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perf symbols: Fix a memory leak due to symbol__delete not being used
[linux-2.6-block.git] / tools / perf / util / symbol-elf.c
CommitLineData
e5a1845f
NK		 1#include <fcntl.h>
2#include <stdio.h>
3#include <errno.h>
4#include <string.h>
5#include <unistd.h>
6#include <inttypes.h>
7
8#include "symbol.h"
9#include "debug.h"
10
89fe808a 11#ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
e955d5c4
AH		 12static int elf_getphdrnum(Elf *elf, size_t *dst)
13{
14 GElf_Ehdr gehdr;
15 GElf_Ehdr *ehdr;
16
17 ehdr = gelf_getehdr(elf, &gehdr);
18 if (!ehdr)
19 return -1;
20
21 *dst = ehdr->e_phnum;
22
23 return 0;
24}
25#endif
26
e5a1845f
NK		 27#ifndef NT_GNU_BUILD_ID
28#define NT_GNU_BUILD_ID 3
29#endif
30
31/**
32 * elf_symtab__for_each_symbol - iterate thru all the symbols
33 *
34 * @syms: struct elf_symtab instance to iterate
35 * @idx: uint32_t idx
36 * @sym: GElf_Sym iterator
37 */
38#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
39 for (idx = 0, gelf_getsym(syms, idx, &sym);\
40 idx < nr_syms; \
41 idx++, gelf_getsym(syms, idx, &sym))
42
43static inline uint8_t elf_sym__type(const GElf_Sym *sym)
44{
45 return GELF_ST_TYPE(sym->st_info);
46}
47
48static inline int elf_sym__is_function(const GElf_Sym *sym)
49{
50 return elf_sym__type(sym) == STT_FUNC &&
51 sym->st_name != 0 &&
52 sym->st_shndx != SHN_UNDEF;
53}
54
55static inline bool elf_sym__is_object(const GElf_Sym *sym)
56{
57 return elf_sym__type(sym) == STT_OBJECT &&
58 sym->st_name != 0 &&
59 sym->st_shndx != SHN_UNDEF;
60}
61
62static inline int elf_sym__is_label(const GElf_Sym *sym)
63{
64 return elf_sym__type(sym) == STT_NOTYPE &&
65 sym->st_name != 0 &&
66 sym->st_shndx != SHN_UNDEF &&
67 sym->st_shndx != SHN_ABS;
68}
69
70static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
71{
72 switch (type) {
73 case MAP__FUNCTION:
74 return elf_sym__is_function(sym);
75 case MAP__VARIABLE:
76 return elf_sym__is_object(sym);
77 default:
78 return false;
79 }
80}
81
82static inline const char *elf_sym__name(const GElf_Sym *sym,
83 const Elf_Data *symstrs)
84{
85 return symstrs->d_buf + sym->st_name;
86}
87
88static inline const char *elf_sec__name(const GElf_Shdr *shdr,
89 const Elf_Data *secstrs)
90{
91 return secstrs->d_buf + shdr->sh_name;
92}
93
94static inline int elf_sec__is_text(const GElf_Shdr *shdr,
95 const Elf_Data *secstrs)
96{
97 return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
98}
99
100static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
101 const Elf_Data *secstrs)
102{
103 return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
104}
105
106static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
107 enum map_type type)
108{
109 switch (type) {
110 case MAP__FUNCTION:
111 return elf_sec__is_text(shdr, secstrs);
112 case MAP__VARIABLE:
113 return elf_sec__is_data(shdr, secstrs);
114 default:
115 return false;
116 }
117}
118
119static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
120{
121 Elf_Scn *sec = NULL;
122 GElf_Shdr shdr;
123 size_t cnt = 1;
124
125 while ((sec = elf_nextscn(elf, sec)) != NULL) {
126 gelf_getshdr(sec, &shdr);
127
128 if ((addr >= shdr.sh_addr) &&
129 (addr < (shdr.sh_addr + shdr.sh_size)))
130 return cnt;
131
132 ++cnt;
133 }
134
135 return -1;
136}
137
138static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
139 GElf_Shdr *shp, const char *name,
140 size_t *idx)
141{
142 Elf_Scn *sec = NULL;
143 size_t cnt = 1;
144
49274654
CS		 145 /* Elf is corrupted/truncated, avoid calling elf_strptr. */
146 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
147 return NULL;
148
e5a1845f
NK		 149 while ((sec = elf_nextscn(elf, sec)) != NULL) {
150 char *str;
151
152 gelf_getshdr(sec, shp);
153 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
154 if (!strcmp(name, str)) {
155 if (idx)
156 *idx = cnt;
157 break;
158 }
159 ++cnt;
160 }
161
162 return sec;
163}
164
165#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
166 for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
167 idx < nr_entries; \
168 ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
169
170#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
171 for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
172 idx < nr_entries; \
173 ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
174
175/*
176 * We need to check if we have a .dynsym, so that we can handle the
177 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
178 * .dynsym or .symtab).
179 * And always look at the original dso, not at debuginfo packages, that
180 * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
181 */
a44f605b 182int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
e5a1845f
NK		 183 symbol_filter_t filter)
184{
185 uint32_t nr_rel_entries, idx;
186 GElf_Sym sym;
187 u64 plt_offset;
188 GElf_Shdr shdr_plt;
189 struct symbol *f;
190 GElf_Shdr shdr_rel_plt, shdr_dynsym;
191 Elf_Data *reldata, *syms, *symstrs;
192 Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
193 size_t dynsym_idx;
194 GElf_Ehdr ehdr;
195 char sympltname[1024];
196 Elf *elf;
a44f605b 197 int nr = 0, symidx, err = 0;
e5a1845f 198
f47b58b7
DA		 199 if (!ss->dynsym)
200 return 0;
201
a44f605b
CS		 202 elf = ss->elf;
203 ehdr = ss->ehdr;
e5a1845f 204
a44f605b
CS		 205 scn_dynsym = ss->dynsym;
206 shdr_dynsym = ss->dynshdr;
207 dynsym_idx = ss->dynsym_idx;
e5a1845f 208
e5a1845f
NK		 209 if (scn_dynsym == NULL)
210 goto out_elf_end;
211
212 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
213 ".rela.plt", NULL);
214 if (scn_plt_rel == NULL) {
215 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
216 ".rel.plt", NULL);
217 if (scn_plt_rel == NULL)
218 goto out_elf_end;
219 }
220
221 err = -1;
222
223 if (shdr_rel_plt.sh_link != dynsym_idx)
224 goto out_elf_end;
225
226 if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
227 goto out_elf_end;
228
229 /*
230 * Fetch the relocation section to find the idxes to the GOT
231 * and the symbols in the .dynsym they refer to.
232 */
233 reldata = elf_getdata(scn_plt_rel, NULL);
234 if (reldata == NULL)
235 goto out_elf_end;
236
237 syms = elf_getdata(scn_dynsym, NULL);
238 if (syms == NULL)
239 goto out_elf_end;
240
241 scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
242 if (scn_symstrs == NULL)
243 goto out_elf_end;
244
245 symstrs = elf_getdata(scn_symstrs, NULL);
246 if (symstrs == NULL)
247 goto out_elf_end;
248
52f9ddba
CS		 249 if (symstrs->d_size == 0)
250 goto out_elf_end;
251
e5a1845f
NK		 252 nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
253 plt_offset = shdr_plt.sh_offset;
254
255 if (shdr_rel_plt.sh_type == SHT_RELA) {
256 GElf_Rela pos_mem, *pos;
257
258 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
259 nr_rel_entries) {
260 symidx = GELF_R_SYM(pos->r_info);
261 plt_offset += shdr_plt.sh_entsize;
262 gelf_getsym(syms, symidx, &sym);
263 snprintf(sympltname, sizeof(sympltname),
264 "%s@plt", elf_sym__name(&sym, symstrs));
265
266 f = symbol__new(plt_offset, shdr_plt.sh_entsize,
267 STB_GLOBAL, sympltname);
268 if (!f)
269 goto out_elf_end;
270
271 if (filter && filter(map, f))
272 symbol__delete(f);
273 else {
274 symbols__insert(&dso->symbols[map->type], f);
275 ++nr;
276 }
277 }
278 } else if (shdr_rel_plt.sh_type == SHT_REL) {
279 GElf_Rel pos_mem, *pos;
280 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
281 nr_rel_entries) {
282 symidx = GELF_R_SYM(pos->r_info);
283 plt_offset += shdr_plt.sh_entsize;
284 gelf_getsym(syms, symidx, &sym);
285 snprintf(sympltname, sizeof(sympltname),
286 "%s@plt", elf_sym__name(&sym, symstrs));
287
288 f = symbol__new(plt_offset, shdr_plt.sh_entsize,
289 STB_GLOBAL, sympltname);
290 if (!f)
291 goto out_elf_end;
292
293 if (filter && filter(map, f))
294 symbol__delete(f);
295 else {
296 symbols__insert(&dso->symbols[map->type], f);
297 ++nr;
298 }
299 }
300 }
301
302 err = 0;
303out_elf_end:
e5a1845f
NK		 304 if (err == 0)
305 return nr;
e5a1845f
NK		 306 pr_debug("%s: problems reading %s PLT info.\n",
307 __func__, dso->long_name);
308 return 0;
309}
310
311/*
312 * Align offset to 4 bytes as needed for note name and descriptor data.
313 */
314#define NOTE_ALIGN(n) (((n) + 3) & -4U)
315
316static int elf_read_build_id(Elf *elf, void *bf, size_t size)
317{
318 int err = -1;
319 GElf_Ehdr ehdr;
320 GElf_Shdr shdr;
321 Elf_Data *data;
322 Elf_Scn *sec;
323 Elf_Kind ek;
324 void *ptr;
325
326 if (size < BUILD_ID_SIZE)
327 goto out;
328
329 ek = elf_kind(elf);
330 if (ek != ELF_K_ELF)
331 goto out;
332
333 if (gelf_getehdr(elf, &ehdr) == NULL) {
334 pr_err("%s: cannot get elf header.\n", __func__);
335 goto out;
336 }
337
338 /*
339 * Check following sections for notes:
340 * '.note.gnu.build-id'
341 * '.notes'
342 * '.note' (VDSO specific)
343 */
344 do {
345 sec = elf_section_by_name(elf, &ehdr, &shdr,
346 ".note.gnu.build-id", NULL);
347 if (sec)
348 break;
349
350 sec = elf_section_by_name(elf, &ehdr, &shdr,
351 ".notes", NULL);
352 if (sec)
353 break;
354
355 sec = elf_section_by_name(elf, &ehdr, &shdr,
356 ".note", NULL);
357 if (sec)
358 break;
359
360 return err;
361
362 } while (0);
363
364 data = elf_getdata(sec, NULL);
365 if (data == NULL)
366 goto out;
367
368 ptr = data->d_buf;
369 while (ptr < (data->d_buf + data->d_size)) {
370 GElf_Nhdr *nhdr = ptr;
371 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
372 descsz = NOTE_ALIGN(nhdr->n_descsz);
373 const char *name;
374
375 ptr += sizeof(*nhdr);
376 name = ptr;
377 ptr += namesz;
378 if (nhdr->n_type == NT_GNU_BUILD_ID &&
379 nhdr->n_namesz == sizeof("GNU")) {
380 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
381 size_t sz = min(size, descsz);
382 memcpy(bf, ptr, sz);
383 memset(bf + sz, 0, size - sz);
384 err = descsz;
385 break;
386 }
387 }
388 ptr += descsz;
389 }
390
391out:
392 return err;
393}
394
395int filename__read_build_id(const char *filename, void *bf, size_t size)
396{
397 int fd, err = -1;
398 Elf *elf;
399
400 if (size < BUILD_ID_SIZE)
401 goto out;
402
403 fd = open(filename, O_RDONLY);
404 if (fd < 0)
405 goto out;
406
407 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
408 if (elf == NULL) {
409 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
410 goto out_close;
411 }
412
413 err = elf_read_build_id(elf, bf, size);
414
415 elf_end(elf);
416out_close:
417 close(fd);
418out:
419 return err;
420}
421
422int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
423{
424 int fd, err = -1;
425
426 if (size < BUILD_ID_SIZE)
427 goto out;
428
429 fd = open(filename, O_RDONLY);
430 if (fd < 0)
431 goto out;
432
433 while (1) {
434 char bf[BUFSIZ];
435 GElf_Nhdr nhdr;
436 size_t namesz, descsz;
437
438 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
439 break;
440
441 namesz = NOTE_ALIGN(nhdr.n_namesz);
442 descsz = NOTE_ALIGN(nhdr.n_descsz);
443 if (nhdr.n_type == NT_GNU_BUILD_ID &&
444 nhdr.n_namesz == sizeof("GNU")) {
445 if (read(fd, bf, namesz) != (ssize_t)namesz)
446 break;
447 if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
448 size_t sz = min(descsz, size);
449 if (read(fd, build_id, sz) == (ssize_t)sz) {
450 memset(build_id + sz, 0, size - sz);
451 err = 0;
452 break;
453 }
454 } else if (read(fd, bf, descsz) != (ssize_t)descsz)
455 break;
456 } else {
457 int n = namesz + descsz;
458 if (read(fd, bf, n) != n)
459 break;
460 }
461 }
462 close(fd);
463out:
464 return err;
465}
466
467int filename__read_debuglink(const char *filename, char *debuglink,
468 size_t size)
469{
470 int fd, err = -1;
471 Elf *elf;
472 GElf_Ehdr ehdr;
473 GElf_Shdr shdr;
474 Elf_Data *data;
475 Elf_Scn *sec;
476 Elf_Kind ek;
477
478 fd = open(filename, O_RDONLY);
479 if (fd < 0)
480 goto out;
481
482 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
483 if (elf == NULL) {
484 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
485 goto out_close;
486 }
487
488 ek = elf_kind(elf);
489 if (ek != ELF_K_ELF)
490 goto out_close;
491
492 if (gelf_getehdr(elf, &ehdr) == NULL) {
493 pr_err("%s: cannot get elf header.\n", __func__);
494 goto out_close;
495 }
496
497 sec = elf_section_by_name(elf, &ehdr, &shdr,
498 ".gnu_debuglink", NULL);
499 if (sec == NULL)
500 goto out_close;
501
502 data = elf_getdata(sec, NULL);
503 if (data == NULL)
504 goto out_close;
505
506 /* the start of this section is a zero-terminated string */
507 strncpy(debuglink, data->d_buf, size);
508
509 elf_end(elf);
510
511out_close:
512 close(fd);
513out:
514 return err;
515}
516
517static int dso__swap_init(struct dso *dso, unsigned char eidata)
518{
519 static unsigned int const endian = 1;
520
521 dso->needs_swap = DSO_SWAP__NO;
522
523 switch (eidata) {
524 case ELFDATA2LSB:
525 /* We are big endian, DSO is little endian. */
526 if (*(unsigned char const *)&endian != 1)
527 dso->needs_swap = DSO_SWAP__YES;
528 break;
529
530 case ELFDATA2MSB:
531 /* We are little endian, DSO is big endian. */
532 if (*(unsigned char const *)&endian != 0)
533 dso->needs_swap = DSO_SWAP__YES;
534 break;
535
536 default:
537 pr_err("unrecognized DSO data encoding %d\n", eidata);
538 return -EINVAL;
539 }
540
541 return 0;
542}
543
3aafe5ae
CS		 544bool symsrc__possibly_runtime(struct symsrc *ss)
545{
546 return ss->dynsym || ss->opdsec;
547}
548
d26cd12b
CS		 549bool symsrc__has_symtab(struct symsrc *ss)
550{
551 return ss->symtab != NULL;
552}
b68e2f91
CS		 553
554void symsrc__destroy(struct symsrc *ss)
555{
556 free(ss->name);
557 elf_end(ss->elf);
558 close(ss->fd);
559}
560
561int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
562 enum dso_binary_type type)
e5a1845f 563{
e5a1845f 564 int err = -1;
e5a1845f 565 GElf_Ehdr ehdr;
e5a1845f 566 Elf *elf;
b68e2f91
CS		 567 int fd;
568
569 fd = open(name, O_RDONLY);
570 if (fd < 0)
571 return -1;
e5a1845f
NK		 572
573 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
574 if (elf == NULL) {
575 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
576 goto out_close;
577 }
578
579 if (gelf_getehdr(elf, &ehdr) == NULL) {
580 pr_debug("%s: cannot get elf header.\n", __func__);
581 goto out_elf_end;
582 }
583
584 if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
585 goto out_elf_end;
586
587 /* Always reject images with a mismatched build-id: */
588 if (dso->has_build_id) {
589 u8 build_id[BUILD_ID_SIZE];
590
591 if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
592 goto out_elf_end;
593
594 if (!dso__build_id_equal(dso, build_id))
595 goto out_elf_end;
596 }
597
b68e2f91
CS		 598 ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
599 NULL);
600 if (ss->symshdr.sh_type != SHT_SYMTAB)
601 ss->symtab = NULL;
602
603 ss->dynsym_idx = 0;
604 ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
605 &ss->dynsym_idx);
606 if (ss->dynshdr.sh_type != SHT_DYNSYM)
607 ss->dynsym = NULL;
608
609 ss->opdidx = 0;
610 ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
611 &ss->opdidx);
612 if (ss->opdshdr.sh_type != SHT_PROGBITS)
613 ss->opdsec = NULL;
614
615 if (dso->kernel == DSO_TYPE_USER) {
616 GElf_Shdr shdr;
617 ss->adjust_symbols = (ehdr.e_type == ET_EXEC ||
0131c4ec 618 ehdr.e_type == ET_REL ||
b68e2f91
CS		 619 elf_section_by_name(elf, &ehdr, &shdr,
620 ".gnu.prelink_undo",
621 NULL) != NULL);
622 } else {
0131c4ec
AH		 623 ss->adjust_symbols = ehdr.e_type == ET_EXEC ||
624 ehdr.e_type == ET_REL;
b68e2f91
CS		 625 }
626
627 ss->name = strdup(name);
628 if (!ss->name)
629 goto out_elf_end;
630
631 ss->elf = elf;
632 ss->fd = fd;
633 ss->ehdr = ehdr;
634 ss->type = type;
635
636 return 0;
637
638out_elf_end:
639 elf_end(elf);
640out_close:
641 close(fd);
642 return err;
643}
644
39b12f78
AH		 645/**
646 * ref_reloc_sym_not_found - has kernel relocation symbol been found.
647 * @kmap: kernel maps and relocation reference symbol
648 *
649 * This function returns %true if we are dealing with the kernel maps and the
650 * relocation reference symbol has not yet been found. Otherwise %false is
651 * returned.
652 */
653static bool ref_reloc_sym_not_found(struct kmap *kmap)
654{
655 return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
656 !kmap->ref_reloc_sym->unrelocated_addr;
657}
658
659/**
660 * ref_reloc - kernel relocation offset.
661 * @kmap: kernel maps and relocation reference symbol
662 *
663 * This function returns the offset of kernel addresses as determined by using
664 * the relocation reference symbol i.e. if the kernel has not been relocated
665 * then the return value is zero.
666 */
667static u64 ref_reloc(struct kmap *kmap)
668{
669 if (kmap && kmap->ref_reloc_sym &&
670 kmap->ref_reloc_sym->unrelocated_addr)
671 return kmap->ref_reloc_sym->addr -
672 kmap->ref_reloc_sym->unrelocated_addr;
673 return 0;
674}
675
261360b6
CS		 676int dso__load_sym(struct dso *dso, struct map *map,
677 struct symsrc *syms_ss, struct symsrc *runtime_ss,
d26cd12b 678 symbol_filter_t filter, int kmodule)
b68e2f91
CS		 679{
680 struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
681 struct map *curr_map = map;
682 struct dso *curr_dso = dso;
683 Elf_Data *symstrs, *secstrs;
684 uint32_t nr_syms;
685 int err = -1;
686 uint32_t idx;
687 GElf_Ehdr ehdr;
261360b6 688 GElf_Shdr shdr;
b68e2f91
CS		 689 Elf_Data *syms, *opddata = NULL;
690 GElf_Sym sym;
261360b6 691 Elf_Scn *sec, *sec_strndx;
b68e2f91
CS		 692 Elf *elf;
693 int nr = 0;
39b12f78 694 bool remap_kernel = false, adjust_kernel_syms = false;
b68e2f91 695
261360b6 696 dso->symtab_type = syms_ss->type;
0131c4ec
AH		 697 dso->rel = syms_ss->ehdr.e_type == ET_REL;
698
699 /*
700 * Modules may already have symbols from kallsyms, but those symbols
701 * have the wrong values for the dso maps, so remove them.
702 */
703 if (kmodule && syms_ss->symtab)
704 symbols__delete(&dso->symbols[map->type]);
005f9294 705
261360b6
CS		 706 if (!syms_ss->symtab) {
707 syms_ss->symtab = syms_ss->dynsym;
708 syms_ss->symshdr = syms_ss->dynshdr;
d26cd12b
CS		 709 }
710
261360b6
CS		 711 elf = syms_ss->elf;
712 ehdr = syms_ss->ehdr;
713 sec = syms_ss->symtab;
714 shdr = syms_ss->symshdr;
b68e2f91 715
261360b6
CS		 716 if (runtime_ss->opdsec)
717 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
e5a1845f
NK		 718
719 syms = elf_getdata(sec, NULL);
720 if (syms == NULL)
721 goto out_elf_end;
722
723 sec = elf_getscn(elf, shdr.sh_link);
724 if (sec == NULL)
725 goto out_elf_end;
726
727 symstrs = elf_getdata(sec, NULL);
728 if (symstrs == NULL)
729 goto out_elf_end;
730
731 sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
732 if (sec_strndx == NULL)
733 goto out_elf_end;
734
735 secstrs = elf_getdata(sec_strndx, NULL);
736 if (secstrs == NULL)
737 goto out_elf_end;
738
739 nr_syms = shdr.sh_size / shdr.sh_entsize;
740
741 memset(&sym, 0, sizeof(sym));
39b12f78
AH		 742
743 /*
744 * The kernel relocation symbol is needed in advance in order to adjust
745 * kernel maps correctly.
746 */
747 if (ref_reloc_sym_not_found(kmap)) {
748 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
749 const char *elf_name = elf_sym__name(&sym, symstrs);
750
751 if (strcmp(elf_name, kmap->ref_reloc_sym->name))
752 continue;
753 kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
754 break;
755 }
756 }
757
758 dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
759 /*
760 * Initial kernel and module mappings do not map to the dso. For
761 * function mappings, flag the fixups.
762 */
763 if (map->type == MAP__FUNCTION && (dso->kernel || kmodule)) {
764 remap_kernel = true;
765 adjust_kernel_syms = dso->adjust_symbols;
766 }
e5a1845f
NK		 767 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
768 struct symbol *f;
769 const char *elf_name = elf_sym__name(&sym, symstrs);
770 char *demangled = NULL;
771 int is_label = elf_sym__is_label(&sym);
772 const char *section_name;
261360b6 773 bool used_opd = false;
e5a1845f 774
e5a1845f
NK		 775 if (!is_label && !elf_sym__is_a(&sym, map->type))
776 continue;
777
778 /* Reject ARM ELF "mapping symbols": these aren't unique and
779 * don't identify functions, so will confuse the profile
780 * output: */
781 if (ehdr.e_machine == EM_ARM) {
782 if (!strcmp(elf_name, "$a") ||
783 !strcmp(elf_name, "$d") ||
784 !strcmp(elf_name, "$t"))
785 continue;
786 }
787
261360b6
CS		 788 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
789 u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
e5a1845f
NK		 790 u64 *opd = opddata->d_buf + offset;
791 sym.st_value = DSO__SWAP(dso, u64, *opd);
261360b6
CS		 792 sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
793 sym.st_value);
794 used_opd = true;
e5a1845f 795 }
3843b05d
NK		 796 /*
797 * When loading symbols in a data mapping, ABS symbols (which
798 * has a value of SHN_ABS in its st_shndx) failed at
799 * elf_getscn(). And it marks the loading as a failure so
800 * already loaded symbols cannot be fixed up.
801 *
802 * I'm not sure what should be done. Just ignore them for now.
803 * - Namhyung Kim
804 */
805 if (sym.st_shndx == SHN_ABS)
806 continue;
e5a1845f 807
261360b6 808 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
e5a1845f
NK		 809 if (!sec)
810 goto out_elf_end;
811
812 gelf_getshdr(sec, &shdr);
813
814 if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
815 continue;
816
817 section_name = elf_sec__name(&shdr, secstrs);
818
819 /* On ARM, symbols for thumb functions have 1 added to
820 * the symbol address as a flag - remove it */
821 if ((ehdr.e_machine == EM_ARM) &&
822 (map->type == MAP__FUNCTION) &&
823 (sym.st_value & 1))
824 --sym.st_value;
825
39b12f78 826 if (dso->kernel || kmodule) {
e5a1845f
NK		 827 char dso_name[PATH_MAX];
828
39b12f78
AH		 829 /* Adjust symbol to map to file offset */
830 if (adjust_kernel_syms)
831 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
832
e5a1845f
NK		 833 if (strcmp(section_name,
834 (curr_dso->short_name +
835 dso->short_name_len)) == 0)
836 goto new_symbol;
837
838 if (strcmp(section_name, ".text") == 0) {
39b12f78
AH		 839 /*
840 * The initial kernel mapping is based on
841 * kallsyms and identity maps. Overwrite it to
842 * map to the kernel dso.
843 */
844 if (remap_kernel && dso->kernel) {
845 remap_kernel = false;
846 map->start = shdr.sh_addr +
847 ref_reloc(kmap);
848 map->end = map->start + shdr.sh_size;
849 map->pgoff = shdr.sh_offset;
850 map->map_ip = map__map_ip;
851 map->unmap_ip = map__unmap_ip;
852 /* Ensure maps are correctly ordered */
853 map_groups__remove(kmap->kmaps, map);
854 map_groups__insert(kmap->kmaps, map);
855 }
856
0131c4ec
AH		 857 /*
858 * The initial module mapping is based on
859 * /proc/modules mapped to offset zero.
860 * Overwrite it to map to the module dso.
861 */
862 if (remap_kernel && kmodule) {
863 remap_kernel = false;
864 map->pgoff = shdr.sh_offset;
865 }
866
e5a1845f
NK		 867 curr_map = map;
868 curr_dso = dso;
869 goto new_symbol;
870 }
871
0131c4ec
AH		 872 if (!kmap)
873 goto new_symbol;
874
e5a1845f
NK		 875 snprintf(dso_name, sizeof(dso_name),
876 "%s%s", dso->short_name, section_name);
877
878 curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
879 if (curr_map == NULL) {
880 u64 start = sym.st_value;
881
882 if (kmodule)
883 start += map->start + shdr.sh_offset;
884
885 curr_dso = dso__new(dso_name);
886 if (curr_dso == NULL)
887 goto out_elf_end;
888 curr_dso->kernel = dso->kernel;
889 curr_dso->long_name = dso->long_name;
890 curr_dso->long_name_len = dso->long_name_len;
891 curr_map = map__new2(start, curr_dso,
892 map->type);
893 if (curr_map == NULL) {
894 dso__delete(curr_dso);
895 goto out_elf_end;
896 }
39b12f78
AH		 897 if (adjust_kernel_syms) {
898 curr_map->start = shdr.sh_addr +
899 ref_reloc(kmap);
900 curr_map->end = curr_map->start +
901 shdr.sh_size;
902 curr_map->pgoff = shdr.sh_offset;
903 } else {
904 curr_map->map_ip = identity__map_ip;
905 curr_map->unmap_ip = identity__map_ip;
906 }
e5a1845f
NK		 907 curr_dso->symtab_type = dso->symtab_type;
908 map_groups__insert(kmap->kmaps, curr_map);
909 dsos__add(&dso->node, curr_dso);
910 dso__set_loaded(curr_dso, map->type);
911 } else
912 curr_dso = curr_map->dso;
913
914 goto new_symbol;
915 }
916
261360b6
CS		 917 if ((used_opd && runtime_ss->adjust_symbols)
918 || (!used_opd && syms_ss->adjust_symbols)) {
e5a1845f
NK		 919 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
920 "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
921 (u64)sym.st_value, (u64)shdr.sh_addr,
922 (u64)shdr.sh_offset);
923 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
924 }
925 /*
926 * We need to figure out if the object was created from C++ sources
927 * DWARF DW_compile_unit has this, but we don't always have access
928 * to it...
929 */
328ccdac 930 if (symbol_conf.demangle) {
14951f22 931 demangled = bfd_demangle(NULL, elf_name,
328ccdac
NK		 932 DMGL_PARAMS | DMGL_ANSI);
933 if (demangled != NULL)
934 elf_name = demangled;
935 }
e5a1845f
NK		 936new_symbol:
937 f = symbol__new(sym.st_value, sym.st_size,
938 GELF_ST_BIND(sym.st_info), elf_name);
939 free(demangled);
940 if (!f)
941 goto out_elf_end;
942
943 if (filter && filter(curr_map, f))
944 symbol__delete(f);
945 else {
946 symbols__insert(&curr_dso->symbols[curr_map->type], f);
947 nr++;
948 }
949 }
950
951 /*
952 * For misannotated, zeroed, ASM function sizes.
953 */
954 if (nr > 0) {
955 symbols__fixup_duplicate(&dso->symbols[map->type]);
956 symbols__fixup_end(&dso->symbols[map->type]);
957 if (kmap) {
958 /*
959 * We need to fixup this here too because we create new
960 * maps here, for things like vsyscall sections.
961 */
962 __map_groups__fixup_end(kmap->kmaps, map->type);
963 }
964 }
965 err = nr;
966out_elf_end:
e5a1845f
NK		 967 return err;
968}
969
8e0cf965
AH		 970static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
971{
972 GElf_Phdr phdr;
973 size_t i, phdrnum;
974 int err;
975 u64 sz;
976
977 if (elf_getphdrnum(elf, &phdrnum))
978 return -1;
979
980 for (i = 0; i < phdrnum; i++) {
981 if (gelf_getphdr(elf, i, &phdr) == NULL)
982 return -1;
983 if (phdr.p_type != PT_LOAD)
984 continue;
985 if (exe) {
986 if (!(phdr.p_flags & PF_X))
987 continue;
988 } else {
989 if (!(phdr.p_flags & PF_R))
990 continue;
991 }
992 sz = min(phdr.p_memsz, phdr.p_filesz);
993 if (!sz)
994 continue;
995 err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
996 if (err)
997 return err;
998 }
999 return 0;
1000}
1001
1002int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
1003 bool *is_64_bit)
1004{
1005 int err;
1006 Elf *elf;
1007
1008 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1009 if (elf == NULL)
1010 return -1;
1011
1012 if (is_64_bit)
1013 *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
1014
1015 err = elf_read_maps(elf, exe, mapfn, data);
1016
1017 elf_end(elf);
1018 return err;
1019}
1020
afba19d9
AH		 1021static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
1022{
1023 ssize_t r;
1024 size_t n;
1025 int err = -1;
1026 char *buf = malloc(page_size);
1027
1028 if (buf == NULL)
1029 return -1;
1030
1031 if (lseek(to, to_offs, SEEK_SET) != to_offs)
1032 goto out;
1033
1034 if (lseek(from, from_offs, SEEK_SET) != from_offs)
1035 goto out;
1036
1037 while (len) {
1038 n = page_size;
1039 if (len < n)
1040 n = len;
1041 /* Use read because mmap won't work on proc files */
1042 r = read(from, buf, n);
1043 if (r < 0)
1044 goto out;
1045 if (!r)
1046 break;
1047 n = r;
1048 r = write(to, buf, n);
1049 if (r < 0)
1050 goto out;
1051 if ((size_t)r != n)
1052 goto out;
1053 len -= n;
1054 }
1055
1056 err = 0;
1057out:
1058 free(buf);
1059 return err;
1060}
1061
1062struct kcore {
1063 int fd;
1064 int elfclass;
1065 Elf *elf;
1066 GElf_Ehdr ehdr;
1067};
1068
1069static int kcore__open(struct kcore *kcore, const char *filename)
1070{
1071 GElf_Ehdr *ehdr;
1072
1073 kcore->fd = open(filename, O_RDONLY);
1074 if (kcore->fd == -1)
1075 return -1;
1076
1077 kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
1078 if (!kcore->elf)
1079 goto out_close;
1080
1081 kcore->elfclass = gelf_getclass(kcore->elf);
1082 if (kcore->elfclass == ELFCLASSNONE)
1083 goto out_end;
1084
1085 ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1086 if (!ehdr)
1087 goto out_end;
1088
1089 return 0;
1090
1091out_end:
1092 elf_end(kcore->elf);
1093out_close:
1094 close(kcore->fd);
1095 return -1;
1096}
1097
1098static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
1099 bool temp)
1100{
1101 GElf_Ehdr *ehdr;
1102
1103 kcore->elfclass = elfclass;
1104
1105 if (temp)
1106 kcore->fd = mkstemp(filename);
1107 else
1108 kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
1109 if (kcore->fd == -1)
1110 return -1;
1111
1112 kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
1113 if (!kcore->elf)
1114 goto out_close;
1115
1116 if (!gelf_newehdr(kcore->elf, elfclass))
1117 goto out_end;
1118
1119 ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1120 if (!ehdr)
1121 goto out_end;
1122
1123 return 0;
1124
1125out_end:
1126 elf_end(kcore->elf);
1127out_close:
1128 close(kcore->fd);
1129 unlink(filename);
1130 return -1;
1131}
1132
1133static void kcore__close(struct kcore *kcore)
1134{
1135 elf_end(kcore->elf);
1136 close(kcore->fd);
1137}
1138
1139static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
1140{
1141 GElf_Ehdr *ehdr = &to->ehdr;
1142 GElf_Ehdr *kehdr = &from->ehdr;
1143
1144 memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
1145 ehdr->e_type = kehdr->e_type;
1146 ehdr->e_machine = kehdr->e_machine;
1147 ehdr->e_version = kehdr->e_version;
1148 ehdr->e_entry = 0;
1149 ehdr->e_shoff = 0;
1150 ehdr->e_flags = kehdr->e_flags;
1151 ehdr->e_phnum = count;
1152 ehdr->e_shentsize = 0;
1153 ehdr->e_shnum = 0;
1154 ehdr->e_shstrndx = 0;
1155
1156 if (from->elfclass == ELFCLASS32) {
1157 ehdr->e_phoff = sizeof(Elf32_Ehdr);
1158 ehdr->e_ehsize = sizeof(Elf32_Ehdr);
1159 ehdr->e_phentsize = sizeof(Elf32_Phdr);
1160 } else {
1161 ehdr->e_phoff = sizeof(Elf64_Ehdr);
1162 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1163 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1164 }
1165
1166 if (!gelf_update_ehdr(to->elf, ehdr))
1167 return -1;
1168
1169 if (!gelf_newphdr(to->elf, count))
1170 return -1;
1171
1172 return 0;
1173}
1174
1175static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
1176 u64 addr, u64 len)
1177{
1178 GElf_Phdr gphdr;
1179 GElf_Phdr *phdr;
1180
1181 phdr = gelf_getphdr(kcore->elf, idx, &gphdr);
1182 if (!phdr)
1183 return -1;
1184
1185 phdr->p_type = PT_LOAD;
1186 phdr->p_flags = PF_R | PF_W | PF_X;
1187 phdr->p_offset = offset;
1188 phdr->p_vaddr = addr;
1189 phdr->p_paddr = 0;
1190 phdr->p_filesz = len;
1191 phdr->p_memsz = len;
1192 phdr->p_align = page_size;
1193
1194 if (!gelf_update_phdr(kcore->elf, idx, phdr))
1195 return -1;
1196
1197 return 0;
1198}
1199
1200static off_t kcore__write(struct kcore *kcore)
1201{
1202 return elf_update(kcore->elf, ELF_C_WRITE);
1203}
1204
fc1b691d
AH		 1205struct phdr_data {
1206 off_t offset;
1207 u64 addr;
1208 u64 len;
1209};
1210
1211struct kcore_copy_info {
1212 u64 stext;
1213 u64 etext;
1214 u64 first_symbol;
1215 u64 last_symbol;
1216 u64 first_module;
1217 u64 last_module_symbol;
1218 struct phdr_data kernel_map;
1219 struct phdr_data modules_map;
1220};
1221
1222static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
1223 u64 start)
1224{
1225 struct kcore_copy_info *kci = arg;
1226
1227 if (!symbol_type__is_a(type, MAP__FUNCTION))
1228 return 0;
1229
1230 if (strchr(name, '[')) {
1231 if (start > kci->last_module_symbol)
1232 kci->last_module_symbol = start;
1233 return 0;
1234 }
1235
1236 if (!kci->first_symbol || start < kci->first_symbol)
1237 kci->first_symbol = start;
1238
1239 if (!kci->last_symbol || start > kci->last_symbol)
1240 kci->last_symbol = start;
1241
1242 if (!strcmp(name, "_stext")) {
1243 kci->stext = start;
1244 return 0;
1245 }
1246
1247 if (!strcmp(name, "_etext")) {
1248 kci->etext = start;
1249 return 0;
1250 }
1251
1252 return 0;
1253}
1254
1255static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
1256 const char *dir)
1257{
1258 char kallsyms_filename[PATH_MAX];
1259
1260 scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
1261
1262 if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
1263 return -1;
1264
1265 if (kallsyms__parse(kallsyms_filename, kci,
1266 kcore_copy__process_kallsyms) < 0)
1267 return -1;
1268
1269 return 0;
1270}
1271
1272static int kcore_copy__process_modules(void *arg,
1273 const char *name __maybe_unused,
1274 u64 start)
1275{
1276 struct kcore_copy_info *kci = arg;
1277
1278 if (!kci->first_module || start < kci->first_module)
1279 kci->first_module = start;
1280
1281 return 0;
1282}
1283
1284static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
1285 const char *dir)
1286{
1287 char modules_filename[PATH_MAX];
1288
1289 scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
1290
1291 if (symbol__restricted_filename(modules_filename, "/proc/modules"))
1292 return -1;
1293
1294 if (modules__parse(modules_filename, kci,
1295 kcore_copy__process_modules) < 0)
1296 return -1;
1297
1298 return 0;
1299}
1300
1301static void kcore_copy__map(struct phdr_data *p, u64 start, u64 end, u64 pgoff,
1302 u64 s, u64 e)
1303{
1304 if (p->addr || s < start || s >= end)
1305 return;
1306
1307 p->addr = s;
1308 p->offset = (s - start) + pgoff;
1309 p->len = e < end ? e - s : end - s;
1310}
1311
1312static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
1313{
1314 struct kcore_copy_info *kci = data;
1315 u64 end = start + len;
1316
1317 kcore_copy__map(&kci->kernel_map, start, end, pgoff, kci->stext,
1318 kci->etext);
1319
1320 kcore_copy__map(&kci->modules_map, start, end, pgoff, kci->first_module,
1321 kci->last_module_symbol);
1322
1323 return 0;
1324}
1325
1326static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
1327{
1328 if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
1329 return -1;
1330
1331 return 0;
1332}
1333
1334static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
1335 Elf *elf)
1336{
1337 if (kcore_copy__parse_kallsyms(kci, dir))
1338 return -1;
1339
1340 if (kcore_copy__parse_modules(kci, dir))
1341 return -1;
1342
1343 if (kci->stext)
1344 kci->stext = round_down(kci->stext, page_size);
1345 else
1346 kci->stext = round_down(kci->first_symbol, page_size);
1347
1348 if (kci->etext) {
1349 kci->etext = round_up(kci->etext, page_size);
1350 } else if (kci->last_symbol) {
1351 kci->etext = round_up(kci->last_symbol, page_size);
1352 kci->etext += page_size;
1353 }
1354
1355 kci->first_module = round_down(kci->first_module, page_size);
1356
1357 if (kci->last_module_symbol) {
1358 kci->last_module_symbol = round_up(kci->last_module_symbol,
1359 page_size);
1360 kci->last_module_symbol += page_size;
1361 }
1362
1363 if (!kci->stext || !kci->etext)
1364 return -1;
1365
1366 if (kci->first_module && !kci->last_module_symbol)
1367 return -1;
1368
1369 return kcore_copy__read_maps(kci, elf);
1370}
1371
1372static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
1373 const char *name)
1374{
1375 char from_filename[PATH_MAX];
1376 char to_filename[PATH_MAX];
1377
1378 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1379 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1380
1381 return copyfile_mode(from_filename, to_filename, 0400);
1382}
1383
1384static int kcore_copy__unlink(const char *dir, const char *name)
1385{
1386 char filename[PATH_MAX];
1387
1388 scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
1389
1390 return unlink(filename);
1391}
1392
1393static int kcore_copy__compare_fds(int from, int to)
1394{
1395 char *buf_from;
1396 char *buf_to;
1397 ssize_t ret;
1398 size_t len;
1399 int err = -1;
1400
1401 buf_from = malloc(page_size);
1402 buf_to = malloc(page_size);
1403 if (!buf_from || !buf_to)
1404 goto out;
1405
1406 while (1) {
1407 /* Use read because mmap won't work on proc files */
1408 ret = read(from, buf_from, page_size);
1409 if (ret < 0)
1410 goto out;
1411
1412 if (!ret)
1413 break;
1414
1415 len = ret;
1416
1417 if (readn(to, buf_to, len) != (int)len)
1418 goto out;
1419
1420 if (memcmp(buf_from, buf_to, len))
1421 goto out;
1422 }
1423
1424 err = 0;
1425out:
1426 free(buf_to);
1427 free(buf_from);
1428 return err;
1429}
1430
1431static int kcore_copy__compare_files(const char *from_filename,
1432 const char *to_filename)
1433{
1434 int from, to, err = -1;
1435
1436 from = open(from_filename, O_RDONLY);
1437 if (from < 0)
1438 return -1;
1439
1440 to = open(to_filename, O_RDONLY);
1441 if (to < 0)
1442 goto out_close_from;
1443
1444 err = kcore_copy__compare_fds(from, to);
1445
1446 close(to);
1447out_close_from:
1448 close(from);
1449 return err;
1450}
1451
1452static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
1453 const char *name)
1454{
1455 char from_filename[PATH_MAX];
1456 char to_filename[PATH_MAX];
1457
1458 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1459 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1460
1461 return kcore_copy__compare_files(from_filename, to_filename);
1462}
1463
1464/**
1465 * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
1466 * @from_dir: from directory
1467 * @to_dir: to directory
1468 *
1469 * This function copies kallsyms, modules and kcore files from one directory to
1470 * another. kallsyms and modules are copied entirely. Only code segments are
1471 * copied from kcore. It is assumed that two segments suffice: one for the
1472 * kernel proper and one for all the modules. The code segments are determined
1473 * from kallsyms and modules files. The kernel map starts at _stext or the
1474 * lowest function symbol, and ends at _etext or the highest function symbol.
1475 * The module map starts at the lowest module address and ends at the highest
1476 * module symbol. Start addresses are rounded down to the nearest page. End
1477 * addresses are rounded up to the nearest page. An extra page is added to the
1478 * highest kernel symbol and highest module symbol to, hopefully, encompass that
1479 * symbol too. Because it contains only code sections, the resulting kcore is
1480 * unusual. One significant peculiarity is that the mapping (start -> pgoff)
1481 * is not the same for the kernel map and the modules map. That happens because
1482 * the data is copied adjacently whereas the original kcore has gaps. Finally,
1483 * kallsyms and modules files are compared with their copies to check that
1484 * modules have not been loaded or unloaded while the copies were taking place.
1485 *
1486 * Return: %0 on success, %-1 on failure.
1487 */
1488int kcore_copy(const char *from_dir, const char *to_dir)
1489{
1490 struct kcore kcore;
1491 struct kcore extract;
1492 size_t count = 2;
1493 int idx = 0, err = -1;
1494 off_t offset = page_size, sz, modules_offset = 0;
1495 struct kcore_copy_info kci = { .stext = 0, };
1496 char kcore_filename[PATH_MAX];
1497 char extract_filename[PATH_MAX];
1498
1499 if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
1500 return -1;
1501
1502 if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
1503 goto out_unlink_kallsyms;
1504
1505 scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
1506 scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
1507
1508 if (kcore__open(&kcore, kcore_filename))
1509 goto out_unlink_modules;
1510
1511 if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
1512 goto out_kcore_close;
1513
1514 if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
1515 goto out_kcore_close;
1516
1517 if (!kci.modules_map.addr)
1518 count -= 1;
1519
1520 if (kcore__copy_hdr(&kcore, &extract, count))
1521 goto out_extract_close;
1522
1523 if (kcore__add_phdr(&extract, idx++, offset, kci.kernel_map.addr,
1524 kci.kernel_map.len))
1525 goto out_extract_close;
1526
1527 if (kci.modules_map.addr) {
1528 modules_offset = offset + kci.kernel_map.len;
1529 if (kcore__add_phdr(&extract, idx, modules_offset,
1530 kci.modules_map.addr, kci.modules_map.len))
1531 goto out_extract_close;
1532 }
1533
1534 sz = kcore__write(&extract);
1535 if (sz < 0 || sz > offset)
1536 goto out_extract_close;
1537
1538 if (copy_bytes(kcore.fd, kci.kernel_map.offset, extract.fd, offset,
1539 kci.kernel_map.len))
1540 goto out_extract_close;
1541
1542 if (modules_offset && copy_bytes(kcore.fd, kci.modules_map.offset,
1543 extract.fd, modules_offset,
1544 kci.modules_map.len))
1545 goto out_extract_close;
1546
1547 if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
1548 goto out_extract_close;
1549
1550 if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
1551 goto out_extract_close;
1552
1553 err = 0;
1554
1555out_extract_close:
1556 kcore__close(&extract);
1557 if (err)
1558 unlink(extract_filename);
1559out_kcore_close:
1560 kcore__close(&kcore);
1561out_unlink_modules:
1562 if (err)
1563 kcore_copy__unlink(to_dir, "modules");
1564out_unlink_kallsyms:
1565 if (err)
1566 kcore_copy__unlink(to_dir, "kallsyms");
1567
1568 return err;
1569}
1570
afba19d9
AH		 1571int kcore_extract__create(struct kcore_extract *kce)
1572{
1573 struct kcore kcore;
1574 struct kcore extract;
1575 size_t count = 1;
1576 int idx = 0, err = -1;
1577 off_t offset = page_size, sz;
1578
1579 if (kcore__open(&kcore, kce->kcore_filename))
1580 return -1;
1581
1582 strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
1583 if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
1584 goto out_kcore_close;
1585
1586 if (kcore__copy_hdr(&kcore, &extract, count))
1587 goto out_extract_close;
1588
1589 if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
1590 goto out_extract_close;
1591
1592 sz = kcore__write(&extract);
1593 if (sz < 0 || sz > offset)
1594 goto out_extract_close;
1595
1596 if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
1597 goto out_extract_close;
1598
1599 err = 0;
1600
1601out_extract_close:
1602 kcore__close(&extract);
1603 if (err)
1604 unlink(kce->extract_filename);
1605out_kcore_close:
1606 kcore__close(&kcore);
1607
1608 return err;
1609}
1610
1611void kcore_extract__delete(struct kcore_extract *kce)
1612{
1613 unlink(kce->extract_filename);
1614}
1615
e5a1845f
NK		 1616void symbol__elf_init(void)
1617{
1618 elf_version(EV_CURRENT);
1619}
Linux 6.x block layer and io_uring tree(s)