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" | |
922d0e4d | 9 | #include "vdso.h" |
c506c96b | 10 | #include <symbol/kallsyms.h> |
e5a1845f NK |
11 | #include "debug.h" |
12 | ||
89fe808a | 13 | #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT |
e955d5c4 AH |
14 | static int elf_getphdrnum(Elf *elf, size_t *dst) |
15 | { | |
16 | GElf_Ehdr gehdr; | |
17 | GElf_Ehdr *ehdr; | |
18 | ||
19 | ehdr = gelf_getehdr(elf, &gehdr); | |
20 | if (!ehdr) | |
21 | return -1; | |
22 | ||
23 | *dst = ehdr->e_phnum; | |
24 | ||
25 | return 0; | |
26 | } | |
27 | #endif | |
28 | ||
e5a1845f NK |
29 | #ifndef NT_GNU_BUILD_ID |
30 | #define NT_GNU_BUILD_ID 3 | |
31 | #endif | |
32 | ||
33 | /** | |
34 | * elf_symtab__for_each_symbol - iterate thru all the symbols | |
35 | * | |
36 | * @syms: struct elf_symtab instance to iterate | |
37 | * @idx: uint32_t idx | |
38 | * @sym: GElf_Sym iterator | |
39 | */ | |
40 | #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \ | |
41 | for (idx = 0, gelf_getsym(syms, idx, &sym);\ | |
42 | idx < nr_syms; \ | |
43 | idx++, gelf_getsym(syms, idx, &sym)) | |
44 | ||
45 | static inline uint8_t elf_sym__type(const GElf_Sym *sym) | |
46 | { | |
47 | return GELF_ST_TYPE(sym->st_info); | |
48 | } | |
49 | ||
50 | static inline int elf_sym__is_function(const GElf_Sym *sym) | |
51 | { | |
52 | return elf_sym__type(sym) == STT_FUNC && | |
53 | sym->st_name != 0 && | |
54 | sym->st_shndx != SHN_UNDEF; | |
55 | } | |
56 | ||
57 | static inline bool elf_sym__is_object(const GElf_Sym *sym) | |
58 | { | |
59 | return elf_sym__type(sym) == STT_OBJECT && | |
60 | sym->st_name != 0 && | |
61 | sym->st_shndx != SHN_UNDEF; | |
62 | } | |
63 | ||
64 | static inline int elf_sym__is_label(const GElf_Sym *sym) | |
65 | { | |
66 | return elf_sym__type(sym) == STT_NOTYPE && | |
67 | sym->st_name != 0 && | |
68 | sym->st_shndx != SHN_UNDEF && | |
69 | sym->st_shndx != SHN_ABS; | |
70 | } | |
71 | ||
72 | static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type) | |
73 | { | |
74 | switch (type) { | |
75 | case MAP__FUNCTION: | |
76 | return elf_sym__is_function(sym); | |
77 | case MAP__VARIABLE: | |
78 | return elf_sym__is_object(sym); | |
79 | default: | |
80 | return false; | |
81 | } | |
82 | } | |
83 | ||
84 | static inline const char *elf_sym__name(const GElf_Sym *sym, | |
85 | const Elf_Data *symstrs) | |
86 | { | |
87 | return symstrs->d_buf + sym->st_name; | |
88 | } | |
89 | ||
90 | static inline const char *elf_sec__name(const GElf_Shdr *shdr, | |
91 | const Elf_Data *secstrs) | |
92 | { | |
93 | return secstrs->d_buf + shdr->sh_name; | |
94 | } | |
95 | ||
96 | static inline int elf_sec__is_text(const GElf_Shdr *shdr, | |
97 | const Elf_Data *secstrs) | |
98 | { | |
99 | return strstr(elf_sec__name(shdr, secstrs), "text") != NULL; | |
100 | } | |
101 | ||
102 | static inline bool elf_sec__is_data(const GElf_Shdr *shdr, | |
103 | const Elf_Data *secstrs) | |
104 | { | |
105 | return strstr(elf_sec__name(shdr, secstrs), "data") != NULL; | |
106 | } | |
107 | ||
108 | static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs, | |
109 | enum map_type type) | |
110 | { | |
111 | switch (type) { | |
112 | case MAP__FUNCTION: | |
113 | return elf_sec__is_text(shdr, secstrs); | |
114 | case MAP__VARIABLE: | |
115 | return elf_sec__is_data(shdr, secstrs); | |
116 | default: | |
117 | return false; | |
118 | } | |
119 | } | |
120 | ||
121 | static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr) | |
122 | { | |
123 | Elf_Scn *sec = NULL; | |
124 | GElf_Shdr shdr; | |
125 | size_t cnt = 1; | |
126 | ||
127 | while ((sec = elf_nextscn(elf, sec)) != NULL) { | |
128 | gelf_getshdr(sec, &shdr); | |
129 | ||
130 | if ((addr >= shdr.sh_addr) && | |
131 | (addr < (shdr.sh_addr + shdr.sh_size))) | |
132 | return cnt; | |
133 | ||
134 | ++cnt; | |
135 | } | |
136 | ||
137 | return -1; | |
138 | } | |
139 | ||
99ca4233 MH |
140 | Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep, |
141 | GElf_Shdr *shp, const char *name, size_t *idx) | |
e5a1845f NK |
142 | { |
143 | Elf_Scn *sec = NULL; | |
144 | size_t cnt = 1; | |
145 | ||
49274654 CS |
146 | /* Elf is corrupted/truncated, avoid calling elf_strptr. */ |
147 | if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) | |
148 | return NULL; | |
149 | ||
e5a1845f NK |
150 | while ((sec = elf_nextscn(elf, sec)) != NULL) { |
151 | char *str; | |
152 | ||
153 | gelf_getshdr(sec, shp); | |
154 | str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name); | |
155b3a13 | 155 | if (str && !strcmp(name, str)) { |
e5a1845f NK |
156 | if (idx) |
157 | *idx = cnt; | |
155b3a13 | 158 | return sec; |
e5a1845f NK |
159 | } |
160 | ++cnt; | |
161 | } | |
162 | ||
155b3a13 | 163 | return NULL; |
e5a1845f NK |
164 | } |
165 | ||
166 | #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \ | |
167 | for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \ | |
168 | idx < nr_entries; \ | |
169 | ++idx, pos = gelf_getrel(reldata, idx, &pos_mem)) | |
170 | ||
171 | #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \ | |
172 | for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \ | |
173 | idx < nr_entries; \ | |
174 | ++idx, pos = gelf_getrela(reldata, idx, &pos_mem)) | |
175 | ||
176 | /* | |
177 | * We need to check if we have a .dynsym, so that we can handle the | |
178 | * .plt, synthesizing its symbols, that aren't on the symtabs (be it | |
179 | * .dynsym or .symtab). | |
180 | * And always look at the original dso, not at debuginfo packages, that | |
181 | * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS). | |
182 | */ | |
a44f605b | 183 | int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map, |
e5a1845f NK |
184 | symbol_filter_t filter) |
185 | { | |
186 | uint32_t nr_rel_entries, idx; | |
187 | GElf_Sym sym; | |
188 | u64 plt_offset; | |
189 | GElf_Shdr shdr_plt; | |
190 | struct symbol *f; | |
191 | GElf_Shdr shdr_rel_plt, shdr_dynsym; | |
192 | Elf_Data *reldata, *syms, *symstrs; | |
193 | Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym; | |
194 | size_t dynsym_idx; | |
195 | GElf_Ehdr ehdr; | |
196 | char sympltname[1024]; | |
197 | Elf *elf; | |
a44f605b | 198 | int nr = 0, symidx, err = 0; |
e5a1845f | 199 | |
f47b58b7 DA |
200 | if (!ss->dynsym) |
201 | return 0; | |
202 | ||
a44f605b CS |
203 | elf = ss->elf; |
204 | ehdr = ss->ehdr; | |
e5a1845f | 205 | |
a44f605b CS |
206 | scn_dynsym = ss->dynsym; |
207 | shdr_dynsym = ss->dynshdr; | |
208 | dynsym_idx = ss->dynsym_idx; | |
e5a1845f | 209 | |
e5a1845f NK |
210 | if (scn_dynsym == NULL) |
211 | goto out_elf_end; | |
212 | ||
213 | scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, | |
214 | ".rela.plt", NULL); | |
215 | if (scn_plt_rel == NULL) { | |
216 | scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, | |
217 | ".rel.plt", NULL); | |
218 | if (scn_plt_rel == NULL) | |
219 | goto out_elf_end; | |
220 | } | |
221 | ||
222 | err = -1; | |
223 | ||
224 | if (shdr_rel_plt.sh_link != dynsym_idx) | |
225 | goto out_elf_end; | |
226 | ||
227 | if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL) | |
228 | goto out_elf_end; | |
229 | ||
230 | /* | |
231 | * Fetch the relocation section to find the idxes to the GOT | |
232 | * and the symbols in the .dynsym they refer to. | |
233 | */ | |
234 | reldata = elf_getdata(scn_plt_rel, NULL); | |
235 | if (reldata == NULL) | |
236 | goto out_elf_end; | |
237 | ||
238 | syms = elf_getdata(scn_dynsym, NULL); | |
239 | if (syms == NULL) | |
240 | goto out_elf_end; | |
241 | ||
242 | scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link); | |
243 | if (scn_symstrs == NULL) | |
244 | goto out_elf_end; | |
245 | ||
246 | symstrs = elf_getdata(scn_symstrs, NULL); | |
247 | if (symstrs == NULL) | |
248 | goto out_elf_end; | |
249 | ||
52f9ddba CS |
250 | if (symstrs->d_size == 0) |
251 | goto out_elf_end; | |
252 | ||
e5a1845f NK |
253 | nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize; |
254 | plt_offset = shdr_plt.sh_offset; | |
255 | ||
256 | if (shdr_rel_plt.sh_type == SHT_RELA) { | |
257 | GElf_Rela pos_mem, *pos; | |
258 | ||
259 | elf_section__for_each_rela(reldata, pos, pos_mem, idx, | |
260 | nr_rel_entries) { | |
261 | symidx = GELF_R_SYM(pos->r_info); | |
262 | plt_offset += shdr_plt.sh_entsize; | |
263 | gelf_getsym(syms, symidx, &sym); | |
264 | snprintf(sympltname, sizeof(sympltname), | |
265 | "%s@plt", elf_sym__name(&sym, symstrs)); | |
266 | ||
267 | f = symbol__new(plt_offset, shdr_plt.sh_entsize, | |
268 | STB_GLOBAL, sympltname); | |
269 | if (!f) | |
270 | goto out_elf_end; | |
271 | ||
272 | if (filter && filter(map, f)) | |
273 | symbol__delete(f); | |
274 | else { | |
275 | symbols__insert(&dso->symbols[map->type], f); | |
276 | ++nr; | |
277 | } | |
278 | } | |
279 | } else if (shdr_rel_plt.sh_type == SHT_REL) { | |
280 | GElf_Rel pos_mem, *pos; | |
281 | elf_section__for_each_rel(reldata, pos, pos_mem, idx, | |
282 | nr_rel_entries) { | |
283 | symidx = GELF_R_SYM(pos->r_info); | |
284 | plt_offset += shdr_plt.sh_entsize; | |
285 | gelf_getsym(syms, symidx, &sym); | |
286 | snprintf(sympltname, sizeof(sympltname), | |
287 | "%s@plt", elf_sym__name(&sym, symstrs)); | |
288 | ||
289 | f = symbol__new(plt_offset, shdr_plt.sh_entsize, | |
290 | STB_GLOBAL, sympltname); | |
291 | if (!f) | |
292 | goto out_elf_end; | |
293 | ||
294 | if (filter && filter(map, f)) | |
295 | symbol__delete(f); | |
296 | else { | |
297 | symbols__insert(&dso->symbols[map->type], f); | |
298 | ++nr; | |
299 | } | |
300 | } | |
301 | } | |
302 | ||
303 | err = 0; | |
304 | out_elf_end: | |
e5a1845f NK |
305 | if (err == 0) |
306 | return nr; | |
e5a1845f NK |
307 | pr_debug("%s: problems reading %s PLT info.\n", |
308 | __func__, dso->long_name); | |
309 | return 0; | |
310 | } | |
311 | ||
312 | /* | |
313 | * Align offset to 4 bytes as needed for note name and descriptor data. | |
314 | */ | |
315 | #define NOTE_ALIGN(n) (((n) + 3) & -4U) | |
316 | ||
317 | static int elf_read_build_id(Elf *elf, void *bf, size_t size) | |
318 | { | |
319 | int err = -1; | |
320 | GElf_Ehdr ehdr; | |
321 | GElf_Shdr shdr; | |
322 | Elf_Data *data; | |
323 | Elf_Scn *sec; | |
324 | Elf_Kind ek; | |
325 | void *ptr; | |
326 | ||
327 | if (size < BUILD_ID_SIZE) | |
328 | goto out; | |
329 | ||
330 | ek = elf_kind(elf); | |
331 | if (ek != ELF_K_ELF) | |
332 | goto out; | |
333 | ||
334 | if (gelf_getehdr(elf, &ehdr) == NULL) { | |
335 | pr_err("%s: cannot get elf header.\n", __func__); | |
336 | goto out; | |
337 | } | |
338 | ||
339 | /* | |
340 | * Check following sections for notes: | |
341 | * '.note.gnu.build-id' | |
342 | * '.notes' | |
343 | * '.note' (VDSO specific) | |
344 | */ | |
345 | do { | |
346 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
347 | ".note.gnu.build-id", NULL); | |
348 | if (sec) | |
349 | break; | |
350 | ||
351 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
352 | ".notes", NULL); | |
353 | if (sec) | |
354 | break; | |
355 | ||
356 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
357 | ".note", NULL); | |
358 | if (sec) | |
359 | break; | |
360 | ||
361 | return err; | |
362 | ||
363 | } while (0); | |
364 | ||
365 | data = elf_getdata(sec, NULL); | |
366 | if (data == NULL) | |
367 | goto out; | |
368 | ||
369 | ptr = data->d_buf; | |
370 | while (ptr < (data->d_buf + data->d_size)) { | |
371 | GElf_Nhdr *nhdr = ptr; | |
372 | size_t namesz = NOTE_ALIGN(nhdr->n_namesz), | |
373 | descsz = NOTE_ALIGN(nhdr->n_descsz); | |
374 | const char *name; | |
375 | ||
376 | ptr += sizeof(*nhdr); | |
377 | name = ptr; | |
378 | ptr += namesz; | |
379 | if (nhdr->n_type == NT_GNU_BUILD_ID && | |
380 | nhdr->n_namesz == sizeof("GNU")) { | |
381 | if (memcmp(name, "GNU", sizeof("GNU")) == 0) { | |
382 | size_t sz = min(size, descsz); | |
383 | memcpy(bf, ptr, sz); | |
384 | memset(bf + sz, 0, size - sz); | |
385 | err = descsz; | |
386 | break; | |
387 | } | |
388 | } | |
389 | ptr += descsz; | |
390 | } | |
391 | ||
392 | out: | |
393 | return err; | |
394 | } | |
395 | ||
396 | int filename__read_build_id(const char *filename, void *bf, size_t size) | |
397 | { | |
398 | int fd, err = -1; | |
399 | Elf *elf; | |
400 | ||
401 | if (size < BUILD_ID_SIZE) | |
402 | goto out; | |
403 | ||
404 | fd = open(filename, O_RDONLY); | |
405 | if (fd < 0) | |
406 | goto out; | |
407 | ||
408 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
409 | if (elf == NULL) { | |
410 | pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename); | |
411 | goto out_close; | |
412 | } | |
413 | ||
414 | err = elf_read_build_id(elf, bf, size); | |
415 | ||
416 | elf_end(elf); | |
417 | out_close: | |
418 | close(fd); | |
419 | out: | |
420 | return err; | |
421 | } | |
422 | ||
423 | int sysfs__read_build_id(const char *filename, void *build_id, size_t size) | |
424 | { | |
425 | int fd, err = -1; | |
426 | ||
427 | if (size < BUILD_ID_SIZE) | |
428 | goto out; | |
429 | ||
430 | fd = open(filename, O_RDONLY); | |
431 | if (fd < 0) | |
432 | goto out; | |
433 | ||
434 | while (1) { | |
435 | char bf[BUFSIZ]; | |
436 | GElf_Nhdr nhdr; | |
437 | size_t namesz, descsz; | |
438 | ||
439 | if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr)) | |
440 | break; | |
441 | ||
442 | namesz = NOTE_ALIGN(nhdr.n_namesz); | |
443 | descsz = NOTE_ALIGN(nhdr.n_descsz); | |
444 | if (nhdr.n_type == NT_GNU_BUILD_ID && | |
445 | nhdr.n_namesz == sizeof("GNU")) { | |
446 | if (read(fd, bf, namesz) != (ssize_t)namesz) | |
447 | break; | |
448 | if (memcmp(bf, "GNU", sizeof("GNU")) == 0) { | |
449 | size_t sz = min(descsz, size); | |
450 | if (read(fd, build_id, sz) == (ssize_t)sz) { | |
451 | memset(build_id + sz, 0, size - sz); | |
452 | err = 0; | |
453 | break; | |
454 | } | |
455 | } else if (read(fd, bf, descsz) != (ssize_t)descsz) | |
456 | break; | |
457 | } else { | |
458 | int n = namesz + descsz; | |
459 | if (read(fd, bf, n) != n) | |
460 | break; | |
461 | } | |
462 | } | |
463 | close(fd); | |
464 | out: | |
465 | return err; | |
466 | } | |
467 | ||
468 | int filename__read_debuglink(const char *filename, char *debuglink, | |
469 | size_t size) | |
470 | { | |
471 | int fd, err = -1; | |
472 | Elf *elf; | |
473 | GElf_Ehdr ehdr; | |
474 | GElf_Shdr shdr; | |
475 | Elf_Data *data; | |
476 | Elf_Scn *sec; | |
477 | Elf_Kind ek; | |
478 | ||
479 | fd = open(filename, O_RDONLY); | |
480 | if (fd < 0) | |
481 | goto out; | |
482 | ||
483 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
484 | if (elf == NULL) { | |
485 | pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename); | |
486 | goto out_close; | |
487 | } | |
488 | ||
489 | ek = elf_kind(elf); | |
490 | if (ek != ELF_K_ELF) | |
784f3390 | 491 | goto out_elf_end; |
e5a1845f NK |
492 | |
493 | if (gelf_getehdr(elf, &ehdr) == NULL) { | |
494 | pr_err("%s: cannot get elf header.\n", __func__); | |
784f3390 | 495 | goto out_elf_end; |
e5a1845f NK |
496 | } |
497 | ||
498 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
499 | ".gnu_debuglink", NULL); | |
500 | if (sec == NULL) | |
784f3390 | 501 | goto out_elf_end; |
e5a1845f NK |
502 | |
503 | data = elf_getdata(sec, NULL); | |
504 | if (data == NULL) | |
784f3390 | 505 | goto out_elf_end; |
e5a1845f NK |
506 | |
507 | /* the start of this section is a zero-terminated string */ | |
508 | strncpy(debuglink, data->d_buf, size); | |
509 | ||
0d3dc5e8 SE |
510 | err = 0; |
511 | ||
784f3390 | 512 | out_elf_end: |
e5a1845f | 513 | elf_end(elf); |
e5a1845f NK |
514 | out_close: |
515 | close(fd); | |
516 | out: | |
517 | return err; | |
518 | } | |
519 | ||
520 | static int dso__swap_init(struct dso *dso, unsigned char eidata) | |
521 | { | |
522 | static unsigned int const endian = 1; | |
523 | ||
524 | dso->needs_swap = DSO_SWAP__NO; | |
525 | ||
526 | switch (eidata) { | |
527 | case ELFDATA2LSB: | |
528 | /* We are big endian, DSO is little endian. */ | |
529 | if (*(unsigned char const *)&endian != 1) | |
530 | dso->needs_swap = DSO_SWAP__YES; | |
531 | break; | |
532 | ||
533 | case ELFDATA2MSB: | |
534 | /* We are little endian, DSO is big endian. */ | |
535 | if (*(unsigned char const *)&endian != 0) | |
536 | dso->needs_swap = DSO_SWAP__YES; | |
537 | break; | |
538 | ||
539 | default: | |
540 | pr_err("unrecognized DSO data encoding %d\n", eidata); | |
541 | return -EINVAL; | |
542 | } | |
543 | ||
544 | return 0; | |
545 | } | |
546 | ||
3aafe5ae CS |
547 | bool symsrc__possibly_runtime(struct symsrc *ss) |
548 | { | |
549 | return ss->dynsym || ss->opdsec; | |
550 | } | |
551 | ||
d26cd12b CS |
552 | bool symsrc__has_symtab(struct symsrc *ss) |
553 | { | |
554 | return ss->symtab != NULL; | |
555 | } | |
b68e2f91 CS |
556 | |
557 | void symsrc__destroy(struct symsrc *ss) | |
558 | { | |
74cf249d | 559 | zfree(&ss->name); |
b68e2f91 CS |
560 | elf_end(ss->elf); |
561 | close(ss->fd); | |
562 | } | |
563 | ||
564 | int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, | |
565 | enum dso_binary_type type) | |
e5a1845f | 566 | { |
e5a1845f | 567 | int err = -1; |
e5a1845f | 568 | GElf_Ehdr ehdr; |
e5a1845f | 569 | Elf *elf; |
b68e2f91 CS |
570 | int fd; |
571 | ||
572 | fd = open(name, O_RDONLY); | |
573 | if (fd < 0) | |
574 | return -1; | |
e5a1845f NK |
575 | |
576 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
577 | if (elf == NULL) { | |
578 | pr_debug("%s: cannot read %s ELF file.\n", __func__, name); | |
579 | goto out_close; | |
580 | } | |
581 | ||
582 | if (gelf_getehdr(elf, &ehdr) == NULL) { | |
583 | pr_debug("%s: cannot get elf header.\n", __func__); | |
584 | goto out_elf_end; | |
585 | } | |
586 | ||
587 | if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) | |
588 | goto out_elf_end; | |
589 | ||
590 | /* Always reject images with a mismatched build-id: */ | |
591 | if (dso->has_build_id) { | |
592 | u8 build_id[BUILD_ID_SIZE]; | |
593 | ||
594 | if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) | |
595 | goto out_elf_end; | |
596 | ||
597 | if (!dso__build_id_equal(dso, build_id)) | |
598 | goto out_elf_end; | |
599 | } | |
600 | ||
b68e2f91 CS |
601 | ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab", |
602 | NULL); | |
603 | if (ss->symshdr.sh_type != SHT_SYMTAB) | |
604 | ss->symtab = NULL; | |
605 | ||
606 | ss->dynsym_idx = 0; | |
607 | ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym", | |
608 | &ss->dynsym_idx); | |
609 | if (ss->dynshdr.sh_type != SHT_DYNSYM) | |
610 | ss->dynsym = NULL; | |
611 | ||
612 | ss->opdidx = 0; | |
613 | ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd", | |
614 | &ss->opdidx); | |
615 | if (ss->opdshdr.sh_type != SHT_PROGBITS) | |
616 | ss->opdsec = NULL; | |
617 | ||
618 | if (dso->kernel == DSO_TYPE_USER) { | |
619 | GElf_Shdr shdr; | |
620 | ss->adjust_symbols = (ehdr.e_type == ET_EXEC || | |
0131c4ec | 621 | ehdr.e_type == ET_REL || |
922d0e4d | 622 | is_vdso_map(dso->short_name) || |
b68e2f91 CS |
623 | elf_section_by_name(elf, &ehdr, &shdr, |
624 | ".gnu.prelink_undo", | |
625 | NULL) != NULL); | |
626 | } else { | |
0131c4ec AH |
627 | ss->adjust_symbols = ehdr.e_type == ET_EXEC || |
628 | ehdr.e_type == ET_REL; | |
b68e2f91 CS |
629 | } |
630 | ||
631 | ss->name = strdup(name); | |
632 | if (!ss->name) | |
633 | goto out_elf_end; | |
634 | ||
635 | ss->elf = elf; | |
636 | ss->fd = fd; | |
637 | ss->ehdr = ehdr; | |
638 | ss->type = type; | |
639 | ||
640 | return 0; | |
641 | ||
642 | out_elf_end: | |
643 | elf_end(elf); | |
644 | out_close: | |
645 | close(fd); | |
646 | return err; | |
647 | } | |
648 | ||
39b12f78 AH |
649 | /** |
650 | * ref_reloc_sym_not_found - has kernel relocation symbol been found. | |
651 | * @kmap: kernel maps and relocation reference symbol | |
652 | * | |
653 | * This function returns %true if we are dealing with the kernel maps and the | |
654 | * relocation reference symbol has not yet been found. Otherwise %false is | |
655 | * returned. | |
656 | */ | |
657 | static bool ref_reloc_sym_not_found(struct kmap *kmap) | |
658 | { | |
659 | return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name && | |
660 | !kmap->ref_reloc_sym->unrelocated_addr; | |
661 | } | |
662 | ||
663 | /** | |
664 | * ref_reloc - kernel relocation offset. | |
665 | * @kmap: kernel maps and relocation reference symbol | |
666 | * | |
667 | * This function returns the offset of kernel addresses as determined by using | |
668 | * the relocation reference symbol i.e. if the kernel has not been relocated | |
669 | * then the return value is zero. | |
670 | */ | |
671 | static u64 ref_reloc(struct kmap *kmap) | |
672 | { | |
673 | if (kmap && kmap->ref_reloc_sym && | |
674 | kmap->ref_reloc_sym->unrelocated_addr) | |
675 | return kmap->ref_reloc_sym->addr - | |
676 | kmap->ref_reloc_sym->unrelocated_addr; | |
677 | return 0; | |
678 | } | |
679 | ||
261360b6 CS |
680 | int dso__load_sym(struct dso *dso, struct map *map, |
681 | struct symsrc *syms_ss, struct symsrc *runtime_ss, | |
d26cd12b | 682 | symbol_filter_t filter, int kmodule) |
b68e2f91 CS |
683 | { |
684 | struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL; | |
685 | struct map *curr_map = map; | |
686 | struct dso *curr_dso = dso; | |
687 | Elf_Data *symstrs, *secstrs; | |
688 | uint32_t nr_syms; | |
689 | int err = -1; | |
690 | uint32_t idx; | |
691 | GElf_Ehdr ehdr; | |
261360b6 | 692 | GElf_Shdr shdr; |
b68e2f91 CS |
693 | Elf_Data *syms, *opddata = NULL; |
694 | GElf_Sym sym; | |
261360b6 | 695 | Elf_Scn *sec, *sec_strndx; |
b68e2f91 CS |
696 | Elf *elf; |
697 | int nr = 0; | |
39b12f78 | 698 | bool remap_kernel = false, adjust_kernel_syms = false; |
b68e2f91 | 699 | |
261360b6 | 700 | dso->symtab_type = syms_ss->type; |
0131c4ec AH |
701 | dso->rel = syms_ss->ehdr.e_type == ET_REL; |
702 | ||
703 | /* | |
704 | * Modules may already have symbols from kallsyms, but those symbols | |
705 | * have the wrong values for the dso maps, so remove them. | |
706 | */ | |
707 | if (kmodule && syms_ss->symtab) | |
708 | symbols__delete(&dso->symbols[map->type]); | |
005f9294 | 709 | |
261360b6 CS |
710 | if (!syms_ss->symtab) { |
711 | syms_ss->symtab = syms_ss->dynsym; | |
712 | syms_ss->symshdr = syms_ss->dynshdr; | |
d26cd12b CS |
713 | } |
714 | ||
261360b6 CS |
715 | elf = syms_ss->elf; |
716 | ehdr = syms_ss->ehdr; | |
717 | sec = syms_ss->symtab; | |
718 | shdr = syms_ss->symshdr; | |
b68e2f91 | 719 | |
261360b6 CS |
720 | if (runtime_ss->opdsec) |
721 | opddata = elf_rawdata(runtime_ss->opdsec, NULL); | |
e5a1845f NK |
722 | |
723 | syms = elf_getdata(sec, NULL); | |
724 | if (syms == NULL) | |
725 | goto out_elf_end; | |
726 | ||
727 | sec = elf_getscn(elf, shdr.sh_link); | |
728 | if (sec == NULL) | |
729 | goto out_elf_end; | |
730 | ||
731 | symstrs = elf_getdata(sec, NULL); | |
732 | if (symstrs == NULL) | |
733 | goto out_elf_end; | |
734 | ||
735 | sec_strndx = elf_getscn(elf, ehdr.e_shstrndx); | |
736 | if (sec_strndx == NULL) | |
737 | goto out_elf_end; | |
738 | ||
739 | secstrs = elf_getdata(sec_strndx, NULL); | |
740 | if (secstrs == NULL) | |
741 | goto out_elf_end; | |
742 | ||
743 | nr_syms = shdr.sh_size / shdr.sh_entsize; | |
744 | ||
745 | memset(&sym, 0, sizeof(sym)); | |
39b12f78 AH |
746 | |
747 | /* | |
748 | * The kernel relocation symbol is needed in advance in order to adjust | |
749 | * kernel maps correctly. | |
750 | */ | |
751 | if (ref_reloc_sym_not_found(kmap)) { | |
752 | elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) { | |
753 | const char *elf_name = elf_sym__name(&sym, symstrs); | |
754 | ||
755 | if (strcmp(elf_name, kmap->ref_reloc_sym->name)) | |
756 | continue; | |
757 | kmap->ref_reloc_sym->unrelocated_addr = sym.st_value; | |
9176753d AH |
758 | map->reloc = kmap->ref_reloc_sym->addr - |
759 | kmap->ref_reloc_sym->unrelocated_addr; | |
39b12f78 AH |
760 | break; |
761 | } | |
762 | } | |
763 | ||
764 | dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap); | |
765 | /* | |
766 | * Initial kernel and module mappings do not map to the dso. For | |
767 | * function mappings, flag the fixups. | |
768 | */ | |
769 | if (map->type == MAP__FUNCTION && (dso->kernel || kmodule)) { | |
770 | remap_kernel = true; | |
771 | adjust_kernel_syms = dso->adjust_symbols; | |
772 | } | |
e5a1845f NK |
773 | elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) { |
774 | struct symbol *f; | |
775 | const char *elf_name = elf_sym__name(&sym, symstrs); | |
776 | char *demangled = NULL; | |
777 | int is_label = elf_sym__is_label(&sym); | |
778 | const char *section_name; | |
261360b6 | 779 | bool used_opd = false; |
e5a1845f | 780 | |
e5a1845f NK |
781 | if (!is_label && !elf_sym__is_a(&sym, map->type)) |
782 | continue; | |
783 | ||
784 | /* Reject ARM ELF "mapping symbols": these aren't unique and | |
785 | * don't identify functions, so will confuse the profile | |
786 | * output: */ | |
787 | if (ehdr.e_machine == EM_ARM) { | |
788 | if (!strcmp(elf_name, "$a") || | |
789 | !strcmp(elf_name, "$d") || | |
790 | !strcmp(elf_name, "$t")) | |
791 | continue; | |
792 | } | |
793 | ||
261360b6 CS |
794 | if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) { |
795 | u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr; | |
e5a1845f NK |
796 | u64 *opd = opddata->d_buf + offset; |
797 | sym.st_value = DSO__SWAP(dso, u64, *opd); | |
261360b6 CS |
798 | sym.st_shndx = elf_addr_to_index(runtime_ss->elf, |
799 | sym.st_value); | |
800 | used_opd = true; | |
e5a1845f | 801 | } |
3843b05d NK |
802 | /* |
803 | * When loading symbols in a data mapping, ABS symbols (which | |
804 | * has a value of SHN_ABS in its st_shndx) failed at | |
805 | * elf_getscn(). And it marks the loading as a failure so | |
806 | * already loaded symbols cannot be fixed up. | |
807 | * | |
808 | * I'm not sure what should be done. Just ignore them for now. | |
809 | * - Namhyung Kim | |
810 | */ | |
811 | if (sym.st_shndx == SHN_ABS) | |
812 | continue; | |
e5a1845f | 813 | |
261360b6 | 814 | sec = elf_getscn(runtime_ss->elf, sym.st_shndx); |
e5a1845f NK |
815 | if (!sec) |
816 | goto out_elf_end; | |
817 | ||
818 | gelf_getshdr(sec, &shdr); | |
819 | ||
820 | if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type)) | |
821 | continue; | |
822 | ||
823 | section_name = elf_sec__name(&shdr, secstrs); | |
824 | ||
825 | /* On ARM, symbols for thumb functions have 1 added to | |
826 | * the symbol address as a flag - remove it */ | |
827 | if ((ehdr.e_machine == EM_ARM) && | |
828 | (map->type == MAP__FUNCTION) && | |
829 | (sym.st_value & 1)) | |
830 | --sym.st_value; | |
831 | ||
39b12f78 | 832 | if (dso->kernel || kmodule) { |
e5a1845f NK |
833 | char dso_name[PATH_MAX]; |
834 | ||
39b12f78 AH |
835 | /* Adjust symbol to map to file offset */ |
836 | if (adjust_kernel_syms) | |
837 | sym.st_value -= shdr.sh_addr - shdr.sh_offset; | |
838 | ||
e5a1845f NK |
839 | if (strcmp(section_name, |
840 | (curr_dso->short_name + | |
841 | dso->short_name_len)) == 0) | |
842 | goto new_symbol; | |
843 | ||
844 | if (strcmp(section_name, ".text") == 0) { | |
39b12f78 AH |
845 | /* |
846 | * The initial kernel mapping is based on | |
847 | * kallsyms and identity maps. Overwrite it to | |
848 | * map to the kernel dso. | |
849 | */ | |
850 | if (remap_kernel && dso->kernel) { | |
851 | remap_kernel = false; | |
852 | map->start = shdr.sh_addr + | |
853 | ref_reloc(kmap); | |
854 | map->end = map->start + shdr.sh_size; | |
855 | map->pgoff = shdr.sh_offset; | |
856 | map->map_ip = map__map_ip; | |
857 | map->unmap_ip = map__unmap_ip; | |
858 | /* Ensure maps are correctly ordered */ | |
859 | map_groups__remove(kmap->kmaps, map); | |
860 | map_groups__insert(kmap->kmaps, map); | |
861 | } | |
862 | ||
0131c4ec AH |
863 | /* |
864 | * The initial module mapping is based on | |
865 | * /proc/modules mapped to offset zero. | |
866 | * Overwrite it to map to the module dso. | |
867 | */ | |
868 | if (remap_kernel && kmodule) { | |
869 | remap_kernel = false; | |
870 | map->pgoff = shdr.sh_offset; | |
871 | } | |
872 | ||
e5a1845f NK |
873 | curr_map = map; |
874 | curr_dso = dso; | |
875 | goto new_symbol; | |
876 | } | |
877 | ||
0131c4ec AH |
878 | if (!kmap) |
879 | goto new_symbol; | |
880 | ||
e5a1845f NK |
881 | snprintf(dso_name, sizeof(dso_name), |
882 | "%s%s", dso->short_name, section_name); | |
883 | ||
884 | curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name); | |
885 | if (curr_map == NULL) { | |
886 | u64 start = sym.st_value; | |
887 | ||
888 | if (kmodule) | |
889 | start += map->start + shdr.sh_offset; | |
890 | ||
891 | curr_dso = dso__new(dso_name); | |
892 | if (curr_dso == NULL) | |
893 | goto out_elf_end; | |
894 | curr_dso->kernel = dso->kernel; | |
895 | curr_dso->long_name = dso->long_name; | |
896 | curr_dso->long_name_len = dso->long_name_len; | |
897 | curr_map = map__new2(start, curr_dso, | |
898 | map->type); | |
899 | if (curr_map == NULL) { | |
900 | dso__delete(curr_dso); | |
901 | goto out_elf_end; | |
902 | } | |
39b12f78 AH |
903 | if (adjust_kernel_syms) { |
904 | curr_map->start = shdr.sh_addr + | |
905 | ref_reloc(kmap); | |
906 | curr_map->end = curr_map->start + | |
907 | shdr.sh_size; | |
908 | curr_map->pgoff = shdr.sh_offset; | |
909 | } else { | |
910 | curr_map->map_ip = identity__map_ip; | |
911 | curr_map->unmap_ip = identity__map_ip; | |
912 | } | |
e5a1845f NK |
913 | curr_dso->symtab_type = dso->symtab_type; |
914 | map_groups__insert(kmap->kmaps, curr_map); | |
915 | dsos__add(&dso->node, curr_dso); | |
916 | dso__set_loaded(curr_dso, map->type); | |
917 | } else | |
918 | curr_dso = curr_map->dso; | |
919 | ||
920 | goto new_symbol; | |
921 | } | |
922 | ||
261360b6 CS |
923 | if ((used_opd && runtime_ss->adjust_symbols) |
924 | || (!used_opd && syms_ss->adjust_symbols)) { | |
e5a1845f NK |
925 | pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " |
926 | "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__, | |
927 | (u64)sym.st_value, (u64)shdr.sh_addr, | |
928 | (u64)shdr.sh_offset); | |
929 | sym.st_value -= shdr.sh_addr - shdr.sh_offset; | |
930 | } | |
950b8354 | 931 | new_symbol: |
e5a1845f NK |
932 | /* |
933 | * We need to figure out if the object was created from C++ sources | |
934 | * DWARF DW_compile_unit has this, but we don't always have access | |
935 | * to it... | |
936 | */ | |
328ccdac | 937 | if (symbol_conf.demangle) { |
14951f22 | 938 | demangled = bfd_demangle(NULL, elf_name, |
328ccdac NK |
939 | DMGL_PARAMS | DMGL_ANSI); |
940 | if (demangled != NULL) | |
941 | elf_name = demangled; | |
942 | } | |
e5a1845f NK |
943 | f = symbol__new(sym.st_value, sym.st_size, |
944 | GELF_ST_BIND(sym.st_info), elf_name); | |
945 | free(demangled); | |
946 | if (!f) | |
947 | goto out_elf_end; | |
948 | ||
949 | if (filter && filter(curr_map, f)) | |
950 | symbol__delete(f); | |
951 | else { | |
952 | symbols__insert(&curr_dso->symbols[curr_map->type], f); | |
953 | nr++; | |
954 | } | |
955 | } | |
956 | ||
957 | /* | |
958 | * For misannotated, zeroed, ASM function sizes. | |
959 | */ | |
960 | if (nr > 0) { | |
961 | symbols__fixup_duplicate(&dso->symbols[map->type]); | |
962 | symbols__fixup_end(&dso->symbols[map->type]); | |
963 | if (kmap) { | |
964 | /* | |
965 | * We need to fixup this here too because we create new | |
966 | * maps here, for things like vsyscall sections. | |
967 | */ | |
968 | __map_groups__fixup_end(kmap->kmaps, map->type); | |
969 | } | |
970 | } | |
971 | err = nr; | |
972 | out_elf_end: | |
e5a1845f NK |
973 | return err; |
974 | } | |
975 | ||
8e0cf965 AH |
976 | static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data) |
977 | { | |
978 | GElf_Phdr phdr; | |
979 | size_t i, phdrnum; | |
980 | int err; | |
981 | u64 sz; | |
982 | ||
983 | if (elf_getphdrnum(elf, &phdrnum)) | |
984 | return -1; | |
985 | ||
986 | for (i = 0; i < phdrnum; i++) { | |
987 | if (gelf_getphdr(elf, i, &phdr) == NULL) | |
988 | return -1; | |
989 | if (phdr.p_type != PT_LOAD) | |
990 | continue; | |
991 | if (exe) { | |
992 | if (!(phdr.p_flags & PF_X)) | |
993 | continue; | |
994 | } else { | |
995 | if (!(phdr.p_flags & PF_R)) | |
996 | continue; | |
997 | } | |
998 | sz = min(phdr.p_memsz, phdr.p_filesz); | |
999 | if (!sz) | |
1000 | continue; | |
1001 | err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data); | |
1002 | if (err) | |
1003 | return err; | |
1004 | } | |
1005 | return 0; | |
1006 | } | |
1007 | ||
1008 | int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data, | |
1009 | bool *is_64_bit) | |
1010 | { | |
1011 | int err; | |
1012 | Elf *elf; | |
1013 | ||
1014 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
1015 | if (elf == NULL) | |
1016 | return -1; | |
1017 | ||
1018 | if (is_64_bit) | |
1019 | *is_64_bit = (gelf_getclass(elf) == ELFCLASS64); | |
1020 | ||
1021 | err = elf_read_maps(elf, exe, mapfn, data); | |
1022 | ||
1023 | elf_end(elf); | |
1024 | return err; | |
1025 | } | |
1026 | ||
afba19d9 AH |
1027 | static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len) |
1028 | { | |
1029 | ssize_t r; | |
1030 | size_t n; | |
1031 | int err = -1; | |
1032 | char *buf = malloc(page_size); | |
1033 | ||
1034 | if (buf == NULL) | |
1035 | return -1; | |
1036 | ||
1037 | if (lseek(to, to_offs, SEEK_SET) != to_offs) | |
1038 | goto out; | |
1039 | ||
1040 | if (lseek(from, from_offs, SEEK_SET) != from_offs) | |
1041 | goto out; | |
1042 | ||
1043 | while (len) { | |
1044 | n = page_size; | |
1045 | if (len < n) | |
1046 | n = len; | |
1047 | /* Use read because mmap won't work on proc files */ | |
1048 | r = read(from, buf, n); | |
1049 | if (r < 0) | |
1050 | goto out; | |
1051 | if (!r) | |
1052 | break; | |
1053 | n = r; | |
1054 | r = write(to, buf, n); | |
1055 | if (r < 0) | |
1056 | goto out; | |
1057 | if ((size_t)r != n) | |
1058 | goto out; | |
1059 | len -= n; | |
1060 | } | |
1061 | ||
1062 | err = 0; | |
1063 | out: | |
1064 | free(buf); | |
1065 | return err; | |
1066 | } | |
1067 | ||
1068 | struct kcore { | |
1069 | int fd; | |
1070 | int elfclass; | |
1071 | Elf *elf; | |
1072 | GElf_Ehdr ehdr; | |
1073 | }; | |
1074 | ||
1075 | static int kcore__open(struct kcore *kcore, const char *filename) | |
1076 | { | |
1077 | GElf_Ehdr *ehdr; | |
1078 | ||
1079 | kcore->fd = open(filename, O_RDONLY); | |
1080 | if (kcore->fd == -1) | |
1081 | return -1; | |
1082 | ||
1083 | kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL); | |
1084 | if (!kcore->elf) | |
1085 | goto out_close; | |
1086 | ||
1087 | kcore->elfclass = gelf_getclass(kcore->elf); | |
1088 | if (kcore->elfclass == ELFCLASSNONE) | |
1089 | goto out_end; | |
1090 | ||
1091 | ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr); | |
1092 | if (!ehdr) | |
1093 | goto out_end; | |
1094 | ||
1095 | return 0; | |
1096 | ||
1097 | out_end: | |
1098 | elf_end(kcore->elf); | |
1099 | out_close: | |
1100 | close(kcore->fd); | |
1101 | return -1; | |
1102 | } | |
1103 | ||
1104 | static int kcore__init(struct kcore *kcore, char *filename, int elfclass, | |
1105 | bool temp) | |
1106 | { | |
1107 | GElf_Ehdr *ehdr; | |
1108 | ||
1109 | kcore->elfclass = elfclass; | |
1110 | ||
1111 | if (temp) | |
1112 | kcore->fd = mkstemp(filename); | |
1113 | else | |
1114 | kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400); | |
1115 | if (kcore->fd == -1) | |
1116 | return -1; | |
1117 | ||
1118 | kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL); | |
1119 | if (!kcore->elf) | |
1120 | goto out_close; | |
1121 | ||
1122 | if (!gelf_newehdr(kcore->elf, elfclass)) | |
1123 | goto out_end; | |
1124 | ||
1125 | ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr); | |
1126 | if (!ehdr) | |
1127 | goto out_end; | |
1128 | ||
1129 | return 0; | |
1130 | ||
1131 | out_end: | |
1132 | elf_end(kcore->elf); | |
1133 | out_close: | |
1134 | close(kcore->fd); | |
1135 | unlink(filename); | |
1136 | return -1; | |
1137 | } | |
1138 | ||
1139 | static void kcore__close(struct kcore *kcore) | |
1140 | { | |
1141 | elf_end(kcore->elf); | |
1142 | close(kcore->fd); | |
1143 | } | |
1144 | ||
1145 | static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count) | |
1146 | { | |
1147 | GElf_Ehdr *ehdr = &to->ehdr; | |
1148 | GElf_Ehdr *kehdr = &from->ehdr; | |
1149 | ||
1150 | memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT); | |
1151 | ehdr->e_type = kehdr->e_type; | |
1152 | ehdr->e_machine = kehdr->e_machine; | |
1153 | ehdr->e_version = kehdr->e_version; | |
1154 | ehdr->e_entry = 0; | |
1155 | ehdr->e_shoff = 0; | |
1156 | ehdr->e_flags = kehdr->e_flags; | |
1157 | ehdr->e_phnum = count; | |
1158 | ehdr->e_shentsize = 0; | |
1159 | ehdr->e_shnum = 0; | |
1160 | ehdr->e_shstrndx = 0; | |
1161 | ||
1162 | if (from->elfclass == ELFCLASS32) { | |
1163 | ehdr->e_phoff = sizeof(Elf32_Ehdr); | |
1164 | ehdr->e_ehsize = sizeof(Elf32_Ehdr); | |
1165 | ehdr->e_phentsize = sizeof(Elf32_Phdr); | |
1166 | } else { | |
1167 | ehdr->e_phoff = sizeof(Elf64_Ehdr); | |
1168 | ehdr->e_ehsize = sizeof(Elf64_Ehdr); | |
1169 | ehdr->e_phentsize = sizeof(Elf64_Phdr); | |
1170 | } | |
1171 | ||
1172 | if (!gelf_update_ehdr(to->elf, ehdr)) | |
1173 | return -1; | |
1174 | ||
1175 | if (!gelf_newphdr(to->elf, count)) | |
1176 | return -1; | |
1177 | ||
1178 | return 0; | |
1179 | } | |
1180 | ||
1181 | static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset, | |
1182 | u64 addr, u64 len) | |
1183 | { | |
1184 | GElf_Phdr gphdr; | |
1185 | GElf_Phdr *phdr; | |
1186 | ||
1187 | phdr = gelf_getphdr(kcore->elf, idx, &gphdr); | |
1188 | if (!phdr) | |
1189 | return -1; | |
1190 | ||
1191 | phdr->p_type = PT_LOAD; | |
1192 | phdr->p_flags = PF_R | PF_W | PF_X; | |
1193 | phdr->p_offset = offset; | |
1194 | phdr->p_vaddr = addr; | |
1195 | phdr->p_paddr = 0; | |
1196 | phdr->p_filesz = len; | |
1197 | phdr->p_memsz = len; | |
1198 | phdr->p_align = page_size; | |
1199 | ||
1200 | if (!gelf_update_phdr(kcore->elf, idx, phdr)) | |
1201 | return -1; | |
1202 | ||
1203 | return 0; | |
1204 | } | |
1205 | ||
1206 | static off_t kcore__write(struct kcore *kcore) | |
1207 | { | |
1208 | return elf_update(kcore->elf, ELF_C_WRITE); | |
1209 | } | |
1210 | ||
fc1b691d AH |
1211 | struct phdr_data { |
1212 | off_t offset; | |
1213 | u64 addr; | |
1214 | u64 len; | |
1215 | }; | |
1216 | ||
1217 | struct kcore_copy_info { | |
1218 | u64 stext; | |
1219 | u64 etext; | |
1220 | u64 first_symbol; | |
1221 | u64 last_symbol; | |
1222 | u64 first_module; | |
1223 | u64 last_module_symbol; | |
1224 | struct phdr_data kernel_map; | |
1225 | struct phdr_data modules_map; | |
1226 | }; | |
1227 | ||
1228 | static int kcore_copy__process_kallsyms(void *arg, const char *name, char type, | |
1229 | u64 start) | |
1230 | { | |
1231 | struct kcore_copy_info *kci = arg; | |
1232 | ||
1233 | if (!symbol_type__is_a(type, MAP__FUNCTION)) | |
1234 | return 0; | |
1235 | ||
1236 | if (strchr(name, '[')) { | |
1237 | if (start > kci->last_module_symbol) | |
1238 | kci->last_module_symbol = start; | |
1239 | return 0; | |
1240 | } | |
1241 | ||
1242 | if (!kci->first_symbol || start < kci->first_symbol) | |
1243 | kci->first_symbol = start; | |
1244 | ||
1245 | if (!kci->last_symbol || start > kci->last_symbol) | |
1246 | kci->last_symbol = start; | |
1247 | ||
1248 | if (!strcmp(name, "_stext")) { | |
1249 | kci->stext = start; | |
1250 | return 0; | |
1251 | } | |
1252 | ||
1253 | if (!strcmp(name, "_etext")) { | |
1254 | kci->etext = start; | |
1255 | return 0; | |
1256 | } | |
1257 | ||
1258 | return 0; | |
1259 | } | |
1260 | ||
1261 | static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci, | |
1262 | const char *dir) | |
1263 | { | |
1264 | char kallsyms_filename[PATH_MAX]; | |
1265 | ||
1266 | scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir); | |
1267 | ||
1268 | if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms")) | |
1269 | return -1; | |
1270 | ||
1271 | if (kallsyms__parse(kallsyms_filename, kci, | |
1272 | kcore_copy__process_kallsyms) < 0) | |
1273 | return -1; | |
1274 | ||
1275 | return 0; | |
1276 | } | |
1277 | ||
1278 | static int kcore_copy__process_modules(void *arg, | |
1279 | const char *name __maybe_unused, | |
1280 | u64 start) | |
1281 | { | |
1282 | struct kcore_copy_info *kci = arg; | |
1283 | ||
1284 | if (!kci->first_module || start < kci->first_module) | |
1285 | kci->first_module = start; | |
1286 | ||
1287 | return 0; | |
1288 | } | |
1289 | ||
1290 | static int kcore_copy__parse_modules(struct kcore_copy_info *kci, | |
1291 | const char *dir) | |
1292 | { | |
1293 | char modules_filename[PATH_MAX]; | |
1294 | ||
1295 | scnprintf(modules_filename, PATH_MAX, "%s/modules", dir); | |
1296 | ||
1297 | if (symbol__restricted_filename(modules_filename, "/proc/modules")) | |
1298 | return -1; | |
1299 | ||
1300 | if (modules__parse(modules_filename, kci, | |
1301 | kcore_copy__process_modules) < 0) | |
1302 | return -1; | |
1303 | ||
1304 | return 0; | |
1305 | } | |
1306 | ||
1307 | static void kcore_copy__map(struct phdr_data *p, u64 start, u64 end, u64 pgoff, | |
1308 | u64 s, u64 e) | |
1309 | { | |
1310 | if (p->addr || s < start || s >= end) | |
1311 | return; | |
1312 | ||
1313 | p->addr = s; | |
1314 | p->offset = (s - start) + pgoff; | |
1315 | p->len = e < end ? e - s : end - s; | |
1316 | } | |
1317 | ||
1318 | static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data) | |
1319 | { | |
1320 | struct kcore_copy_info *kci = data; | |
1321 | u64 end = start + len; | |
1322 | ||
1323 | kcore_copy__map(&kci->kernel_map, start, end, pgoff, kci->stext, | |
1324 | kci->etext); | |
1325 | ||
1326 | kcore_copy__map(&kci->modules_map, start, end, pgoff, kci->first_module, | |
1327 | kci->last_module_symbol); | |
1328 | ||
1329 | return 0; | |
1330 | } | |
1331 | ||
1332 | static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf) | |
1333 | { | |
1334 | if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0) | |
1335 | return -1; | |
1336 | ||
1337 | return 0; | |
1338 | } | |
1339 | ||
1340 | static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir, | |
1341 | Elf *elf) | |
1342 | { | |
1343 | if (kcore_copy__parse_kallsyms(kci, dir)) | |
1344 | return -1; | |
1345 | ||
1346 | if (kcore_copy__parse_modules(kci, dir)) | |
1347 | return -1; | |
1348 | ||
1349 | if (kci->stext) | |
1350 | kci->stext = round_down(kci->stext, page_size); | |
1351 | else | |
1352 | kci->stext = round_down(kci->first_symbol, page_size); | |
1353 | ||
1354 | if (kci->etext) { | |
1355 | kci->etext = round_up(kci->etext, page_size); | |
1356 | } else if (kci->last_symbol) { | |
1357 | kci->etext = round_up(kci->last_symbol, page_size); | |
1358 | kci->etext += page_size; | |
1359 | } | |
1360 | ||
1361 | kci->first_module = round_down(kci->first_module, page_size); | |
1362 | ||
1363 | if (kci->last_module_symbol) { | |
1364 | kci->last_module_symbol = round_up(kci->last_module_symbol, | |
1365 | page_size); | |
1366 | kci->last_module_symbol += page_size; | |
1367 | } | |
1368 | ||
1369 | if (!kci->stext || !kci->etext) | |
1370 | return -1; | |
1371 | ||
1372 | if (kci->first_module && !kci->last_module_symbol) | |
1373 | return -1; | |
1374 | ||
1375 | return kcore_copy__read_maps(kci, elf); | |
1376 | } | |
1377 | ||
1378 | static int kcore_copy__copy_file(const char *from_dir, const char *to_dir, | |
1379 | const char *name) | |
1380 | { | |
1381 | char from_filename[PATH_MAX]; | |
1382 | char to_filename[PATH_MAX]; | |
1383 | ||
1384 | scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name); | |
1385 | scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name); | |
1386 | ||
1387 | return copyfile_mode(from_filename, to_filename, 0400); | |
1388 | } | |
1389 | ||
1390 | static int kcore_copy__unlink(const char *dir, const char *name) | |
1391 | { | |
1392 | char filename[PATH_MAX]; | |
1393 | ||
1394 | scnprintf(filename, PATH_MAX, "%s/%s", dir, name); | |
1395 | ||
1396 | return unlink(filename); | |
1397 | } | |
1398 | ||
1399 | static int kcore_copy__compare_fds(int from, int to) | |
1400 | { | |
1401 | char *buf_from; | |
1402 | char *buf_to; | |
1403 | ssize_t ret; | |
1404 | size_t len; | |
1405 | int err = -1; | |
1406 | ||
1407 | buf_from = malloc(page_size); | |
1408 | buf_to = malloc(page_size); | |
1409 | if (!buf_from || !buf_to) | |
1410 | goto out; | |
1411 | ||
1412 | while (1) { | |
1413 | /* Use read because mmap won't work on proc files */ | |
1414 | ret = read(from, buf_from, page_size); | |
1415 | if (ret < 0) | |
1416 | goto out; | |
1417 | ||
1418 | if (!ret) | |
1419 | break; | |
1420 | ||
1421 | len = ret; | |
1422 | ||
1423 | if (readn(to, buf_to, len) != (int)len) | |
1424 | goto out; | |
1425 | ||
1426 | if (memcmp(buf_from, buf_to, len)) | |
1427 | goto out; | |
1428 | } | |
1429 | ||
1430 | err = 0; | |
1431 | out: | |
1432 | free(buf_to); | |
1433 | free(buf_from); | |
1434 | return err; | |
1435 | } | |
1436 | ||
1437 | static int kcore_copy__compare_files(const char *from_filename, | |
1438 | const char *to_filename) | |
1439 | { | |
1440 | int from, to, err = -1; | |
1441 | ||
1442 | from = open(from_filename, O_RDONLY); | |
1443 | if (from < 0) | |
1444 | return -1; | |
1445 | ||
1446 | to = open(to_filename, O_RDONLY); | |
1447 | if (to < 0) | |
1448 | goto out_close_from; | |
1449 | ||
1450 | err = kcore_copy__compare_fds(from, to); | |
1451 | ||
1452 | close(to); | |
1453 | out_close_from: | |
1454 | close(from); | |
1455 | return err; | |
1456 | } | |
1457 | ||
1458 | static int kcore_copy__compare_file(const char *from_dir, const char *to_dir, | |
1459 | const char *name) | |
1460 | { | |
1461 | char from_filename[PATH_MAX]; | |
1462 | char to_filename[PATH_MAX]; | |
1463 | ||
1464 | scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name); | |
1465 | scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name); | |
1466 | ||
1467 | return kcore_copy__compare_files(from_filename, to_filename); | |
1468 | } | |
1469 | ||
1470 | /** | |
1471 | * kcore_copy - copy kallsyms, modules and kcore from one directory to another. | |
1472 | * @from_dir: from directory | |
1473 | * @to_dir: to directory | |
1474 | * | |
1475 | * This function copies kallsyms, modules and kcore files from one directory to | |
1476 | * another. kallsyms and modules are copied entirely. Only code segments are | |
1477 | * copied from kcore. It is assumed that two segments suffice: one for the | |
1478 | * kernel proper and one for all the modules. The code segments are determined | |
1479 | * from kallsyms and modules files. The kernel map starts at _stext or the | |
1480 | * lowest function symbol, and ends at _etext or the highest function symbol. | |
1481 | * The module map starts at the lowest module address and ends at the highest | |
1482 | * module symbol. Start addresses are rounded down to the nearest page. End | |
1483 | * addresses are rounded up to the nearest page. An extra page is added to the | |
1484 | * highest kernel symbol and highest module symbol to, hopefully, encompass that | |
1485 | * symbol too. Because it contains only code sections, the resulting kcore is | |
1486 | * unusual. One significant peculiarity is that the mapping (start -> pgoff) | |
1487 | * is not the same for the kernel map and the modules map. That happens because | |
1488 | * the data is copied adjacently whereas the original kcore has gaps. Finally, | |
1489 | * kallsyms and modules files are compared with their copies to check that | |
1490 | * modules have not been loaded or unloaded while the copies were taking place. | |
1491 | * | |
1492 | * Return: %0 on success, %-1 on failure. | |
1493 | */ | |
1494 | int kcore_copy(const char *from_dir, const char *to_dir) | |
1495 | { | |
1496 | struct kcore kcore; | |
1497 | struct kcore extract; | |
1498 | size_t count = 2; | |
1499 | int idx = 0, err = -1; | |
1500 | off_t offset = page_size, sz, modules_offset = 0; | |
1501 | struct kcore_copy_info kci = { .stext = 0, }; | |
1502 | char kcore_filename[PATH_MAX]; | |
1503 | char extract_filename[PATH_MAX]; | |
1504 | ||
1505 | if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms")) | |
1506 | return -1; | |
1507 | ||
1508 | if (kcore_copy__copy_file(from_dir, to_dir, "modules")) | |
1509 | goto out_unlink_kallsyms; | |
1510 | ||
1511 | scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir); | |
1512 | scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir); | |
1513 | ||
1514 | if (kcore__open(&kcore, kcore_filename)) | |
1515 | goto out_unlink_modules; | |
1516 | ||
1517 | if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf)) | |
1518 | goto out_kcore_close; | |
1519 | ||
1520 | if (kcore__init(&extract, extract_filename, kcore.elfclass, false)) | |
1521 | goto out_kcore_close; | |
1522 | ||
1523 | if (!kci.modules_map.addr) | |
1524 | count -= 1; | |
1525 | ||
1526 | if (kcore__copy_hdr(&kcore, &extract, count)) | |
1527 | goto out_extract_close; | |
1528 | ||
1529 | if (kcore__add_phdr(&extract, idx++, offset, kci.kernel_map.addr, | |
1530 | kci.kernel_map.len)) | |
1531 | goto out_extract_close; | |
1532 | ||
1533 | if (kci.modules_map.addr) { | |
1534 | modules_offset = offset + kci.kernel_map.len; | |
1535 | if (kcore__add_phdr(&extract, idx, modules_offset, | |
1536 | kci.modules_map.addr, kci.modules_map.len)) | |
1537 | goto out_extract_close; | |
1538 | } | |
1539 | ||
1540 | sz = kcore__write(&extract); | |
1541 | if (sz < 0 || sz > offset) | |
1542 | goto out_extract_close; | |
1543 | ||
1544 | if (copy_bytes(kcore.fd, kci.kernel_map.offset, extract.fd, offset, | |
1545 | kci.kernel_map.len)) | |
1546 | goto out_extract_close; | |
1547 | ||
1548 | if (modules_offset && copy_bytes(kcore.fd, kci.modules_map.offset, | |
1549 | extract.fd, modules_offset, | |
1550 | kci.modules_map.len)) | |
1551 | goto out_extract_close; | |
1552 | ||
1553 | if (kcore_copy__compare_file(from_dir, to_dir, "modules")) | |
1554 | goto out_extract_close; | |
1555 | ||
1556 | if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms")) | |
1557 | goto out_extract_close; | |
1558 | ||
1559 | err = 0; | |
1560 | ||
1561 | out_extract_close: | |
1562 | kcore__close(&extract); | |
1563 | if (err) | |
1564 | unlink(extract_filename); | |
1565 | out_kcore_close: | |
1566 | kcore__close(&kcore); | |
1567 | out_unlink_modules: | |
1568 | if (err) | |
1569 | kcore_copy__unlink(to_dir, "modules"); | |
1570 | out_unlink_kallsyms: | |
1571 | if (err) | |
1572 | kcore_copy__unlink(to_dir, "kallsyms"); | |
1573 | ||
1574 | return err; | |
1575 | } | |
1576 | ||
afba19d9 AH |
1577 | int kcore_extract__create(struct kcore_extract *kce) |
1578 | { | |
1579 | struct kcore kcore; | |
1580 | struct kcore extract; | |
1581 | size_t count = 1; | |
1582 | int idx = 0, err = -1; | |
1583 | off_t offset = page_size, sz; | |
1584 | ||
1585 | if (kcore__open(&kcore, kce->kcore_filename)) | |
1586 | return -1; | |
1587 | ||
1588 | strcpy(kce->extract_filename, PERF_KCORE_EXTRACT); | |
1589 | if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true)) | |
1590 | goto out_kcore_close; | |
1591 | ||
1592 | if (kcore__copy_hdr(&kcore, &extract, count)) | |
1593 | goto out_extract_close; | |
1594 | ||
1595 | if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len)) | |
1596 | goto out_extract_close; | |
1597 | ||
1598 | sz = kcore__write(&extract); | |
1599 | if (sz < 0 || sz > offset) | |
1600 | goto out_extract_close; | |
1601 | ||
1602 | if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len)) | |
1603 | goto out_extract_close; | |
1604 | ||
1605 | err = 0; | |
1606 | ||
1607 | out_extract_close: | |
1608 | kcore__close(&extract); | |
1609 | if (err) | |
1610 | unlink(kce->extract_filename); | |
1611 | out_kcore_close: | |
1612 | kcore__close(&kcore); | |
1613 | ||
1614 | return err; | |
1615 | } | |
1616 | ||
1617 | void kcore_extract__delete(struct kcore_extract *kce) | |
1618 | { | |
1619 | unlink(kce->extract_filename); | |
1620 | } | |
1621 | ||
e5a1845f NK |
1622 | void symbol__elf_init(void) |
1623 | { | |
1624 | elf_version(EV_CURRENT); | |
1625 | } |