blob: db0cc92cf2eaf25a3528429154b1f9713f1d91d8 [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
David Ahernf47b58b2012-08-19 09:47:14 -0600186 if (!ss->dynsym)
187 return 0;
188
Cody P Schafera44f6052012-08-10 15:22:59 -0700189 elf = ss->elf;
190 ehdr = ss->ehdr;
Namhyung Kime5a18452012-08-06 13:41:20 +0900191
Cody P Schafera44f6052012-08-10 15:22:59 -0700192 scn_dynsym = ss->dynsym;
193 shdr_dynsym = ss->dynshdr;
194 dynsym_idx = ss->dynsym_idx;
Namhyung Kime5a18452012-08-06 13:41:20 +0900195
Namhyung Kime5a18452012-08-06 13:41:20 +0900196 if (scn_dynsym == NULL)
197 goto out_elf_end;
198
199 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
200 ".rela.plt", NULL);
201 if (scn_plt_rel == NULL) {
202 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
203 ".rel.plt", NULL);
204 if (scn_plt_rel == NULL)
205 goto out_elf_end;
206 }
207
208 err = -1;
209
210 if (shdr_rel_plt.sh_link != dynsym_idx)
211 goto out_elf_end;
212
213 if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
214 goto out_elf_end;
215
216 /*
217 * Fetch the relocation section to find the idxes to the GOT
218 * and the symbols in the .dynsym they refer to.
219 */
220 reldata = elf_getdata(scn_plt_rel, NULL);
221 if (reldata == NULL)
222 goto out_elf_end;
223
224 syms = elf_getdata(scn_dynsym, NULL);
225 if (syms == NULL)
226 goto out_elf_end;
227
228 scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
229 if (scn_symstrs == NULL)
230 goto out_elf_end;
231
232 symstrs = elf_getdata(scn_symstrs, NULL);
233 if (symstrs == NULL)
234 goto out_elf_end;
235
Cody P Schafer52f9ddb2012-08-10 15:22:51 -0700236 if (symstrs->d_size == 0)
237 goto out_elf_end;
238
Namhyung Kime5a18452012-08-06 13:41:20 +0900239 nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
240 plt_offset = shdr_plt.sh_offset;
241
242 if (shdr_rel_plt.sh_type == SHT_RELA) {
243 GElf_Rela pos_mem, *pos;
244
245 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
246 nr_rel_entries) {
247 symidx = GELF_R_SYM(pos->r_info);
248 plt_offset += shdr_plt.sh_entsize;
249 gelf_getsym(syms, symidx, &sym);
250 snprintf(sympltname, sizeof(sympltname),
251 "%s@plt", elf_sym__name(&sym, symstrs));
252
253 f = symbol__new(plt_offset, shdr_plt.sh_entsize,
254 STB_GLOBAL, sympltname);
255 if (!f)
256 goto out_elf_end;
257
258 if (filter && filter(map, f))
259 symbol__delete(f);
260 else {
261 symbols__insert(&dso->symbols[map->type], f);
262 ++nr;
263 }
264 }
265 } else if (shdr_rel_plt.sh_type == SHT_REL) {
266 GElf_Rel pos_mem, *pos;
267 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
268 nr_rel_entries) {
269 symidx = GELF_R_SYM(pos->r_info);
270 plt_offset += shdr_plt.sh_entsize;
271 gelf_getsym(syms, symidx, &sym);
272 snprintf(sympltname, sizeof(sympltname),
273 "%s@plt", elf_sym__name(&sym, symstrs));
274
275 f = symbol__new(plt_offset, shdr_plt.sh_entsize,
276 STB_GLOBAL, sympltname);
277 if (!f)
278 goto out_elf_end;
279
280 if (filter && filter(map, f))
281 symbol__delete(f);
282 else {
283 symbols__insert(&dso->symbols[map->type], f);
284 ++nr;
285 }
286 }
287 }
288
289 err = 0;
290out_elf_end:
Namhyung Kime5a18452012-08-06 13:41:20 +0900291 if (err == 0)
292 return nr;
Namhyung Kime5a18452012-08-06 13:41:20 +0900293 pr_debug("%s: problems reading %s PLT info.\n",
294 __func__, dso->long_name);
295 return 0;
296}
297
298/*
299 * Align offset to 4 bytes as needed for note name and descriptor data.
300 */
301#define NOTE_ALIGN(n) (((n) + 3) & -4U)
302
303static int elf_read_build_id(Elf *elf, void *bf, size_t size)
304{
305 int err = -1;
306 GElf_Ehdr ehdr;
307 GElf_Shdr shdr;
308 Elf_Data *data;
309 Elf_Scn *sec;
310 Elf_Kind ek;
311 void *ptr;
312
313 if (size < BUILD_ID_SIZE)
314 goto out;
315
316 ek = elf_kind(elf);
317 if (ek != ELF_K_ELF)
318 goto out;
319
320 if (gelf_getehdr(elf, &ehdr) == NULL) {
321 pr_err("%s: cannot get elf header.\n", __func__);
322 goto out;
323 }
324
325 /*
326 * Check following sections for notes:
327 * '.note.gnu.build-id'
328 * '.notes'
329 * '.note' (VDSO specific)
330 */
331 do {
332 sec = elf_section_by_name(elf, &ehdr, &shdr,
333 ".note.gnu.build-id", NULL);
334 if (sec)
335 break;
336
337 sec = elf_section_by_name(elf, &ehdr, &shdr,
338 ".notes", NULL);
339 if (sec)
340 break;
341
342 sec = elf_section_by_name(elf, &ehdr, &shdr,
343 ".note", NULL);
344 if (sec)
345 break;
346
347 return err;
348
349 } while (0);
350
351 data = elf_getdata(sec, NULL);
352 if (data == NULL)
353 goto out;
354
355 ptr = data->d_buf;
356 while (ptr < (data->d_buf + data->d_size)) {
357 GElf_Nhdr *nhdr = ptr;
358 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
359 descsz = NOTE_ALIGN(nhdr->n_descsz);
360 const char *name;
361
362 ptr += sizeof(*nhdr);
363 name = ptr;
364 ptr += namesz;
365 if (nhdr->n_type == NT_GNU_BUILD_ID &&
366 nhdr->n_namesz == sizeof("GNU")) {
367 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
368 size_t sz = min(size, descsz);
369 memcpy(bf, ptr, sz);
370 memset(bf + sz, 0, size - sz);
371 err = descsz;
372 break;
373 }
374 }
375 ptr += descsz;
376 }
377
378out:
379 return err;
380}
381
382int filename__read_build_id(const char *filename, void *bf, size_t size)
383{
384 int fd, err = -1;
385 Elf *elf;
386
387 if (size < BUILD_ID_SIZE)
388 goto out;
389
390 fd = open(filename, O_RDONLY);
391 if (fd < 0)
392 goto out;
393
394 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
395 if (elf == NULL) {
396 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
397 goto out_close;
398 }
399
400 err = elf_read_build_id(elf, bf, size);
401
402 elf_end(elf);
403out_close:
404 close(fd);
405out:
406 return err;
407}
408
409int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
410{
411 int fd, err = -1;
412
413 if (size < BUILD_ID_SIZE)
414 goto out;
415
416 fd = open(filename, O_RDONLY);
417 if (fd < 0)
418 goto out;
419
420 while (1) {
421 char bf[BUFSIZ];
422 GElf_Nhdr nhdr;
423 size_t namesz, descsz;
424
425 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
426 break;
427
428 namesz = NOTE_ALIGN(nhdr.n_namesz);
429 descsz = NOTE_ALIGN(nhdr.n_descsz);
430 if (nhdr.n_type == NT_GNU_BUILD_ID &&
431 nhdr.n_namesz == sizeof("GNU")) {
432 if (read(fd, bf, namesz) != (ssize_t)namesz)
433 break;
434 if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
435 size_t sz = min(descsz, size);
436 if (read(fd, build_id, sz) == (ssize_t)sz) {
437 memset(build_id + sz, 0, size - sz);
438 err = 0;
439 break;
440 }
441 } else if (read(fd, bf, descsz) != (ssize_t)descsz)
442 break;
443 } else {
444 int n = namesz + descsz;
445 if (read(fd, bf, n) != n)
446 break;
447 }
448 }
449 close(fd);
450out:
451 return err;
452}
453
454int filename__read_debuglink(const char *filename, char *debuglink,
455 size_t size)
456{
457 int fd, err = -1;
458 Elf *elf;
459 GElf_Ehdr ehdr;
460 GElf_Shdr shdr;
461 Elf_Data *data;
462 Elf_Scn *sec;
463 Elf_Kind ek;
464
465 fd = open(filename, O_RDONLY);
466 if (fd < 0)
467 goto out;
468
469 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
470 if (elf == NULL) {
471 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
472 goto out_close;
473 }
474
475 ek = elf_kind(elf);
476 if (ek != ELF_K_ELF)
477 goto out_close;
478
479 if (gelf_getehdr(elf, &ehdr) == NULL) {
480 pr_err("%s: cannot get elf header.\n", __func__);
481 goto out_close;
482 }
483
484 sec = elf_section_by_name(elf, &ehdr, &shdr,
485 ".gnu_debuglink", NULL);
486 if (sec == NULL)
487 goto out_close;
488
489 data = elf_getdata(sec, NULL);
490 if (data == NULL)
491 goto out_close;
492
493 /* the start of this section is a zero-terminated string */
494 strncpy(debuglink, data->d_buf, size);
495
496 elf_end(elf);
497
498out_close:
499 close(fd);
500out:
501 return err;
502}
503
504static int dso__swap_init(struct dso *dso, unsigned char eidata)
505{
506 static unsigned int const endian = 1;
507
508 dso->needs_swap = DSO_SWAP__NO;
509
510 switch (eidata) {
511 case ELFDATA2LSB:
512 /* We are big endian, DSO is little endian. */
513 if (*(unsigned char const *)&endian != 1)
514 dso->needs_swap = DSO_SWAP__YES;
515 break;
516
517 case ELFDATA2MSB:
518 /* We are little endian, DSO is big endian. */
519 if (*(unsigned char const *)&endian != 0)
520 dso->needs_swap = DSO_SWAP__YES;
521 break;
522
523 default:
524 pr_err("unrecognized DSO data encoding %d\n", eidata);
525 return -EINVAL;
526 }
527
528 return 0;
529}
530
Cody P Schafer3aafe5a2012-08-10 15:23:02 -0700531bool symsrc__possibly_runtime(struct symsrc *ss)
532{
533 return ss->dynsym || ss->opdsec;
534}
535
Cody P Schaferd26cd122012-08-10 15:23:00 -0700536bool symsrc__has_symtab(struct symsrc *ss)
537{
538 return ss->symtab != NULL;
539}
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700540
541void symsrc__destroy(struct symsrc *ss)
Namhyung Kime5a18452012-08-06 13:41:20 +0900542{
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700543 free(ss->name);
544 elf_end(ss->elf);
545 close(ss->fd);
546}
547
548int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
549 enum dso_binary_type type)
550{
Namhyung Kime5a18452012-08-06 13:41:20 +0900551 int err = -1;
Namhyung Kime5a18452012-08-06 13:41:20 +0900552 GElf_Ehdr ehdr;
Namhyung Kime5a18452012-08-06 13:41:20 +0900553 Elf *elf;
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700554 int fd;
555
556 fd = open(name, O_RDONLY);
557 if (fd < 0)
558 return -1;
Namhyung Kime5a18452012-08-06 13:41:20 +0900559
560 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
561 if (elf == NULL) {
562 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
563 goto out_close;
564 }
565
566 if (gelf_getehdr(elf, &ehdr) == NULL) {
567 pr_debug("%s: cannot get elf header.\n", __func__);
568 goto out_elf_end;
569 }
570
571 if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
572 goto out_elf_end;
573
574 /* Always reject images with a mismatched build-id: */
575 if (dso->has_build_id) {
576 u8 build_id[BUILD_ID_SIZE];
577
578 if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
579 goto out_elf_end;
580
581 if (!dso__build_id_equal(dso, build_id))
582 goto out_elf_end;
583 }
584
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700585 ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
586 NULL);
587 if (ss->symshdr.sh_type != SHT_SYMTAB)
588 ss->symtab = NULL;
589
590 ss->dynsym_idx = 0;
591 ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
592 &ss->dynsym_idx);
593 if (ss->dynshdr.sh_type != SHT_DYNSYM)
594 ss->dynsym = NULL;
595
596 ss->opdidx = 0;
597 ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
598 &ss->opdidx);
599 if (ss->opdshdr.sh_type != SHT_PROGBITS)
600 ss->opdsec = NULL;
601
602 if (dso->kernel == DSO_TYPE_USER) {
603 GElf_Shdr shdr;
604 ss->adjust_symbols = (ehdr.e_type == ET_EXEC ||
605 elf_section_by_name(elf, &ehdr, &shdr,
606 ".gnu.prelink_undo",
607 NULL) != NULL);
608 } else {
609 ss->adjust_symbols = 0;
610 }
611
612 ss->name = strdup(name);
613 if (!ss->name)
614 goto out_elf_end;
615
616 ss->elf = elf;
617 ss->fd = fd;
618 ss->ehdr = ehdr;
619 ss->type = type;
620
621 return 0;
622
623out_elf_end:
624 elf_end(elf);
625out_close:
626 close(fd);
627 return err;
628}
629
Cody P Schafer261360b2012-08-10 15:23:01 -0700630int dso__load_sym(struct dso *dso, struct map *map,
631 struct symsrc *syms_ss, struct symsrc *runtime_ss,
Cody P Schaferd26cd122012-08-10 15:23:00 -0700632 symbol_filter_t filter, int kmodule)
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700633{
634 struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
635 struct map *curr_map = map;
636 struct dso *curr_dso = dso;
637 Elf_Data *symstrs, *secstrs;
638 uint32_t nr_syms;
639 int err = -1;
640 uint32_t idx;
641 GElf_Ehdr ehdr;
Cody P Schafer261360b2012-08-10 15:23:01 -0700642 GElf_Shdr shdr;
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700643 Elf_Data *syms, *opddata = NULL;
644 GElf_Sym sym;
Cody P Schafer261360b2012-08-10 15:23:01 -0700645 Elf_Scn *sec, *sec_strndx;
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700646 Elf *elf;
647 int nr = 0;
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700648
Cody P Schafer261360b2012-08-10 15:23:01 -0700649 dso->symtab_type = syms_ss->type;
Cody P Schafer005f9292012-08-10 15:22:58 -0700650
Cody P Schafer261360b2012-08-10 15:23:01 -0700651 if (!syms_ss->symtab) {
652 syms_ss->symtab = syms_ss->dynsym;
653 syms_ss->symshdr = syms_ss->dynshdr;
Cody P Schaferd26cd122012-08-10 15:23:00 -0700654 }
655
Cody P Schafer261360b2012-08-10 15:23:01 -0700656 elf = syms_ss->elf;
657 ehdr = syms_ss->ehdr;
658 sec = syms_ss->symtab;
659 shdr = syms_ss->symshdr;
Cody P Schaferb68e2f92012-08-10 15:22:57 -0700660
Cody P Schafer261360b2012-08-10 15:23:01 -0700661 if (runtime_ss->opdsec)
662 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
Namhyung Kime5a18452012-08-06 13:41:20 +0900663
664 syms = elf_getdata(sec, NULL);
665 if (syms == NULL)
666 goto out_elf_end;
667
668 sec = elf_getscn(elf, shdr.sh_link);
669 if (sec == NULL)
670 goto out_elf_end;
671
672 symstrs = elf_getdata(sec, NULL);
673 if (symstrs == NULL)
674 goto out_elf_end;
675
676 sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
677 if (sec_strndx == NULL)
678 goto out_elf_end;
679
680 secstrs = elf_getdata(sec_strndx, NULL);
681 if (secstrs == NULL)
682 goto out_elf_end;
683
684 nr_syms = shdr.sh_size / shdr.sh_entsize;
685
686 memset(&sym, 0, sizeof(sym));
Cody P Schafer261360b2012-08-10 15:23:01 -0700687 dso->adjust_symbols = runtime_ss->adjust_symbols;
Namhyung Kime5a18452012-08-06 13:41:20 +0900688 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
689 struct symbol *f;
690 const char *elf_name = elf_sym__name(&sym, symstrs);
691 char *demangled = NULL;
692 int is_label = elf_sym__is_label(&sym);
693 const char *section_name;
Cody P Schafer261360b2012-08-10 15:23:01 -0700694 bool used_opd = false;
Namhyung Kime5a18452012-08-06 13:41:20 +0900695
696 if (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
697 strcmp(elf_name, kmap->ref_reloc_sym->name) == 0)
698 kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
699
700 if (!is_label && !elf_sym__is_a(&sym, map->type))
701 continue;
702
703 /* Reject ARM ELF "mapping symbols": these aren't unique and
704 * don't identify functions, so will confuse the profile
705 * output: */
706 if (ehdr.e_machine == EM_ARM) {
707 if (!strcmp(elf_name, "$a") ||
708 !strcmp(elf_name, "$d") ||
709 !strcmp(elf_name, "$t"))
710 continue;
711 }
712
Cody P Schafer261360b2012-08-10 15:23:01 -0700713 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
714 u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
Namhyung Kime5a18452012-08-06 13:41:20 +0900715 u64 *opd = opddata->d_buf + offset;
716 sym.st_value = DSO__SWAP(dso, u64, *opd);
Cody P Schafer261360b2012-08-10 15:23:01 -0700717 sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
718 sym.st_value);
719 used_opd = true;
Namhyung Kime5a18452012-08-06 13:41:20 +0900720 }
721
Cody P Schafer261360b2012-08-10 15:23:01 -0700722 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
Namhyung Kime5a18452012-08-06 13:41:20 +0900723 if (!sec)
724 goto out_elf_end;
725
726 gelf_getshdr(sec, &shdr);
727
728 if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
729 continue;
730
731 section_name = elf_sec__name(&shdr, secstrs);
732
733 /* On ARM, symbols for thumb functions have 1 added to
734 * the symbol address as a flag - remove it */
735 if ((ehdr.e_machine == EM_ARM) &&
736 (map->type == MAP__FUNCTION) &&
737 (sym.st_value & 1))
738 --sym.st_value;
739
740 if (dso->kernel != DSO_TYPE_USER || kmodule) {
741 char dso_name[PATH_MAX];
742
743 if (strcmp(section_name,
744 (curr_dso->short_name +
745 dso->short_name_len)) == 0)
746 goto new_symbol;
747
748 if (strcmp(section_name, ".text") == 0) {
749 curr_map = map;
750 curr_dso = dso;
751 goto new_symbol;
752 }
753
754 snprintf(dso_name, sizeof(dso_name),
755 "%s%s", dso->short_name, section_name);
756
757 curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
758 if (curr_map == NULL) {
759 u64 start = sym.st_value;
760
761 if (kmodule)
762 start += map->start + shdr.sh_offset;
763
764 curr_dso = dso__new(dso_name);
765 if (curr_dso == NULL)
766 goto out_elf_end;
767 curr_dso->kernel = dso->kernel;
768 curr_dso->long_name = dso->long_name;
769 curr_dso->long_name_len = dso->long_name_len;
770 curr_map = map__new2(start, curr_dso,
771 map->type);
772 if (curr_map == NULL) {
773 dso__delete(curr_dso);
774 goto out_elf_end;
775 }
776 curr_map->map_ip = identity__map_ip;
777 curr_map->unmap_ip = identity__map_ip;
778 curr_dso->symtab_type = dso->symtab_type;
779 map_groups__insert(kmap->kmaps, curr_map);
780 dsos__add(&dso->node, curr_dso);
781 dso__set_loaded(curr_dso, map->type);
782 } else
783 curr_dso = curr_map->dso;
784
785 goto new_symbol;
786 }
787
Cody P Schafer261360b2012-08-10 15:23:01 -0700788 if ((used_opd && runtime_ss->adjust_symbols)
789 || (!used_opd && syms_ss->adjust_symbols)) {
Namhyung Kime5a18452012-08-06 13:41:20 +0900790 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
791 "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
792 (u64)sym.st_value, (u64)shdr.sh_addr,
793 (u64)shdr.sh_offset);
794 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
795 }
796 /*
797 * We need to figure out if the object was created from C++ sources
798 * DWARF DW_compile_unit has this, but we don't always have access
799 * to it...
800 */
801 demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI);
802 if (demangled != NULL)
803 elf_name = demangled;
804new_symbol:
805 f = symbol__new(sym.st_value, sym.st_size,
806 GELF_ST_BIND(sym.st_info), elf_name);
807 free(demangled);
808 if (!f)
809 goto out_elf_end;
810
811 if (filter && filter(curr_map, f))
812 symbol__delete(f);
813 else {
814 symbols__insert(&curr_dso->symbols[curr_map->type], f);
815 nr++;
816 }
817 }
818
819 /*
820 * For misannotated, zeroed, ASM function sizes.
821 */
822 if (nr > 0) {
823 symbols__fixup_duplicate(&dso->symbols[map->type]);
824 symbols__fixup_end(&dso->symbols[map->type]);
825 if (kmap) {
826 /*
827 * We need to fixup this here too because we create new
828 * maps here, for things like vsyscall sections.
829 */
830 __map_groups__fixup_end(kmap->kmaps, map->type);
831 }
832 }
833 err = nr;
834out_elf_end:
Namhyung Kime5a18452012-08-06 13:41:20 +0900835 return err;
836}
837
838void symbol__elf_init(void)
839{
840 elf_version(EV_CURRENT);
841}