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Merge tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux
[linux/fpc-iii.git] / tools / perf / util / symbol-elf.c
blob6864661a79dd03a6543d54320f470543304bdb1b
1 #include <fcntl.h>
2 #include <stdio.h>
3 #include <errno.h>
4 #include <string.h>
5 #include <unistd.h>
6 #include <inttypes.h>
7
8 #include "symbol.h"
9 #include "vdso.h"
10 #include <symbol/kallsyms.h>
11 #include "debug.h"
12
13 #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
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
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
140 Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
141 GElf_Shdr *shp, const char *name, size_t *idx)
142 {
143 Elf_Scn *sec = NULL;
144 size_t cnt = 1;
145
146 /* Elf is corrupted/truncated, avoid calling elf_strptr. */
147 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
148 return NULL;
149
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);
155 if (str && !strcmp(name, str)) {
156 if (idx)
157 *idx = cnt;
158 return sec;
159 }
160 ++cnt;
161 }
162
163 return NULL;
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 */
183 int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
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;
198 int nr = 0, symidx, err = 0;
199
200 if (!ss->dynsym)
201 return 0;
202
203 elf = ss->elf;
204 ehdr = ss->ehdr;
205
206 scn_dynsym = ss->dynsym;
207 shdr_dynsym = ss->dynshdr;
208 dynsym_idx = ss->dynsym_idx;
209
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
250 if (symstrs->d_size == 0)
251 goto out_elf_end;
252
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:
305 if (err == 0)
306 return nr;
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)
491 goto out_elf_end;
492
493 if (gelf_getehdr(elf, &ehdr) == NULL) {
494 pr_err("%s: cannot get elf header.\n", __func__);
495 goto out_elf_end;
496 }
497
498 sec = elf_section_by_name(elf, &ehdr, &shdr,
499 ".gnu_debuglink", NULL);
500 if (sec == NULL)
501 goto out_elf_end;
502
503 data = elf_getdata(sec, NULL);
504 if (data == NULL)
505 goto out_elf_end;
506
507 /* the start of this section is a zero-terminated string */
508 strncpy(debuglink, data->d_buf, size);
509
510 err = 0;
511
512 out_elf_end:
513 elf_end(elf);
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
547 bool symsrc__possibly_runtime(struct symsrc *ss)
548 {
549 return ss->dynsym || ss->opdsec;
550 }
551
552 bool symsrc__has_symtab(struct symsrc *ss)
553 {
554 return ss->symtab != NULL;
555 }
556
557 void symsrc__destroy(struct symsrc *ss)
558 {
559 zfree(&ss->name);
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)
566 {
567 int err = -1;
568 GElf_Ehdr ehdr;
569 Elf *elf;
570 int fd;
571
572 fd = open(name, O_RDONLY);
573 if (fd < 0)
574 return -1;
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
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 ||
621 ehdr.e_type == ET_REL ||
622 is_vdso_map(dso->short_name) ||
623 elf_section_by_name(elf, &ehdr, &shdr,
624 ".gnu.prelink_undo",
625 NULL) != NULL);
626 } else {
627 ss->adjust_symbols = ehdr.e_type == ET_EXEC ||
628 ehdr.e_type == ET_REL;
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
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
680 int dso__load_sym(struct dso *dso, struct map *map,
681 struct symsrc *syms_ss, struct symsrc *runtime_ss,
682 symbol_filter_t filter, int kmodule)
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;
692 GElf_Shdr shdr;
693 Elf_Data *syms, *opddata = NULL;
694 GElf_Sym sym;
695 Elf_Scn *sec, *sec_strndx;
696 Elf *elf;
697 int nr = 0;
698 bool remap_kernel = false, adjust_kernel_syms = false;
699
700 dso->symtab_type = syms_ss->type;
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]);
709
710 if (!syms_ss->symtab) {
711 syms_ss->symtab = syms_ss->dynsym;
712 syms_ss->symshdr = syms_ss->dynshdr;
713 }
714
715 elf = syms_ss->elf;
716 ehdr = syms_ss->ehdr;
717 sec = syms_ss->symtab;
718 shdr = syms_ss->symshdr;
719
720 if (runtime_ss->opdsec)
721 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
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));
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;
758 map->reloc = kmap->ref_reloc_sym->addr -
759 kmap->ref_reloc_sym->unrelocated_addr;
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 }
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;
779 bool used_opd = false;
780
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
794 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
795 u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
796 u64 *opd = opddata->d_buf + offset;
797 sym.st_value = DSO__SWAP(dso, u64, *opd);
798 sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
799 sym.st_value);
800 used_opd = true;
801 }
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;
813
814 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
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
832 if (dso->kernel || kmodule) {
833 char dso_name[PATH_MAX];
834
835 /* Adjust symbol to map to file offset */
836 if (adjust_kernel_syms)
837 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
838
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) {
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
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
873 curr_map = map;
874 curr_dso = dso;
875 goto new_symbol;
876 }
877
878 if (!kmap)
879 goto new_symbol;
880
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 }
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 }
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
923 if ((used_opd && runtime_ss->adjust_symbols)
924 || (!used_opd && syms_ss->adjust_symbols)) {
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 }
931 new_symbol:
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 */
937 if (symbol_conf.demangle) {
938 demangled = bfd_demangle(NULL, elf_name,
939 DMGL_PARAMS | DMGL_ANSI);
940 if (demangled != NULL)
941 elf_name = demangled;
942 }
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:
973 return err;
974 }
975
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
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
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
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
1622 void symbol__elf_init(void)
1623 {
1624 elf_version(EV_CURRENT);
1625 }
Linux with added FPC-III support