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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
122static int fn_is_fake_mcount(Elf_Rel const *rp)
123{
124 return 0;
125}
126static int (*is_fake_mcount)(Elf_Rel const *rp) = fn_is_fake_mcount;
127
128static uint_t fn_ELF_R_SYM(Elf_Rel const *rp)
129{
130 return ELF_R_SYM(_w(rp->r_info));
131}
132static uint_t (*Elf_r_sym)(Elf_Rel const *rp) = fn_ELF_R_SYM;
133
134static 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}
138static void (*Elf_r_info)(Elf_Rel *const rp, unsigned sym, unsigned type) = fn_ELF_R_INFO;
139
140static int mcount_adjust = 0;
141
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160
161#define MIPS_FAKEMCOUNT_OFFSET 4
162
163static 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
177static 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
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);
202 new_e_shoff = t;
203
204
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
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
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));
249 ulseek(fd_map, 0, SEEK_SET);
250 uwrite(fd_map, ehdr, sizeof(*ehdr));
251}
252
253static 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;
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
275static 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
300
301
302
303static 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
350
351
352
353static 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
385 if (!make_nop)
386 return;
387 }
388 }
389
390
391
392
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
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411
412
413
414
415
416static 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
433 && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) {
434
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
450static char const *
451__has_rel_mcount(Elf_Shdr const *const relhdr,
452 Elf_Shdr const *const shdr0,
453 char const *const shstrtab,
454 char const *const fname)
455{
456
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
471static 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
482static 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
501static void
502do_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
515 unsigned const totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname);
516 Elf_Rel *const mrel0 = umalloc(totrelsz);
517 Elf_Rel * mrelp = mrel0;
518
519
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
543
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}
555