blob: 5b37e13f08fb81b747ea2cbc813eac57b3b491c7 [file] [log] [blame]
Namhyung Kime5a18452012-08-06 13:41:20 +09001#include <libelf.h>
2#include <gelf.h>
3#include <elf.h>
4#include <fcntl.h>
5#include <stdio.h>
6#include <errno.h>
7#include <string.h>
8#include <unistd.h>
9#include <inttypes.h>
10
11#include "symbol.h"
12#include "debug.h"
13
14#ifndef NT_GNU_BUILD_ID
15#define NT_GNU_BUILD_ID 3
16#endif
17
18/**
19 * elf_symtab__for_each_symbol - iterate thru all the symbols
20 *
21 * @syms: struct elf_symtab instance to iterate
22 * @idx: uint32_t idx
23 * @sym: GElf_Sym iterator
24 */
25#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
26 for (idx = 0, gelf_getsym(syms, idx, &sym);\
27 idx < nr_syms; \
28 idx++, gelf_getsym(syms, idx, &sym))
29
30static inline uint8_t elf_sym__type(const GElf_Sym *sym)
31{
32 return GELF_ST_TYPE(sym->st_info);
33}
34
35static inline int elf_sym__is_function(const GElf_Sym *sym)
36{
37 return elf_sym__type(sym) == STT_FUNC &&
38 sym->st_name != 0 &&
39 sym->st_shndx != SHN_UNDEF;
40}
41
42static inline bool elf_sym__is_object(const GElf_Sym *sym)
43{
44 return elf_sym__type(sym) == STT_OBJECT &&
45 sym->st_name != 0 &&
46 sym->st_shndx != SHN_UNDEF;
47}
48
49static inline int elf_sym__is_label(const GElf_Sym *sym)
50{
51 return elf_sym__type(sym) == STT_NOTYPE &&
52 sym->st_name != 0 &&
53 sym->st_shndx != SHN_UNDEF &&
54 sym->st_shndx != SHN_ABS;
55}
56
57static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
58{
59 switch (type) {
60 case MAP__FUNCTION:
61 return elf_sym__is_function(sym);
62 case MAP__VARIABLE:
63 return elf_sym__is_object(sym);
64 default:
65 return false;
66 }
67}
68
69static inline const char *elf_sym__name(const GElf_Sym *sym,
70 const Elf_Data *symstrs)
71{
72 return symstrs->d_buf + sym->st_name;
73}
74
75static inline const char *elf_sec__name(const GElf_Shdr *shdr,
76 const Elf_Data *secstrs)
77{
78 return secstrs->d_buf + shdr->sh_name;
79}
80
81static inline int elf_sec__is_text(const GElf_Shdr *shdr,
82 const Elf_Data *secstrs)
83{
84 return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
85}
86
87static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
88 const Elf_Data *secstrs)
89{
90 return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
91}
92
93static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
94 enum map_type type)
95{
96 switch (type) {
97 case MAP__FUNCTION:
98 return elf_sec__is_text(shdr, secstrs);
99 case MAP__VARIABLE:
100 return elf_sec__is_data(shdr, secstrs);
101 default:
102 return false;
103 }
104}
105
106static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
107{
108 Elf_Scn *sec = NULL;
109 GElf_Shdr shdr;
110 size_t cnt = 1;
111
112 while ((sec = elf_nextscn(elf, sec)) != NULL) {
113 gelf_getshdr(sec, &shdr);
114
115 if ((addr >= shdr.sh_addr) &&
116 (addr < (shdr.sh_addr + shdr.sh_size)))
117 return cnt;
118
119 ++cnt;
120 }
121
122 return -1;
123}
124
125static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
126 GElf_Shdr *shp, const char *name,
127 size_t *idx)
128{
129 Elf_Scn *sec = NULL;
130 size_t cnt = 1;
131
Cody P Schafer49274652012-08-10 15:22:55 -0700132 /* Elf is corrupted/truncated, avoid calling elf_strptr. */
133 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
134 return NULL;
135
Namhyung Kime5a18452012-08-06 13:41:20 +0900136 while ((sec = elf_nextscn(elf, sec)) != NULL) {
137 char *str;
138
139 gelf_getshdr(sec, shp);
140 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
141 if (!strcmp(name, str)) {
142 if (idx)
143 *idx = cnt;
144 break;
145 }
146 ++cnt;
147 }
148
149 return sec;
150}
151
152#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
153 for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
154 idx < nr_entries; \
155 ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
156
157#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
158 for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
159 idx < nr_entries; \
160 ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
161
162/*
163 * We need to check if we have a .dynsym, so that we can handle the
164 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
165 * .dynsym or .symtab).
166 * And always look at the original dso, not at debuginfo packages, that
167 * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
168 */
Cody P Schafera44f6052012-08-10 15:22:59 -0700169int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
Namhyung Kime5a18452012-08-06 13:41:20 +0900170 symbol_filter_t filter)
171{
172 uint32_t nr_rel_entries, idx;
173 GElf_Sym sym;
174 u64 plt_offset;
175 GElf_Shdr shdr_plt;
176 struct symbol *f;
177 GElf_Shdr shdr_rel_plt, shdr_dynsym;
178 Elf_Data *reldata, *syms, *symstrs;
179 Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
180 size_t dynsym_idx;
181 GElf_Ehdr ehdr;
182 char sympltname[1024];
183 Elf *elf;
Cody P Schafera44f6052012-08-10 15:22:59 -0700184 int nr = 0, symidx, err = 0;
Namhyung Kime5a18452012-08-06 13:41:20 +0900185
Cody P Schafera44f6052012-08-10 15:22:59 -0700186 elf = ss->elf;
187 ehdr = ss->ehdr;
Namhyung Kime5a18452012-08-06 13:41:20 +0900188
Cody P Schafera44f6052012-08-10 15:22:59 -0700189 scn_dynsym = ss->dynsym;
190 shdr_dynsym = ss->dynshdr;
191 dynsym_idx = ss->dynsym_idx;
Namhyung Kime5a18452012-08-06 13:41:20 +0900192
Namhyung Kime5a18452012-08-06 13:41:20 +0900193 if (scn_dynsym == NULL)
194 goto out_elf_end;
195
196 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
197 ".rela.plt", NULL);
198 if (scn_plt_rel == NULL) {
199 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
200 ".rel.plt", NULL);
201 if (scn_plt_rel == NULL)
202 goto out_elf_end;
203 }
204
205 err = -1;
206
207 if (shdr_rel_plt.sh_link != dynsym_idx)
208 goto out_elf_end;
209
210 if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
211 goto out_elf_end;
212
213 /*
214 * Fetch the relocation section to find the idxes to the GOT
215 * and the symbols in the .dynsym they refer to.
216 */
217 reldata = elf_getdata(scn_plt_rel, NULL);
218 if (reldata == NULL)
219 goto out_elf_end;
220
221 syms = elf_getdata(scn_dynsym, NULL);
222 if (syms == NULL)
223 goto out_elf_end;
224
225 scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
226 if (scn_symstrs == NULL)
227 goto out_elf_end;
228
229 symstrs = elf_getdata(scn_symstrs, NULL);
230 if (symstrs == NULL)
231 goto out_elf_end;
232
Cody P Schafer52f9ddb2012-08-10 15:22:51 -0700233 if (symstrs->d_size == 0)
234 goto out_elf_end;
235
Namhyung Kime5a18452012-08-06 13:41:20 +0900236 nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
237 plt_offset = shdr_plt.sh_offset;
238
239 if (shdr_rel_plt.sh_type == SHT_RELA) {
240 GElf_Rela pos_mem, *pos;
241
242 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
243 nr_rel_entries) {
244 symidx = GELF_R_SYM(pos->r_info);
245 plt_offset += shdr_plt.sh_entsize;
246 gelf_getsym(syms, symidx, &sym);
247 snprintf(sympltname, sizeof(sympltname),
248 "%s@plt", elf_sym__name(&sym, symstrs));
249
250 f = symbol__new(plt_offset, shdr_plt.sh_entsize,
251 STB_GLOBAL, sympltname);
252 if (!f)
253 goto out_elf_end;
254
255 if (filter && filter(map, f))
256 symbol__delete(f);
257 else {
258 symbols__insert(&dso->symbols[map->type], f);
259 ++nr;
260 }
261 }
262 } else if (shdr_rel_plt.sh_type == SHT_REL) {
263 GElf_Rel pos_mem, *pos;
264 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
265 nr_rel_entries) {
266 symidx = GELF_R_SYM(pos->r_info);
267 plt_offset += shdr_plt.sh_entsize;
268 gelf_getsym(syms, symidx, &sym);
269 snprintf(sympltname, sizeof(sympltname),
270 "%s@plt", elf_sym__name(&sym, symstrs));
271
272 f = symbol__new(plt_offset, shdr_plt.sh_entsize,
273 STB_GLOBAL, sympltname);
274 if (!f)
275 goto out_elf_end;
276
277 if (filter && filter(map, f))
278 symbol__delete(f);
279 else {
280 symbols__insert(&dso->symbols[map->type], f);
281 ++nr;
282 }
283 }
284 }
285
286 err = 0;
287out_elf_end:
Namhyung Kime5a18452012-08-06 13:41:20 +0900288 if (err == 0)
289 return nr;
Namhyung Kime5a18452012-08-06 13:41:20 +0900290 pr_debug("%s: problems reading %s PLT info.\n",
291 __func__, dso->long_name);
292 return 0;
293}
294
295/*
296 * Align offset to 4 bytes as needed for note name and descriptor data.
297 */
298#define NOTE_ALIGN(n) (((n) + 3) & -4U)
299
300static int elf_read_build_id(Elf *elf, void *bf, size_t size)
301{
302 int err = -1;
303 GElf_Ehdr ehdr;
304 GElf_Shdr shdr;
305 Elf_Data *data;
306 Elf_Scn *sec;
307 Elf_Kind ek;
308 void *ptr;
309
310 if (size < BUILD_ID_SIZE)
311 goto out;
312
313 ek = elf_kind(elf);
314 if (ek != ELF_K_ELF)
315 goto out;
316
317 if (gelf_getehdr(elf, &ehdr) == NULL) {
318 pr_err("%s: cannot get elf header.\n", __func__);
319 goto out;
320 }
321
322 /*
323 * Check following sections for notes:
324 * '.note.gnu.build-id'
325 * '.notes'
326 * '.note' (VDSO specific)
327 */
328 do {
329 sec = elf_section_by_name(elf, &ehdr, &shdr,
330 ".note.gnu.build-id", NULL);
331 if (sec)
332 break;
333
334 sec = elf_section_by_name(elf, &ehdr, &shdr,
335 ".notes", NULL);
336 if (sec)
337 break;
338
339 sec = elf_section_by_name(elf, &ehdr, &shdr,
340 ".note", NULL);
341 if (sec)
342 break;
343
344 return err;
345
346 } while (0);
347
348 data = elf_getdata(sec, NULL);
349 if (data == NULL)
350 goto out;
351
352 ptr = data->d_buf;
353 while (ptr < (data->d_buf + data->d_size)) {
354 GElf_Nhdr *nhdr = ptr;
355 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
356 descsz = NOTE_ALIGN(nhdr->n_descsz);
357 const char *name;
358
359 ptr += sizeof(*nhdr);
360 name = ptr;
361 ptr += namesz;
362 if (nhdr->n_type == NT_GNU_BUILD_ID &&
363 nhdr->n_namesz == sizeof("GNU")) {
364 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
365 size_t sz = min(size, descsz);
366 memcpy(bf, ptr, sz);
367 memset(bf + sz, 0, size - sz);
368 err = descsz;
369 break;
370 }
371 }
372 ptr += descsz;
373 }
374
375out:
376 return err;
377}
378
379int filename__read_build_id(const char *filename, void *bf, size_t size)
380{
381 int fd, err = -1;
382 Elf *elf;
383
384 if (size < BUILD_ID_SIZE)
385 goto out;
386
387 fd = open(filename, O_RDONLY);
388 if (fd < 0)
389 goto out;
390
391 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
392 if (elf == NULL) {
393 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
394 goto out_close;
395 }
396
397 err = elf_read_build_id(elf, bf, size);
398
399 elf_end(elf);
400out_close:
401 close(fd);
402out:
403 return err;
404}
405
406int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
407{
408 int fd, err = -1;
409
410 if (size < BUILD_ID_SIZE)
411 goto out;
412
413 fd = open(filename, O_RDONLY);
414 if (fd < 0)
415 goto out;
416
417 while (1) {
418 char bf[BUFSIZ];
419 GElf_Nhdr nhdr;
420 size_t namesz, descsz;
421
422 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
423 break;
424
425 namesz = NOTE_ALIGN(nhdr.n_namesz);
426 descsz = NOTE_ALIGN(nhdr.n_descsz);
427 if (nhdr.n_type == NT_GNU_BUILD_ID &&
428 nhdr.n_namesz == sizeof("GNU")) {
429 if (read(fd, bf, namesz) != (ssize_t)namesz)
430 break;
431 if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
432 size_t sz = min(descsz, size);
433 if (read(fd, build_id, sz) == (ssize_t)sz) {
434 memset(build_id + sz, 0, size - sz);
435 err = 0;
436 break;
437 }
438 } else if (read(fd, bf, descsz) != (ssize_t)descsz)
439 break;
440 } else {
441 int n = namesz + descsz;
442 if (read(fd, bf, n) != n)
443 break;
444 }
445 }
446 close(fd);
447out:
448 return err;
449}
450
451int filename__read_debuglink(const char *filename, char *debuglink,
452 size_t size)
453{
454 int fd, err = -1;
455 Elf *elf;
456 GElf_Ehdr ehdr;
457 GElf_Shdr shdr;
458 Elf_Data *data;
459 Elf_Scn *sec;
460 Elf_Kind ek;
461
462 fd = open(filename, O_RDONLY);
463 if (fd < 0)
464 goto out;
465
466 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
467 if (elf == NULL) {
468 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
469 goto out_close;
470 }
471
472 ek = elf_kind(elf);
473 if (ek != ELF_K_ELF)
474 goto out_close;
475
476 if (gelf_getehdr(elf, &ehdr) == NULL) {
477 pr_err("%s: cannot get elf header.\n", __func__);
478 goto out_close;
479 }
480
481 sec = elf_section_by_name(elf, &ehdr, &shdr,
482 ".gnu_debuglink", NULL);
483 if (sec == NULL)
484 goto out_close;
485
486 data = elf_getdata(sec, NULL);
487 if (data == NULL)
488 goto out_close;
489
490 /* the start of this section is a zero-terminated string */
491 strncpy(debuglink, data->d_buf, size);
492
493 elf_end(elf);
494
495out_close:
496 close(fd);
497out:
498 return err;
499}
500
501static int dso__swap_init(struct dso *dso, unsigned char eidata)
502{
503 static unsigned int const endian = 1;
504
505 dso->needs_swap = DSO_SWAP__NO;
506
507 switch (eidata) {
508 case ELFDATA2LSB:
509 /* We are big endian, DSO is little endian. */
510 if (*(unsigned char const *)&endian != 1)
511 dso->needs_swap = DSO_SWAP__YES;
512 break;
513
514 case ELFDATA2MSB:
515 /* We are little endian, DSO is big endian. */
516 if (*(unsigned char const *)&endian != 0)
517 dso->needs_swap = DSO_SWAP__YES;
518 break;
519
520 default:
521 pr_err("unrecognized DSO data encoding %d\n", eidata);
522 return -EINVAL;
523 }
524
525 return 0;
526}
527
Cody P Schafer3aafe5a2012-08-10 15:23:02 -0700528bool symsrc__possibly_runtime(struct symsrc *ss)
529{
530 return ss->dynsym || ss->opdsec;
531}
532
Cody P Schaferd26cd122012-08-10 15:23:00 -0700533bool symsrc__has_symtab(struct symsrc *ss)
534{
535 return ss->symtab != NULL;
536}
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700537
538void symsrc__destroy(struct symsrc *ss)
Namhyung Kime5a18452012-08-06 13:41:20 +0900539{
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700540 free(ss->name);
541 elf_end(ss->elf);
542 close(ss->fd);
543}
544
545int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
546 enum dso_binary_type type)
547{
Namhyung Kime5a18452012-08-06 13:41:20 +0900548 int err = -1;
Namhyung Kime5a18452012-08-06 13:41:20 +0900549 GElf_Ehdr ehdr;
Namhyung Kime5a18452012-08-06 13:41:20 +0900550 Elf *elf;
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700551 int fd;
552
553 fd = open(name, O_RDONLY);
554 if (fd < 0)
555 return -1;
Namhyung Kime5a18452012-08-06 13:41:20 +0900556
557 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
558 if (elf == NULL) {
559 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
560 goto out_close;
561 }
562
563 if (gelf_getehdr(elf, &ehdr) == NULL) {
564 pr_debug("%s: cannot get elf header.\n", __func__);
565 goto out_elf_end;
566 }
567
568 if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
569 goto out_elf_end;
570
571 /* Always reject images with a mismatched build-id: */
572 if (dso->has_build_id) {
573 u8 build_id[BUILD_ID_SIZE];
574
575 if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
576 goto out_elf_end;
577
578 if (!dso__build_id_equal(dso, build_id))
579 goto out_elf_end;
580 }
581
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700582 ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
583 NULL);
584 if (ss->symshdr.sh_type != SHT_SYMTAB)
585 ss->symtab = NULL;
586
587 ss->dynsym_idx = 0;
588 ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
589 &ss->dynsym_idx);
590 if (ss->dynshdr.sh_type != SHT_DYNSYM)
591 ss->dynsym = NULL;
592
593 ss->opdidx = 0;
594 ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
595 &ss->opdidx);
596 if (ss->opdshdr.sh_type != SHT_PROGBITS)
597 ss->opdsec = NULL;
598
599 if (dso->kernel == DSO_TYPE_USER) {
600 GElf_Shdr shdr;
601 ss->adjust_symbols = (ehdr.e_type == ET_EXEC ||
602 elf_section_by_name(elf, &ehdr, &shdr,
603 ".gnu.prelink_undo",
604 NULL) != NULL);
605 } else {
606 ss->adjust_symbols = 0;
607 }
608
609 ss->name = strdup(name);
610 if (!ss->name)
611 goto out_elf_end;
612
613 ss->elf = elf;
614 ss->fd = fd;
615 ss->ehdr = ehdr;
616 ss->type = type;
617
618 return 0;
619
620out_elf_end:
621 elf_end(elf);
622out_close:
623 close(fd);
624 return err;
625}
626
Cody P Schafer261360b2012-08-10 15:23:01 -0700627int dso__load_sym(struct dso *dso, struct map *map,
628 struct symsrc *syms_ss, struct symsrc *runtime_ss,
Cody P Schaferd26cd122012-08-10 15:23:00 -0700629 symbol_filter_t filter, int kmodule)
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700630{
631 struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
632 struct map *curr_map = map;
633 struct dso *curr_dso = dso;
634 Elf_Data *symstrs, *secstrs;
635 uint32_t nr_syms;
636 int err = -1;
637 uint32_t idx;
638 GElf_Ehdr ehdr;
Cody P Schafer261360b2012-08-10 15:23:01 -0700639 GElf_Shdr shdr;
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700640 Elf_Data *syms, *opddata = NULL;
641 GElf_Sym sym;
Cody P Schafer261360b2012-08-10 15:23:01 -0700642 Elf_Scn *sec, *sec_strndx;
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700643 Elf *elf;
644 int nr = 0;
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700645
Cody P Schafer261360b2012-08-10 15:23:01 -0700646 dso->symtab_type = syms_ss->type;
Cody P Schafer005f9292012-08-10 15:22:58 -0700647
Cody P Schafer261360b2012-08-10 15:23:01 -0700648 if (!syms_ss->symtab) {
649 syms_ss->symtab = syms_ss->dynsym;
650 syms_ss->symshdr = syms_ss->dynshdr;
Cody P Schaferd26cd122012-08-10 15:23:00 -0700651 }
652
Cody P Schafer261360b2012-08-10 15:23:01 -0700653 elf = syms_ss->elf;
654 ehdr = syms_ss->ehdr;
655 sec = syms_ss->symtab;
656 shdr = syms_ss->symshdr;
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700657
Cody P Schafer261360b2012-08-10 15:23:01 -0700658 if (runtime_ss->opdsec)
659 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
Namhyung Kime5a18452012-08-06 13:41:20 +0900660
661 syms = elf_getdata(sec, NULL);
662 if (syms == NULL)
663 goto out_elf_end;
664
665 sec = elf_getscn(elf, shdr.sh_link);
666 if (sec == NULL)
667 goto out_elf_end;
668
669 symstrs = elf_getdata(sec, NULL);
670 if (symstrs == NULL)
671 goto out_elf_end;
672
673 sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
674 if (sec_strndx == NULL)
675 goto out_elf_end;
676
677 secstrs = elf_getdata(sec_strndx, NULL);
678 if (secstrs == NULL)
679 goto out_elf_end;
680
681 nr_syms = shdr.sh_size / shdr.sh_entsize;
682
683 memset(&sym, 0, sizeof(sym));
Cody P Schafer261360b2012-08-10 15:23:01 -0700684 dso->adjust_symbols = runtime_ss->adjust_symbols;
Namhyung Kime5a18452012-08-06 13:41:20 +0900685 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
686 struct symbol *f;
687 const char *elf_name = elf_sym__name(&sym, symstrs);
688 char *demangled = NULL;
689 int is_label = elf_sym__is_label(&sym);
690 const char *section_name;
Cody P Schafer261360b2012-08-10 15:23:01 -0700691 bool used_opd = false;
Namhyung Kime5a18452012-08-06 13:41:20 +0900692
693 if (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
694 strcmp(elf_name, kmap->ref_reloc_sym->name) == 0)
695 kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
696
697 if (!is_label && !elf_sym__is_a(&sym, map->type))
698 continue;
699
700 /* Reject ARM ELF "mapping symbols": these aren't unique and
701 * don't identify functions, so will confuse the profile
702 * output: */
703 if (ehdr.e_machine == EM_ARM) {
704 if (!strcmp(elf_name, "$a") ||
705 !strcmp(elf_name, "$d") ||
706 !strcmp(elf_name, "$t"))
707 continue;
708 }
709
Cody P Schafer261360b2012-08-10 15:23:01 -0700710 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
711 u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
Namhyung Kime5a18452012-08-06 13:41:20 +0900712 u64 *opd = opddata->d_buf + offset;
713 sym.st_value = DSO__SWAP(dso, u64, *opd);
Cody P Schafer261360b2012-08-10 15:23:01 -0700714 sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
715 sym.st_value);
716 used_opd = true;
Namhyung Kime5a18452012-08-06 13:41:20 +0900717 }
718
Cody P Schafer261360b2012-08-10 15:23:01 -0700719 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
Namhyung Kime5a18452012-08-06 13:41:20 +0900720 if (!sec)
721 goto out_elf_end;
722
723 gelf_getshdr(sec, &shdr);
724
725 if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
726 continue;
727
728 section_name = elf_sec__name(&shdr, secstrs);
729
730 /* On ARM, symbols for thumb functions have 1 added to
731 * the symbol address as a flag - remove it */
732 if ((ehdr.e_machine == EM_ARM) &&
733 (map->type == MAP__FUNCTION) &&
734 (sym.st_value & 1))
735 --sym.st_value;
736
737 if (dso->kernel != DSO_TYPE_USER || kmodule) {
738 char dso_name[PATH_MAX];
739
740 if (strcmp(section_name,
741 (curr_dso->short_name +
742 dso->short_name_len)) == 0)
743 goto new_symbol;
744
745 if (strcmp(section_name, ".text") == 0) {
746 curr_map = map;
747 curr_dso = dso;
748 goto new_symbol;
749 }
750
751 snprintf(dso_name, sizeof(dso_name),
752 "%s%s", dso->short_name, section_name);
753
754 curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
755 if (curr_map == NULL) {
756 u64 start = sym.st_value;
757
758 if (kmodule)
759 start += map->start + shdr.sh_offset;
760
761 curr_dso = dso__new(dso_name);
762 if (curr_dso == NULL)
763 goto out_elf_end;
764 curr_dso->kernel = dso->kernel;
765 curr_dso->long_name = dso->long_name;
766 curr_dso->long_name_len = dso->long_name_len;
767 curr_map = map__new2(start, curr_dso,
768 map->type);
769 if (curr_map == NULL) {
770 dso__delete(curr_dso);
771 goto out_elf_end;
772 }
773 curr_map->map_ip = identity__map_ip;
774 curr_map->unmap_ip = identity__map_ip;
775 curr_dso->symtab_type = dso->symtab_type;
776 map_groups__insert(kmap->kmaps, curr_map);
777 dsos__add(&dso->node, curr_dso);
778 dso__set_loaded(curr_dso, map->type);
779 } else
780 curr_dso = curr_map->dso;
781
782 goto new_symbol;
783 }
784
Cody P Schafer261360b2012-08-10 15:23:01 -0700785 if ((used_opd && runtime_ss->adjust_symbols)
786 || (!used_opd && syms_ss->adjust_symbols)) {
Namhyung Kime5a18452012-08-06 13:41:20 +0900787 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
788 "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
789 (u64)sym.st_value, (u64)shdr.sh_addr,
790 (u64)shdr.sh_offset);
791 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
792 }
793 /*
794 * We need to figure out if the object was created from C++ sources
795 * DWARF DW_compile_unit has this, but we don't always have access
796 * to it...
797 */
798 demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI);
799 if (demangled != NULL)
800 elf_name = demangled;
801new_symbol:
802 f = symbol__new(sym.st_value, sym.st_size,
803 GELF_ST_BIND(sym.st_info), elf_name);
804 free(demangled);
805 if (!f)
806 goto out_elf_end;
807
808 if (filter && filter(curr_map, f))
809 symbol__delete(f);
810 else {
811 symbols__insert(&curr_dso->symbols[curr_map->type], f);
812 nr++;
813 }
814 }
815
816 /*
817 * For misannotated, zeroed, ASM function sizes.
818 */
819 if (nr > 0) {
820 symbols__fixup_duplicate(&dso->symbols[map->type]);
821 symbols__fixup_end(&dso->symbols[map->type]);
822 if (kmap) {
823 /*
824 * We need to fixup this here too because we create new
825 * maps here, for things like vsyscall sections.
826 */
827 __map_groups__fixup_end(kmap->kmaps, map->type);
828 }
829 }
830 err = nr;
831out_elf_end:
Namhyung Kime5a18452012-08-06 13:41:20 +0900832 return err;
833}
834
835void symbol__elf_init(void)
836{
837 elf_version(EV_CURRENT);
838}