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" | |
8fa7d87f | 9 | #include "machine.h" |
922d0e4d | 10 | #include "vdso.h" |
c506c96b | 11 | #include <symbol/kallsyms.h> |
e5a1845f NK |
12 | #include "debug.h" |
13 | ||
89fe808a | 14 | #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT |
e955d5c4 AH |
15 | static int elf_getphdrnum(Elf *elf, size_t *dst) |
16 | { | |
17 | GElf_Ehdr gehdr; | |
18 | GElf_Ehdr *ehdr; | |
19 | ||
20 | ehdr = gelf_getehdr(elf, &gehdr); | |
21 | if (!ehdr) | |
22 | return -1; | |
23 | ||
24 | *dst = ehdr->e_phnum; | |
25 | ||
26 | return 0; | |
27 | } | |
28 | #endif | |
29 | ||
e5a1845f NK |
30 | #ifndef NT_GNU_BUILD_ID |
31 | #define NT_GNU_BUILD_ID 3 | |
32 | #endif | |
33 | ||
34 | /** | |
35 | * elf_symtab__for_each_symbol - iterate thru all the symbols | |
36 | * | |
37 | * @syms: struct elf_symtab instance to iterate | |
38 | * @idx: uint32_t idx | |
39 | * @sym: GElf_Sym iterator | |
40 | */ | |
41 | #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \ | |
42 | for (idx = 0, gelf_getsym(syms, idx, &sym);\ | |
43 | idx < nr_syms; \ | |
44 | idx++, gelf_getsym(syms, idx, &sym)) | |
45 | ||
46 | static inline uint8_t elf_sym__type(const GElf_Sym *sym) | |
47 | { | |
48 | return GELF_ST_TYPE(sym->st_info); | |
49 | } | |
50 | ||
51 | static inline int elf_sym__is_function(const GElf_Sym *sym) | |
52 | { | |
a2f3b6bf AH |
53 | return (elf_sym__type(sym) == STT_FUNC || |
54 | elf_sym__type(sym) == STT_GNU_IFUNC) && | |
e5a1845f NK |
55 | sym->st_name != 0 && |
56 | sym->st_shndx != SHN_UNDEF; | |
57 | } | |
58 | ||
59 | static inline bool elf_sym__is_object(const GElf_Sym *sym) | |
60 | { | |
61 | return elf_sym__type(sym) == STT_OBJECT && | |
62 | sym->st_name != 0 && | |
63 | sym->st_shndx != SHN_UNDEF; | |
64 | } | |
65 | ||
66 | static inline int elf_sym__is_label(const GElf_Sym *sym) | |
67 | { | |
68 | return elf_sym__type(sym) == STT_NOTYPE && | |
69 | sym->st_name != 0 && | |
70 | sym->st_shndx != SHN_UNDEF && | |
71 | sym->st_shndx != SHN_ABS; | |
72 | } | |
73 | ||
74 | static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type) | |
75 | { | |
76 | switch (type) { | |
77 | case MAP__FUNCTION: | |
78 | return elf_sym__is_function(sym); | |
79 | case MAP__VARIABLE: | |
80 | return elf_sym__is_object(sym); | |
81 | default: | |
82 | return false; | |
83 | } | |
84 | } | |
85 | ||
86 | static inline const char *elf_sym__name(const GElf_Sym *sym, | |
87 | const Elf_Data *symstrs) | |
88 | { | |
89 | return symstrs->d_buf + sym->st_name; | |
90 | } | |
91 | ||
92 | static inline const char *elf_sec__name(const GElf_Shdr *shdr, | |
93 | const Elf_Data *secstrs) | |
94 | { | |
95 | return secstrs->d_buf + shdr->sh_name; | |
96 | } | |
97 | ||
98 | static inline int elf_sec__is_text(const GElf_Shdr *shdr, | |
99 | const Elf_Data *secstrs) | |
100 | { | |
101 | return strstr(elf_sec__name(shdr, secstrs), "text") != NULL; | |
102 | } | |
103 | ||
104 | static inline bool elf_sec__is_data(const GElf_Shdr *shdr, | |
105 | const Elf_Data *secstrs) | |
106 | { | |
107 | return strstr(elf_sec__name(shdr, secstrs), "data") != NULL; | |
108 | } | |
109 | ||
110 | static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs, | |
111 | enum map_type type) | |
112 | { | |
113 | switch (type) { | |
114 | case MAP__FUNCTION: | |
115 | return elf_sec__is_text(shdr, secstrs); | |
116 | case MAP__VARIABLE: | |
117 | return elf_sec__is_data(shdr, secstrs); | |
118 | default: | |
119 | return false; | |
120 | } | |
121 | } | |
122 | ||
123 | static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr) | |
124 | { | |
125 | Elf_Scn *sec = NULL; | |
126 | GElf_Shdr shdr; | |
127 | size_t cnt = 1; | |
128 | ||
129 | while ((sec = elf_nextscn(elf, sec)) != NULL) { | |
130 | gelf_getshdr(sec, &shdr); | |
131 | ||
132 | if ((addr >= shdr.sh_addr) && | |
133 | (addr < (shdr.sh_addr + shdr.sh_size))) | |
134 | return cnt; | |
135 | ||
136 | ++cnt; | |
137 | } | |
138 | ||
139 | return -1; | |
140 | } | |
141 | ||
99ca4233 MH |
142 | Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep, |
143 | GElf_Shdr *shp, const char *name, size_t *idx) | |
e5a1845f NK |
144 | { |
145 | Elf_Scn *sec = NULL; | |
146 | size_t cnt = 1; | |
147 | ||
49274654 CS |
148 | /* Elf is corrupted/truncated, avoid calling elf_strptr. */ |
149 | if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) | |
150 | return NULL; | |
151 | ||
e5a1845f NK |
152 | while ((sec = elf_nextscn(elf, sec)) != NULL) { |
153 | char *str; | |
154 | ||
155 | gelf_getshdr(sec, shp); | |
156 | str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name); | |
155b3a13 | 157 | if (str && !strcmp(name, str)) { |
e5a1845f NK |
158 | if (idx) |
159 | *idx = cnt; | |
155b3a13 | 160 | return sec; |
e5a1845f NK |
161 | } |
162 | ++cnt; | |
163 | } | |
164 | ||
155b3a13 | 165 | return NULL; |
e5a1845f NK |
166 | } |
167 | ||
168 | #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \ | |
169 | for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \ | |
170 | idx < nr_entries; \ | |
171 | ++idx, pos = gelf_getrel(reldata, idx, &pos_mem)) | |
172 | ||
173 | #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \ | |
174 | for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \ | |
175 | idx < nr_entries; \ | |
176 | ++idx, pos = gelf_getrela(reldata, idx, &pos_mem)) | |
177 | ||
178 | /* | |
179 | * We need to check if we have a .dynsym, so that we can handle the | |
180 | * .plt, synthesizing its symbols, that aren't on the symtabs (be it | |
181 | * .dynsym or .symtab). | |
182 | * And always look at the original dso, not at debuginfo packages, that | |
183 | * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS). | |
184 | */ | |
a44f605b | 185 | int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map, |
e5a1845f NK |
186 | symbol_filter_t filter) |
187 | { | |
188 | uint32_t nr_rel_entries, idx; | |
189 | GElf_Sym sym; | |
190 | u64 plt_offset; | |
191 | GElf_Shdr shdr_plt; | |
192 | struct symbol *f; | |
193 | GElf_Shdr shdr_rel_plt, shdr_dynsym; | |
194 | Elf_Data *reldata, *syms, *symstrs; | |
195 | Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym; | |
196 | size_t dynsym_idx; | |
197 | GElf_Ehdr ehdr; | |
198 | char sympltname[1024]; | |
199 | Elf *elf; | |
a44f605b | 200 | int nr = 0, symidx, err = 0; |
e5a1845f | 201 | |
f47b58b7 DA |
202 | if (!ss->dynsym) |
203 | return 0; | |
204 | ||
a44f605b CS |
205 | elf = ss->elf; |
206 | ehdr = ss->ehdr; | |
e5a1845f | 207 | |
a44f605b CS |
208 | scn_dynsym = ss->dynsym; |
209 | shdr_dynsym = ss->dynshdr; | |
210 | dynsym_idx = ss->dynsym_idx; | |
e5a1845f | 211 | |
e5a1845f NK |
212 | if (scn_dynsym == NULL) |
213 | goto out_elf_end; | |
214 | ||
215 | scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, | |
216 | ".rela.plt", NULL); | |
217 | if (scn_plt_rel == NULL) { | |
218 | scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, | |
219 | ".rel.plt", NULL); | |
220 | if (scn_plt_rel == NULL) | |
221 | goto out_elf_end; | |
222 | } | |
223 | ||
224 | err = -1; | |
225 | ||
226 | if (shdr_rel_plt.sh_link != dynsym_idx) | |
227 | goto out_elf_end; | |
228 | ||
229 | if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL) | |
230 | goto out_elf_end; | |
231 | ||
232 | /* | |
233 | * Fetch the relocation section to find the idxes to the GOT | |
234 | * and the symbols in the .dynsym they refer to. | |
235 | */ | |
236 | reldata = elf_getdata(scn_plt_rel, NULL); | |
237 | if (reldata == NULL) | |
238 | goto out_elf_end; | |
239 | ||
240 | syms = elf_getdata(scn_dynsym, NULL); | |
241 | if (syms == NULL) | |
242 | goto out_elf_end; | |
243 | ||
244 | scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link); | |
245 | if (scn_symstrs == NULL) | |
246 | goto out_elf_end; | |
247 | ||
248 | symstrs = elf_getdata(scn_symstrs, NULL); | |
249 | if (symstrs == NULL) | |
250 | goto out_elf_end; | |
251 | ||
52f9ddba CS |
252 | if (symstrs->d_size == 0) |
253 | goto out_elf_end; | |
254 | ||
e5a1845f NK |
255 | nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize; |
256 | plt_offset = shdr_plt.sh_offset; | |
257 | ||
258 | if (shdr_rel_plt.sh_type == SHT_RELA) { | |
259 | GElf_Rela pos_mem, *pos; | |
260 | ||
261 | elf_section__for_each_rela(reldata, pos, pos_mem, idx, | |
262 | nr_rel_entries) { | |
263 | symidx = GELF_R_SYM(pos->r_info); | |
264 | plt_offset += shdr_plt.sh_entsize; | |
265 | gelf_getsym(syms, symidx, &sym); | |
266 | snprintf(sympltname, sizeof(sympltname), | |
267 | "%s@plt", elf_sym__name(&sym, symstrs)); | |
268 | ||
269 | f = symbol__new(plt_offset, shdr_plt.sh_entsize, | |
270 | STB_GLOBAL, sympltname); | |
271 | if (!f) | |
272 | goto out_elf_end; | |
273 | ||
274 | if (filter && filter(map, f)) | |
275 | symbol__delete(f); | |
276 | else { | |
277 | symbols__insert(&dso->symbols[map->type], f); | |
278 | ++nr; | |
279 | } | |
280 | } | |
281 | } else if (shdr_rel_plt.sh_type == SHT_REL) { | |
282 | GElf_Rel pos_mem, *pos; | |
283 | elf_section__for_each_rel(reldata, pos, pos_mem, idx, | |
284 | nr_rel_entries) { | |
285 | symidx = GELF_R_SYM(pos->r_info); | |
286 | plt_offset += shdr_plt.sh_entsize; | |
287 | gelf_getsym(syms, symidx, &sym); | |
288 | snprintf(sympltname, sizeof(sympltname), | |
289 | "%s@plt", elf_sym__name(&sym, symstrs)); | |
290 | ||
291 | f = symbol__new(plt_offset, shdr_plt.sh_entsize, | |
292 | STB_GLOBAL, sympltname); | |
293 | if (!f) | |
294 | goto out_elf_end; | |
295 | ||
296 | if (filter && filter(map, f)) | |
297 | symbol__delete(f); | |
298 | else { | |
299 | symbols__insert(&dso->symbols[map->type], f); | |
300 | ++nr; | |
301 | } | |
302 | } | |
303 | } | |
304 | ||
305 | err = 0; | |
306 | out_elf_end: | |
e5a1845f NK |
307 | if (err == 0) |
308 | return nr; | |
e5a1845f NK |
309 | pr_debug("%s: problems reading %s PLT info.\n", |
310 | __func__, dso->long_name); | |
311 | return 0; | |
312 | } | |
313 | ||
314 | /* | |
315 | * Align offset to 4 bytes as needed for note name and descriptor data. | |
316 | */ | |
317 | #define NOTE_ALIGN(n) (((n) + 3) & -4U) | |
318 | ||
319 | static int elf_read_build_id(Elf *elf, void *bf, size_t size) | |
320 | { | |
321 | int err = -1; | |
322 | GElf_Ehdr ehdr; | |
323 | GElf_Shdr shdr; | |
324 | Elf_Data *data; | |
325 | Elf_Scn *sec; | |
326 | Elf_Kind ek; | |
327 | void *ptr; | |
328 | ||
329 | if (size < BUILD_ID_SIZE) | |
330 | goto out; | |
331 | ||
332 | ek = elf_kind(elf); | |
333 | if (ek != ELF_K_ELF) | |
334 | goto out; | |
335 | ||
336 | if (gelf_getehdr(elf, &ehdr) == NULL) { | |
337 | pr_err("%s: cannot get elf header.\n", __func__); | |
338 | goto out; | |
339 | } | |
340 | ||
341 | /* | |
342 | * Check following sections for notes: | |
343 | * '.note.gnu.build-id' | |
344 | * '.notes' | |
345 | * '.note' (VDSO specific) | |
346 | */ | |
347 | do { | |
348 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
349 | ".note.gnu.build-id", NULL); | |
350 | if (sec) | |
351 | break; | |
352 | ||
353 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
354 | ".notes", NULL); | |
355 | if (sec) | |
356 | break; | |
357 | ||
358 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
359 | ".note", NULL); | |
360 | if (sec) | |
361 | break; | |
362 | ||
363 | return err; | |
364 | ||
365 | } while (0); | |
366 | ||
367 | data = elf_getdata(sec, NULL); | |
368 | if (data == NULL) | |
369 | goto out; | |
370 | ||
371 | ptr = data->d_buf; | |
372 | while (ptr < (data->d_buf + data->d_size)) { | |
373 | GElf_Nhdr *nhdr = ptr; | |
374 | size_t namesz = NOTE_ALIGN(nhdr->n_namesz), | |
375 | descsz = NOTE_ALIGN(nhdr->n_descsz); | |
376 | const char *name; | |
377 | ||
378 | ptr += sizeof(*nhdr); | |
379 | name = ptr; | |
380 | ptr += namesz; | |
381 | if (nhdr->n_type == NT_GNU_BUILD_ID && | |
382 | nhdr->n_namesz == sizeof("GNU")) { | |
383 | if (memcmp(name, "GNU", sizeof("GNU")) == 0) { | |
384 | size_t sz = min(size, descsz); | |
385 | memcpy(bf, ptr, sz); | |
386 | memset(bf + sz, 0, size - sz); | |
387 | err = descsz; | |
388 | break; | |
389 | } | |
390 | } | |
391 | ptr += descsz; | |
392 | } | |
393 | ||
394 | out: | |
395 | return err; | |
396 | } | |
397 | ||
398 | int filename__read_build_id(const char *filename, void *bf, size_t size) | |
399 | { | |
400 | int fd, err = -1; | |
401 | Elf *elf; | |
402 | ||
403 | if (size < BUILD_ID_SIZE) | |
404 | goto out; | |
405 | ||
406 | fd = open(filename, O_RDONLY); | |
407 | if (fd < 0) | |
408 | goto out; | |
409 | ||
410 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
411 | if (elf == NULL) { | |
412 | pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename); | |
413 | goto out_close; | |
414 | } | |
415 | ||
416 | err = elf_read_build_id(elf, bf, size); | |
417 | ||
418 | elf_end(elf); | |
419 | out_close: | |
420 | close(fd); | |
421 | out: | |
422 | return err; | |
423 | } | |
424 | ||
425 | int sysfs__read_build_id(const char *filename, void *build_id, size_t size) | |
426 | { | |
427 | int fd, err = -1; | |
428 | ||
429 | if (size < BUILD_ID_SIZE) | |
430 | goto out; | |
431 | ||
432 | fd = open(filename, O_RDONLY); | |
433 | if (fd < 0) | |
434 | goto out; | |
435 | ||
436 | while (1) { | |
437 | char bf[BUFSIZ]; | |
438 | GElf_Nhdr nhdr; | |
439 | size_t namesz, descsz; | |
440 | ||
441 | if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr)) | |
442 | break; | |
443 | ||
444 | namesz = NOTE_ALIGN(nhdr.n_namesz); | |
445 | descsz = NOTE_ALIGN(nhdr.n_descsz); | |
446 | if (nhdr.n_type == NT_GNU_BUILD_ID && | |
447 | nhdr.n_namesz == sizeof("GNU")) { | |
448 | if (read(fd, bf, namesz) != (ssize_t)namesz) | |
449 | break; | |
450 | if (memcmp(bf, "GNU", sizeof("GNU")) == 0) { | |
451 | size_t sz = min(descsz, size); | |
452 | if (read(fd, build_id, sz) == (ssize_t)sz) { | |
453 | memset(build_id + sz, 0, size - sz); | |
454 | err = 0; | |
455 | break; | |
456 | } | |
457 | } else if (read(fd, bf, descsz) != (ssize_t)descsz) | |
458 | break; | |
459 | } else { | |
460 | int n = namesz + descsz; | |
461 | if (read(fd, bf, n) != n) | |
462 | break; | |
463 | } | |
464 | } | |
465 | close(fd); | |
466 | out: | |
467 | return err; | |
468 | } | |
469 | ||
470 | int filename__read_debuglink(const char *filename, char *debuglink, | |
471 | size_t size) | |
472 | { | |
473 | int fd, err = -1; | |
474 | Elf *elf; | |
475 | GElf_Ehdr ehdr; | |
476 | GElf_Shdr shdr; | |
477 | Elf_Data *data; | |
478 | Elf_Scn *sec; | |
479 | Elf_Kind ek; | |
480 | ||
481 | fd = open(filename, O_RDONLY); | |
482 | if (fd < 0) | |
483 | goto out; | |
484 | ||
485 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
486 | if (elf == NULL) { | |
487 | pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename); | |
488 | goto out_close; | |
489 | } | |
490 | ||
491 | ek = elf_kind(elf); | |
492 | if (ek != ELF_K_ELF) | |
784f3390 | 493 | goto out_elf_end; |
e5a1845f NK |
494 | |
495 | if (gelf_getehdr(elf, &ehdr) == NULL) { | |
496 | pr_err("%s: cannot get elf header.\n", __func__); | |
784f3390 | 497 | goto out_elf_end; |
e5a1845f NK |
498 | } |
499 | ||
500 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
501 | ".gnu_debuglink", NULL); | |
502 | if (sec == NULL) | |
784f3390 | 503 | goto out_elf_end; |
e5a1845f NK |
504 | |
505 | data = elf_getdata(sec, NULL); | |
506 | if (data == NULL) | |
784f3390 | 507 | goto out_elf_end; |
e5a1845f NK |
508 | |
509 | /* the start of this section is a zero-terminated string */ | |
510 | strncpy(debuglink, data->d_buf, size); | |
511 | ||
0d3dc5e8 SE |
512 | err = 0; |
513 | ||
784f3390 | 514 | out_elf_end: |
e5a1845f | 515 | elf_end(elf); |
e5a1845f NK |
516 | out_close: |
517 | close(fd); | |
518 | out: | |
519 | return err; | |
520 | } | |
521 | ||
522 | static int dso__swap_init(struct dso *dso, unsigned char eidata) | |
523 | { | |
524 | static unsigned int const endian = 1; | |
525 | ||
526 | dso->needs_swap = DSO_SWAP__NO; | |
527 | ||
528 | switch (eidata) { | |
529 | case ELFDATA2LSB: | |
530 | /* We are big endian, DSO is little endian. */ | |
531 | if (*(unsigned char const *)&endian != 1) | |
532 | dso->needs_swap = DSO_SWAP__YES; | |
533 | break; | |
534 | ||
535 | case ELFDATA2MSB: | |
536 | /* We are little endian, DSO is big endian. */ | |
537 | if (*(unsigned char const *)&endian != 0) | |
538 | dso->needs_swap = DSO_SWAP__YES; | |
539 | break; | |
540 | ||
541 | default: | |
542 | pr_err("unrecognized DSO data encoding %d\n", eidata); | |
543 | return -EINVAL; | |
544 | } | |
545 | ||
546 | return 0; | |
547 | } | |
548 | ||
c00c48fc NK |
549 | static int decompress_kmodule(struct dso *dso, const char *name, |
550 | enum dso_binary_type type) | |
551 | { | |
552 | int fd; | |
553 | const char *ext = strrchr(name, '.'); | |
554 | char tmpbuf[] = "/tmp/perf-kmod-XXXXXX"; | |
555 | ||
556 | if ((type != DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP && | |
557 | type != DSO_BINARY_TYPE__GUEST_KMODULE_COMP) || | |
558 | type != dso->symtab_type) | |
559 | return -1; | |
560 | ||
561 | if (!ext || !is_supported_compression(ext + 1)) | |
562 | return -1; | |
563 | ||
564 | fd = mkstemp(tmpbuf); | |
565 | if (fd < 0) | |
566 | return -1; | |
567 | ||
568 | if (!decompress_to_file(ext + 1, name, fd)) { | |
569 | close(fd); | |
570 | fd = -1; | |
571 | } | |
572 | ||
573 | unlink(tmpbuf); | |
574 | ||
575 | return fd; | |
576 | } | |
577 | ||
3aafe5ae CS |
578 | bool symsrc__possibly_runtime(struct symsrc *ss) |
579 | { | |
580 | return ss->dynsym || ss->opdsec; | |
581 | } | |
582 | ||
d26cd12b CS |
583 | bool symsrc__has_symtab(struct symsrc *ss) |
584 | { | |
585 | return ss->symtab != NULL; | |
586 | } | |
b68e2f91 CS |
587 | |
588 | void symsrc__destroy(struct symsrc *ss) | |
589 | { | |
74cf249d | 590 | zfree(&ss->name); |
b68e2f91 CS |
591 | elf_end(ss->elf); |
592 | close(ss->fd); | |
593 | } | |
594 | ||
595 | int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, | |
596 | enum dso_binary_type type) | |
e5a1845f | 597 | { |
e5a1845f | 598 | int err = -1; |
e5a1845f | 599 | GElf_Ehdr ehdr; |
e5a1845f | 600 | Elf *elf; |
b68e2f91 CS |
601 | int fd; |
602 | ||
c00c48fc NK |
603 | if (dso__needs_decompress(dso)) |
604 | fd = decompress_kmodule(dso, name, type); | |
605 | else | |
606 | fd = open(name, O_RDONLY); | |
607 | ||
b68e2f91 CS |
608 | if (fd < 0) |
609 | return -1; | |
e5a1845f NK |
610 | |
611 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
612 | if (elf == NULL) { | |
613 | pr_debug("%s: cannot read %s ELF file.\n", __func__, name); | |
614 | goto out_close; | |
615 | } | |
616 | ||
617 | if (gelf_getehdr(elf, &ehdr) == NULL) { | |
618 | pr_debug("%s: cannot get elf header.\n", __func__); | |
619 | goto out_elf_end; | |
620 | } | |
621 | ||
622 | if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) | |
623 | goto out_elf_end; | |
624 | ||
625 | /* Always reject images with a mismatched build-id: */ | |
626 | if (dso->has_build_id) { | |
627 | u8 build_id[BUILD_ID_SIZE]; | |
628 | ||
629 | if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) | |
630 | goto out_elf_end; | |
631 | ||
632 | if (!dso__build_id_equal(dso, build_id)) | |
633 | goto out_elf_end; | |
634 | } | |
635 | ||
c6d8f2a4 AH |
636 | ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64); |
637 | ||
b68e2f91 CS |
638 | ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab", |
639 | NULL); | |
640 | if (ss->symshdr.sh_type != SHT_SYMTAB) | |
641 | ss->symtab = NULL; | |
642 | ||
643 | ss->dynsym_idx = 0; | |
644 | ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym", | |
645 | &ss->dynsym_idx); | |
646 | if (ss->dynshdr.sh_type != SHT_DYNSYM) | |
647 | ss->dynsym = NULL; | |
648 | ||
649 | ss->opdidx = 0; | |
650 | ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd", | |
651 | &ss->opdidx); | |
652 | if (ss->opdshdr.sh_type != SHT_PROGBITS) | |
653 | ss->opdsec = NULL; | |
654 | ||
655 | if (dso->kernel == DSO_TYPE_USER) { | |
656 | GElf_Shdr shdr; | |
657 | ss->adjust_symbols = (ehdr.e_type == ET_EXEC || | |
0131c4ec | 658 | ehdr.e_type == ET_REL || |
51682dc7 | 659 | dso__is_vdso(dso) || |
b68e2f91 CS |
660 | elf_section_by_name(elf, &ehdr, &shdr, |
661 | ".gnu.prelink_undo", | |
662 | NULL) != NULL); | |
663 | } else { | |
0131c4ec AH |
664 | ss->adjust_symbols = ehdr.e_type == ET_EXEC || |
665 | ehdr.e_type == ET_REL; | |
b68e2f91 CS |
666 | } |
667 | ||
668 | ss->name = strdup(name); | |
669 | if (!ss->name) | |
670 | goto out_elf_end; | |
671 | ||
672 | ss->elf = elf; | |
673 | ss->fd = fd; | |
674 | ss->ehdr = ehdr; | |
675 | ss->type = type; | |
676 | ||
677 | return 0; | |
678 | ||
679 | out_elf_end: | |
680 | elf_end(elf); | |
681 | out_close: | |
682 | close(fd); | |
683 | return err; | |
684 | } | |
685 | ||
39b12f78 AH |
686 | /** |
687 | * ref_reloc_sym_not_found - has kernel relocation symbol been found. | |
688 | * @kmap: kernel maps and relocation reference symbol | |
689 | * | |
690 | * This function returns %true if we are dealing with the kernel maps and the | |
691 | * relocation reference symbol has not yet been found. Otherwise %false is | |
692 | * returned. | |
693 | */ | |
694 | static bool ref_reloc_sym_not_found(struct kmap *kmap) | |
695 | { | |
696 | return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name && | |
697 | !kmap->ref_reloc_sym->unrelocated_addr; | |
698 | } | |
699 | ||
700 | /** | |
701 | * ref_reloc - kernel relocation offset. | |
702 | * @kmap: kernel maps and relocation reference symbol | |
703 | * | |
704 | * This function returns the offset of kernel addresses as determined by using | |
705 | * the relocation reference symbol i.e. if the kernel has not been relocated | |
706 | * then the return value is zero. | |
707 | */ | |
708 | static u64 ref_reloc(struct kmap *kmap) | |
709 | { | |
710 | if (kmap && kmap->ref_reloc_sym && | |
711 | kmap->ref_reloc_sym->unrelocated_addr) | |
712 | return kmap->ref_reloc_sym->addr - | |
713 | kmap->ref_reloc_sym->unrelocated_addr; | |
714 | return 0; | |
715 | } | |
716 | ||
763122ad AK |
717 | static bool want_demangle(bool is_kernel_sym) |
718 | { | |
719 | return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle; | |
720 | } | |
721 | ||
261360b6 CS |
722 | int dso__load_sym(struct dso *dso, struct map *map, |
723 | struct symsrc *syms_ss, struct symsrc *runtime_ss, | |
d26cd12b | 724 | symbol_filter_t filter, int kmodule) |
b68e2f91 CS |
725 | { |
726 | struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL; | |
727 | struct map *curr_map = map; | |
728 | struct dso *curr_dso = dso; | |
729 | Elf_Data *symstrs, *secstrs; | |
730 | uint32_t nr_syms; | |
731 | int err = -1; | |
732 | uint32_t idx; | |
733 | GElf_Ehdr ehdr; | |
261360b6 | 734 | GElf_Shdr shdr; |
b68e2f91 CS |
735 | Elf_Data *syms, *opddata = NULL; |
736 | GElf_Sym sym; | |
261360b6 | 737 | Elf_Scn *sec, *sec_strndx; |
b68e2f91 CS |
738 | Elf *elf; |
739 | int nr = 0; | |
39b12f78 | 740 | bool remap_kernel = false, adjust_kernel_syms = false; |
b68e2f91 | 741 | |
261360b6 | 742 | dso->symtab_type = syms_ss->type; |
c6d8f2a4 | 743 | dso->is_64_bit = syms_ss->is_64_bit; |
0131c4ec AH |
744 | dso->rel = syms_ss->ehdr.e_type == ET_REL; |
745 | ||
746 | /* | |
747 | * Modules may already have symbols from kallsyms, but those symbols | |
748 | * have the wrong values for the dso maps, so remove them. | |
749 | */ | |
750 | if (kmodule && syms_ss->symtab) | |
751 | symbols__delete(&dso->symbols[map->type]); | |
005f9294 | 752 | |
261360b6 | 753 | if (!syms_ss->symtab) { |
d0b0d040 AB |
754 | /* |
755 | * If the vmlinux is stripped, fail so we will fall back | |
756 | * to using kallsyms. The vmlinux runtime symbols aren't | |
757 | * of much use. | |
758 | */ | |
759 | if (dso->kernel) | |
760 | goto out_elf_end; | |
761 | ||
261360b6 CS |
762 | syms_ss->symtab = syms_ss->dynsym; |
763 | syms_ss->symshdr = syms_ss->dynshdr; | |
d26cd12b CS |
764 | } |
765 | ||
261360b6 CS |
766 | elf = syms_ss->elf; |
767 | ehdr = syms_ss->ehdr; | |
768 | sec = syms_ss->symtab; | |
769 | shdr = syms_ss->symshdr; | |
b68e2f91 | 770 | |
261360b6 CS |
771 | if (runtime_ss->opdsec) |
772 | opddata = elf_rawdata(runtime_ss->opdsec, NULL); | |
e5a1845f NK |
773 | |
774 | syms = elf_getdata(sec, NULL); | |
775 | if (syms == NULL) | |
776 | goto out_elf_end; | |
777 | ||
778 | sec = elf_getscn(elf, shdr.sh_link); | |
779 | if (sec == NULL) | |
780 | goto out_elf_end; | |
781 | ||
782 | symstrs = elf_getdata(sec, NULL); | |
783 | if (symstrs == NULL) | |
784 | goto out_elf_end; | |
785 | ||
f247fb81 | 786 | sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx); |
e5a1845f NK |
787 | if (sec_strndx == NULL) |
788 | goto out_elf_end; | |
789 | ||
790 | secstrs = elf_getdata(sec_strndx, NULL); | |
791 | if (secstrs == NULL) | |
792 | goto out_elf_end; | |
793 | ||
794 | nr_syms = shdr.sh_size / shdr.sh_entsize; | |
795 | ||
796 | memset(&sym, 0, sizeof(sym)); | |
39b12f78 AH |
797 | |
798 | /* | |
799 | * The kernel relocation symbol is needed in advance in order to adjust | |
800 | * kernel maps correctly. | |
801 | */ | |
802 | if (ref_reloc_sym_not_found(kmap)) { | |
803 | elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) { | |
804 | const char *elf_name = elf_sym__name(&sym, symstrs); | |
805 | ||
806 | if (strcmp(elf_name, kmap->ref_reloc_sym->name)) | |
807 | continue; | |
808 | kmap->ref_reloc_sym->unrelocated_addr = sym.st_value; | |
9176753d AH |
809 | map->reloc = kmap->ref_reloc_sym->addr - |
810 | kmap->ref_reloc_sym->unrelocated_addr; | |
39b12f78 AH |
811 | break; |
812 | } | |
813 | } | |
814 | ||
815 | dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap); | |
816 | /* | |
817 | * Initial kernel and module mappings do not map to the dso. For | |
818 | * function mappings, flag the fixups. | |
819 | */ | |
820 | if (map->type == MAP__FUNCTION && (dso->kernel || kmodule)) { | |
821 | remap_kernel = true; | |
822 | adjust_kernel_syms = dso->adjust_symbols; | |
823 | } | |
e5a1845f NK |
824 | elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) { |
825 | struct symbol *f; | |
826 | const char *elf_name = elf_sym__name(&sym, symstrs); | |
827 | char *demangled = NULL; | |
828 | int is_label = elf_sym__is_label(&sym); | |
829 | const char *section_name; | |
261360b6 | 830 | bool used_opd = false; |
e5a1845f | 831 | |
e5a1845f NK |
832 | if (!is_label && !elf_sym__is_a(&sym, map->type)) |
833 | continue; | |
834 | ||
835 | /* Reject ARM ELF "mapping symbols": these aren't unique and | |
836 | * don't identify functions, so will confuse the profile | |
837 | * output: */ | |
838 | if (ehdr.e_machine == EM_ARM) { | |
839 | if (!strcmp(elf_name, "$a") || | |
840 | !strcmp(elf_name, "$d") || | |
841 | !strcmp(elf_name, "$t")) | |
842 | continue; | |
843 | } | |
844 | ||
261360b6 CS |
845 | if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) { |
846 | u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr; | |
e5a1845f NK |
847 | u64 *opd = opddata->d_buf + offset; |
848 | sym.st_value = DSO__SWAP(dso, u64, *opd); | |
261360b6 CS |
849 | sym.st_shndx = elf_addr_to_index(runtime_ss->elf, |
850 | sym.st_value); | |
851 | used_opd = true; | |
e5a1845f | 852 | } |
3843b05d NK |
853 | /* |
854 | * When loading symbols in a data mapping, ABS symbols (which | |
855 | * has a value of SHN_ABS in its st_shndx) failed at | |
856 | * elf_getscn(). And it marks the loading as a failure so | |
857 | * already loaded symbols cannot be fixed up. | |
858 | * | |
859 | * I'm not sure what should be done. Just ignore them for now. | |
860 | * - Namhyung Kim | |
861 | */ | |
862 | if (sym.st_shndx == SHN_ABS) | |
863 | continue; | |
e5a1845f | 864 | |
261360b6 | 865 | sec = elf_getscn(runtime_ss->elf, sym.st_shndx); |
e5a1845f NK |
866 | if (!sec) |
867 | goto out_elf_end; | |
868 | ||
869 | gelf_getshdr(sec, &shdr); | |
870 | ||
871 | if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type)) | |
872 | continue; | |
873 | ||
874 | section_name = elf_sec__name(&shdr, secstrs); | |
875 | ||
876 | /* On ARM, symbols for thumb functions have 1 added to | |
877 | * the symbol address as a flag - remove it */ | |
878 | if ((ehdr.e_machine == EM_ARM) && | |
879 | (map->type == MAP__FUNCTION) && | |
880 | (sym.st_value & 1)) | |
881 | --sym.st_value; | |
882 | ||
39b12f78 | 883 | if (dso->kernel || kmodule) { |
e5a1845f NK |
884 | char dso_name[PATH_MAX]; |
885 | ||
39b12f78 AH |
886 | /* Adjust symbol to map to file offset */ |
887 | if (adjust_kernel_syms) | |
888 | sym.st_value -= shdr.sh_addr - shdr.sh_offset; | |
889 | ||
e5a1845f NK |
890 | if (strcmp(section_name, |
891 | (curr_dso->short_name + | |
892 | dso->short_name_len)) == 0) | |
893 | goto new_symbol; | |
894 | ||
895 | if (strcmp(section_name, ".text") == 0) { | |
39b12f78 AH |
896 | /* |
897 | * The initial kernel mapping is based on | |
898 | * kallsyms and identity maps. Overwrite it to | |
899 | * map to the kernel dso. | |
900 | */ | |
901 | if (remap_kernel && dso->kernel) { | |
902 | remap_kernel = false; | |
903 | map->start = shdr.sh_addr + | |
904 | ref_reloc(kmap); | |
905 | map->end = map->start + shdr.sh_size; | |
906 | map->pgoff = shdr.sh_offset; | |
907 | map->map_ip = map__map_ip; | |
908 | map->unmap_ip = map__unmap_ip; | |
909 | /* Ensure maps are correctly ordered */ | |
910 | map_groups__remove(kmap->kmaps, map); | |
911 | map_groups__insert(kmap->kmaps, map); | |
912 | } | |
913 | ||
0131c4ec AH |
914 | /* |
915 | * The initial module mapping is based on | |
916 | * /proc/modules mapped to offset zero. | |
917 | * Overwrite it to map to the module dso. | |
918 | */ | |
919 | if (remap_kernel && kmodule) { | |
920 | remap_kernel = false; | |
921 | map->pgoff = shdr.sh_offset; | |
922 | } | |
923 | ||
e5a1845f NK |
924 | curr_map = map; |
925 | curr_dso = dso; | |
926 | goto new_symbol; | |
927 | } | |
928 | ||
0131c4ec AH |
929 | if (!kmap) |
930 | goto new_symbol; | |
931 | ||
e5a1845f NK |
932 | snprintf(dso_name, sizeof(dso_name), |
933 | "%s%s", dso->short_name, section_name); | |
934 | ||
935 | curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name); | |
936 | if (curr_map == NULL) { | |
937 | u64 start = sym.st_value; | |
938 | ||
939 | if (kmodule) | |
940 | start += map->start + shdr.sh_offset; | |
941 | ||
942 | curr_dso = dso__new(dso_name); | |
943 | if (curr_dso == NULL) | |
944 | goto out_elf_end; | |
945 | curr_dso->kernel = dso->kernel; | |
946 | curr_dso->long_name = dso->long_name; | |
947 | curr_dso->long_name_len = dso->long_name_len; | |
948 | curr_map = map__new2(start, curr_dso, | |
949 | map->type); | |
950 | if (curr_map == NULL) { | |
951 | dso__delete(curr_dso); | |
952 | goto out_elf_end; | |
953 | } | |
39b12f78 AH |
954 | if (adjust_kernel_syms) { |
955 | curr_map->start = shdr.sh_addr + | |
956 | ref_reloc(kmap); | |
957 | curr_map->end = curr_map->start + | |
958 | shdr.sh_size; | |
959 | curr_map->pgoff = shdr.sh_offset; | |
960 | } else { | |
961 | curr_map->map_ip = identity__map_ip; | |
962 | curr_map->unmap_ip = identity__map_ip; | |
963 | } | |
e5a1845f NK |
964 | curr_dso->symtab_type = dso->symtab_type; |
965 | map_groups__insert(kmap->kmaps, curr_map); | |
8fa7d87f WL |
966 | /* |
967 | * The new DSO should go to the kernel DSOS | |
968 | */ | |
969 | dsos__add(&map->groups->machine->kernel_dsos, | |
970 | curr_dso); | |
e5a1845f NK |
971 | dso__set_loaded(curr_dso, map->type); |
972 | } else | |
973 | curr_dso = curr_map->dso; | |
974 | ||
975 | goto new_symbol; | |
976 | } | |
977 | ||
261360b6 CS |
978 | if ((used_opd && runtime_ss->adjust_symbols) |
979 | || (!used_opd && syms_ss->adjust_symbols)) { | |
e5a1845f NK |
980 | pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " |
981 | "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__, | |
982 | (u64)sym.st_value, (u64)shdr.sh_addr, | |
983 | (u64)shdr.sh_offset); | |
984 | sym.st_value -= shdr.sh_addr - shdr.sh_offset; | |
985 | } | |
950b8354 | 986 | new_symbol: |
e5a1845f NK |
987 | /* |
988 | * We need to figure out if the object was created from C++ sources | |
989 | * DWARF DW_compile_unit has this, but we don't always have access | |
990 | * to it... | |
991 | */ | |
763122ad | 992 | if (want_demangle(dso->kernel || kmodule)) { |
e71e7945 NK |
993 | int demangle_flags = DMGL_NO_OPTS; |
994 | if (verbose) | |
995 | demangle_flags = DMGL_PARAMS | DMGL_ANSI; | |
996 | ||
997 | demangled = bfd_demangle(NULL, elf_name, demangle_flags); | |
328ccdac NK |
998 | if (demangled != NULL) |
999 | elf_name = demangled; | |
1000 | } | |
e5a1845f NK |
1001 | f = symbol__new(sym.st_value, sym.st_size, |
1002 | GELF_ST_BIND(sym.st_info), elf_name); | |
1003 | free(demangled); | |
1004 | if (!f) | |
1005 | goto out_elf_end; | |
1006 | ||
1007 | if (filter && filter(curr_map, f)) | |
1008 | symbol__delete(f); | |
1009 | else { | |
1010 | symbols__insert(&curr_dso->symbols[curr_map->type], f); | |
1011 | nr++; | |
1012 | } | |
1013 | } | |
1014 | ||
1015 | /* | |
1016 | * For misannotated, zeroed, ASM function sizes. | |
1017 | */ | |
1018 | if (nr > 0) { | |
1019 | symbols__fixup_duplicate(&dso->symbols[map->type]); | |
1020 | symbols__fixup_end(&dso->symbols[map->type]); | |
1021 | if (kmap) { | |
1022 | /* | |
1023 | * We need to fixup this here too because we create new | |
1024 | * maps here, for things like vsyscall sections. | |
1025 | */ | |
1026 | __map_groups__fixup_end(kmap->kmaps, map->type); | |
1027 | } | |
1028 | } | |
1029 | err = nr; | |
1030 | out_elf_end: | |
e5a1845f NK |
1031 | return err; |
1032 | } | |
1033 | ||
8e0cf965 AH |
1034 | static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data) |
1035 | { | |
1036 | GElf_Phdr phdr; | |
1037 | size_t i, phdrnum; | |
1038 | int err; | |
1039 | u64 sz; | |
1040 | ||
1041 | if (elf_getphdrnum(elf, &phdrnum)) | |
1042 | return -1; | |
1043 | ||
1044 | for (i = 0; i < phdrnum; i++) { | |
1045 | if (gelf_getphdr(elf, i, &phdr) == NULL) | |
1046 | return -1; | |
1047 | if (phdr.p_type != PT_LOAD) | |
1048 | continue; | |
1049 | if (exe) { | |
1050 | if (!(phdr.p_flags & PF_X)) | |
1051 | continue; | |
1052 | } else { | |
1053 | if (!(phdr.p_flags & PF_R)) | |
1054 | continue; | |
1055 | } | |
1056 | sz = min(phdr.p_memsz, phdr.p_filesz); | |
1057 | if (!sz) | |
1058 | continue; | |
1059 | err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data); | |
1060 | if (err) | |
1061 | return err; | |
1062 | } | |
1063 | return 0; | |
1064 | } | |
1065 | ||
1066 | int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data, | |
1067 | bool *is_64_bit) | |
1068 | { | |
1069 | int err; | |
1070 | Elf *elf; | |
1071 | ||
1072 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
1073 | if (elf == NULL) | |
1074 | return -1; | |
1075 | ||
1076 | if (is_64_bit) | |
1077 | *is_64_bit = (gelf_getclass(elf) == ELFCLASS64); | |
1078 | ||
1079 | err = elf_read_maps(elf, exe, mapfn, data); | |
1080 | ||
1081 | elf_end(elf); | |
1082 | return err; | |
1083 | } | |
1084 | ||
2b5b8bb2 AH |
1085 | enum dso_type dso__type_fd(int fd) |
1086 | { | |
1087 | enum dso_type dso_type = DSO__TYPE_UNKNOWN; | |
1088 | GElf_Ehdr ehdr; | |
1089 | Elf_Kind ek; | |
1090 | Elf *elf; | |
1091 | ||
1092 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
1093 | if (elf == NULL) | |
1094 | goto out; | |
1095 | ||
1096 | ek = elf_kind(elf); | |
1097 | if (ek != ELF_K_ELF) | |
1098 | goto out_end; | |
1099 | ||
1100 | if (gelf_getclass(elf) == ELFCLASS64) { | |
1101 | dso_type = DSO__TYPE_64BIT; | |
1102 | goto out_end; | |
1103 | } | |
1104 | ||
1105 | if (gelf_getehdr(elf, &ehdr) == NULL) | |
1106 | goto out_end; | |
1107 | ||
1108 | if (ehdr.e_machine == EM_X86_64) | |
1109 | dso_type = DSO__TYPE_X32BIT; | |
1110 | else | |
1111 | dso_type = DSO__TYPE_32BIT; | |
1112 | out_end: | |
1113 | elf_end(elf); | |
1114 | out: | |
1115 | return dso_type; | |
1116 | } | |
1117 | ||
afba19d9 AH |
1118 | static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len) |
1119 | { | |
1120 | ssize_t r; | |
1121 | size_t n; | |
1122 | int err = -1; | |
1123 | char *buf = malloc(page_size); | |
1124 | ||
1125 | if (buf == NULL) | |
1126 | return -1; | |
1127 | ||
1128 | if (lseek(to, to_offs, SEEK_SET) != to_offs) | |
1129 | goto out; | |
1130 | ||
1131 | if (lseek(from, from_offs, SEEK_SET) != from_offs) | |
1132 | goto out; | |
1133 | ||
1134 | while (len) { | |
1135 | n = page_size; | |
1136 | if (len < n) | |
1137 | n = len; | |
1138 | /* Use read because mmap won't work on proc files */ | |
1139 | r = read(from, buf, n); | |
1140 | if (r < 0) | |
1141 | goto out; | |
1142 | if (!r) | |
1143 | break; | |
1144 | n = r; | |
1145 | r = write(to, buf, n); | |
1146 | if (r < 0) | |
1147 | goto out; | |
1148 | if ((size_t)r != n) | |
1149 | goto out; | |
1150 | len -= n; | |
1151 | } | |
1152 | ||
1153 | err = 0; | |
1154 | out: | |
1155 | free(buf); | |
1156 | return err; | |
1157 | } | |
1158 | ||
1159 | struct kcore { | |
1160 | int fd; | |
1161 | int elfclass; | |
1162 | Elf *elf; | |
1163 | GElf_Ehdr ehdr; | |
1164 | }; | |
1165 | ||
1166 | static int kcore__open(struct kcore *kcore, const char *filename) | |
1167 | { | |
1168 | GElf_Ehdr *ehdr; | |
1169 | ||
1170 | kcore->fd = open(filename, O_RDONLY); | |
1171 | if (kcore->fd == -1) | |
1172 | return -1; | |
1173 | ||
1174 | kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL); | |
1175 | if (!kcore->elf) | |
1176 | goto out_close; | |
1177 | ||
1178 | kcore->elfclass = gelf_getclass(kcore->elf); | |
1179 | if (kcore->elfclass == ELFCLASSNONE) | |
1180 | goto out_end; | |
1181 | ||
1182 | ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr); | |
1183 | if (!ehdr) | |
1184 | goto out_end; | |
1185 | ||
1186 | return 0; | |
1187 | ||
1188 | out_end: | |
1189 | elf_end(kcore->elf); | |
1190 | out_close: | |
1191 | close(kcore->fd); | |
1192 | return -1; | |
1193 | } | |
1194 | ||
1195 | static int kcore__init(struct kcore *kcore, char *filename, int elfclass, | |
1196 | bool temp) | |
1197 | { | |
1198 | GElf_Ehdr *ehdr; | |
1199 | ||
1200 | kcore->elfclass = elfclass; | |
1201 | ||
1202 | if (temp) | |
1203 | kcore->fd = mkstemp(filename); | |
1204 | else | |
1205 | kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400); | |
1206 | if (kcore->fd == -1) | |
1207 | return -1; | |
1208 | ||
1209 | kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL); | |
1210 | if (!kcore->elf) | |
1211 | goto out_close; | |
1212 | ||
1213 | if (!gelf_newehdr(kcore->elf, elfclass)) | |
1214 | goto out_end; | |
1215 | ||
1216 | ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr); | |
1217 | if (!ehdr) | |
1218 | goto out_end; | |
1219 | ||
1220 | return 0; | |
1221 | ||
1222 | out_end: | |
1223 | elf_end(kcore->elf); | |
1224 | out_close: | |
1225 | close(kcore->fd); | |
1226 | unlink(filename); | |
1227 | return -1; | |
1228 | } | |
1229 | ||
1230 | static void kcore__close(struct kcore *kcore) | |
1231 | { | |
1232 | elf_end(kcore->elf); | |
1233 | close(kcore->fd); | |
1234 | } | |
1235 | ||
1236 | static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count) | |
1237 | { | |
1238 | GElf_Ehdr *ehdr = &to->ehdr; | |
1239 | GElf_Ehdr *kehdr = &from->ehdr; | |
1240 | ||
1241 | memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT); | |
1242 | ehdr->e_type = kehdr->e_type; | |
1243 | ehdr->e_machine = kehdr->e_machine; | |
1244 | ehdr->e_version = kehdr->e_version; | |
1245 | ehdr->e_entry = 0; | |
1246 | ehdr->e_shoff = 0; | |
1247 | ehdr->e_flags = kehdr->e_flags; | |
1248 | ehdr->e_phnum = count; | |
1249 | ehdr->e_shentsize = 0; | |
1250 | ehdr->e_shnum = 0; | |
1251 | ehdr->e_shstrndx = 0; | |
1252 | ||
1253 | if (from->elfclass == ELFCLASS32) { | |
1254 | ehdr->e_phoff = sizeof(Elf32_Ehdr); | |
1255 | ehdr->e_ehsize = sizeof(Elf32_Ehdr); | |
1256 | ehdr->e_phentsize = sizeof(Elf32_Phdr); | |
1257 | } else { | |
1258 | ehdr->e_phoff = sizeof(Elf64_Ehdr); | |
1259 | ehdr->e_ehsize = sizeof(Elf64_Ehdr); | |
1260 | ehdr->e_phentsize = sizeof(Elf64_Phdr); | |
1261 | } | |
1262 | ||
1263 | if (!gelf_update_ehdr(to->elf, ehdr)) | |
1264 | return -1; | |
1265 | ||
1266 | if (!gelf_newphdr(to->elf, count)) | |
1267 | return -1; | |
1268 | ||
1269 | return 0; | |
1270 | } | |
1271 | ||
1272 | static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset, | |
1273 | u64 addr, u64 len) | |
1274 | { | |
1275 | GElf_Phdr gphdr; | |
1276 | GElf_Phdr *phdr; | |
1277 | ||
1278 | phdr = gelf_getphdr(kcore->elf, idx, &gphdr); | |
1279 | if (!phdr) | |
1280 | return -1; | |
1281 | ||
1282 | phdr->p_type = PT_LOAD; | |
1283 | phdr->p_flags = PF_R | PF_W | PF_X; | |
1284 | phdr->p_offset = offset; | |
1285 | phdr->p_vaddr = addr; | |
1286 | phdr->p_paddr = 0; | |
1287 | phdr->p_filesz = len; | |
1288 | phdr->p_memsz = len; | |
1289 | phdr->p_align = page_size; | |
1290 | ||
1291 | if (!gelf_update_phdr(kcore->elf, idx, phdr)) | |
1292 | return -1; | |
1293 | ||
1294 | return 0; | |
1295 | } | |
1296 | ||
1297 | static off_t kcore__write(struct kcore *kcore) | |
1298 | { | |
1299 | return elf_update(kcore->elf, ELF_C_WRITE); | |
1300 | } | |
1301 | ||
fc1b691d AH |
1302 | struct phdr_data { |
1303 | off_t offset; | |
1304 | u64 addr; | |
1305 | u64 len; | |
1306 | }; | |
1307 | ||
1308 | struct kcore_copy_info { | |
1309 | u64 stext; | |
1310 | u64 etext; | |
1311 | u64 first_symbol; | |
1312 | u64 last_symbol; | |
1313 | u64 first_module; | |
1314 | u64 last_module_symbol; | |
1315 | struct phdr_data kernel_map; | |
1316 | struct phdr_data modules_map; | |
1317 | }; | |
1318 | ||
1319 | static int kcore_copy__process_kallsyms(void *arg, const char *name, char type, | |
1320 | u64 start) | |
1321 | { | |
1322 | struct kcore_copy_info *kci = arg; | |
1323 | ||
1324 | if (!symbol_type__is_a(type, MAP__FUNCTION)) | |
1325 | return 0; | |
1326 | ||
1327 | if (strchr(name, '[')) { | |
1328 | if (start > kci->last_module_symbol) | |
1329 | kci->last_module_symbol = start; | |
1330 | return 0; | |
1331 | } | |
1332 | ||
1333 | if (!kci->first_symbol || start < kci->first_symbol) | |
1334 | kci->first_symbol = start; | |
1335 | ||
1336 | if (!kci->last_symbol || start > kci->last_symbol) | |
1337 | kci->last_symbol = start; | |
1338 | ||
1339 | if (!strcmp(name, "_stext")) { | |
1340 | kci->stext = start; | |
1341 | return 0; | |
1342 | } | |
1343 | ||
1344 | if (!strcmp(name, "_etext")) { | |
1345 | kci->etext = start; | |
1346 | return 0; | |
1347 | } | |
1348 | ||
1349 | return 0; | |
1350 | } | |
1351 | ||
1352 | static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci, | |
1353 | const char *dir) | |
1354 | { | |
1355 | char kallsyms_filename[PATH_MAX]; | |
1356 | ||
1357 | scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir); | |
1358 | ||
1359 | if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms")) | |
1360 | return -1; | |
1361 | ||
1362 | if (kallsyms__parse(kallsyms_filename, kci, | |
1363 | kcore_copy__process_kallsyms) < 0) | |
1364 | return -1; | |
1365 | ||
1366 | return 0; | |
1367 | } | |
1368 | ||
1369 | static int kcore_copy__process_modules(void *arg, | |
1370 | const char *name __maybe_unused, | |
1371 | u64 start) | |
1372 | { | |
1373 | struct kcore_copy_info *kci = arg; | |
1374 | ||
1375 | if (!kci->first_module || start < kci->first_module) | |
1376 | kci->first_module = start; | |
1377 | ||
1378 | return 0; | |
1379 | } | |
1380 | ||
1381 | static int kcore_copy__parse_modules(struct kcore_copy_info *kci, | |
1382 | const char *dir) | |
1383 | { | |
1384 | char modules_filename[PATH_MAX]; | |
1385 | ||
1386 | scnprintf(modules_filename, PATH_MAX, "%s/modules", dir); | |
1387 | ||
1388 | if (symbol__restricted_filename(modules_filename, "/proc/modules")) | |
1389 | return -1; | |
1390 | ||
1391 | if (modules__parse(modules_filename, kci, | |
1392 | kcore_copy__process_modules) < 0) | |
1393 | return -1; | |
1394 | ||
1395 | return 0; | |
1396 | } | |
1397 | ||
1398 | static void kcore_copy__map(struct phdr_data *p, u64 start, u64 end, u64 pgoff, | |
1399 | u64 s, u64 e) | |
1400 | { | |
1401 | if (p->addr || s < start || s >= end) | |
1402 | return; | |
1403 | ||
1404 | p->addr = s; | |
1405 | p->offset = (s - start) + pgoff; | |
1406 | p->len = e < end ? e - s : end - s; | |
1407 | } | |
1408 | ||
1409 | static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data) | |
1410 | { | |
1411 | struct kcore_copy_info *kci = data; | |
1412 | u64 end = start + len; | |
1413 | ||
1414 | kcore_copy__map(&kci->kernel_map, start, end, pgoff, kci->stext, | |
1415 | kci->etext); | |
1416 | ||
1417 | kcore_copy__map(&kci->modules_map, start, end, pgoff, kci->first_module, | |
1418 | kci->last_module_symbol); | |
1419 | ||
1420 | return 0; | |
1421 | } | |
1422 | ||
1423 | static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf) | |
1424 | { | |
1425 | if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0) | |
1426 | return -1; | |
1427 | ||
1428 | return 0; | |
1429 | } | |
1430 | ||
1431 | static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir, | |
1432 | Elf *elf) | |
1433 | { | |
1434 | if (kcore_copy__parse_kallsyms(kci, dir)) | |
1435 | return -1; | |
1436 | ||
1437 | if (kcore_copy__parse_modules(kci, dir)) | |
1438 | return -1; | |
1439 | ||
1440 | if (kci->stext) | |
1441 | kci->stext = round_down(kci->stext, page_size); | |
1442 | else | |
1443 | kci->stext = round_down(kci->first_symbol, page_size); | |
1444 | ||
1445 | if (kci->etext) { | |
1446 | kci->etext = round_up(kci->etext, page_size); | |
1447 | } else if (kci->last_symbol) { | |
1448 | kci->etext = round_up(kci->last_symbol, page_size); | |
1449 | kci->etext += page_size; | |
1450 | } | |
1451 | ||
1452 | kci->first_module = round_down(kci->first_module, page_size); | |
1453 | ||
1454 | if (kci->last_module_symbol) { | |
1455 | kci->last_module_symbol = round_up(kci->last_module_symbol, | |
1456 | page_size); | |
1457 | kci->last_module_symbol += page_size; | |
1458 | } | |
1459 | ||
1460 | if (!kci->stext || !kci->etext) | |
1461 | return -1; | |
1462 | ||
1463 | if (kci->first_module && !kci->last_module_symbol) | |
1464 | return -1; | |
1465 | ||
1466 | return kcore_copy__read_maps(kci, elf); | |
1467 | } | |
1468 | ||
1469 | static int kcore_copy__copy_file(const char *from_dir, const char *to_dir, | |
1470 | const char *name) | |
1471 | { | |
1472 | char from_filename[PATH_MAX]; | |
1473 | char to_filename[PATH_MAX]; | |
1474 | ||
1475 | scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name); | |
1476 | scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name); | |
1477 | ||
1478 | return copyfile_mode(from_filename, to_filename, 0400); | |
1479 | } | |
1480 | ||
1481 | static int kcore_copy__unlink(const char *dir, const char *name) | |
1482 | { | |
1483 | char filename[PATH_MAX]; | |
1484 | ||
1485 | scnprintf(filename, PATH_MAX, "%s/%s", dir, name); | |
1486 | ||
1487 | return unlink(filename); | |
1488 | } | |
1489 | ||
1490 | static int kcore_copy__compare_fds(int from, int to) | |
1491 | { | |
1492 | char *buf_from; | |
1493 | char *buf_to; | |
1494 | ssize_t ret; | |
1495 | size_t len; | |
1496 | int err = -1; | |
1497 | ||
1498 | buf_from = malloc(page_size); | |
1499 | buf_to = malloc(page_size); | |
1500 | if (!buf_from || !buf_to) | |
1501 | goto out; | |
1502 | ||
1503 | while (1) { | |
1504 | /* Use read because mmap won't work on proc files */ | |
1505 | ret = read(from, buf_from, page_size); | |
1506 | if (ret < 0) | |
1507 | goto out; | |
1508 | ||
1509 | if (!ret) | |
1510 | break; | |
1511 | ||
1512 | len = ret; | |
1513 | ||
1514 | if (readn(to, buf_to, len) != (int)len) | |
1515 | goto out; | |
1516 | ||
1517 | if (memcmp(buf_from, buf_to, len)) | |
1518 | goto out; | |
1519 | } | |
1520 | ||
1521 | err = 0; | |
1522 | out: | |
1523 | free(buf_to); | |
1524 | free(buf_from); | |
1525 | return err; | |
1526 | } | |
1527 | ||
1528 | static int kcore_copy__compare_files(const char *from_filename, | |
1529 | const char *to_filename) | |
1530 | { | |
1531 | int from, to, err = -1; | |
1532 | ||
1533 | from = open(from_filename, O_RDONLY); | |
1534 | if (from < 0) | |
1535 | return -1; | |
1536 | ||
1537 | to = open(to_filename, O_RDONLY); | |
1538 | if (to < 0) | |
1539 | goto out_close_from; | |
1540 | ||
1541 | err = kcore_copy__compare_fds(from, to); | |
1542 | ||
1543 | close(to); | |
1544 | out_close_from: | |
1545 | close(from); | |
1546 | return err; | |
1547 | } | |
1548 | ||
1549 | static int kcore_copy__compare_file(const char *from_dir, const char *to_dir, | |
1550 | const char *name) | |
1551 | { | |
1552 | char from_filename[PATH_MAX]; | |
1553 | char to_filename[PATH_MAX]; | |
1554 | ||
1555 | scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name); | |
1556 | scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name); | |
1557 | ||
1558 | return kcore_copy__compare_files(from_filename, to_filename); | |
1559 | } | |
1560 | ||
1561 | /** | |
1562 | * kcore_copy - copy kallsyms, modules and kcore from one directory to another. | |
1563 | * @from_dir: from directory | |
1564 | * @to_dir: to directory | |
1565 | * | |
1566 | * This function copies kallsyms, modules and kcore files from one directory to | |
1567 | * another. kallsyms and modules are copied entirely. Only code segments are | |
1568 | * copied from kcore. It is assumed that two segments suffice: one for the | |
1569 | * kernel proper and one for all the modules. The code segments are determined | |
1570 | * from kallsyms and modules files. The kernel map starts at _stext or the | |
1571 | * lowest function symbol, and ends at _etext or the highest function symbol. | |
1572 | * The module map starts at the lowest module address and ends at the highest | |
1573 | * module symbol. Start addresses are rounded down to the nearest page. End | |
1574 | * addresses are rounded up to the nearest page. An extra page is added to the | |
1575 | * highest kernel symbol and highest module symbol to, hopefully, encompass that | |
1576 | * symbol too. Because it contains only code sections, the resulting kcore is | |
1577 | * unusual. One significant peculiarity is that the mapping (start -> pgoff) | |
1578 | * is not the same for the kernel map and the modules map. That happens because | |
1579 | * the data is copied adjacently whereas the original kcore has gaps. Finally, | |
1580 | * kallsyms and modules files are compared with their copies to check that | |
1581 | * modules have not been loaded or unloaded while the copies were taking place. | |
1582 | * | |
1583 | * Return: %0 on success, %-1 on failure. | |
1584 | */ | |
1585 | int kcore_copy(const char *from_dir, const char *to_dir) | |
1586 | { | |
1587 | struct kcore kcore; | |
1588 | struct kcore extract; | |
1589 | size_t count = 2; | |
1590 | int idx = 0, err = -1; | |
1591 | off_t offset = page_size, sz, modules_offset = 0; | |
1592 | struct kcore_copy_info kci = { .stext = 0, }; | |
1593 | char kcore_filename[PATH_MAX]; | |
1594 | char extract_filename[PATH_MAX]; | |
1595 | ||
1596 | if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms")) | |
1597 | return -1; | |
1598 | ||
1599 | if (kcore_copy__copy_file(from_dir, to_dir, "modules")) | |
1600 | goto out_unlink_kallsyms; | |
1601 | ||
1602 | scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir); | |
1603 | scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir); | |
1604 | ||
1605 | if (kcore__open(&kcore, kcore_filename)) | |
1606 | goto out_unlink_modules; | |
1607 | ||
1608 | if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf)) | |
1609 | goto out_kcore_close; | |
1610 | ||
1611 | if (kcore__init(&extract, extract_filename, kcore.elfclass, false)) | |
1612 | goto out_kcore_close; | |
1613 | ||
1614 | if (!kci.modules_map.addr) | |
1615 | count -= 1; | |
1616 | ||
1617 | if (kcore__copy_hdr(&kcore, &extract, count)) | |
1618 | goto out_extract_close; | |
1619 | ||
1620 | if (kcore__add_phdr(&extract, idx++, offset, kci.kernel_map.addr, | |
1621 | kci.kernel_map.len)) | |
1622 | goto out_extract_close; | |
1623 | ||
1624 | if (kci.modules_map.addr) { | |
1625 | modules_offset = offset + kci.kernel_map.len; | |
1626 | if (kcore__add_phdr(&extract, idx, modules_offset, | |
1627 | kci.modules_map.addr, kci.modules_map.len)) | |
1628 | goto out_extract_close; | |
1629 | } | |
1630 | ||
1631 | sz = kcore__write(&extract); | |
1632 | if (sz < 0 || sz > offset) | |
1633 | goto out_extract_close; | |
1634 | ||
1635 | if (copy_bytes(kcore.fd, kci.kernel_map.offset, extract.fd, offset, | |
1636 | kci.kernel_map.len)) | |
1637 | goto out_extract_close; | |
1638 | ||
1639 | if (modules_offset && copy_bytes(kcore.fd, kci.modules_map.offset, | |
1640 | extract.fd, modules_offset, | |
1641 | kci.modules_map.len)) | |
1642 | goto out_extract_close; | |
1643 | ||
1644 | if (kcore_copy__compare_file(from_dir, to_dir, "modules")) | |
1645 | goto out_extract_close; | |
1646 | ||
1647 | if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms")) | |
1648 | goto out_extract_close; | |
1649 | ||
1650 | err = 0; | |
1651 | ||
1652 | out_extract_close: | |
1653 | kcore__close(&extract); | |
1654 | if (err) | |
1655 | unlink(extract_filename); | |
1656 | out_kcore_close: | |
1657 | kcore__close(&kcore); | |
1658 | out_unlink_modules: | |
1659 | if (err) | |
1660 | kcore_copy__unlink(to_dir, "modules"); | |
1661 | out_unlink_kallsyms: | |
1662 | if (err) | |
1663 | kcore_copy__unlink(to_dir, "kallsyms"); | |
1664 | ||
1665 | return err; | |
1666 | } | |
1667 | ||
afba19d9 AH |
1668 | int kcore_extract__create(struct kcore_extract *kce) |
1669 | { | |
1670 | struct kcore kcore; | |
1671 | struct kcore extract; | |
1672 | size_t count = 1; | |
1673 | int idx = 0, err = -1; | |
1674 | off_t offset = page_size, sz; | |
1675 | ||
1676 | if (kcore__open(&kcore, kce->kcore_filename)) | |
1677 | return -1; | |
1678 | ||
1679 | strcpy(kce->extract_filename, PERF_KCORE_EXTRACT); | |
1680 | if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true)) | |
1681 | goto out_kcore_close; | |
1682 | ||
1683 | if (kcore__copy_hdr(&kcore, &extract, count)) | |
1684 | goto out_extract_close; | |
1685 | ||
1686 | if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len)) | |
1687 | goto out_extract_close; | |
1688 | ||
1689 | sz = kcore__write(&extract); | |
1690 | if (sz < 0 || sz > offset) | |
1691 | goto out_extract_close; | |
1692 | ||
1693 | if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len)) | |
1694 | goto out_extract_close; | |
1695 | ||
1696 | err = 0; | |
1697 | ||
1698 | out_extract_close: | |
1699 | kcore__close(&extract); | |
1700 | if (err) | |
1701 | unlink(kce->extract_filename); | |
1702 | out_kcore_close: | |
1703 | kcore__close(&kcore); | |
1704 | ||
1705 | return err; | |
1706 | } | |
1707 | ||
1708 | void kcore_extract__delete(struct kcore_extract *kce) | |
1709 | { | |
1710 | unlink(kce->extract_filename); | |
1711 | } | |
1712 | ||
e5a1845f NK |
1713 | void symbol__elf_init(void) |
1714 | { | |
1715 | elf_version(EV_CURRENT); | |
1716 | } |