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e5a1845f NK |
1 | #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 | ||
30 | static inline uint8_t elf_sym__type(const GElf_Sym *sym) | |
31 | { | |
32 | return GELF_ST_TYPE(sym->st_info); | |
33 | } | |
34 | ||
35 | static 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 | ||
42 | static 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 | ||
49 | static 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 | ||
57 | static 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 | ||
69 | static 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 | ||
75 | static 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 | ||
81 | static 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 | ||
87 | static 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 | ||
93 | static 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 | ||
106 | static 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 | ||
125 | static 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 | ||
132 | while ((sec = elf_nextscn(elf, sec)) != NULL) { | |
133 | char *str; | |
134 | ||
135 | gelf_getshdr(sec, shp); | |
136 | str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name); | |
137 | if (!strcmp(name, str)) { | |
138 | if (idx) | |
139 | *idx = cnt; | |
140 | break; | |
141 | } | |
142 | ++cnt; | |
143 | } | |
144 | ||
145 | return sec; | |
146 | } | |
147 | ||
148 | #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \ | |
149 | for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \ | |
150 | idx < nr_entries; \ | |
151 | ++idx, pos = gelf_getrel(reldata, idx, &pos_mem)) | |
152 | ||
153 | #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \ | |
154 | for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \ | |
155 | idx < nr_entries; \ | |
156 | ++idx, pos = gelf_getrela(reldata, idx, &pos_mem)) | |
157 | ||
158 | /* | |
159 | * We need to check if we have a .dynsym, so that we can handle the | |
160 | * .plt, synthesizing its symbols, that aren't on the symtabs (be it | |
161 | * .dynsym or .symtab). | |
162 | * And always look at the original dso, not at debuginfo packages, that | |
163 | * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS). | |
164 | */ | |
165 | int dso__synthesize_plt_symbols(struct dso *dso, char *name, struct map *map, | |
166 | symbol_filter_t filter) | |
167 | { | |
168 | uint32_t nr_rel_entries, idx; | |
169 | GElf_Sym sym; | |
170 | u64 plt_offset; | |
171 | GElf_Shdr shdr_plt; | |
172 | struct symbol *f; | |
173 | GElf_Shdr shdr_rel_plt, shdr_dynsym; | |
174 | Elf_Data *reldata, *syms, *symstrs; | |
175 | Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym; | |
176 | size_t dynsym_idx; | |
177 | GElf_Ehdr ehdr; | |
178 | char sympltname[1024]; | |
179 | Elf *elf; | |
180 | int nr = 0, symidx, fd, err = 0; | |
181 | ||
182 | fd = open(name, O_RDONLY); | |
183 | if (fd < 0) | |
184 | goto out; | |
185 | ||
186 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
187 | if (elf == NULL) | |
188 | goto out_close; | |
189 | ||
190 | if (gelf_getehdr(elf, &ehdr) == NULL) | |
191 | goto out_elf_end; | |
192 | ||
193 | scn_dynsym = elf_section_by_name(elf, &ehdr, &shdr_dynsym, | |
194 | ".dynsym", &dynsym_idx); | |
195 | if (scn_dynsym == NULL) | |
196 | goto out_elf_end; | |
197 | ||
198 | scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, | |
199 | ".rela.plt", NULL); | |
200 | if (scn_plt_rel == NULL) { | |
201 | scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, | |
202 | ".rel.plt", NULL); | |
203 | if (scn_plt_rel == NULL) | |
204 | goto out_elf_end; | |
205 | } | |
206 | ||
207 | err = -1; | |
208 | ||
209 | if (shdr_rel_plt.sh_link != dynsym_idx) | |
210 | goto out_elf_end; | |
211 | ||
212 | if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL) | |
213 | goto out_elf_end; | |
214 | ||
215 | /* | |
216 | * Fetch the relocation section to find the idxes to the GOT | |
217 | * and the symbols in the .dynsym they refer to. | |
218 | */ | |
219 | reldata = elf_getdata(scn_plt_rel, NULL); | |
220 | if (reldata == NULL) | |
221 | goto out_elf_end; | |
222 | ||
223 | syms = elf_getdata(scn_dynsym, NULL); | |
224 | if (syms == NULL) | |
225 | goto out_elf_end; | |
226 | ||
227 | scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link); | |
228 | if (scn_symstrs == NULL) | |
229 | goto out_elf_end; | |
230 | ||
231 | symstrs = elf_getdata(scn_symstrs, NULL); | |
232 | if (symstrs == NULL) | |
233 | goto out_elf_end; | |
234 | ||
52f9ddba CS |
235 | if (symstrs->d_size == 0) |
236 | goto out_elf_end; | |
237 | ||
e5a1845f NK |
238 | nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize; |
239 | plt_offset = shdr_plt.sh_offset; | |
240 | ||
241 | if (shdr_rel_plt.sh_type == SHT_RELA) { | |
242 | GElf_Rela pos_mem, *pos; | |
243 | ||
244 | elf_section__for_each_rela(reldata, pos, pos_mem, idx, | |
245 | nr_rel_entries) { | |
246 | symidx = GELF_R_SYM(pos->r_info); | |
247 | plt_offset += shdr_plt.sh_entsize; | |
248 | gelf_getsym(syms, symidx, &sym); | |
249 | snprintf(sympltname, sizeof(sympltname), | |
250 | "%s@plt", elf_sym__name(&sym, symstrs)); | |
251 | ||
252 | f = symbol__new(plt_offset, shdr_plt.sh_entsize, | |
253 | STB_GLOBAL, sympltname); | |
254 | if (!f) | |
255 | goto out_elf_end; | |
256 | ||
257 | if (filter && filter(map, f)) | |
258 | symbol__delete(f); | |
259 | else { | |
260 | symbols__insert(&dso->symbols[map->type], f); | |
261 | ++nr; | |
262 | } | |
263 | } | |
264 | } else if (shdr_rel_plt.sh_type == SHT_REL) { | |
265 | GElf_Rel pos_mem, *pos; | |
266 | elf_section__for_each_rel(reldata, pos, pos_mem, idx, | |
267 | nr_rel_entries) { | |
268 | symidx = GELF_R_SYM(pos->r_info); | |
269 | plt_offset += shdr_plt.sh_entsize; | |
270 | gelf_getsym(syms, symidx, &sym); | |
271 | snprintf(sympltname, sizeof(sympltname), | |
272 | "%s@plt", elf_sym__name(&sym, symstrs)); | |
273 | ||
274 | f = symbol__new(plt_offset, shdr_plt.sh_entsize, | |
275 | STB_GLOBAL, sympltname); | |
276 | if (!f) | |
277 | goto out_elf_end; | |
278 | ||
279 | if (filter && filter(map, f)) | |
280 | symbol__delete(f); | |
281 | else { | |
282 | symbols__insert(&dso->symbols[map->type], f); | |
283 | ++nr; | |
284 | } | |
285 | } | |
286 | } | |
287 | ||
288 | err = 0; | |
289 | out_elf_end: | |
290 | elf_end(elf); | |
291 | out_close: | |
292 | close(fd); | |
293 | ||
294 | if (err == 0) | |
295 | return nr; | |
296 | out: | |
297 | pr_debug("%s: problems reading %s PLT info.\n", | |
298 | __func__, dso->long_name); | |
299 | return 0; | |
300 | } | |
301 | ||
302 | /* | |
303 | * Align offset to 4 bytes as needed for note name and descriptor data. | |
304 | */ | |
305 | #define NOTE_ALIGN(n) (((n) + 3) & -4U) | |
306 | ||
307 | static int elf_read_build_id(Elf *elf, void *bf, size_t size) | |
308 | { | |
309 | int err = -1; | |
310 | GElf_Ehdr ehdr; | |
311 | GElf_Shdr shdr; | |
312 | Elf_Data *data; | |
313 | Elf_Scn *sec; | |
314 | Elf_Kind ek; | |
315 | void *ptr; | |
316 | ||
317 | if (size < BUILD_ID_SIZE) | |
318 | goto out; | |
319 | ||
320 | ek = elf_kind(elf); | |
321 | if (ek != ELF_K_ELF) | |
322 | goto out; | |
323 | ||
324 | if (gelf_getehdr(elf, &ehdr) == NULL) { | |
325 | pr_err("%s: cannot get elf header.\n", __func__); | |
326 | goto out; | |
327 | } | |
328 | ||
329 | /* | |
330 | * Check following sections for notes: | |
331 | * '.note.gnu.build-id' | |
332 | * '.notes' | |
333 | * '.note' (VDSO specific) | |
334 | */ | |
335 | do { | |
336 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
337 | ".note.gnu.build-id", NULL); | |
338 | if (sec) | |
339 | break; | |
340 | ||
341 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
342 | ".notes", NULL); | |
343 | if (sec) | |
344 | break; | |
345 | ||
346 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
347 | ".note", NULL); | |
348 | if (sec) | |
349 | break; | |
350 | ||
351 | return err; | |
352 | ||
353 | } while (0); | |
354 | ||
355 | data = elf_getdata(sec, NULL); | |
356 | if (data == NULL) | |
357 | goto out; | |
358 | ||
359 | ptr = data->d_buf; | |
360 | while (ptr < (data->d_buf + data->d_size)) { | |
361 | GElf_Nhdr *nhdr = ptr; | |
362 | size_t namesz = NOTE_ALIGN(nhdr->n_namesz), | |
363 | descsz = NOTE_ALIGN(nhdr->n_descsz); | |
364 | const char *name; | |
365 | ||
366 | ptr += sizeof(*nhdr); | |
367 | name = ptr; | |
368 | ptr += namesz; | |
369 | if (nhdr->n_type == NT_GNU_BUILD_ID && | |
370 | nhdr->n_namesz == sizeof("GNU")) { | |
371 | if (memcmp(name, "GNU", sizeof("GNU")) == 0) { | |
372 | size_t sz = min(size, descsz); | |
373 | memcpy(bf, ptr, sz); | |
374 | memset(bf + sz, 0, size - sz); | |
375 | err = descsz; | |
376 | break; | |
377 | } | |
378 | } | |
379 | ptr += descsz; | |
380 | } | |
381 | ||
382 | out: | |
383 | return err; | |
384 | } | |
385 | ||
386 | int filename__read_build_id(const char *filename, void *bf, size_t size) | |
387 | { | |
388 | int fd, err = -1; | |
389 | Elf *elf; | |
390 | ||
391 | if (size < BUILD_ID_SIZE) | |
392 | goto out; | |
393 | ||
394 | fd = open(filename, O_RDONLY); | |
395 | if (fd < 0) | |
396 | goto out; | |
397 | ||
398 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
399 | if (elf == NULL) { | |
400 | pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename); | |
401 | goto out_close; | |
402 | } | |
403 | ||
404 | err = elf_read_build_id(elf, bf, size); | |
405 | ||
406 | elf_end(elf); | |
407 | out_close: | |
408 | close(fd); | |
409 | out: | |
410 | return err; | |
411 | } | |
412 | ||
413 | int sysfs__read_build_id(const char *filename, void *build_id, size_t size) | |
414 | { | |
415 | int fd, err = -1; | |
416 | ||
417 | if (size < BUILD_ID_SIZE) | |
418 | goto out; | |
419 | ||
420 | fd = open(filename, O_RDONLY); | |
421 | if (fd < 0) | |
422 | goto out; | |
423 | ||
424 | while (1) { | |
425 | char bf[BUFSIZ]; | |
426 | GElf_Nhdr nhdr; | |
427 | size_t namesz, descsz; | |
428 | ||
429 | if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr)) | |
430 | break; | |
431 | ||
432 | namesz = NOTE_ALIGN(nhdr.n_namesz); | |
433 | descsz = NOTE_ALIGN(nhdr.n_descsz); | |
434 | if (nhdr.n_type == NT_GNU_BUILD_ID && | |
435 | nhdr.n_namesz == sizeof("GNU")) { | |
436 | if (read(fd, bf, namesz) != (ssize_t)namesz) | |
437 | break; | |
438 | if (memcmp(bf, "GNU", sizeof("GNU")) == 0) { | |
439 | size_t sz = min(descsz, size); | |
440 | if (read(fd, build_id, sz) == (ssize_t)sz) { | |
441 | memset(build_id + sz, 0, size - sz); | |
442 | err = 0; | |
443 | break; | |
444 | } | |
445 | } else if (read(fd, bf, descsz) != (ssize_t)descsz) | |
446 | break; | |
447 | } else { | |
448 | int n = namesz + descsz; | |
449 | if (read(fd, bf, n) != n) | |
450 | break; | |
451 | } | |
452 | } | |
453 | close(fd); | |
454 | out: | |
455 | return err; | |
456 | } | |
457 | ||
458 | int filename__read_debuglink(const char *filename, char *debuglink, | |
459 | size_t size) | |
460 | { | |
461 | int fd, err = -1; | |
462 | Elf *elf; | |
463 | GElf_Ehdr ehdr; | |
464 | GElf_Shdr shdr; | |
465 | Elf_Data *data; | |
466 | Elf_Scn *sec; | |
467 | Elf_Kind ek; | |
468 | ||
469 | fd = open(filename, O_RDONLY); | |
470 | if (fd < 0) | |
471 | goto out; | |
472 | ||
473 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
474 | if (elf == NULL) { | |
475 | pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename); | |
476 | goto out_close; | |
477 | } | |
478 | ||
479 | ek = elf_kind(elf); | |
480 | if (ek != ELF_K_ELF) | |
481 | goto out_close; | |
482 | ||
483 | if (gelf_getehdr(elf, &ehdr) == NULL) { | |
484 | pr_err("%s: cannot get elf header.\n", __func__); | |
485 | goto out_close; | |
486 | } | |
487 | ||
488 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
489 | ".gnu_debuglink", NULL); | |
490 | if (sec == NULL) | |
491 | goto out_close; | |
492 | ||
493 | data = elf_getdata(sec, NULL); | |
494 | if (data == NULL) | |
495 | goto out_close; | |
496 | ||
497 | /* the start of this section is a zero-terminated string */ | |
498 | strncpy(debuglink, data->d_buf, size); | |
499 | ||
500 | elf_end(elf); | |
501 | ||
502 | out_close: | |
503 | close(fd); | |
504 | out: | |
505 | return err; | |
506 | } | |
507 | ||
508 | static int dso__swap_init(struct dso *dso, unsigned char eidata) | |
509 | { | |
510 | static unsigned int const endian = 1; | |
511 | ||
512 | dso->needs_swap = DSO_SWAP__NO; | |
513 | ||
514 | switch (eidata) { | |
515 | case ELFDATA2LSB: | |
516 | /* We are big endian, DSO is little endian. */ | |
517 | if (*(unsigned char const *)&endian != 1) | |
518 | dso->needs_swap = DSO_SWAP__YES; | |
519 | break; | |
520 | ||
521 | case ELFDATA2MSB: | |
522 | /* We are little endian, DSO is big endian. */ | |
523 | if (*(unsigned char const *)&endian != 0) | |
524 | dso->needs_swap = DSO_SWAP__YES; | |
525 | break; | |
526 | ||
527 | default: | |
528 | pr_err("unrecognized DSO data encoding %d\n", eidata); | |
529 | return -EINVAL; | |
530 | } | |
531 | ||
532 | return 0; | |
533 | } | |
534 | ||
535 | int dso__load_sym(struct dso *dso, struct map *map, const char *name, int fd, | |
536 | symbol_filter_t filter, int kmodule, int want_symtab) | |
537 | { | |
538 | struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL; | |
539 | struct map *curr_map = map; | |
540 | struct dso *curr_dso = dso; | |
541 | Elf_Data *symstrs, *secstrs; | |
542 | uint32_t nr_syms; | |
543 | int err = -1; | |
544 | uint32_t idx; | |
545 | GElf_Ehdr ehdr; | |
546 | GElf_Shdr shdr, opdshdr; | |
547 | Elf_Data *syms, *opddata = NULL; | |
548 | GElf_Sym sym; | |
549 | Elf_Scn *sec, *sec_strndx, *opdsec; | |
550 | Elf *elf; | |
551 | int nr = 0; | |
552 | size_t opdidx = 0; | |
553 | ||
554 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
555 | if (elf == NULL) { | |
556 | pr_debug("%s: cannot read %s ELF file.\n", __func__, name); | |
557 | goto out_close; | |
558 | } | |
559 | ||
560 | if (gelf_getehdr(elf, &ehdr) == NULL) { | |
561 | pr_debug("%s: cannot get elf header.\n", __func__); | |
562 | goto out_elf_end; | |
563 | } | |
564 | ||
565 | if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) | |
566 | goto out_elf_end; | |
567 | ||
568 | /* Always reject images with a mismatched build-id: */ | |
569 | if (dso->has_build_id) { | |
570 | u8 build_id[BUILD_ID_SIZE]; | |
571 | ||
572 | if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) | |
573 | goto out_elf_end; | |
574 | ||
575 | if (!dso__build_id_equal(dso, build_id)) | |
576 | goto out_elf_end; | |
577 | } | |
578 | ||
579 | sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL); | |
580 | if (sec == NULL) { | |
581 | if (want_symtab) | |
582 | goto out_elf_end; | |
583 | ||
584 | sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL); | |
585 | if (sec == NULL) | |
586 | goto out_elf_end; | |
587 | } | |
588 | ||
589 | opdsec = elf_section_by_name(elf, &ehdr, &opdshdr, ".opd", &opdidx); | |
590 | if (opdshdr.sh_type != SHT_PROGBITS) | |
591 | opdsec = NULL; | |
592 | if (opdsec) | |
593 | opddata = elf_rawdata(opdsec, NULL); | |
594 | ||
595 | syms = elf_getdata(sec, NULL); | |
596 | if (syms == NULL) | |
597 | goto out_elf_end; | |
598 | ||
599 | sec = elf_getscn(elf, shdr.sh_link); | |
600 | if (sec == NULL) | |
601 | goto out_elf_end; | |
602 | ||
603 | symstrs = elf_getdata(sec, NULL); | |
604 | if (symstrs == NULL) | |
605 | goto out_elf_end; | |
606 | ||
607 | sec_strndx = elf_getscn(elf, ehdr.e_shstrndx); | |
608 | if (sec_strndx == NULL) | |
609 | goto out_elf_end; | |
610 | ||
611 | secstrs = elf_getdata(sec_strndx, NULL); | |
612 | if (secstrs == NULL) | |
613 | goto out_elf_end; | |
614 | ||
615 | nr_syms = shdr.sh_size / shdr.sh_entsize; | |
616 | ||
617 | memset(&sym, 0, sizeof(sym)); | |
618 | if (dso->kernel == DSO_TYPE_USER) { | |
619 | dso->adjust_symbols = (ehdr.e_type == ET_EXEC || | |
620 | elf_section_by_name(elf, &ehdr, &shdr, | |
621 | ".gnu.prelink_undo", | |
622 | NULL) != NULL); | |
623 | } else { | |
624 | dso->adjust_symbols = 0; | |
625 | } | |
626 | elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) { | |
627 | struct symbol *f; | |
628 | const char *elf_name = elf_sym__name(&sym, symstrs); | |
629 | char *demangled = NULL; | |
630 | int is_label = elf_sym__is_label(&sym); | |
631 | const char *section_name; | |
632 | ||
633 | if (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name && | |
634 | strcmp(elf_name, kmap->ref_reloc_sym->name) == 0) | |
635 | kmap->ref_reloc_sym->unrelocated_addr = sym.st_value; | |
636 | ||
637 | if (!is_label && !elf_sym__is_a(&sym, map->type)) | |
638 | continue; | |
639 | ||
640 | /* Reject ARM ELF "mapping symbols": these aren't unique and | |
641 | * don't identify functions, so will confuse the profile | |
642 | * output: */ | |
643 | if (ehdr.e_machine == EM_ARM) { | |
644 | if (!strcmp(elf_name, "$a") || | |
645 | !strcmp(elf_name, "$d") || | |
646 | !strcmp(elf_name, "$t")) | |
647 | continue; | |
648 | } | |
649 | ||
650 | if (opdsec && sym.st_shndx == opdidx) { | |
651 | u32 offset = sym.st_value - opdshdr.sh_addr; | |
652 | u64 *opd = opddata->d_buf + offset; | |
653 | sym.st_value = DSO__SWAP(dso, u64, *opd); | |
654 | sym.st_shndx = elf_addr_to_index(elf, sym.st_value); | |
655 | } | |
656 | ||
657 | sec = elf_getscn(elf, sym.st_shndx); | |
658 | if (!sec) | |
659 | goto out_elf_end; | |
660 | ||
661 | gelf_getshdr(sec, &shdr); | |
662 | ||
663 | if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type)) | |
664 | continue; | |
665 | ||
666 | section_name = elf_sec__name(&shdr, secstrs); | |
667 | ||
668 | /* On ARM, symbols for thumb functions have 1 added to | |
669 | * the symbol address as a flag - remove it */ | |
670 | if ((ehdr.e_machine == EM_ARM) && | |
671 | (map->type == MAP__FUNCTION) && | |
672 | (sym.st_value & 1)) | |
673 | --sym.st_value; | |
674 | ||
675 | if (dso->kernel != DSO_TYPE_USER || kmodule) { | |
676 | char dso_name[PATH_MAX]; | |
677 | ||
678 | if (strcmp(section_name, | |
679 | (curr_dso->short_name + | |
680 | dso->short_name_len)) == 0) | |
681 | goto new_symbol; | |
682 | ||
683 | if (strcmp(section_name, ".text") == 0) { | |
684 | curr_map = map; | |
685 | curr_dso = dso; | |
686 | goto new_symbol; | |
687 | } | |
688 | ||
689 | snprintf(dso_name, sizeof(dso_name), | |
690 | "%s%s", dso->short_name, section_name); | |
691 | ||
692 | curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name); | |
693 | if (curr_map == NULL) { | |
694 | u64 start = sym.st_value; | |
695 | ||
696 | if (kmodule) | |
697 | start += map->start + shdr.sh_offset; | |
698 | ||
699 | curr_dso = dso__new(dso_name); | |
700 | if (curr_dso == NULL) | |
701 | goto out_elf_end; | |
702 | curr_dso->kernel = dso->kernel; | |
703 | curr_dso->long_name = dso->long_name; | |
704 | curr_dso->long_name_len = dso->long_name_len; | |
705 | curr_map = map__new2(start, curr_dso, | |
706 | map->type); | |
707 | if (curr_map == NULL) { | |
708 | dso__delete(curr_dso); | |
709 | goto out_elf_end; | |
710 | } | |
711 | curr_map->map_ip = identity__map_ip; | |
712 | curr_map->unmap_ip = identity__map_ip; | |
713 | curr_dso->symtab_type = dso->symtab_type; | |
714 | map_groups__insert(kmap->kmaps, curr_map); | |
715 | dsos__add(&dso->node, curr_dso); | |
716 | dso__set_loaded(curr_dso, map->type); | |
717 | } else | |
718 | curr_dso = curr_map->dso; | |
719 | ||
720 | goto new_symbol; | |
721 | } | |
722 | ||
8db24c70 | 723 | if (curr_dso->adjust_symbols && sym.st_value) { |
e5a1845f NK |
724 | pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " |
725 | "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__, | |
726 | (u64)sym.st_value, (u64)shdr.sh_addr, | |
727 | (u64)shdr.sh_offset); | |
728 | sym.st_value -= shdr.sh_addr - shdr.sh_offset; | |
729 | } | |
730 | /* | |
731 | * We need to figure out if the object was created from C++ sources | |
732 | * DWARF DW_compile_unit has this, but we don't always have access | |
733 | * to it... | |
734 | */ | |
735 | demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI); | |
736 | if (demangled != NULL) | |
737 | elf_name = demangled; | |
738 | new_symbol: | |
739 | f = symbol__new(sym.st_value, sym.st_size, | |
740 | GELF_ST_BIND(sym.st_info), elf_name); | |
741 | free(demangled); | |
742 | if (!f) | |
743 | goto out_elf_end; | |
744 | ||
745 | if (filter && filter(curr_map, f)) | |
746 | symbol__delete(f); | |
747 | else { | |
748 | symbols__insert(&curr_dso->symbols[curr_map->type], f); | |
749 | nr++; | |
750 | } | |
751 | } | |
752 | ||
753 | /* | |
754 | * For misannotated, zeroed, ASM function sizes. | |
755 | */ | |
756 | if (nr > 0) { | |
757 | symbols__fixup_duplicate(&dso->symbols[map->type]); | |
758 | symbols__fixup_end(&dso->symbols[map->type]); | |
759 | if (kmap) { | |
760 | /* | |
761 | * We need to fixup this here too because we create new | |
762 | * maps here, for things like vsyscall sections. | |
763 | */ | |
764 | __map_groups__fixup_end(kmap->kmaps, map->type); | |
765 | } | |
766 | } | |
767 | err = nr; | |
768 | out_elf_end: | |
769 | elf_end(elf); | |
770 | out_close: | |
771 | return err; | |
772 | } | |
773 | ||
774 | void symbol__elf_init(void) | |
775 | { | |
776 | elf_version(EV_CURRENT); | |
777 | } |