Commit | Line | Data |
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e5a1845f NK |
1 | #include <fcntl.h> |
2 | #include <stdio.h> | |
3 | #include <errno.h> | |
4 | #include <string.h> | |
5 | #include <unistd.h> | |
6 | #include <inttypes.h> | |
7 | ||
8 | #include "symbol.h" | |
9 | #include "debug.h" | |
10 | ||
11 | #ifndef NT_GNU_BUILD_ID | |
12 | #define NT_GNU_BUILD_ID 3 | |
13 | #endif | |
14 | ||
15 | /** | |
16 | * elf_symtab__for_each_symbol - iterate thru all the symbols | |
17 | * | |
18 | * @syms: struct elf_symtab instance to iterate | |
19 | * @idx: uint32_t idx | |
20 | * @sym: GElf_Sym iterator | |
21 | */ | |
22 | #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \ | |
23 | for (idx = 0, gelf_getsym(syms, idx, &sym);\ | |
24 | idx < nr_syms; \ | |
25 | idx++, gelf_getsym(syms, idx, &sym)) | |
26 | ||
27 | static inline uint8_t elf_sym__type(const GElf_Sym *sym) | |
28 | { | |
29 | return GELF_ST_TYPE(sym->st_info); | |
30 | } | |
31 | ||
32 | static inline int elf_sym__is_function(const GElf_Sym *sym) | |
33 | { | |
34 | return elf_sym__type(sym) == STT_FUNC && | |
35 | sym->st_name != 0 && | |
36 | sym->st_shndx != SHN_UNDEF; | |
37 | } | |
38 | ||
39 | static inline bool elf_sym__is_object(const GElf_Sym *sym) | |
40 | { | |
41 | return elf_sym__type(sym) == STT_OBJECT && | |
42 | sym->st_name != 0 && | |
43 | sym->st_shndx != SHN_UNDEF; | |
44 | } | |
45 | ||
46 | static inline int elf_sym__is_label(const GElf_Sym *sym) | |
47 | { | |
48 | return elf_sym__type(sym) == STT_NOTYPE && | |
49 | sym->st_name != 0 && | |
50 | sym->st_shndx != SHN_UNDEF && | |
51 | sym->st_shndx != SHN_ABS; | |
52 | } | |
53 | ||
54 | static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type) | |
55 | { | |
56 | switch (type) { | |
57 | case MAP__FUNCTION: | |
58 | return elf_sym__is_function(sym); | |
59 | case MAP__VARIABLE: | |
60 | return elf_sym__is_object(sym); | |
61 | default: | |
62 | return false; | |
63 | } | |
64 | } | |
65 | ||
66 | static inline const char *elf_sym__name(const GElf_Sym *sym, | |
67 | const Elf_Data *symstrs) | |
68 | { | |
69 | return symstrs->d_buf + sym->st_name; | |
70 | } | |
71 | ||
72 | static inline const char *elf_sec__name(const GElf_Shdr *shdr, | |
73 | const Elf_Data *secstrs) | |
74 | { | |
75 | return secstrs->d_buf + shdr->sh_name; | |
76 | } | |
77 | ||
78 | static inline int elf_sec__is_text(const GElf_Shdr *shdr, | |
79 | const Elf_Data *secstrs) | |
80 | { | |
81 | return strstr(elf_sec__name(shdr, secstrs), "text") != NULL; | |
82 | } | |
83 | ||
84 | static inline bool elf_sec__is_data(const GElf_Shdr *shdr, | |
85 | const Elf_Data *secstrs) | |
86 | { | |
87 | return strstr(elf_sec__name(shdr, secstrs), "data") != NULL; | |
88 | } | |
89 | ||
90 | static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs, | |
91 | enum map_type type) | |
92 | { | |
93 | switch (type) { | |
94 | case MAP__FUNCTION: | |
95 | return elf_sec__is_text(shdr, secstrs); | |
96 | case MAP__VARIABLE: | |
97 | return elf_sec__is_data(shdr, secstrs); | |
98 | default: | |
99 | return false; | |
100 | } | |
101 | } | |
102 | ||
103 | static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr) | |
104 | { | |
105 | Elf_Scn *sec = NULL; | |
106 | GElf_Shdr shdr; | |
107 | size_t cnt = 1; | |
108 | ||
109 | while ((sec = elf_nextscn(elf, sec)) != NULL) { | |
110 | gelf_getshdr(sec, &shdr); | |
111 | ||
112 | if ((addr >= shdr.sh_addr) && | |
113 | (addr < (shdr.sh_addr + shdr.sh_size))) | |
114 | return cnt; | |
115 | ||
116 | ++cnt; | |
117 | } | |
118 | ||
119 | return -1; | |
120 | } | |
121 | ||
122 | static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep, | |
123 | GElf_Shdr *shp, const char *name, | |
124 | size_t *idx) | |
125 | { | |
126 | Elf_Scn *sec = NULL; | |
127 | size_t cnt = 1; | |
128 | ||
49274654 CS |
129 | /* Elf is corrupted/truncated, avoid calling elf_strptr. */ |
130 | if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) | |
131 | return NULL; | |
132 | ||
e5a1845f NK |
133 | while ((sec = elf_nextscn(elf, sec)) != NULL) { |
134 | char *str; | |
135 | ||
136 | gelf_getshdr(sec, shp); | |
137 | str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name); | |
138 | if (!strcmp(name, str)) { | |
139 | if (idx) | |
140 | *idx = cnt; | |
141 | break; | |
142 | } | |
143 | ++cnt; | |
144 | } | |
145 | ||
146 | return sec; | |
147 | } | |
148 | ||
149 | #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \ | |
150 | for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \ | |
151 | idx < nr_entries; \ | |
152 | ++idx, pos = gelf_getrel(reldata, idx, &pos_mem)) | |
153 | ||
154 | #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \ | |
155 | for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \ | |
156 | idx < nr_entries; \ | |
157 | ++idx, pos = gelf_getrela(reldata, idx, &pos_mem)) | |
158 | ||
159 | /* | |
160 | * We need to check if we have a .dynsym, so that we can handle the | |
161 | * .plt, synthesizing its symbols, that aren't on the symtabs (be it | |
162 | * .dynsym or .symtab). | |
163 | * And always look at the original dso, not at debuginfo packages, that | |
164 | * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS). | |
165 | */ | |
a44f605b | 166 | int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map, |
e5a1845f NK |
167 | symbol_filter_t filter) |
168 | { | |
169 | uint32_t nr_rel_entries, idx; | |
170 | GElf_Sym sym; | |
171 | u64 plt_offset; | |
172 | GElf_Shdr shdr_plt; | |
173 | struct symbol *f; | |
174 | GElf_Shdr shdr_rel_plt, shdr_dynsym; | |
175 | Elf_Data *reldata, *syms, *symstrs; | |
176 | Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym; | |
177 | size_t dynsym_idx; | |
178 | GElf_Ehdr ehdr; | |
179 | char sympltname[1024]; | |
180 | Elf *elf; | |
a44f605b | 181 | int nr = 0, symidx, err = 0; |
e5a1845f | 182 | |
f47b58b7 DA |
183 | if (!ss->dynsym) |
184 | return 0; | |
185 | ||
a44f605b CS |
186 | elf = ss->elf; |
187 | ehdr = ss->ehdr; | |
e5a1845f | 188 | |
a44f605b CS |
189 | scn_dynsym = ss->dynsym; |
190 | shdr_dynsym = ss->dynshdr; | |
191 | dynsym_idx = ss->dynsym_idx; | |
e5a1845f | 192 | |
e5a1845f NK |
193 | 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 | ||
52f9ddba CS |
233 | if (symstrs->d_size == 0) |
234 | goto out_elf_end; | |
235 | ||
e5a1845f NK |
236 | 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; | |
287 | out_elf_end: | |
e5a1845f NK |
288 | if (err == 0) |
289 | return nr; | |
e5a1845f NK |
290 | 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 | ||
300 | static 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 | ||
375 | out: | |
376 | return err; | |
377 | } | |
378 | ||
379 | int 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); | |
400 | out_close: | |
401 | close(fd); | |
402 | out: | |
403 | return err; | |
404 | } | |
405 | ||
406 | int 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); | |
447 | out: | |
448 | return err; | |
449 | } | |
450 | ||
451 | int 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 | ||
495 | out_close: | |
496 | close(fd); | |
497 | out: | |
498 | return err; | |
499 | } | |
500 | ||
501 | static 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 | ||
3aafe5ae CS |
528 | bool symsrc__possibly_runtime(struct symsrc *ss) |
529 | { | |
530 | return ss->dynsym || ss->opdsec; | |
531 | } | |
532 | ||
d26cd12b CS |
533 | bool symsrc__has_symtab(struct symsrc *ss) |
534 | { | |
535 | return ss->symtab != NULL; | |
536 | } | |
b68e2f91 CS |
537 | |
538 | void symsrc__destroy(struct symsrc *ss) | |
539 | { | |
540 | free(ss->name); | |
541 | elf_end(ss->elf); | |
542 | close(ss->fd); | |
543 | } | |
544 | ||
545 | int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, | |
546 | enum dso_binary_type type) | |
e5a1845f | 547 | { |
e5a1845f | 548 | int err = -1; |
e5a1845f | 549 | GElf_Ehdr ehdr; |
e5a1845f | 550 | Elf *elf; |
b68e2f91 CS |
551 | int fd; |
552 | ||
553 | fd = open(name, O_RDONLY); | |
554 | if (fd < 0) | |
555 | return -1; | |
e5a1845f NK |
556 | |
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 | ||
b68e2f91 CS |
582 | 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 | ||
620 | out_elf_end: | |
621 | elf_end(elf); | |
622 | out_close: | |
623 | close(fd); | |
624 | return err; | |
625 | } | |
626 | ||
261360b6 CS |
627 | int dso__load_sym(struct dso *dso, struct map *map, |
628 | struct symsrc *syms_ss, struct symsrc *runtime_ss, | |
d26cd12b | 629 | symbol_filter_t filter, int kmodule) |
b68e2f91 CS |
630 | { |
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; | |
261360b6 | 639 | GElf_Shdr shdr; |
b68e2f91 CS |
640 | Elf_Data *syms, *opddata = NULL; |
641 | GElf_Sym sym; | |
261360b6 | 642 | Elf_Scn *sec, *sec_strndx; |
b68e2f91 CS |
643 | Elf *elf; |
644 | int nr = 0; | |
b68e2f91 | 645 | |
261360b6 | 646 | dso->symtab_type = syms_ss->type; |
005f9294 | 647 | |
261360b6 CS |
648 | if (!syms_ss->symtab) { |
649 | syms_ss->symtab = syms_ss->dynsym; | |
650 | syms_ss->symshdr = syms_ss->dynshdr; | |
d26cd12b CS |
651 | } |
652 | ||
261360b6 CS |
653 | elf = syms_ss->elf; |
654 | ehdr = syms_ss->ehdr; | |
655 | sec = syms_ss->symtab; | |
656 | shdr = syms_ss->symshdr; | |
b68e2f91 | 657 | |
261360b6 CS |
658 | if (runtime_ss->opdsec) |
659 | opddata = elf_rawdata(runtime_ss->opdsec, NULL); | |
e5a1845f NK |
660 | |
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)); | |
261360b6 | 684 | dso->adjust_symbols = runtime_ss->adjust_symbols; |
e5a1845f NK |
685 | 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; | |
261360b6 | 691 | bool used_opd = false; |
e5a1845f NK |
692 | |
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 | ||
261360b6 CS |
710 | if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) { |
711 | u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr; | |
e5a1845f NK |
712 | u64 *opd = opddata->d_buf + offset; |
713 | sym.st_value = DSO__SWAP(dso, u64, *opd); | |
261360b6 CS |
714 | sym.st_shndx = elf_addr_to_index(runtime_ss->elf, |
715 | sym.st_value); | |
716 | used_opd = true; | |
e5a1845f | 717 | } |
3843b05d NK |
718 | /* |
719 | * When loading symbols in a data mapping, ABS symbols (which | |
720 | * has a value of SHN_ABS in its st_shndx) failed at | |
721 | * elf_getscn(). And it marks the loading as a failure so | |
722 | * already loaded symbols cannot be fixed up. | |
723 | * | |
724 | * I'm not sure what should be done. Just ignore them for now. | |
725 | * - Namhyung Kim | |
726 | */ | |
727 | if (sym.st_shndx == SHN_ABS) | |
728 | continue; | |
e5a1845f | 729 | |
261360b6 | 730 | sec = elf_getscn(runtime_ss->elf, sym.st_shndx); |
e5a1845f NK |
731 | if (!sec) |
732 | goto out_elf_end; | |
733 | ||
734 | gelf_getshdr(sec, &shdr); | |
735 | ||
736 | if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type)) | |
737 | continue; | |
738 | ||
739 | section_name = elf_sec__name(&shdr, secstrs); | |
740 | ||
741 | /* On ARM, symbols for thumb functions have 1 added to | |
742 | * the symbol address as a flag - remove it */ | |
743 | if ((ehdr.e_machine == EM_ARM) && | |
744 | (map->type == MAP__FUNCTION) && | |
745 | (sym.st_value & 1)) | |
746 | --sym.st_value; | |
747 | ||
748 | if (dso->kernel != DSO_TYPE_USER || kmodule) { | |
749 | char dso_name[PATH_MAX]; | |
750 | ||
751 | if (strcmp(section_name, | |
752 | (curr_dso->short_name + | |
753 | dso->short_name_len)) == 0) | |
754 | goto new_symbol; | |
755 | ||
756 | if (strcmp(section_name, ".text") == 0) { | |
757 | curr_map = map; | |
758 | curr_dso = dso; | |
759 | goto new_symbol; | |
760 | } | |
761 | ||
762 | snprintf(dso_name, sizeof(dso_name), | |
763 | "%s%s", dso->short_name, section_name); | |
764 | ||
765 | curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name); | |
766 | if (curr_map == NULL) { | |
767 | u64 start = sym.st_value; | |
768 | ||
769 | if (kmodule) | |
770 | start += map->start + shdr.sh_offset; | |
771 | ||
772 | curr_dso = dso__new(dso_name); | |
773 | if (curr_dso == NULL) | |
774 | goto out_elf_end; | |
775 | curr_dso->kernel = dso->kernel; | |
776 | curr_dso->long_name = dso->long_name; | |
777 | curr_dso->long_name_len = dso->long_name_len; | |
778 | curr_map = map__new2(start, curr_dso, | |
779 | map->type); | |
780 | if (curr_map == NULL) { | |
781 | dso__delete(curr_dso); | |
782 | goto out_elf_end; | |
783 | } | |
784 | curr_map->map_ip = identity__map_ip; | |
785 | curr_map->unmap_ip = identity__map_ip; | |
786 | curr_dso->symtab_type = dso->symtab_type; | |
787 | map_groups__insert(kmap->kmaps, curr_map); | |
788 | dsos__add(&dso->node, curr_dso); | |
789 | dso__set_loaded(curr_dso, map->type); | |
790 | } else | |
791 | curr_dso = curr_map->dso; | |
792 | ||
793 | goto new_symbol; | |
794 | } | |
795 | ||
261360b6 CS |
796 | if ((used_opd && runtime_ss->adjust_symbols) |
797 | || (!used_opd && syms_ss->adjust_symbols)) { | |
e5a1845f NK |
798 | pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " |
799 | "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__, | |
800 | (u64)sym.st_value, (u64)shdr.sh_addr, | |
801 | (u64)shdr.sh_offset); | |
802 | sym.st_value -= shdr.sh_addr - shdr.sh_offset; | |
803 | } | |
804 | /* | |
805 | * We need to figure out if the object was created from C++ sources | |
806 | * DWARF DW_compile_unit has this, but we don't always have access | |
807 | * to it... | |
808 | */ | |
328ccdac NK |
809 | if (symbol_conf.demangle) { |
810 | demangled = bfd_demangle(NULL, elf_name, | |
811 | DMGL_PARAMS | DMGL_ANSI); | |
812 | if (demangled != NULL) | |
813 | elf_name = demangled; | |
814 | } | |
e5a1845f NK |
815 | new_symbol: |
816 | f = symbol__new(sym.st_value, sym.st_size, | |
817 | GELF_ST_BIND(sym.st_info), elf_name); | |
818 | free(demangled); | |
819 | if (!f) | |
820 | goto out_elf_end; | |
821 | ||
822 | if (filter && filter(curr_map, f)) | |
823 | symbol__delete(f); | |
824 | else { | |
825 | symbols__insert(&curr_dso->symbols[curr_map->type], f); | |
826 | nr++; | |
827 | } | |
828 | } | |
829 | ||
830 | /* | |
831 | * For misannotated, zeroed, ASM function sizes. | |
832 | */ | |
833 | if (nr > 0) { | |
834 | symbols__fixup_duplicate(&dso->symbols[map->type]); | |
835 | symbols__fixup_end(&dso->symbols[map->type]); | |
836 | if (kmap) { | |
837 | /* | |
838 | * We need to fixup this here too because we create new | |
839 | * maps here, for things like vsyscall sections. | |
840 | */ | |
841 | __map_groups__fixup_end(kmap->kmaps, map->type); | |
842 | } | |
843 | } | |
844 | err = nr; | |
845 | out_elf_end: | |
e5a1845f NK |
846 | return err; |
847 | } | |
848 | ||
849 | void symbol__elf_init(void) | |
850 | { | |
851 | elf_version(EV_CURRENT); | |
852 | } |