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Merge tag 'staging-4.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...
[deliverable/linux.git] / tools / perf / util / symbol-elf.c
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 "machine.h"
10 #include "vdso.h"
11 #include <symbol/kallsyms.h>
12 #include "debug.h"
13
14 #ifndef EM_AARCH64
15 #define EM_AARCH64 183 /* ARM 64 bit */
16 #endif
17
18
19 #ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
20 extern char *cplus_demangle(const char *, int);
21
22 static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
23 {
24 return cplus_demangle(c, i);
25 }
26 #else
27 #ifdef NO_DEMANGLE
28 static inline char *bfd_demangle(void __maybe_unused *v,
29 const char __maybe_unused *c,
30 int __maybe_unused i)
31 {
32 return NULL;
33 }
34 #else
35 #define PACKAGE 'perf'
36 #include <bfd.h>
37 #endif
38 #endif
39
40 #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
41 static int elf_getphdrnum(Elf *elf, size_t *dst)
42 {
43 GElf_Ehdr gehdr;
44 GElf_Ehdr *ehdr;
45
46 ehdr = gelf_getehdr(elf, &gehdr);
47 if (!ehdr)
48 return -1;
49
50 *dst = ehdr->e_phnum;
51
52 return 0;
53 }
54 #endif
55
56 #ifndef NT_GNU_BUILD_ID
57 #define NT_GNU_BUILD_ID 3
58 #endif
59
60 /**
61 * elf_symtab__for_each_symbol - iterate thru all the symbols
62 *
63 * @syms: struct elf_symtab instance to iterate
64 * @idx: uint32_t idx
65 * @sym: GElf_Sym iterator
66 */
67 #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
68 for (idx = 0, gelf_getsym(syms, idx, &sym);\
69 idx < nr_syms; \
70 idx++, gelf_getsym(syms, idx, &sym))
71
72 static inline uint8_t elf_sym__type(const GElf_Sym *sym)
73 {
74 return GELF_ST_TYPE(sym->st_info);
75 }
76
77 static inline int elf_sym__is_function(const GElf_Sym *sym)
78 {
79 return (elf_sym__type(sym) == STT_FUNC ||
80 elf_sym__type(sym) == STT_GNU_IFUNC) &&
81 sym->st_name != 0 &&
82 sym->st_shndx != SHN_UNDEF;
83 }
84
85 static inline bool elf_sym__is_object(const GElf_Sym *sym)
86 {
87 return elf_sym__type(sym) == STT_OBJECT &&
88 sym->st_name != 0 &&
89 sym->st_shndx != SHN_UNDEF;
90 }
91
92 static inline int elf_sym__is_label(const GElf_Sym *sym)
93 {
94 return elf_sym__type(sym) == STT_NOTYPE &&
95 sym->st_name != 0 &&
96 sym->st_shndx != SHN_UNDEF &&
97 sym->st_shndx != SHN_ABS;
98 }
99
100 static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
101 {
102 switch (type) {
103 case MAP__FUNCTION:
104 return elf_sym__is_function(sym);
105 case MAP__VARIABLE:
106 return elf_sym__is_object(sym);
107 default:
108 return false;
109 }
110 }
111
112 static inline const char *elf_sym__name(const GElf_Sym *sym,
113 const Elf_Data *symstrs)
114 {
115 return symstrs->d_buf + sym->st_name;
116 }
117
118 static inline const char *elf_sec__name(const GElf_Shdr *shdr,
119 const Elf_Data *secstrs)
120 {
121 return secstrs->d_buf + shdr->sh_name;
122 }
123
124 static inline int elf_sec__is_text(const GElf_Shdr *shdr,
125 const Elf_Data *secstrs)
126 {
127 return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
128 }
129
130 static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
131 const Elf_Data *secstrs)
132 {
133 return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
134 }
135
136 static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
137 enum map_type type)
138 {
139 switch (type) {
140 case MAP__FUNCTION:
141 return elf_sec__is_text(shdr, secstrs);
142 case MAP__VARIABLE:
143 return elf_sec__is_data(shdr, secstrs);
144 default:
145 return false;
146 }
147 }
148
149 static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
150 {
151 Elf_Scn *sec = NULL;
152 GElf_Shdr shdr;
153 size_t cnt = 1;
154
155 while ((sec = elf_nextscn(elf, sec)) != NULL) {
156 gelf_getshdr(sec, &shdr);
157
158 if ((addr >= shdr.sh_addr) &&
159 (addr < (shdr.sh_addr + shdr.sh_size)))
160 return cnt;
161
162 ++cnt;
163 }
164
165 return -1;
166 }
167
168 Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
169 GElf_Shdr *shp, const char *name, size_t *idx)
170 {
171 Elf_Scn *sec = NULL;
172 size_t cnt = 1;
173
174 /* Elf is corrupted/truncated, avoid calling elf_strptr. */
175 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
176 return NULL;
177
178 while ((sec = elf_nextscn(elf, sec)) != NULL) {
179 char *str;
180
181 gelf_getshdr(sec, shp);
182 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
183 if (str && !strcmp(name, str)) {
184 if (idx)
185 *idx = cnt;
186 return sec;
187 }
188 ++cnt;
189 }
190
191 return NULL;
192 }
193
194 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
195 for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
196 idx < nr_entries; \
197 ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
198
199 #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
200 for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
201 idx < nr_entries; \
202 ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
203
204 /*
205 * We need to check if we have a .dynsym, so that we can handle the
206 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
207 * .dynsym or .symtab).
208 * And always look at the original dso, not at debuginfo packages, that
209 * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
210 */
211 int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
212 symbol_filter_t filter)
213 {
214 uint32_t nr_rel_entries, idx;
215 GElf_Sym sym;
216 u64 plt_offset;
217 GElf_Shdr shdr_plt;
218 struct symbol *f;
219 GElf_Shdr shdr_rel_plt, shdr_dynsym;
220 Elf_Data *reldata, *syms, *symstrs;
221 Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
222 size_t dynsym_idx;
223 GElf_Ehdr ehdr;
224 char sympltname[1024];
225 Elf *elf;
226 int nr = 0, symidx, err = 0;
227
228 if (!ss->dynsym)
229 return 0;
230
231 elf = ss->elf;
232 ehdr = ss->ehdr;
233
234 scn_dynsym = ss->dynsym;
235 shdr_dynsym = ss->dynshdr;
236 dynsym_idx = ss->dynsym_idx;
237
238 if (scn_dynsym == NULL)
239 goto out_elf_end;
240
241 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
242 ".rela.plt", NULL);
243 if (scn_plt_rel == NULL) {
244 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
245 ".rel.plt", NULL);
246 if (scn_plt_rel == NULL)
247 goto out_elf_end;
248 }
249
250 err = -1;
251
252 if (shdr_rel_plt.sh_link != dynsym_idx)
253 goto out_elf_end;
254
255 if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
256 goto out_elf_end;
257
258 /*
259 * Fetch the relocation section to find the idxes to the GOT
260 * and the symbols in the .dynsym they refer to.
261 */
262 reldata = elf_getdata(scn_plt_rel, NULL);
263 if (reldata == NULL)
264 goto out_elf_end;
265
266 syms = elf_getdata(scn_dynsym, NULL);
267 if (syms == NULL)
268 goto out_elf_end;
269
270 scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
271 if (scn_symstrs == NULL)
272 goto out_elf_end;
273
274 symstrs = elf_getdata(scn_symstrs, NULL);
275 if (symstrs == NULL)
276 goto out_elf_end;
277
278 if (symstrs->d_size == 0)
279 goto out_elf_end;
280
281 nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
282 plt_offset = shdr_plt.sh_offset;
283
284 if (shdr_rel_plt.sh_type == SHT_RELA) {
285 GElf_Rela pos_mem, *pos;
286
287 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
288 nr_rel_entries) {
289 symidx = GELF_R_SYM(pos->r_info);
290 plt_offset += shdr_plt.sh_entsize;
291 gelf_getsym(syms, symidx, &sym);
292 snprintf(sympltname, sizeof(sympltname),
293 "%s@plt", elf_sym__name(&sym, symstrs));
294
295 f = symbol__new(plt_offset, shdr_plt.sh_entsize,
296 STB_GLOBAL, sympltname);
297 if (!f)
298 goto out_elf_end;
299
300 if (filter && filter(map, f))
301 symbol__delete(f);
302 else {
303 symbols__insert(&dso->symbols[map->type], f);
304 ++nr;
305 }
306 }
307 } else if (shdr_rel_plt.sh_type == SHT_REL) {
308 GElf_Rel pos_mem, *pos;
309 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
310 nr_rel_entries) {
311 symidx = GELF_R_SYM(pos->r_info);
312 plt_offset += shdr_plt.sh_entsize;
313 gelf_getsym(syms, symidx, &sym);
314 snprintf(sympltname, sizeof(sympltname),
315 "%s@plt", elf_sym__name(&sym, symstrs));
316
317 f = symbol__new(plt_offset, shdr_plt.sh_entsize,
318 STB_GLOBAL, sympltname);
319 if (!f)
320 goto out_elf_end;
321
322 if (filter && filter(map, f))
323 symbol__delete(f);
324 else {
325 symbols__insert(&dso->symbols[map->type], f);
326 ++nr;
327 }
328 }
329 }
330
331 err = 0;
332 out_elf_end:
333 if (err == 0)
334 return nr;
335 pr_debug("%s: problems reading %s PLT info.\n",
336 __func__, dso->long_name);
337 return 0;
338 }
339
340 /*
341 * Align offset to 4 bytes as needed for note name and descriptor data.
342 */
343 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
344
345 static int elf_read_build_id(Elf *elf, void *bf, size_t size)
346 {
347 int err = -1;
348 GElf_Ehdr ehdr;
349 GElf_Shdr shdr;
350 Elf_Data *data;
351 Elf_Scn *sec;
352 Elf_Kind ek;
353 void *ptr;
354
355 if (size < BUILD_ID_SIZE)
356 goto out;
357
358 ek = elf_kind(elf);
359 if (ek != ELF_K_ELF)
360 goto out;
361
362 if (gelf_getehdr(elf, &ehdr) == NULL) {
363 pr_err("%s: cannot get elf header.\n", __func__);
364 goto out;
365 }
366
367 /*
368 * Check following sections for notes:
369 * '.note.gnu.build-id'
370 * '.notes'
371 * '.note' (VDSO specific)
372 */
373 do {
374 sec = elf_section_by_name(elf, &ehdr, &shdr,
375 ".note.gnu.build-id", NULL);
376 if (sec)
377 break;
378
379 sec = elf_section_by_name(elf, &ehdr, &shdr,
380 ".notes", NULL);
381 if (sec)
382 break;
383
384 sec = elf_section_by_name(elf, &ehdr, &shdr,
385 ".note", NULL);
386 if (sec)
387 break;
388
389 return err;
390
391 } while (0);
392
393 data = elf_getdata(sec, NULL);
394 if (data == NULL)
395 goto out;
396
397 ptr = data->d_buf;
398 while (ptr < (data->d_buf + data->d_size)) {
399 GElf_Nhdr *nhdr = ptr;
400 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
401 descsz = NOTE_ALIGN(nhdr->n_descsz);
402 const char *name;
403
404 ptr += sizeof(*nhdr);
405 name = ptr;
406 ptr += namesz;
407 if (nhdr->n_type == NT_GNU_BUILD_ID &&
408 nhdr->n_namesz == sizeof("GNU")) {
409 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
410 size_t sz = min(size, descsz);
411 memcpy(bf, ptr, sz);
412 memset(bf + sz, 0, size - sz);
413 err = descsz;
414 break;
415 }
416 }
417 ptr += descsz;
418 }
419
420 out:
421 return err;
422 }
423
424 int filename__read_build_id(const char *filename, void *bf, size_t size)
425 {
426 int fd, err = -1;
427 Elf *elf;
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 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
437 if (elf == NULL) {
438 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
439 goto out_close;
440 }
441
442 err = elf_read_build_id(elf, bf, size);
443
444 elf_end(elf);
445 out_close:
446 close(fd);
447 out:
448 return err;
449 }
450
451 int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
452 {
453 int fd, err = -1;
454
455 if (size < BUILD_ID_SIZE)
456 goto out;
457
458 fd = open(filename, O_RDONLY);
459 if (fd < 0)
460 goto out;
461
462 while (1) {
463 char bf[BUFSIZ];
464 GElf_Nhdr nhdr;
465 size_t namesz, descsz;
466
467 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
468 break;
469
470 namesz = NOTE_ALIGN(nhdr.n_namesz);
471 descsz = NOTE_ALIGN(nhdr.n_descsz);
472 if (nhdr.n_type == NT_GNU_BUILD_ID &&
473 nhdr.n_namesz == sizeof("GNU")) {
474 if (read(fd, bf, namesz) != (ssize_t)namesz)
475 break;
476 if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
477 size_t sz = min(descsz, size);
478 if (read(fd, build_id, sz) == (ssize_t)sz) {
479 memset(build_id + sz, 0, size - sz);
480 err = 0;
481 break;
482 }
483 } else if (read(fd, bf, descsz) != (ssize_t)descsz)
484 break;
485 } else {
486 int n = namesz + descsz;
487 if (read(fd, bf, n) != n)
488 break;
489 }
490 }
491 close(fd);
492 out:
493 return err;
494 }
495
496 int filename__read_debuglink(const char *filename, char *debuglink,
497 size_t size)
498 {
499 int fd, err = -1;
500 Elf *elf;
501 GElf_Ehdr ehdr;
502 GElf_Shdr shdr;
503 Elf_Data *data;
504 Elf_Scn *sec;
505 Elf_Kind ek;
506
507 fd = open(filename, O_RDONLY);
508 if (fd < 0)
509 goto out;
510
511 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
512 if (elf == NULL) {
513 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
514 goto out_close;
515 }
516
517 ek = elf_kind(elf);
518 if (ek != ELF_K_ELF)
519 goto out_elf_end;
520
521 if (gelf_getehdr(elf, &ehdr) == NULL) {
522 pr_err("%s: cannot get elf header.\n", __func__);
523 goto out_elf_end;
524 }
525
526 sec = elf_section_by_name(elf, &ehdr, &shdr,
527 ".gnu_debuglink", NULL);
528 if (sec == NULL)
529 goto out_elf_end;
530
531 data = elf_getdata(sec, NULL);
532 if (data == NULL)
533 goto out_elf_end;
534
535 /* the start of this section is a zero-terminated string */
536 strncpy(debuglink, data->d_buf, size);
537
538 err = 0;
539
540 out_elf_end:
541 elf_end(elf);
542 out_close:
543 close(fd);
544 out:
545 return err;
546 }
547
548 static int dso__swap_init(struct dso *dso, unsigned char eidata)
549 {
550 static unsigned int const endian = 1;
551
552 dso->needs_swap = DSO_SWAP__NO;
553
554 switch (eidata) {
555 case ELFDATA2LSB:
556 /* We are big endian, DSO is little endian. */
557 if (*(unsigned char const *)&endian != 1)
558 dso->needs_swap = DSO_SWAP__YES;
559 break;
560
561 case ELFDATA2MSB:
562 /* We are little endian, DSO is big endian. */
563 if (*(unsigned char const *)&endian != 0)
564 dso->needs_swap = DSO_SWAP__YES;
565 break;
566
567 default:
568 pr_err("unrecognized DSO data encoding %d\n", eidata);
569 return -EINVAL;
570 }
571
572 return 0;
573 }
574
575 static int decompress_kmodule(struct dso *dso, const char *name,
576 enum dso_binary_type type)
577 {
578 int fd;
579 const char *ext = strrchr(name, '.');
580 char tmpbuf[] = "/tmp/perf-kmod-XXXXXX";
581
582 if (type != DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP &&
583 type != DSO_BINARY_TYPE__GUEST_KMODULE_COMP &&
584 type != DSO_BINARY_TYPE__BUILD_ID_CACHE)
585 return -1;
586
587 if (!ext || !is_supported_compression(ext + 1)) {
588 ext = strrchr(dso->name, '.');
589 if (!ext || !is_supported_compression(ext + 1))
590 return -1;
591 }
592
593 fd = mkstemp(tmpbuf);
594 if (fd < 0)
595 return -1;
596
597 if (!decompress_to_file(ext + 1, name, fd)) {
598 close(fd);
599 fd = -1;
600 }
601
602 unlink(tmpbuf);
603
604 return fd;
605 }
606
607 bool symsrc__possibly_runtime(struct symsrc *ss)
608 {
609 return ss->dynsym || ss->opdsec;
610 }
611
612 bool symsrc__has_symtab(struct symsrc *ss)
613 {
614 return ss->symtab != NULL;
615 }
616
617 void symsrc__destroy(struct symsrc *ss)
618 {
619 zfree(&ss->name);
620 elf_end(ss->elf);
621 close(ss->fd);
622 }
623
624 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
625 enum dso_binary_type type)
626 {
627 int err = -1;
628 GElf_Ehdr ehdr;
629 Elf *elf;
630 int fd;
631
632 if (dso__needs_decompress(dso))
633 fd = decompress_kmodule(dso, name, type);
634 else
635 fd = open(name, O_RDONLY);
636
637 if (fd < 0)
638 return -1;
639
640 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
641 if (elf == NULL) {
642 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
643 goto out_close;
644 }
645
646 if (gelf_getehdr(elf, &ehdr) == NULL) {
647 pr_debug("%s: cannot get elf header.\n", __func__);
648 goto out_elf_end;
649 }
650
651 if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
652 goto out_elf_end;
653
654 /* Always reject images with a mismatched build-id: */
655 if (dso->has_build_id) {
656 u8 build_id[BUILD_ID_SIZE];
657
658 if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
659 goto out_elf_end;
660
661 if (!dso__build_id_equal(dso, build_id))
662 goto out_elf_end;
663 }
664
665 ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
666
667 ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
668 NULL);
669 if (ss->symshdr.sh_type != SHT_SYMTAB)
670 ss->symtab = NULL;
671
672 ss->dynsym_idx = 0;
673 ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
674 &ss->dynsym_idx);
675 if (ss->dynshdr.sh_type != SHT_DYNSYM)
676 ss->dynsym = NULL;
677
678 ss->opdidx = 0;
679 ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
680 &ss->opdidx);
681 if (ss->opdshdr.sh_type != SHT_PROGBITS)
682 ss->opdsec = NULL;
683
684 if (dso->kernel == DSO_TYPE_USER) {
685 GElf_Shdr shdr;
686 ss->adjust_symbols = (ehdr.e_type == ET_EXEC ||
687 ehdr.e_type == ET_REL ||
688 dso__is_vdso(dso) ||
689 elf_section_by_name(elf, &ehdr, &shdr,
690 ".gnu.prelink_undo",
691 NULL) != NULL);
692 } else {
693 ss->adjust_symbols = ehdr.e_type == ET_EXEC ||
694 ehdr.e_type == ET_REL;
695 }
696
697 ss->name = strdup(name);
698 if (!ss->name)
699 goto out_elf_end;
700
701 ss->elf = elf;
702 ss->fd = fd;
703 ss->ehdr = ehdr;
704 ss->type = type;
705
706 return 0;
707
708 out_elf_end:
709 elf_end(elf);
710 out_close:
711 close(fd);
712 return err;
713 }
714
715 /**
716 * ref_reloc_sym_not_found - has kernel relocation symbol been found.
717 * @kmap: kernel maps and relocation reference symbol
718 *
719 * This function returns %true if we are dealing with the kernel maps and the
720 * relocation reference symbol has not yet been found. Otherwise %false is
721 * returned.
722 */
723 static bool ref_reloc_sym_not_found(struct kmap *kmap)
724 {
725 return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
726 !kmap->ref_reloc_sym->unrelocated_addr;
727 }
728
729 /**
730 * ref_reloc - kernel relocation offset.
731 * @kmap: kernel maps and relocation reference symbol
732 *
733 * This function returns the offset of kernel addresses as determined by using
734 * the relocation reference symbol i.e. if the kernel has not been relocated
735 * then the return value is zero.
736 */
737 static u64 ref_reloc(struct kmap *kmap)
738 {
739 if (kmap && kmap->ref_reloc_sym &&
740 kmap->ref_reloc_sym->unrelocated_addr)
741 return kmap->ref_reloc_sym->addr -
742 kmap->ref_reloc_sym->unrelocated_addr;
743 return 0;
744 }
745
746 static bool want_demangle(bool is_kernel_sym)
747 {
748 return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
749 }
750
751 int dso__load_sym(struct dso *dso, struct map *map,
752 struct symsrc *syms_ss, struct symsrc *runtime_ss,
753 symbol_filter_t filter, int kmodule)
754 {
755 struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
756 struct map *curr_map = map;
757 struct dso *curr_dso = dso;
758 Elf_Data *symstrs, *secstrs;
759 uint32_t nr_syms;
760 int err = -1;
761 uint32_t idx;
762 GElf_Ehdr ehdr;
763 GElf_Shdr shdr;
764 Elf_Data *syms, *opddata = NULL;
765 GElf_Sym sym;
766 Elf_Scn *sec, *sec_strndx;
767 Elf *elf;
768 int nr = 0;
769 bool remap_kernel = false, adjust_kernel_syms = false;
770
771 dso->symtab_type = syms_ss->type;
772 dso->is_64_bit = syms_ss->is_64_bit;
773 dso->rel = syms_ss->ehdr.e_type == ET_REL;
774
775 /*
776 * Modules may already have symbols from kallsyms, but those symbols
777 * have the wrong values for the dso maps, so remove them.
778 */
779 if (kmodule && syms_ss->symtab)
780 symbols__delete(&dso->symbols[map->type]);
781
782 if (!syms_ss->symtab) {
783 /*
784 * If the vmlinux is stripped, fail so we will fall back
785 * to using kallsyms. The vmlinux runtime symbols aren't
786 * of much use.
787 */
788 if (dso->kernel)
789 goto out_elf_end;
790
791 syms_ss->symtab = syms_ss->dynsym;
792 syms_ss->symshdr = syms_ss->dynshdr;
793 }
794
795 elf = syms_ss->elf;
796 ehdr = syms_ss->ehdr;
797 sec = syms_ss->symtab;
798 shdr = syms_ss->symshdr;
799
800 if (runtime_ss->opdsec)
801 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
802
803 syms = elf_getdata(sec, NULL);
804 if (syms == NULL)
805 goto out_elf_end;
806
807 sec = elf_getscn(elf, shdr.sh_link);
808 if (sec == NULL)
809 goto out_elf_end;
810
811 symstrs = elf_getdata(sec, NULL);
812 if (symstrs == NULL)
813 goto out_elf_end;
814
815 sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
816 if (sec_strndx == NULL)
817 goto out_elf_end;
818
819 secstrs = elf_getdata(sec_strndx, NULL);
820 if (secstrs == NULL)
821 goto out_elf_end;
822
823 nr_syms = shdr.sh_size / shdr.sh_entsize;
824
825 memset(&sym, 0, sizeof(sym));
826
827 /*
828 * The kernel relocation symbol is needed in advance in order to adjust
829 * kernel maps correctly.
830 */
831 if (ref_reloc_sym_not_found(kmap)) {
832 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
833 const char *elf_name = elf_sym__name(&sym, symstrs);
834
835 if (strcmp(elf_name, kmap->ref_reloc_sym->name))
836 continue;
837 kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
838 map->reloc = kmap->ref_reloc_sym->addr -
839 kmap->ref_reloc_sym->unrelocated_addr;
840 break;
841 }
842 }
843
844 dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
845 /*
846 * Initial kernel and module mappings do not map to the dso. For
847 * function mappings, flag the fixups.
848 */
849 if (map->type == MAP__FUNCTION && (dso->kernel || kmodule)) {
850 remap_kernel = true;
851 adjust_kernel_syms = dso->adjust_symbols;
852 }
853 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
854 struct symbol *f;
855 const char *elf_name = elf_sym__name(&sym, symstrs);
856 char *demangled = NULL;
857 int is_label = elf_sym__is_label(&sym);
858 const char *section_name;
859 bool used_opd = false;
860
861 if (!is_label && !elf_sym__is_a(&sym, map->type))
862 continue;
863
864 /* Reject ARM ELF "mapping symbols": these aren't unique and
865 * don't identify functions, so will confuse the profile
866 * output: */
867 if (ehdr.e_machine == EM_ARM) {
868 if (!strcmp(elf_name, "$a") ||
869 !strcmp(elf_name, "$d") ||
870 !strcmp(elf_name, "$t"))
871 continue;
872 }
873
874 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
875 u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
876 u64 *opd = opddata->d_buf + offset;
877 sym.st_value = DSO__SWAP(dso, u64, *opd);
878 sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
879 sym.st_value);
880 used_opd = true;
881 }
882 /*
883 * When loading symbols in a data mapping, ABS symbols (which
884 * has a value of SHN_ABS in its st_shndx) failed at
885 * elf_getscn(). And it marks the loading as a failure so
886 * already loaded symbols cannot be fixed up.
887 *
888 * I'm not sure what should be done. Just ignore them for now.
889 * - Namhyung Kim
890 */
891 if (sym.st_shndx == SHN_ABS)
892 continue;
893
894 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
895 if (!sec)
896 goto out_elf_end;
897
898 gelf_getshdr(sec, &shdr);
899
900 if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
901 continue;
902
903 section_name = elf_sec__name(&shdr, secstrs);
904
905 /* On ARM, symbols for thumb functions have 1 added to
906 * the symbol address as a flag - remove it */
907 if ((ehdr.e_machine == EM_ARM) &&
908 (map->type == MAP__FUNCTION) &&
909 (sym.st_value & 1))
910 --sym.st_value;
911
912 if (dso->kernel || kmodule) {
913 char dso_name[PATH_MAX];
914
915 /* Adjust symbol to map to file offset */
916 if (adjust_kernel_syms)
917 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
918
919 if (strcmp(section_name,
920 (curr_dso->short_name +
921 dso->short_name_len)) == 0)
922 goto new_symbol;
923
924 if (strcmp(section_name, ".text") == 0) {
925 /*
926 * The initial kernel mapping is based on
927 * kallsyms and identity maps. Overwrite it to
928 * map to the kernel dso.
929 */
930 if (remap_kernel && dso->kernel) {
931 remap_kernel = false;
932 map->start = shdr.sh_addr +
933 ref_reloc(kmap);
934 map->end = map->start + shdr.sh_size;
935 map->pgoff = shdr.sh_offset;
936 map->map_ip = map__map_ip;
937 map->unmap_ip = map__unmap_ip;
938 /* Ensure maps are correctly ordered */
939 map_groups__remove(kmap->kmaps, map);
940 map_groups__insert(kmap->kmaps, map);
941 }
942
943 /*
944 * The initial module mapping is based on
945 * /proc/modules mapped to offset zero.
946 * Overwrite it to map to the module dso.
947 */
948 if (remap_kernel && kmodule) {
949 remap_kernel = false;
950 map->pgoff = shdr.sh_offset;
951 }
952
953 curr_map = map;
954 curr_dso = dso;
955 goto new_symbol;
956 }
957
958 if (!kmap)
959 goto new_symbol;
960
961 snprintf(dso_name, sizeof(dso_name),
962 "%s%s", dso->short_name, section_name);
963
964 curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
965 if (curr_map == NULL) {
966 u64 start = sym.st_value;
967
968 if (kmodule)
969 start += map->start + shdr.sh_offset;
970
971 curr_dso = dso__new(dso_name);
972 if (curr_dso == NULL)
973 goto out_elf_end;
974 curr_dso->kernel = dso->kernel;
975 curr_dso->long_name = dso->long_name;
976 curr_dso->long_name_len = dso->long_name_len;
977 curr_map = map__new2(start, curr_dso,
978 map->type);
979 if (curr_map == NULL) {
980 dso__delete(curr_dso);
981 goto out_elf_end;
982 }
983 if (adjust_kernel_syms) {
984 curr_map->start = shdr.sh_addr +
985 ref_reloc(kmap);
986 curr_map->end = curr_map->start +
987 shdr.sh_size;
988 curr_map->pgoff = shdr.sh_offset;
989 } else {
990 curr_map->map_ip = identity__map_ip;
991 curr_map->unmap_ip = identity__map_ip;
992 }
993 curr_dso->symtab_type = dso->symtab_type;
994 map_groups__insert(kmap->kmaps, curr_map);
995 /*
996 * The new DSO should go to the kernel DSOS
997 */
998 dsos__add(&map->groups->machine->kernel_dsos,
999 curr_dso);
1000 dso__set_loaded(curr_dso, map->type);
1001 } else
1002 curr_dso = curr_map->dso;
1003
1004 goto new_symbol;
1005 }
1006
1007 if ((used_opd && runtime_ss->adjust_symbols)
1008 || (!used_opd && syms_ss->adjust_symbols)) {
1009 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1010 "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
1011 (u64)sym.st_value, (u64)shdr.sh_addr,
1012 (u64)shdr.sh_offset);
1013 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1014 }
1015 new_symbol:
1016 /*
1017 * We need to figure out if the object was created from C++ sources
1018 * DWARF DW_compile_unit has this, but we don't always have access
1019 * to it...
1020 */
1021 if (want_demangle(dso->kernel || kmodule)) {
1022 int demangle_flags = DMGL_NO_OPTS;
1023 if (verbose)
1024 demangle_flags = DMGL_PARAMS | DMGL_ANSI;
1025
1026 demangled = bfd_demangle(NULL, elf_name, demangle_flags);
1027 if (demangled != NULL)
1028 elf_name = demangled;
1029 }
1030 f = symbol__new(sym.st_value, sym.st_size,
1031 GELF_ST_BIND(sym.st_info), elf_name);
1032 free(demangled);
1033 if (!f)
1034 goto out_elf_end;
1035
1036 if (filter && filter(curr_map, f))
1037 symbol__delete(f);
1038 else {
1039 symbols__insert(&curr_dso->symbols[curr_map->type], f);
1040 nr++;
1041 }
1042 }
1043
1044 /*
1045 * For misannotated, zeroed, ASM function sizes.
1046 */
1047 if (nr > 0) {
1048 symbols__fixup_duplicate(&dso->symbols[map->type]);
1049 symbols__fixup_end(&dso->symbols[map->type]);
1050 if (kmap) {
1051 /*
1052 * We need to fixup this here too because we create new
1053 * maps here, for things like vsyscall sections.
1054 */
1055 __map_groups__fixup_end(kmap->kmaps, map->type);
1056 }
1057 }
1058 err = nr;
1059 out_elf_end:
1060 return err;
1061 }
1062
1063 static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
1064 {
1065 GElf_Phdr phdr;
1066 size_t i, phdrnum;
1067 int err;
1068 u64 sz;
1069
1070 if (elf_getphdrnum(elf, &phdrnum))
1071 return -1;
1072
1073 for (i = 0; i < phdrnum; i++) {
1074 if (gelf_getphdr(elf, i, &phdr) == NULL)
1075 return -1;
1076 if (phdr.p_type != PT_LOAD)
1077 continue;
1078 if (exe) {
1079 if (!(phdr.p_flags & PF_X))
1080 continue;
1081 } else {
1082 if (!(phdr.p_flags & PF_R))
1083 continue;
1084 }
1085 sz = min(phdr.p_memsz, phdr.p_filesz);
1086 if (!sz)
1087 continue;
1088 err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
1089 if (err)
1090 return err;
1091 }
1092 return 0;
1093 }
1094
1095 int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
1096 bool *is_64_bit)
1097 {
1098 int err;
1099 Elf *elf;
1100
1101 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1102 if (elf == NULL)
1103 return -1;
1104
1105 if (is_64_bit)
1106 *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
1107
1108 err = elf_read_maps(elf, exe, mapfn, data);
1109
1110 elf_end(elf);
1111 return err;
1112 }
1113
1114 enum dso_type dso__type_fd(int fd)
1115 {
1116 enum dso_type dso_type = DSO__TYPE_UNKNOWN;
1117 GElf_Ehdr ehdr;
1118 Elf_Kind ek;
1119 Elf *elf;
1120
1121 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1122 if (elf == NULL)
1123 goto out;
1124
1125 ek = elf_kind(elf);
1126 if (ek != ELF_K_ELF)
1127 goto out_end;
1128
1129 if (gelf_getclass(elf) == ELFCLASS64) {
1130 dso_type = DSO__TYPE_64BIT;
1131 goto out_end;
1132 }
1133
1134 if (gelf_getehdr(elf, &ehdr) == NULL)
1135 goto out_end;
1136
1137 if (ehdr.e_machine == EM_X86_64)
1138 dso_type = DSO__TYPE_X32BIT;
1139 else
1140 dso_type = DSO__TYPE_32BIT;
1141 out_end:
1142 elf_end(elf);
1143 out:
1144 return dso_type;
1145 }
1146
1147 static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
1148 {
1149 ssize_t r;
1150 size_t n;
1151 int err = -1;
1152 char *buf = malloc(page_size);
1153
1154 if (buf == NULL)
1155 return -1;
1156
1157 if (lseek(to, to_offs, SEEK_SET) != to_offs)
1158 goto out;
1159
1160 if (lseek(from, from_offs, SEEK_SET) != from_offs)
1161 goto out;
1162
1163 while (len) {
1164 n = page_size;
1165 if (len < n)
1166 n = len;
1167 /* Use read because mmap won't work on proc files */
1168 r = read(from, buf, n);
1169 if (r < 0)
1170 goto out;
1171 if (!r)
1172 break;
1173 n = r;
1174 r = write(to, buf, n);
1175 if (r < 0)
1176 goto out;
1177 if ((size_t)r != n)
1178 goto out;
1179 len -= n;
1180 }
1181
1182 err = 0;
1183 out:
1184 free(buf);
1185 return err;
1186 }
1187
1188 struct kcore {
1189 int fd;
1190 int elfclass;
1191 Elf *elf;
1192 GElf_Ehdr ehdr;
1193 };
1194
1195 static int kcore__open(struct kcore *kcore, const char *filename)
1196 {
1197 GElf_Ehdr *ehdr;
1198
1199 kcore->fd = open(filename, O_RDONLY);
1200 if (kcore->fd == -1)
1201 return -1;
1202
1203 kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
1204 if (!kcore->elf)
1205 goto out_close;
1206
1207 kcore->elfclass = gelf_getclass(kcore->elf);
1208 if (kcore->elfclass == ELFCLASSNONE)
1209 goto out_end;
1210
1211 ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1212 if (!ehdr)
1213 goto out_end;
1214
1215 return 0;
1216
1217 out_end:
1218 elf_end(kcore->elf);
1219 out_close:
1220 close(kcore->fd);
1221 return -1;
1222 }
1223
1224 static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
1225 bool temp)
1226 {
1227 GElf_Ehdr *ehdr;
1228
1229 kcore->elfclass = elfclass;
1230
1231 if (temp)
1232 kcore->fd = mkstemp(filename);
1233 else
1234 kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
1235 if (kcore->fd == -1)
1236 return -1;
1237
1238 kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
1239 if (!kcore->elf)
1240 goto out_close;
1241
1242 if (!gelf_newehdr(kcore->elf, elfclass))
1243 goto out_end;
1244
1245 ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1246 if (!ehdr)
1247 goto out_end;
1248
1249 return 0;
1250
1251 out_end:
1252 elf_end(kcore->elf);
1253 out_close:
1254 close(kcore->fd);
1255 unlink(filename);
1256 return -1;
1257 }
1258
1259 static void kcore__close(struct kcore *kcore)
1260 {
1261 elf_end(kcore->elf);
1262 close(kcore->fd);
1263 }
1264
1265 static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
1266 {
1267 GElf_Ehdr *ehdr = &to->ehdr;
1268 GElf_Ehdr *kehdr = &from->ehdr;
1269
1270 memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
1271 ehdr->e_type = kehdr->e_type;
1272 ehdr->e_machine = kehdr->e_machine;
1273 ehdr->e_version = kehdr->e_version;
1274 ehdr->e_entry = 0;
1275 ehdr->e_shoff = 0;
1276 ehdr->e_flags = kehdr->e_flags;
1277 ehdr->e_phnum = count;
1278 ehdr->e_shentsize = 0;
1279 ehdr->e_shnum = 0;
1280 ehdr->e_shstrndx = 0;
1281
1282 if (from->elfclass == ELFCLASS32) {
1283 ehdr->e_phoff = sizeof(Elf32_Ehdr);
1284 ehdr->e_ehsize = sizeof(Elf32_Ehdr);
1285 ehdr->e_phentsize = sizeof(Elf32_Phdr);
1286 } else {
1287 ehdr->e_phoff = sizeof(Elf64_Ehdr);
1288 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1289 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1290 }
1291
1292 if (!gelf_update_ehdr(to->elf, ehdr))
1293 return -1;
1294
1295 if (!gelf_newphdr(to->elf, count))
1296 return -1;
1297
1298 return 0;
1299 }
1300
1301 static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
1302 u64 addr, u64 len)
1303 {
1304 GElf_Phdr gphdr;
1305 GElf_Phdr *phdr;
1306
1307 phdr = gelf_getphdr(kcore->elf, idx, &gphdr);
1308 if (!phdr)
1309 return -1;
1310
1311 phdr->p_type = PT_LOAD;
1312 phdr->p_flags = PF_R | PF_W | PF_X;
1313 phdr->p_offset = offset;
1314 phdr->p_vaddr = addr;
1315 phdr->p_paddr = 0;
1316 phdr->p_filesz = len;
1317 phdr->p_memsz = len;
1318 phdr->p_align = page_size;
1319
1320 if (!gelf_update_phdr(kcore->elf, idx, phdr))
1321 return -1;
1322
1323 return 0;
1324 }
1325
1326 static off_t kcore__write(struct kcore *kcore)
1327 {
1328 return elf_update(kcore->elf, ELF_C_WRITE);
1329 }
1330
1331 struct phdr_data {
1332 off_t offset;
1333 u64 addr;
1334 u64 len;
1335 };
1336
1337 struct kcore_copy_info {
1338 u64 stext;
1339 u64 etext;
1340 u64 first_symbol;
1341 u64 last_symbol;
1342 u64 first_module;
1343 u64 last_module_symbol;
1344 struct phdr_data kernel_map;
1345 struct phdr_data modules_map;
1346 };
1347
1348 static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
1349 u64 start)
1350 {
1351 struct kcore_copy_info *kci = arg;
1352
1353 if (!symbol_type__is_a(type, MAP__FUNCTION))
1354 return 0;
1355
1356 if (strchr(name, '[')) {
1357 if (start > kci->last_module_symbol)
1358 kci->last_module_symbol = start;
1359 return 0;
1360 }
1361
1362 if (!kci->first_symbol || start < kci->first_symbol)
1363 kci->first_symbol = start;
1364
1365 if (!kci->last_symbol || start > kci->last_symbol)
1366 kci->last_symbol = start;
1367
1368 if (!strcmp(name, "_stext")) {
1369 kci->stext = start;
1370 return 0;
1371 }
1372
1373 if (!strcmp(name, "_etext")) {
1374 kci->etext = start;
1375 return 0;
1376 }
1377
1378 return 0;
1379 }
1380
1381 static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
1382 const char *dir)
1383 {
1384 char kallsyms_filename[PATH_MAX];
1385
1386 scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
1387
1388 if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
1389 return -1;
1390
1391 if (kallsyms__parse(kallsyms_filename, kci,
1392 kcore_copy__process_kallsyms) < 0)
1393 return -1;
1394
1395 return 0;
1396 }
1397
1398 static int kcore_copy__process_modules(void *arg,
1399 const char *name __maybe_unused,
1400 u64 start)
1401 {
1402 struct kcore_copy_info *kci = arg;
1403
1404 if (!kci->first_module || start < kci->first_module)
1405 kci->first_module = start;
1406
1407 return 0;
1408 }
1409
1410 static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
1411 const char *dir)
1412 {
1413 char modules_filename[PATH_MAX];
1414
1415 scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
1416
1417 if (symbol__restricted_filename(modules_filename, "/proc/modules"))
1418 return -1;
1419
1420 if (modules__parse(modules_filename, kci,
1421 kcore_copy__process_modules) < 0)
1422 return -1;
1423
1424 return 0;
1425 }
1426
1427 static void kcore_copy__map(struct phdr_data *p, u64 start, u64 end, u64 pgoff,
1428 u64 s, u64 e)
1429 {
1430 if (p->addr || s < start || s >= end)
1431 return;
1432
1433 p->addr = s;
1434 p->offset = (s - start) + pgoff;
1435 p->len = e < end ? e - s : end - s;
1436 }
1437
1438 static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
1439 {
1440 struct kcore_copy_info *kci = data;
1441 u64 end = start + len;
1442
1443 kcore_copy__map(&kci->kernel_map, start, end, pgoff, kci->stext,
1444 kci->etext);
1445
1446 kcore_copy__map(&kci->modules_map, start, end, pgoff, kci->first_module,
1447 kci->last_module_symbol);
1448
1449 return 0;
1450 }
1451
1452 static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
1453 {
1454 if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
1455 return -1;
1456
1457 return 0;
1458 }
1459
1460 static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
1461 Elf *elf)
1462 {
1463 if (kcore_copy__parse_kallsyms(kci, dir))
1464 return -1;
1465
1466 if (kcore_copy__parse_modules(kci, dir))
1467 return -1;
1468
1469 if (kci->stext)
1470 kci->stext = round_down(kci->stext, page_size);
1471 else
1472 kci->stext = round_down(kci->first_symbol, page_size);
1473
1474 if (kci->etext) {
1475 kci->etext = round_up(kci->etext, page_size);
1476 } else if (kci->last_symbol) {
1477 kci->etext = round_up(kci->last_symbol, page_size);
1478 kci->etext += page_size;
1479 }
1480
1481 kci->first_module = round_down(kci->first_module, page_size);
1482
1483 if (kci->last_module_symbol) {
1484 kci->last_module_symbol = round_up(kci->last_module_symbol,
1485 page_size);
1486 kci->last_module_symbol += page_size;
1487 }
1488
1489 if (!kci->stext || !kci->etext)
1490 return -1;
1491
1492 if (kci->first_module && !kci->last_module_symbol)
1493 return -1;
1494
1495 return kcore_copy__read_maps(kci, elf);
1496 }
1497
1498 static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
1499 const char *name)
1500 {
1501 char from_filename[PATH_MAX];
1502 char to_filename[PATH_MAX];
1503
1504 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1505 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1506
1507 return copyfile_mode(from_filename, to_filename, 0400);
1508 }
1509
1510 static int kcore_copy__unlink(const char *dir, const char *name)
1511 {
1512 char filename[PATH_MAX];
1513
1514 scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
1515
1516 return unlink(filename);
1517 }
1518
1519 static int kcore_copy__compare_fds(int from, int to)
1520 {
1521 char *buf_from;
1522 char *buf_to;
1523 ssize_t ret;
1524 size_t len;
1525 int err = -1;
1526
1527 buf_from = malloc(page_size);
1528 buf_to = malloc(page_size);
1529 if (!buf_from || !buf_to)
1530 goto out;
1531
1532 while (1) {
1533 /* Use read because mmap won't work on proc files */
1534 ret = read(from, buf_from, page_size);
1535 if (ret < 0)
1536 goto out;
1537
1538 if (!ret)
1539 break;
1540
1541 len = ret;
1542
1543 if (readn(to, buf_to, len) != (int)len)
1544 goto out;
1545
1546 if (memcmp(buf_from, buf_to, len))
1547 goto out;
1548 }
1549
1550 err = 0;
1551 out:
1552 free(buf_to);
1553 free(buf_from);
1554 return err;
1555 }
1556
1557 static int kcore_copy__compare_files(const char *from_filename,
1558 const char *to_filename)
1559 {
1560 int from, to, err = -1;
1561
1562 from = open(from_filename, O_RDONLY);
1563 if (from < 0)
1564 return -1;
1565
1566 to = open(to_filename, O_RDONLY);
1567 if (to < 0)
1568 goto out_close_from;
1569
1570 err = kcore_copy__compare_fds(from, to);
1571
1572 close(to);
1573 out_close_from:
1574 close(from);
1575 return err;
1576 }
1577
1578 static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
1579 const char *name)
1580 {
1581 char from_filename[PATH_MAX];
1582 char to_filename[PATH_MAX];
1583
1584 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1585 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1586
1587 return kcore_copy__compare_files(from_filename, to_filename);
1588 }
1589
1590 /**
1591 * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
1592 * @from_dir: from directory
1593 * @to_dir: to directory
1594 *
1595 * This function copies kallsyms, modules and kcore files from one directory to
1596 * another. kallsyms and modules are copied entirely. Only code segments are
1597 * copied from kcore. It is assumed that two segments suffice: one for the
1598 * kernel proper and one for all the modules. The code segments are determined
1599 * from kallsyms and modules files. The kernel map starts at _stext or the
1600 * lowest function symbol, and ends at _etext or the highest function symbol.
1601 * The module map starts at the lowest module address and ends at the highest
1602 * module symbol. Start addresses are rounded down to the nearest page. End
1603 * addresses are rounded up to the nearest page. An extra page is added to the
1604 * highest kernel symbol and highest module symbol to, hopefully, encompass that
1605 * symbol too. Because it contains only code sections, the resulting kcore is
1606 * unusual. One significant peculiarity is that the mapping (start -> pgoff)
1607 * is not the same for the kernel map and the modules map. That happens because
1608 * the data is copied adjacently whereas the original kcore has gaps. Finally,
1609 * kallsyms and modules files are compared with their copies to check that
1610 * modules have not been loaded or unloaded while the copies were taking place.
1611 *
1612 * Return: %0 on success, %-1 on failure.
1613 */
1614 int kcore_copy(const char *from_dir, const char *to_dir)
1615 {
1616 struct kcore kcore;
1617 struct kcore extract;
1618 size_t count = 2;
1619 int idx = 0, err = -1;
1620 off_t offset = page_size, sz, modules_offset = 0;
1621 struct kcore_copy_info kci = { .stext = 0, };
1622 char kcore_filename[PATH_MAX];
1623 char extract_filename[PATH_MAX];
1624
1625 if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
1626 return -1;
1627
1628 if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
1629 goto out_unlink_kallsyms;
1630
1631 scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
1632 scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
1633
1634 if (kcore__open(&kcore, kcore_filename))
1635 goto out_unlink_modules;
1636
1637 if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
1638 goto out_kcore_close;
1639
1640 if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
1641 goto out_kcore_close;
1642
1643 if (!kci.modules_map.addr)
1644 count -= 1;
1645
1646 if (kcore__copy_hdr(&kcore, &extract, count))
1647 goto out_extract_close;
1648
1649 if (kcore__add_phdr(&extract, idx++, offset, kci.kernel_map.addr,
1650 kci.kernel_map.len))
1651 goto out_extract_close;
1652
1653 if (kci.modules_map.addr) {
1654 modules_offset = offset + kci.kernel_map.len;
1655 if (kcore__add_phdr(&extract, idx, modules_offset,
1656 kci.modules_map.addr, kci.modules_map.len))
1657 goto out_extract_close;
1658 }
1659
1660 sz = kcore__write(&extract);
1661 if (sz < 0 || sz > offset)
1662 goto out_extract_close;
1663
1664 if (copy_bytes(kcore.fd, kci.kernel_map.offset, extract.fd, offset,
1665 kci.kernel_map.len))
1666 goto out_extract_close;
1667
1668 if (modules_offset && copy_bytes(kcore.fd, kci.modules_map.offset,
1669 extract.fd, modules_offset,
1670 kci.modules_map.len))
1671 goto out_extract_close;
1672
1673 if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
1674 goto out_extract_close;
1675
1676 if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
1677 goto out_extract_close;
1678
1679 err = 0;
1680
1681 out_extract_close:
1682 kcore__close(&extract);
1683 if (err)
1684 unlink(extract_filename);
1685 out_kcore_close:
1686 kcore__close(&kcore);
1687 out_unlink_modules:
1688 if (err)
1689 kcore_copy__unlink(to_dir, "modules");
1690 out_unlink_kallsyms:
1691 if (err)
1692 kcore_copy__unlink(to_dir, "kallsyms");
1693
1694 return err;
1695 }
1696
1697 int kcore_extract__create(struct kcore_extract *kce)
1698 {
1699 struct kcore kcore;
1700 struct kcore extract;
1701 size_t count = 1;
1702 int idx = 0, err = -1;
1703 off_t offset = page_size, sz;
1704
1705 if (kcore__open(&kcore, kce->kcore_filename))
1706 return -1;
1707
1708 strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
1709 if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
1710 goto out_kcore_close;
1711
1712 if (kcore__copy_hdr(&kcore, &extract, count))
1713 goto out_extract_close;
1714
1715 if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
1716 goto out_extract_close;
1717
1718 sz = kcore__write(&extract);
1719 if (sz < 0 || sz > offset)
1720 goto out_extract_close;
1721
1722 if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
1723 goto out_extract_close;
1724
1725 err = 0;
1726
1727 out_extract_close:
1728 kcore__close(&extract);
1729 if (err)
1730 unlink(kce->extract_filename);
1731 out_kcore_close:
1732 kcore__close(&kcore);
1733
1734 return err;
1735 }
1736
1737 void kcore_extract__delete(struct kcore_extract *kce)
1738 {
1739 unlink(kce->extract_filename);
1740 }
1741
1742 void symbol__elf_init(void)
1743 {
1744 elf_version(EV_CURRENT);
1745 }
Linux kernel - Deliverables
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