh_type) ||
617− !is_mcounted_section_name(txtname))
618− return NULL;
619− return txtname;
620−}
621−
622−static char const *has64_rel_mcount(Elf64_Shdr const *const relhdr,
623− Elf64_Shdr const *const shdr0,
624− char const *const shstrtab,
625− char const *const fname)
626−{
627− if (SHT_REL != w(relhdr->sh_type) && SHT_RELA != w(relhdr->sh_type))
628− return NULL;
629− return __has64_rel_mcount(relhdr, shdr0, shstrtab, fname);
630−}
631−
632−static unsigned tot32_relsize(Elf32_Shdr const *const shdr0,
633− unsigned nhdr,
634− const char *const shstrtab,
635− const char *const fname)
636−{
637− unsigned totrelsz = 0;
638− Elf32_Shdr const *shdrp = shdr0;
639− for (; 0 != nhdr; --nhdr, ++shdrp) {
640− if (has32_rel_mcount(shdrp, shdr0, shstrtab, fname))
641− totrelsz += w(shdrp->sh_size);
642− }
643− return totrelsz;
644−}
645−
646−static unsigned tot64_relsize(Elf64_Shdr const *const shdr0,
647− unsigned nhdr,
648− const char *const shstrtab,
649− const char *const fname)
650−{
651− unsigned totrelsz = 0;
652− Elf64_Shdr const *shdrp = shdr0;
653−
654− for (; nhdr; --nhdr, ++shdrp) {
655− if (has64_rel_mcount(shdrp, shdr0, shstrtab, fname))
656− totrelsz += w8(shdrp->sh_size);
657− }
658− return totrelsz;
659−}
660−
661−/* Overall supervision for Elf32 ET_REL file. */
662−static void
663−do32(Elf32_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
664−{
665− Elf32_Shdr *const shdr0 = (Elf32_Shdr *)(w(ehdr->e_shoff)
666− + (void *)ehdr);
667− unsigned const nhdr = w2(ehdr->e_shnum);
668− Elf32_Shdr *const shstr = &shdr0[w2(ehdr->e_shstrndx)];
669− char const *const shstrtab = (char const *)(w(shstr->sh_offset)
670− + (void *)ehdr);
671−
672− Elf32_Shdr const *relhdr;
673− unsigned k;
674−
675− /* Upper bound on space: assume all relevant relocs are for mcount. */
676− unsigned const totrelsz = tot32_relsize(shdr0, nhdr, shstrtab, fname);
677− Elf32_Rel *const mrel0 = umalloc(totrelsz);
678− Elf32_Rel * mrelp = mrel0;
679−
680− /* 2*sizeof(address) <= sizeof(Elf32_Rel) */
681− uint32_t *const mloc0 = umalloc(totrelsz>>1);
682− uint32_t * mlocp = mloc0;
683−
684− unsigned rel_entsize = 0;
685− unsigned symsec_sh_link = 0;
686−
687− for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) {
688− char const *const txtname = has32_rel_mcount(relhdr, shdr0,
689− shstrtab, fname);
690− if (txtname) {
691− uint32_t recval = 0;
692− unsigned const recsym = find32_secsym_ndx(
693− w(relhdr->sh_info), txtname, &recval,
694− &shdr0[symsec_sh_link = w(relhdr->sh_link)],
695− ehdr);
696−
697− rel_entsize = w(relhdr->sh_entsize);
698− mlocp = sift32_rel_mcount(mlocp,
699− (void *)mlocp - (void *)mloc0, &mrelp,
700− relhdr, ehdr, recsym, recval, reltype);
701− }
702− }
703− if (mloc0 != mlocp) {
704− append32(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
705− rel_entsize, symsec_sh_link);
706− }
707− free(mrel0);
708− free(mloc0);
709−}
710−
711−static void
712−do64(Elf64_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
713−{
714− Elf64_Shdr *const shdr0 = (Elf64_Shdr *)(w8(ehdr->e_shoff)
715− + (void *)ehdr);
716− unsigned const nhdr = w2(ehdr->e_shnum);
717− Elf64_Shdr *const shstr = &shdr0[w2(ehdr->e_shstrndx)];
718− char const *const shstrtab = (char const *)(w8(shstr->sh_offset)
719− + (void *)ehdr);
720−
721− Elf64_Shdr const *relhdr;
722− unsigned k;
723−
724− /* Upper bound on space: assume all relevant relocs are for mcount. */
725− unsigned const totrelsz = tot64_relsize(shdr0, nhdr, shstrtab, fname);
726− Elf64_Rel *const mrel0 = umalloc(totrelsz);
727− Elf64_Rel * mrelp = mrel0;
728−
729− /* 2*sizeof(address) <= sizeof(Elf64_Rel) */
730− uint64_t *const mloc0 = umalloc(totrelsz>>1);
731− uint64_t * mlocp = mloc0;
732−
733− unsigned rel_entsize = 0;
734− unsigned symsec_sh_link = 0;
735−
736− for ((relhdr = shdr0), k = nhdr; k; --k, ++relhdr) {
737− char const *const txtname = has64_rel_mcount(relhdr, shdr0,
738− shstrtab, fname);
739− if (txtname) {
740− uint64_t recval = 0;
741− unsigned const recsym = find64_secsym_ndx(
742− w(relhdr->sh_info), txtname, &recval,
743− &shdr0[symsec_sh_link = w(relhdr->sh_link)],
744− ehdr);
745−
746− rel_entsize = w8(relhdr->sh_entsize);
747− mlocp = sift64_rel_mcount(mlocp,
748− (void *)mlocp - (void *)mloc0, &mrelp,
749− relhdr, ehdr, recsym, recval, reltype);
750− }
751− }
752− if (mloc0 != mlocp) {
753− append64(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
754− rel_entsize, symsec_sh_link);
755− }
756− free(mrel0);
757− free(mloc0);
758−}
215+/* 32 bit and 64 bit are very similar */
216+#include "recordmcount.h"
217+#define RECORD_MCOUNT_64
218+#include "recordmcount.h"
759219
760220 static void
761221 do_file(char const *const fname)
scripts/recordmcount.h+366−0
@@ -0,0 +1,366 @@
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 sift_rel_mcount
23+#undef find_secsym_ndx
24+#undef __has_rel_mcount
25+#undef has_rel_mcount
26+#undef tot_relsize
27+#undef do_func
28+#undef Elf_Ehdr
29+#undef Elf_Shdr
30+#undef Elf_Rel
31+#undef Elf_Rela
32+#undef Elf_Sym
33+#undef ELF_R_SYM
34+#undef ELF_R_INFO
35+#undef ELF_ST_BIND
36+#undef uint_t
37+#undef _w
38+#undef _align
39+#undef _size
40+
41+#ifdef RECORD_MCOUNT_64
42+# define append_func append64
43+# define sift_rel_mcount sift64_rel_mcount
44+# define find_secsym_ndx find64_secsym_ndx
45+# define __has_rel_mcount __has64_rel_mcount
46+# define has_rel_mcount has64_rel_mcount
47+# define tot_relsize tot64_relsize
48+# define do_func do64
49+# define Elf_Ehdr Elf64_Ehdr
50+# define Elf_Shdr Elf64_Shdr
51+# define Elf_Rel Elf64_Rel
52+# define Elf_Rela Elf64_Rela
53+# define Elf_Sym Elf64_Sym
54+# define ELF_R_SYM ELF64_R_SYM
55+# define ELF_R_INFO ELF64_R_INFO
56+# define ELF_ST_BIND ELF64_ST_BIND
57+# define uint_t uint64_t
58+# define _w w8
59+# define _align 7u
60+# define _size 8
61+#else
62+# define append_func append32
63+# define sift_rel_mcount sift32_rel_mcount
64+# define find_secsym_ndx find32_secsym_ndx
65+# define __has_rel_mcount __has32_rel_mcount
66+# define has_rel_mcount has32_rel_mcount
67+# define tot_relsize tot32_relsize
68+# define do_func do32
69+# define Elf_Ehdr Elf32_Ehdr
70+# define Elf_Shdr Elf32_Shdr
71+# define Elf_Rel Elf32_Rel
72+# define Elf_Rela Elf32_Rela
73+# define Elf_Sym Elf32_Sym
74+# define ELF_R_SYM ELF32_R_SYM
75+# define ELF_R_INFO ELF32_R_INFO
76+# define ELF_ST_BIND ELF32_ST_BIND
77+# define uint_t uint32_t
78+# define _w w
79+# define _align 3u
80+# define _size 4
81+#endif
82+
83+/* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */
84+static void append_func(Elf_Ehdr *const ehdr,
85+ Elf_Shdr *const shstr,
86+ uint_t const *const mloc0,
87+ uint_t const *const mlocp,
88+ Elf_Rel const *const mrel0,
89+ Elf_Rel const *const mrelp,
90+ unsigned int const rel_entsize,
91+ unsigned int const symsec_sh_link)
92+{
93+ /* Begin constructing output file */
94+ Elf_Shdr mcsec;
95+ char const *mc_name = (sizeof(Elf_Rela) == rel_entsize)
96+ ? ".rela__mcount_loc"
97+ : ".rel__mcount_loc";
98+ unsigned const old_shnum = w2(ehdr->e_shnum);
99+ uint_t const old_shoff = _w(ehdr->e_shoff);
100+ uint_t const old_shstr_sh_size = _w(shstr->sh_size);
101+ uint_t const old_shstr_sh_offset = _w(shstr->sh_offset);
102+ uint_t t = 1 + strlen(mc_name) + _w(shstr->sh_size);
103+ uint_t new_e_shoff;
104+
105+ shstr->sh_size = _w(t);
106+ shstr->sh_offset = _w(sb.st_size);
107+ t += sb.st_size;
108+ t += (_align & -t); /* word-byte align */
109+ new_e_shoff = t;
110+
111+ /* body for new shstrtab */
112+ ulseek(fd_map, sb.st_size, SEEK_SET);
113+ uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size);
114+ uwrite(fd_map, mc_name, 1 + strlen(mc_name));
115+
116+ /* old(modified) Elf_Shdr table, word-byte aligned */
117+ ulseek(fd_map, t, SEEK_SET);
118+ t += sizeof(Elf_Shdr) * old_shnum;
119+ uwrite(fd_map, old_shoff + (void *)ehdr,
120+ sizeof(Elf_Shdr) * old_shnum);
121+
122+ /* new sections __mcount_loc and .rel__mcount_loc */
123+ t += 2*sizeof(mcsec);
124+ mcsec.sh_name = w((sizeof(Elf_Rela) == rel_entsize) + strlen(".rel")
125+ + old_shstr_sh_size);
126+ mcsec.sh_type = w(SHT_PROGBITS);
127+ mcsec.sh_flags = _w(SHF_ALLOC);
128+ mcsec.sh_addr = 0;
129+ mcsec.sh_offset = _w(t);
130+ mcsec.sh_size = _w((void *)mlocp - (void *)mloc0);
131+ mcsec.sh_link = 0;
132+ mcsec.sh_info = 0;
133+ mcsec.sh_addralign = _w(_size);
134+ mcsec.sh_entsize = _w(_size);
135+ uwrite(fd_map, &mcsec, sizeof(mcsec));
136+
137+ mcsec.sh_name = w(old_shstr_sh_size);
138+ mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize)
139+ ? w(SHT_RELA)
140+ : w(SHT_REL);
141+ mcsec.sh_flags = 0;
142+ mcsec.sh_addr = 0;
143+ mcsec.sh_offset = _w((void *)mlocp - (void *)mloc0 + t);
144+ mcsec.sh_size = _w((void *)mrelp - (void *)mrel0);
145+ mcsec.sh_link = w(symsec_sh_link);
146+ mcsec.sh_info = w(old_shnum);
147+ mcsec.sh_addralign = _w(_size);
148+ mcsec.sh_entsize = _w(rel_entsize);
149+ uwrite(fd_map, &mcsec, sizeof(mcsec));
150+
151+ uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0);
152+ uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0);
153+
154+ ehdr->e_shoff = _w(new_e_shoff);
155+ ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum)); /* {.rel,}__mcount_loc */
156+ ulseek(fd_map, 0, SEEK_SET);
157+ uwrite(fd_map, ehdr, sizeof(*ehdr));
158+}
159+
160+
161+/*
162+ * Look at the relocations in order to find the calls to mcount.
163+ * Accumulate the section offsets that are found, and their relocation info,
164+ * onto the end of the existing arrays.
165+ */
166+static uint_t *sift_rel_mcount(uint_t *mlocp,
167+ unsigned const offbase,
168+ Elf_Rel **const mrelpp,
169+ Elf_Shdr const *const relhdr,
170+ Elf_Ehdr const *const ehdr,
171+ unsigned const recsym,
172+ uint_t const recval,
173+ unsigned const reltype)
174+{
175+ uint_t *const mloc0 = mlocp;
176+ Elf_Rel *mrelp = *mrelpp;
177+ Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
178+ + (void *)ehdr);
179+ unsigned const symsec_sh_link = w(relhdr->sh_link);
180+ Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];
181+ Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)
182+ + (void *)ehdr);
183+
184+ Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
185+ char const *const str0 = (char const *)(_w(strsec->sh_offset)
186+ + (void *)ehdr);
187+
188+ Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)
189+ + (void *)ehdr);
190+ unsigned rel_entsize = _w(relhdr->sh_entsize);
191+ unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
192+ Elf_Rel const *relp = rel0;
193+
194+ unsigned mcountsym = 0;
195+ unsigned t;
196+
197+ for (t = nrel; t; --t) {
198+ if (!mcountsym) {
199+ Elf_Sym const *const symp =
200+ &sym0[ELF_R_SYM(_w(relp->r_info))];
201+ char const *symname = &str0[w(symp->st_name)];
202+
203+ if ('.' == symname[0])
204+ ++symname; /* ppc64 hack */
205+ if (0 == strcmp((('_' == gpfx) ? "_mcount" : "mcount"),
206+ symname))
207+ mcountsym = ELF_R_SYM(_w(relp->r_info));
208+ }
209+
210+ if (mcountsym == ELF_R_SYM(_w(relp->r_info))) {
211+ uint_t const addend = _w(_w(relp->r_offset) - recval);
212+
213+ mrelp->r_offset = _w(offbase
214+ + ((void *)mlocp - (void *)mloc0));
215+ mrelp->r_info = _w(ELF_R_INFO(recsym, reltype));
216+ if (sizeof(Elf_Rela) == rel_entsize) {
217+ ((Elf_Rela *)mrelp)->r_addend = addend;
218+ *mlocp++ = 0;
219+ } else
220+ *mlocp++ = addend;
221+
222+ mrelp = (Elf_Rel *)(rel_entsize + (void *)mrelp);
223+ }
224+ relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
225+ }
226+ *mrelpp = mrelp;
227+ return mlocp;
228+}
229+
230+
231+/*
232+ * Find a symbol in the given section, to be used as the base for relocating
233+ * the table of offsets of calls to mcount. A local or global symbol suffices,
234+ * but avoid a Weak symbol because it may be overridden; the change in value
235+ * would invalidate the relocations of the offsets of the calls to mcount.
236+ * Often the found symbol will be the unnamed local symbol generated by
237+ * GNU 'as' for the start of each section. For example:
238+ * Num: Value Size Type Bind Vis Ndx Name
239+ * 2: 00000000 0 SECTION LOCAL DEFAULT 1
240+ */
241+static unsigned find_secsym_ndx(unsigned const txtndx,
242+ char const *const txtname,
243+ uint_t *const recvalp,
244+ Elf_Shdr const *const symhdr,
245+ Elf_Ehdr const *const ehdr)
246+{
247+ Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symhdr->sh_offset)
248+ + (void *)ehdr);
249+ unsigned const nsym = _w(symhdr->sh_size) / _w(symhdr->sh_entsize);
250+ Elf_Sym const *symp;
251+ unsigned t;
252+
253+ for (symp = sym0, t = nsym; t; --t, ++symp) {
254+ unsigned int const st_bind = ELF_ST_BIND(symp->st_info);
255+
256+ if (txtndx == w2(symp->st_shndx)
257+ /* avoid STB_WEAK */
258+ && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) {
259+ *recvalp = _w(symp->st_value);
260+ return symp - sym0;
261+ }
262+ }
263+ fprintf(stderr, "Cannot find symbol for section %d: %s.\n",
264+ txtndx, txtname);
265+ fail_file();
266+}
267+
268+
269+/* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */
270+static char const *
271+__has_rel_mcount(Elf_Shdr const *const relhdr, /* is SHT_REL or SHT_RELA */
272+ Elf_Shdr const *const shdr0,
273+ char const *const shstrtab,
274+ char const *const fname)
275+{
276+ /* .sh_info depends on .sh_type == SHT_REL[,A] */
277+ Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)];
278+ char const *const txtname = &shstrtab[w(txthdr->sh_name)];
279+
280+ if (0 == strcmp("__mcount_loc", txtname)) {
281+ fprintf(stderr, "warning: __mcount_loc already exists: %s\n",
282+ fname);
283+ succeed_file();
284+ }
285+ if (SHT_PROGBITS != w(txthdr->sh_type) ||
286+ !is_mcounted_section_name(txtname))
287+ return NULL;
288+ return txtname;
289+}
290+
291+static char const *has_rel_mcount(Elf_Shdr const *const relhdr,
292+ Elf_Shdr const *const shdr0,
293+ char const *const shstrtab,
294+ char const *const fname)
295+{
296+ if (SHT_REL != w(relhdr->sh_type) && SHT_RELA != w(relhdr->sh_type))
297+ return NULL;
298+ return __has_rel_mcount(relhdr, shdr0, shstrtab, fname);
299+}
300+
301+
302+static unsigned tot_relsize(Elf_Shdr const *const shdr0,
303+ unsigned nhdr,
304+ const char *const shstrtab,
305+ const char *const fname)
306+{
307+ unsigned totrelsz = 0;
308+ Elf_Shdr const *shdrp = shdr0;
309+
310+ for (; nhdr; --nhdr, ++shdrp) {
311+ if (has_rel_mcount(shdrp, shdr0, shstrtab, fname))
312+ totrelsz += _w(shdrp->sh_size);
313+ }
314+ return totrelsz;
315+}
316+
317+
318+/* Overall supervision for Elf32 ET_REL file. */
319+static void
320+do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
321+{
322+ Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
323+ + (void *)ehdr);
324+ unsigned const nhdr = w2(ehdr->e_shnum);
325+ Elf_Shdr *const shstr = &shdr0[w2(ehdr->e_shstrndx)];
326+ char const *const shstrtab = (char const *)(_w(shstr->sh_offset)
327+ + (void *)ehdr);
328+
329+ Elf_Shdr const *relhdr;
330+ unsigned k;
331+
332+ /* Upper bound on space: assume all relevant relocs are for mcount. */
333+ unsigned const totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname);
334+ Elf_Rel *const mrel0 = umalloc(totrelsz);
335+ Elf_Rel * mrelp = mrel0;
336+
337+ /* 2*sizeof(address) <= sizeof(Elf_Rel) */
338+ uint_t *const mloc0 = umalloc(totrelsz>>1);
339+ uint_t * mlocp = mloc0;
340+
341+ unsigned rel_entsize = 0;
342+ unsigned symsec_sh_link = 0;
343+
344+ for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) {
345+ char const *const txtname = has_rel_mcount(relhdr, shdr0,
346+ shstrtab, fname);
347+ if (txtname) {
348+ uint_t recval = 0;
349+ unsigned const recsym = find_secsym_ndx(
350+ w(relhdr->sh_info), txtname, &recval,
351+ &shdr0[symsec_sh_link = w(relhdr->sh_link)],
352+ ehdr);
353+
354+ rel_entsize = _w(relhdr->sh_entsize);
355+ mlocp = sift_rel_mcount(mlocp,
356+ (void *)mlocp - (void *)mloc0, &mrelp,
357+ relhdr, ehdr, recsym, recval, reltype);
358+ }
359+ }
360+ if (mloc0 != mlocp) {
361+ append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
362+ rel_entsize, symsec_sh_link);
363+ }
364+ free(mrel0);
365+ free(mloc0);
366+}