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perf top: Fix SIGBUS on sparc64
[deliverable/linux.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"
8fa7d87f 9#include "machine.h"
922d0e4d 10#include "vdso.h"
c506c96b 11#include <symbol/kallsyms.h>
e5a1845f
NK		 12#include "debug.h"
13
aaba4e12
ACM		 14#ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
15extern char *cplus_demangle(const char *, int);
16
17static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
18{
19 return cplus_demangle(c, i);
20}
21#else
22#ifdef NO_DEMANGLE
23static inline char *bfd_demangle(void __maybe_unused *v,
24 const char __maybe_unused *c,
25 int __maybe_unused i)
26{
27 return NULL;
28}
29#else
30#define PACKAGE 'perf'
31#include <bfd.h>
32#endif
33#endif
34
89fe808a 35#ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
e955d5c4
AH		 36static int elf_getphdrnum(Elf *elf, size_t *dst)
37{
38 GElf_Ehdr gehdr;
39 GElf_Ehdr *ehdr;
40
41 ehdr = gelf_getehdr(elf, &gehdr);
42 if (!ehdr)
43 return -1;
44
45 *dst = ehdr->e_phnum;
46
47 return 0;
48}
49#endif
50
e5a1845f
NK		 51#ifndef NT_GNU_BUILD_ID
52#define NT_GNU_BUILD_ID 3
53#endif
54
55/**
56 * elf_symtab__for_each_symbol - iterate thru all the symbols
57 *
58 * @syms: struct elf_symtab instance to iterate
59 * @idx: uint32_t idx
60 * @sym: GElf_Sym iterator
61 */
62#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
63 for (idx = 0, gelf_getsym(syms, idx, &sym);\
64 idx < nr_syms; \
65 idx++, gelf_getsym(syms, idx, &sym))
66
67static inline uint8_t elf_sym__type(const GElf_Sym *sym)
68{
69 return GELF_ST_TYPE(sym->st_info);
70}
71
72static inline int elf_sym__is_function(const GElf_Sym *sym)
73{
a2f3b6bf
AH		 74 return (elf_sym__type(sym) == STT_FUNC ||
75 elf_sym__type(sym) == STT_GNU_IFUNC) &&
e5a1845f
NK		 76 sym->st_name != 0 &&
77 sym->st_shndx != SHN_UNDEF;
78}
79
80static inline bool elf_sym__is_object(const GElf_Sym *sym)
81{
82 return elf_sym__type(sym) == STT_OBJECT &&
83 sym->st_name != 0 &&
84 sym->st_shndx != SHN_UNDEF;
85}
86
87static inline int elf_sym__is_label(const GElf_Sym *sym)
88{
89 return elf_sym__type(sym) == STT_NOTYPE &&
90 sym->st_name != 0 &&
91 sym->st_shndx != SHN_UNDEF &&
92 sym->st_shndx != SHN_ABS;
93}
94
95static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
96{
97 switch (type) {
98 case MAP__FUNCTION:
99 return elf_sym__is_function(sym);
100 case MAP__VARIABLE:
101 return elf_sym__is_object(sym);
102 default:
103 return false;
104 }
105}
106
107static inline const char *elf_sym__name(const GElf_Sym *sym,
108 const Elf_Data *symstrs)
109{
110 return symstrs->d_buf + sym->st_name;
111}
112
113static inline const char *elf_sec__name(const GElf_Shdr *shdr,
114 const Elf_Data *secstrs)
115{
116 return secstrs->d_buf + shdr->sh_name;
117}
118
119static inline int elf_sec__is_text(const GElf_Shdr *shdr,
120 const Elf_Data *secstrs)
121{
122 return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
123}
124
125static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
126 const Elf_Data *secstrs)
127{
128 return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
129}
130
131static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
132 enum map_type type)
133{
134 switch (type) {
135 case MAP__FUNCTION:
136 return elf_sec__is_text(shdr, secstrs);
137 case MAP__VARIABLE:
138 return elf_sec__is_data(shdr, secstrs);
139 default:
140 return false;
141 }
142}
143
144static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
145{
146 Elf_Scn *sec = NULL;
147 GElf_Shdr shdr;
148 size_t cnt = 1;
149
150 while ((sec = elf_nextscn(elf, sec)) != NULL) {
151 gelf_getshdr(sec, &shdr);
152
153 if ((addr >= shdr.sh_addr) &&
154 (addr < (shdr.sh_addr + shdr.sh_size)))
155 return cnt;
156
157 ++cnt;
158 }
159
160 return -1;
161}
162
99ca4233
MH		 163Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
164 GElf_Shdr *shp, const char *name, size_t *idx)
e5a1845f
NK		 165{
166 Elf_Scn *sec = NULL;
167 size_t cnt = 1;
168
49274654
CS		 169 /* Elf is corrupted/truncated, avoid calling elf_strptr. */
170 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
171 return NULL;
172
e5a1845f
NK		 173 while ((sec = elf_nextscn(elf, sec)) != NULL) {
174 char *str;
175
176 gelf_getshdr(sec, shp);
177 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
155b3a13 178 if (str && !strcmp(name, str)) {
e5a1845f
NK		 179 if (idx)
180 *idx = cnt;
155b3a13 181 return sec;
e5a1845f
NK		 182 }
183 ++cnt;
184 }
185
155b3a13 186 return NULL;
e5a1845f
NK		 187}
188
189#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
190 for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
191 idx < nr_entries; \
192 ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
193
194#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
195 for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
196 idx < nr_entries; \
197 ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
198
199/*
200 * We need to check if we have a .dynsym, so that we can handle the
201 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
202 * .dynsym or .symtab).
203 * And always look at the original dso, not at debuginfo packages, that
204 * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
205 */
a44f605b 206int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
e5a1845f
NK		 207 symbol_filter_t filter)
208{
209 uint32_t nr_rel_entries, idx;
210 GElf_Sym sym;
211 u64 plt_offset;
212 GElf_Shdr shdr_plt;
213 struct symbol *f;
214 GElf_Shdr shdr_rel_plt, shdr_dynsym;
215 Elf_Data *reldata, *syms, *symstrs;
216 Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
217 size_t dynsym_idx;
218 GElf_Ehdr ehdr;
219 char sympltname[1024];
220 Elf *elf;
a44f605b 221 int nr = 0, symidx, err = 0;
e5a1845f 222
f47b58b7
DA		 223 if (!ss->dynsym)
224 return 0;
225
a44f605b
CS		 226 elf = ss->elf;
227 ehdr = ss->ehdr;
e5a1845f 228
a44f605b
CS		 229 scn_dynsym = ss->dynsym;
230 shdr_dynsym = ss->dynshdr;
231 dynsym_idx = ss->dynsym_idx;
e5a1845f 232
e5a1845f
NK		 233 if (scn_dynsym == NULL)
234 goto out_elf_end;
235
236 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
237 ".rela.plt", NULL);
238 if (scn_plt_rel == NULL) {
239 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
240 ".rel.plt", NULL);
241 if (scn_plt_rel == NULL)
242 goto out_elf_end;
243 }
244
245 err = -1;
246
247 if (shdr_rel_plt.sh_link != dynsym_idx)
248 goto out_elf_end;
249
250 if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
251 goto out_elf_end;
252
253 /*
254 * Fetch the relocation section to find the idxes to the GOT
255 * and the symbols in the .dynsym they refer to.
256 */
257 reldata = elf_getdata(scn_plt_rel, NULL);
258 if (reldata == NULL)
259 goto out_elf_end;
260
261 syms = elf_getdata(scn_dynsym, NULL);
262 if (syms == NULL)
263 goto out_elf_end;
264
265 scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
266 if (scn_symstrs == NULL)
267 goto out_elf_end;
268
269 symstrs = elf_getdata(scn_symstrs, NULL);
270 if (symstrs == NULL)
271 goto out_elf_end;
272
52f9ddba
CS		 273 if (symstrs->d_size == 0)
274 goto out_elf_end;
275
e5a1845f
NK		 276 nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
277 plt_offset = shdr_plt.sh_offset;
278
279 if (shdr_rel_plt.sh_type == SHT_RELA) {
280 GElf_Rela pos_mem, *pos;
281
282 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
283 nr_rel_entries) {
284 symidx = GELF_R_SYM(pos->r_info);
285 plt_offset += shdr_plt.sh_entsize;
286 gelf_getsym(syms, symidx, &sym);
287 snprintf(sympltname, sizeof(sympltname),
288 "%s@plt", elf_sym__name(&sym, symstrs));
289
290 f = symbol__new(plt_offset, shdr_plt.sh_entsize,
291 STB_GLOBAL, sympltname);
292 if (!f)
293 goto out_elf_end;
294
295 if (filter && filter(map, f))
296 symbol__delete(f);
297 else {
298 symbols__insert(&dso->symbols[map->type], f);
299 ++nr;
300 }
301 }
302 } else if (shdr_rel_plt.sh_type == SHT_REL) {
303 GElf_Rel pos_mem, *pos;
304 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
305 nr_rel_entries) {
306 symidx = GELF_R_SYM(pos->r_info);
307 plt_offset += shdr_plt.sh_entsize;
308 gelf_getsym(syms, symidx, &sym);
309 snprintf(sympltname, sizeof(sympltname),
310 "%s@plt", elf_sym__name(&sym, symstrs));
311
312 f = symbol__new(plt_offset, shdr_plt.sh_entsize,
313 STB_GLOBAL, sympltname);
314 if (!f)
315 goto out_elf_end;
316
317 if (filter && filter(map, f))
318 symbol__delete(f);
319 else {
320 symbols__insert(&dso->symbols[map->type], f);
321 ++nr;
322 }
323 }
324 }
325
326 err = 0;
327out_elf_end:
e5a1845f
NK		 328 if (err == 0)
329 return nr;
e5a1845f
NK		 330 pr_debug("%s: problems reading %s PLT info.\n",
331 __func__, dso->long_name);
332 return 0;
333}
334
335/*
336 * Align offset to 4 bytes as needed for note name and descriptor data.
337 */
338#define NOTE_ALIGN(n) (((n) + 3) & -4U)
339
340static int elf_read_build_id(Elf *elf, void *bf, size_t size)
341{
342 int err = -1;
343 GElf_Ehdr ehdr;
344 GElf_Shdr shdr;
345 Elf_Data *data;
346 Elf_Scn *sec;
347 Elf_Kind ek;
348 void *ptr;
349
350 if (size < BUILD_ID_SIZE)
351 goto out;
352
353 ek = elf_kind(elf);
354 if (ek != ELF_K_ELF)
355 goto out;
356
357 if (gelf_getehdr(elf, &ehdr) == NULL) {
358 pr_err("%s: cannot get elf header.\n", __func__);
359 goto out;
360 }
361
362 /*
363 * Check following sections for notes:
364 * '.note.gnu.build-id'
365 * '.notes'
366 * '.note' (VDSO specific)
367 */
368 do {
369 sec = elf_section_by_name(elf, &ehdr, &shdr,
370 ".note.gnu.build-id", NULL);
371 if (sec)
372 break;
373
374 sec = elf_section_by_name(elf, &ehdr, &shdr,
375 ".notes", NULL);
376 if (sec)
377 break;
378
379 sec = elf_section_by_name(elf, &ehdr, &shdr,
380 ".note", NULL);
381 if (sec)
382 break;
383
384 return err;
385
386 } while (0);
387
388 data = elf_getdata(sec, NULL);
389 if (data == NULL)
390 goto out;
391
392 ptr = data->d_buf;
393 while (ptr < (data->d_buf + data->d_size)) {
394 GElf_Nhdr *nhdr = ptr;
395 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
396 descsz = NOTE_ALIGN(nhdr->n_descsz);
397 const char *name;
398
399 ptr += sizeof(*nhdr);
400 name = ptr;
401 ptr += namesz;
402 if (nhdr->n_type == NT_GNU_BUILD_ID &&
403 nhdr->n_namesz == sizeof("GNU")) {
404 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
405 size_t sz = min(size, descsz);
406 memcpy(bf, ptr, sz);
407 memset(bf + sz, 0, size - sz);
408 err = descsz;
409 break;
410 }
411 }
412 ptr += descsz;
413 }
414
415out:
416 return err;
417}
418
419int filename__read_build_id(const char *filename, void *bf, size_t size)
420{
421 int fd, err = -1;
422 Elf *elf;
423
424 if (size < BUILD_ID_SIZE)
425 goto out;
426
427 fd = open(filename, O_RDONLY);
428 if (fd < 0)
429 goto out;
430
431 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
432 if (elf == NULL) {
433 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
434 goto out_close;
435 }
436
437 err = elf_read_build_id(elf, bf, size);
438
439 elf_end(elf);
440out_close:
441 close(fd);
442out:
443 return err;
444}
445
446int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
447{
448 int fd, err = -1;
449
450 if (size < BUILD_ID_SIZE)
451 goto out;
452
453 fd = open(filename, O_RDONLY);
454 if (fd < 0)
455 goto out;
456
457 while (1) {
458 char bf[BUFSIZ];
459 GElf_Nhdr nhdr;
460 size_t namesz, descsz;
461
462 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
463 break;
464
465 namesz = NOTE_ALIGN(nhdr.n_namesz);
466 descsz = NOTE_ALIGN(nhdr.n_descsz);
467 if (nhdr.n_type == NT_GNU_BUILD_ID &&
468 nhdr.n_namesz == sizeof("GNU")) {
469 if (read(fd, bf, namesz) != (ssize_t)namesz)
470 break;
471 if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
472 size_t sz = min(descsz, size);
473 if (read(fd, build_id, sz) == (ssize_t)sz) {
474 memset(build_id + sz, 0, size - sz);
475 err = 0;
476 break;
477 }
478 } else if (read(fd, bf, descsz) != (ssize_t)descsz)
479 break;
480 } else {
481 int n = namesz + descsz;
482 if (read(fd, bf, n) != n)
483 break;
484 }
485 }
486 close(fd);
487out:
488 return err;
489}
490
491int filename__read_debuglink(const char *filename, char *debuglink,
492 size_t size)
493{
494 int fd, err = -1;
495 Elf *elf;
496 GElf_Ehdr ehdr;
497 GElf_Shdr shdr;
498 Elf_Data *data;
499 Elf_Scn *sec;
500 Elf_Kind ek;
501
502 fd = open(filename, O_RDONLY);
503 if (fd < 0)
504 goto out;
505
506 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
507 if (elf == NULL) {
508 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
509 goto out_close;
510 }
511
512 ek = elf_kind(elf);
513 if (ek != ELF_K_ELF)
784f3390 514 goto out_elf_end;
e5a1845f
NK		 515
516 if (gelf_getehdr(elf, &ehdr) == NULL) {
517 pr_err("%s: cannot get elf header.\n", __func__);
784f3390 518 goto out_elf_end;
e5a1845f
NK		 519 }
520
521 sec = elf_section_by_name(elf, &ehdr, &shdr,
522 ".gnu_debuglink", NULL);
523 if (sec == NULL)
784f3390 524 goto out_elf_end;
e5a1845f
NK		 525
526 data = elf_getdata(sec, NULL);
527 if (data == NULL)
784f3390 528 goto out_elf_end;
e5a1845f
NK		 529
530 /* the start of this section is a zero-terminated string */
531 strncpy(debuglink, data->d_buf, size);
532
0d3dc5e8
SE		 533 err = 0;
534
784f3390 535out_elf_end:
e5a1845f 536 elf_end(elf);
e5a1845f
NK		 537out_close:
538 close(fd);
539out:
540 return err;
541}
542
543static int dso__swap_init(struct dso *dso, unsigned char eidata)
544{
545 static unsigned int const endian = 1;
546
547 dso->needs_swap = DSO_SWAP__NO;
548
549 switch (eidata) {
550 case ELFDATA2LSB:
551 /* We are big endian, DSO is little endian. */
552 if (*(unsigned char const *)&endian != 1)
553 dso->needs_swap = DSO_SWAP__YES;
554 break;
555
556 case ELFDATA2MSB:
557 /* We are little endian, DSO is big endian. */
558 if (*(unsigned char const *)&endian != 0)
559 dso->needs_swap = DSO_SWAP__YES;
560 break;
561
562 default:
563 pr_err("unrecognized DSO data encoding %d\n", eidata);
564 return -EINVAL;
565 }
566
567 return 0;
568}
569
c00c48fc
NK		 570static int decompress_kmodule(struct dso *dso, const char *name,
571 enum dso_binary_type type)
572{
573 int fd;
574 const char *ext = strrchr(name, '.');
575 char tmpbuf[] = "/tmp/perf-kmod-XXXXXX";
576
0b064f43
NK		 577 if (type != DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP &&
578 type != DSO_BINARY_TYPE__GUEST_KMODULE_COMP &&
579 type != DSO_BINARY_TYPE__BUILD_ID_CACHE)
c00c48fc
NK		 580 return -1;
581
0b064f43
NK		 582 if (!ext || !is_supported_compression(ext + 1)) {
583 ext = strrchr(dso->name, '.');
584 if (!ext || !is_supported_compression(ext + 1))
585 return -1;
586 }
c00c48fc
NK		 587
588 fd = mkstemp(tmpbuf);
589 if (fd < 0)
590 return -1;
591
592 if (!decompress_to_file(ext + 1, name, fd)) {
593 close(fd);
594 fd = -1;
595 }
596
597 unlink(tmpbuf);
598
599 return fd;
600}
601
3aafe5ae
CS		 602bool symsrc__possibly_runtime(struct symsrc *ss)
603{
604 return ss->dynsym || ss->opdsec;
605}
606
d26cd12b
CS		 607bool symsrc__has_symtab(struct symsrc *ss)
608{
609 return ss->symtab != NULL;
610}
b68e2f91
CS		 611
612void symsrc__destroy(struct symsrc *ss)
613{
74cf249d 614 zfree(&ss->name);
b68e2f91
CS		 615 elf_end(ss->elf);
616 close(ss->fd);
617}
618
619int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
620 enum dso_binary_type type)
e5a1845f 621{
e5a1845f 622 int err = -1;
e5a1845f 623 GElf_Ehdr ehdr;
e5a1845f 624 Elf *elf;
b68e2f91
CS		 625 int fd;
626
c00c48fc
NK		 627 if (dso__needs_decompress(dso))
628 fd = decompress_kmodule(dso, name, type);
629 else
630 fd = open(name, O_RDONLY);
631
b68e2f91
CS		 632 if (fd < 0)
633 return -1;
e5a1845f
NK		 634
635 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
636 if (elf == NULL) {
637 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
638 goto out_close;
639 }
640
641 if (gelf_getehdr(elf, &ehdr) == NULL) {
642 pr_debug("%s: cannot get elf header.\n", __func__);
643 goto out_elf_end;
644 }
645
646 if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
647 goto out_elf_end;
648
649 /* Always reject images with a mismatched build-id: */
650 if (dso->has_build_id) {
651 u8 build_id[BUILD_ID_SIZE];
652
653 if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
654 goto out_elf_end;
655
656 if (!dso__build_id_equal(dso, build_id))
657 goto out_elf_end;
658 }
659
c6d8f2a4
AH		 660 ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
661
b68e2f91
CS		 662 ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
663 NULL);
664 if (ss->symshdr.sh_type != SHT_SYMTAB)
665 ss->symtab = NULL;
666
667 ss->dynsym_idx = 0;
668 ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
669 &ss->dynsym_idx);
670 if (ss->dynshdr.sh_type != SHT_DYNSYM)
671 ss->dynsym = NULL;
672
673 ss->opdidx = 0;
674 ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
675 &ss->opdidx);
676 if (ss->opdshdr.sh_type != SHT_PROGBITS)
677 ss->opdsec = NULL;
678
679 if (dso->kernel == DSO_TYPE_USER) {
680 GElf_Shdr shdr;
681 ss->adjust_symbols = (ehdr.e_type == ET_EXEC ||
0131c4ec 682 ehdr.e_type == ET_REL ||
51682dc7 683 dso__is_vdso(dso) ||
b68e2f91
CS		 684 elf_section_by_name(elf, &ehdr, &shdr,
685 ".gnu.prelink_undo",
686 NULL) != NULL);
687 } else {
0131c4ec
AH		 688 ss->adjust_symbols = ehdr.e_type == ET_EXEC ||
689 ehdr.e_type == ET_REL;
b68e2f91
CS		 690 }
691
692 ss->name = strdup(name);
693 if (!ss->name)
694 goto out_elf_end;
695
696 ss->elf = elf;
697 ss->fd = fd;
698 ss->ehdr = ehdr;
699 ss->type = type;
700
701 return 0;
702
703out_elf_end:
704 elf_end(elf);
705out_close:
706 close(fd);
707 return err;
708}
709
39b12f78
AH		 710/**
711 * ref_reloc_sym_not_found - has kernel relocation symbol been found.
712 * @kmap: kernel maps and relocation reference symbol
713 *
714 * This function returns %true if we are dealing with the kernel maps and the
715 * relocation reference symbol has not yet been found. Otherwise %false is
716 * returned.
717 */
718static bool ref_reloc_sym_not_found(struct kmap *kmap)
719{
720 return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
721 !kmap->ref_reloc_sym->unrelocated_addr;
722}
723
724/**
725 * ref_reloc - kernel relocation offset.
726 * @kmap: kernel maps and relocation reference symbol
727 *
728 * This function returns the offset of kernel addresses as determined by using
729 * the relocation reference symbol i.e. if the kernel has not been relocated
730 * then the return value is zero.
731 */
732static u64 ref_reloc(struct kmap *kmap)
733{
734 if (kmap && kmap->ref_reloc_sym &&
735 kmap->ref_reloc_sym->unrelocated_addr)
736 return kmap->ref_reloc_sym->addr -
737 kmap->ref_reloc_sym->unrelocated_addr;
738 return 0;
739}
740
763122ad
AK		 741static bool want_demangle(bool is_kernel_sym)
742{
743 return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
744}
745
261360b6
CS		 746int dso__load_sym(struct dso *dso, struct map *map,
747 struct symsrc *syms_ss, struct symsrc *runtime_ss,
d26cd12b 748 symbol_filter_t filter, int kmodule)
b68e2f91
CS		 749{
750 struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
751 struct map *curr_map = map;
752 struct dso *curr_dso = dso;
753 Elf_Data *symstrs, *secstrs;
754 uint32_t nr_syms;
755 int err = -1;
756 uint32_t idx;
757 GElf_Ehdr ehdr;
261360b6 758 GElf_Shdr shdr;
b68e2f91
CS		 759 Elf_Data *syms, *opddata = NULL;
760 GElf_Sym sym;
261360b6 761 Elf_Scn *sec, *sec_strndx;
b68e2f91
CS		 762 Elf *elf;
763 int nr = 0;
39b12f78 764 bool remap_kernel = false, adjust_kernel_syms = false;
b68e2f91 765
261360b6 766 dso->symtab_type = syms_ss->type;
c6d8f2a4 767 dso->is_64_bit = syms_ss->is_64_bit;
0131c4ec
AH		 768 dso->rel = syms_ss->ehdr.e_type == ET_REL;
769
770 /*
771 * Modules may already have symbols from kallsyms, but those symbols
772 * have the wrong values for the dso maps, so remove them.
773 */
774 if (kmodule && syms_ss->symtab)
775 symbols__delete(&dso->symbols[map->type]);
005f9294 776
261360b6 777 if (!syms_ss->symtab) {
d0b0d040
AB		 778 /*
779 * If the vmlinux is stripped, fail so we will fall back
780 * to using kallsyms. The vmlinux runtime symbols aren't
781 * of much use.
782 */
783 if (dso->kernel)
784 goto out_elf_end;
785
261360b6
CS		 786 syms_ss->symtab = syms_ss->dynsym;
787 syms_ss->symshdr = syms_ss->dynshdr;
d26cd12b
CS		 788 }
789
261360b6
CS		 790 elf = syms_ss->elf;
791 ehdr = syms_ss->ehdr;
792 sec = syms_ss->symtab;
793 shdr = syms_ss->symshdr;
b68e2f91 794
261360b6
CS		 795 if (runtime_ss->opdsec)
796 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
e5a1845f
NK		 797
798 syms = elf_getdata(sec, NULL);
799 if (syms == NULL)
800 goto out_elf_end;
801
802 sec = elf_getscn(elf, shdr.sh_link);
803 if (sec == NULL)
804 goto out_elf_end;
805
806 symstrs = elf_getdata(sec, NULL);
807 if (symstrs == NULL)
808 goto out_elf_end;
809
f247fb81 810 sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
e5a1845f
NK		 811 if (sec_strndx == NULL)
812 goto out_elf_end;
813
814 secstrs = elf_getdata(sec_strndx, NULL);
815 if (secstrs == NULL)
816 goto out_elf_end;
817
818 nr_syms = shdr.sh_size / shdr.sh_entsize;
819
820 memset(&sym, 0, sizeof(sym));
39b12f78
AH		 821
822 /*
823 * The kernel relocation symbol is needed in advance in order to adjust
824 * kernel maps correctly.
825 */
826 if (ref_reloc_sym_not_found(kmap)) {
827 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
828 const char *elf_name = elf_sym__name(&sym, symstrs);
829
830 if (strcmp(elf_name, kmap->ref_reloc_sym->name))
831 continue;
832 kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
9176753d
AH		 833 map->reloc = kmap->ref_reloc_sym->addr -
834 kmap->ref_reloc_sym->unrelocated_addr;
39b12f78
AH		 835 break;
836 }
837 }
838
839 dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
840 /*
841 * Initial kernel and module mappings do not map to the dso. For
842 * function mappings, flag the fixups.
843 */
844 if (map->type == MAP__FUNCTION && (dso->kernel || kmodule)) {
845 remap_kernel = true;
846 adjust_kernel_syms = dso->adjust_symbols;
847 }
e5a1845f
NK		 848 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
849 struct symbol *f;
850 const char *elf_name = elf_sym__name(&sym, symstrs);
851 char *demangled = NULL;
852 int is_label = elf_sym__is_label(&sym);
853 const char *section_name;
261360b6 854 bool used_opd = false;
e5a1845f 855
e5a1845f
NK		 856 if (!is_label && !elf_sym__is_a(&sym, map->type))
857 continue;
858
859 /* Reject ARM ELF "mapping symbols": these aren't unique and
860 * don't identify functions, so will confuse the profile
861 * output: */
862 if (ehdr.e_machine == EM_ARM) {
863 if (!strcmp(elf_name, "$a") ||
864 !strcmp(elf_name, "$d") ||
865 !strcmp(elf_name, "$t"))
866 continue;
867 }
868
261360b6
CS		 869 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
870 u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
e5a1845f
NK		 871 u64 *opd = opddata->d_buf + offset;
872 sym.st_value = DSO__SWAP(dso, u64, *opd);
261360b6
CS		 873 sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
874 sym.st_value);
875 used_opd = true;
e5a1845f 876 }
3843b05d
NK		 877 /*
878 * When loading symbols in a data mapping, ABS symbols (which
879 * has a value of SHN_ABS in its st_shndx) failed at
880 * elf_getscn(). And it marks the loading as a failure so
881 * already loaded symbols cannot be fixed up.
882 *
883 * I'm not sure what should be done. Just ignore them for now.
884 * - Namhyung Kim
885 */
886 if (sym.st_shndx == SHN_ABS)
887 continue;
e5a1845f 888
261360b6 889 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
e5a1845f
NK		 890 if (!sec)
891 goto out_elf_end;
892
893 gelf_getshdr(sec, &shdr);
894
895 if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
896 continue;
897
898 section_name = elf_sec__name(&shdr, secstrs);
899
900 /* On ARM, symbols for thumb functions have 1 added to
901 * the symbol address as a flag - remove it */
902 if ((ehdr.e_machine == EM_ARM) &&
903 (map->type == MAP__FUNCTION) &&
904 (sym.st_value & 1))
905 --sym.st_value;
906
39b12f78 907 if (dso->kernel || kmodule) {
e5a1845f
NK		 908 char dso_name[PATH_MAX];
909
39b12f78
AH		 910 /* Adjust symbol to map to file offset */
911 if (adjust_kernel_syms)
912 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
913
e5a1845f
NK		 914 if (strcmp(section_name,
915 (curr_dso->short_name +
916 dso->short_name_len)) == 0)
917 goto new_symbol;
918
919 if (strcmp(section_name, ".text") == 0) {
39b12f78
AH		 920 /*
921 * The initial kernel mapping is based on
922 * kallsyms and identity maps. Overwrite it to
923 * map to the kernel dso.
924 */
925 if (remap_kernel && dso->kernel) {
926 remap_kernel = false;
927 map->start = shdr.sh_addr +
928 ref_reloc(kmap);
929 map->end = map->start + shdr.sh_size;
930 map->pgoff = shdr.sh_offset;
931 map->map_ip = map__map_ip;
932 map->unmap_ip = map__unmap_ip;
933 /* Ensure maps are correctly ordered */
934 map_groups__remove(kmap->kmaps, map);
935 map_groups__insert(kmap->kmaps, map);
936 }
937
0131c4ec
AH		 938 /*
939 * The initial module mapping is based on
940 * /proc/modules mapped to offset zero.
941 * Overwrite it to map to the module dso.
942 */
943 if (remap_kernel && kmodule) {
944 remap_kernel = false;
945 map->pgoff = shdr.sh_offset;
946 }
947
e5a1845f
NK		 948 curr_map = map;
949 curr_dso = dso;
950 goto new_symbol;
951 }
952
0131c4ec
AH		 953 if (!kmap)
954 goto new_symbol;
955
e5a1845f
NK		 956 snprintf(dso_name, sizeof(dso_name),
957 "%s%s", dso->short_name, section_name);
958
959 curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
960 if (curr_map == NULL) {
961 u64 start = sym.st_value;
962
963 if (kmodule)
964 start += map->start + shdr.sh_offset;
965
966 curr_dso = dso__new(dso_name);
967 if (curr_dso == NULL)
968 goto out_elf_end;
969 curr_dso->kernel = dso->kernel;
970 curr_dso->long_name = dso->long_name;
971 curr_dso->long_name_len = dso->long_name_len;
972 curr_map = map__new2(start, curr_dso,
973 map->type);
974 if (curr_map == NULL) {
975 dso__delete(curr_dso);
976 goto out_elf_end;
977 }
39b12f78
AH		 978 if (adjust_kernel_syms) {
979 curr_map->start = shdr.sh_addr +
980 ref_reloc(kmap);
981 curr_map->end = curr_map->start +
982 shdr.sh_size;
983 curr_map->pgoff = shdr.sh_offset;
984 } else {
985 curr_map->map_ip = identity__map_ip;
986 curr_map->unmap_ip = identity__map_ip;
987 }
e5a1845f
NK		 988 curr_dso->symtab_type = dso->symtab_type;
989 map_groups__insert(kmap->kmaps, curr_map);
8fa7d87f
WL		 990 /*
991 * The new DSO should go to the kernel DSOS
992 */
993 dsos__add(&map->groups->machine->kernel_dsos,
994 curr_dso);
e5a1845f
NK		 995 dso__set_loaded(curr_dso, map->type);
996 } else
997 curr_dso = curr_map->dso;
998
999 goto new_symbol;
1000 }
1001
261360b6
CS		 1002 if ((used_opd && runtime_ss->adjust_symbols)
1003 || (!used_opd && syms_ss->adjust_symbols)) {
e5a1845f
NK		 1004 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1005 "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
1006 (u64)sym.st_value, (u64)shdr.sh_addr,
1007 (u64)shdr.sh_offset);
1008 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1009 }
950b8354 1010new_symbol:
e5a1845f
NK		 1011 /*
1012 * We need to figure out if the object was created from C++ sources
1013 * DWARF DW_compile_unit has this, but we don't always have access
1014 * to it...
1015 */
763122ad 1016 if (want_demangle(dso->kernel || kmodule)) {
e71e7945
NK		 1017 int demangle_flags = DMGL_NO_OPTS;
1018 if (verbose)
1019 demangle_flags = DMGL_PARAMS | DMGL_ANSI;
1020
1021 demangled = bfd_demangle(NULL, elf_name, demangle_flags);
328ccdac
NK		 1022 if (demangled != NULL)
1023 elf_name = demangled;
1024 }
e5a1845f
NK		 1025 f = symbol__new(sym.st_value, sym.st_size,
1026 GELF_ST_BIND(sym.st_info), elf_name);
1027 free(demangled);
1028 if (!f)
1029 goto out_elf_end;
1030
1031 if (filter && filter(curr_map, f))
1032 symbol__delete(f);
1033 else {
1034 symbols__insert(&curr_dso->symbols[curr_map->type], f);
1035 nr++;
1036 }
1037 }
1038
1039 /*
1040 * For misannotated, zeroed, ASM function sizes.
1041 */
1042 if (nr > 0) {
1043 symbols__fixup_duplicate(&dso->symbols[map->type]);
1044 symbols__fixup_end(&dso->symbols[map->type]);
1045 if (kmap) {
1046 /*
1047 * We need to fixup this here too because we create new
1048 * maps here, for things like vsyscall sections.
1049 */
1050 __map_groups__fixup_end(kmap->kmaps, map->type);
1051 }
1052 }
1053 err = nr;
1054out_elf_end:
e5a1845f
NK		 1055 return err;
1056}
1057
8e0cf965
AH		 1058static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
1059{
1060 GElf_Phdr phdr;
1061 size_t i, phdrnum;
1062 int err;
1063 u64 sz;
1064
1065 if (elf_getphdrnum(elf, &phdrnum))
1066 return -1;
1067
1068 for (i = 0; i < phdrnum; i++) {
1069 if (gelf_getphdr(elf, i, &phdr) == NULL)
1070 return -1;
1071 if (phdr.p_type != PT_LOAD)
1072 continue;
1073 if (exe) {
1074 if (!(phdr.p_flags & PF_X))
1075 continue;
1076 } else {
1077 if (!(phdr.p_flags & PF_R))
1078 continue;
1079 }
1080 sz = min(phdr.p_memsz, phdr.p_filesz);
1081 if (!sz)
1082 continue;
1083 err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
1084 if (err)
1085 return err;
1086 }
1087 return 0;
1088}
1089
1090int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
1091 bool *is_64_bit)
1092{
1093 int err;
1094 Elf *elf;
1095
1096 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1097 if (elf == NULL)
1098 return -1;
1099
1100 if (is_64_bit)
1101 *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
1102
1103 err = elf_read_maps(elf, exe, mapfn, data);
1104
1105 elf_end(elf);
1106 return err;
1107}
1108
2b5b8bb2
AH		 1109enum dso_type dso__type_fd(int fd)
1110{
1111 enum dso_type dso_type = DSO__TYPE_UNKNOWN;
1112 GElf_Ehdr ehdr;
1113 Elf_Kind ek;
1114 Elf *elf;
1115
1116 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1117 if (elf == NULL)
1118 goto out;
1119
1120 ek = elf_kind(elf);
1121 if (ek != ELF_K_ELF)
1122 goto out_end;
1123
1124 if (gelf_getclass(elf) == ELFCLASS64) {
1125 dso_type = DSO__TYPE_64BIT;
1126 goto out_end;
1127 }
1128
1129 if (gelf_getehdr(elf, &ehdr) == NULL)
1130 goto out_end;
1131
1132 if (ehdr.e_machine == EM_X86_64)
1133 dso_type = DSO__TYPE_X32BIT;
1134 else
1135 dso_type = DSO__TYPE_32BIT;
1136out_end:
1137 elf_end(elf);
1138out:
1139 return dso_type;
1140}
1141
afba19d9
AH		 1142static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
1143{
1144 ssize_t r;
1145 size_t n;
1146 int err = -1;
1147 char *buf = malloc(page_size);
1148
1149 if (buf == NULL)
1150 return -1;
1151
1152 if (lseek(to, to_offs, SEEK_SET) != to_offs)
1153 goto out;
1154
1155 if (lseek(from, from_offs, SEEK_SET) != from_offs)
1156 goto out;
1157
1158 while (len) {
1159 n = page_size;
1160 if (len < n)
1161 n = len;
1162 /* Use read because mmap won't work on proc files */
1163 r = read(from, buf, n);
1164 if (r < 0)
1165 goto out;
1166 if (!r)
1167 break;
1168 n = r;
1169 r = write(to, buf, n);
1170 if (r < 0)
1171 goto out;
1172 if ((size_t)r != n)
1173 goto out;
1174 len -= n;
1175 }
1176
1177 err = 0;
1178out:
1179 free(buf);
1180 return err;
1181}
1182
1183struct kcore {
1184 int fd;
1185 int elfclass;
1186 Elf *elf;
1187 GElf_Ehdr ehdr;
1188};
1189
1190static int kcore__open(struct kcore *kcore, const char *filename)
1191{
1192 GElf_Ehdr *ehdr;
1193
1194 kcore->fd = open(filename, O_RDONLY);
1195 if (kcore->fd == -1)
1196 return -1;
1197
1198 kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
1199 if (!kcore->elf)
1200 goto out_close;
1201
1202 kcore->elfclass = gelf_getclass(kcore->elf);
1203 if (kcore->elfclass == ELFCLASSNONE)
1204 goto out_end;
1205
1206 ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1207 if (!ehdr)
1208 goto out_end;
1209
1210 return 0;
1211
1212out_end:
1213 elf_end(kcore->elf);
1214out_close:
1215 close(kcore->fd);
1216 return -1;
1217}
1218
1219static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
1220 bool temp)
1221{
1222 GElf_Ehdr *ehdr;
1223
1224 kcore->elfclass = elfclass;
1225
1226 if (temp)
1227 kcore->fd = mkstemp(filename);
1228 else
1229 kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
1230 if (kcore->fd == -1)
1231 return -1;
1232
1233 kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
1234 if (!kcore->elf)
1235 goto out_close;
1236
1237 if (!gelf_newehdr(kcore->elf, elfclass))
1238 goto out_end;
1239
1240 ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1241 if (!ehdr)
1242 goto out_end;
1243
1244 return 0;
1245
1246out_end:
1247 elf_end(kcore->elf);
1248out_close:
1249 close(kcore->fd);
1250 unlink(filename);
1251 return -1;
1252}
1253
1254static void kcore__close(struct kcore *kcore)
1255{
1256 elf_end(kcore->elf);
1257 close(kcore->fd);
1258}
1259
1260static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
1261{
1262 GElf_Ehdr *ehdr = &to->ehdr;
1263 GElf_Ehdr *kehdr = &from->ehdr;
1264
1265 memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
1266 ehdr->e_type = kehdr->e_type;
1267 ehdr->e_machine = kehdr->e_machine;
1268 ehdr->e_version = kehdr->e_version;
1269 ehdr->e_entry = 0;
1270 ehdr->e_shoff = 0;
1271 ehdr->e_flags = kehdr->e_flags;
1272 ehdr->e_phnum = count;
1273 ehdr->e_shentsize = 0;
1274 ehdr->e_shnum = 0;
1275 ehdr->e_shstrndx = 0;
1276
1277 if (from->elfclass == ELFCLASS32) {
1278 ehdr->e_phoff = sizeof(Elf32_Ehdr);
1279 ehdr->e_ehsize = sizeof(Elf32_Ehdr);
1280 ehdr->e_phentsize = sizeof(Elf32_Phdr);
1281 } else {
1282 ehdr->e_phoff = sizeof(Elf64_Ehdr);
1283 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1284 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1285 }
1286
1287 if (!gelf_update_ehdr(to->elf, ehdr))
1288 return -1;
1289
1290 if (!gelf_newphdr(to->elf, count))
1291 return -1;
1292
1293 return 0;
1294}
1295
1296static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
1297 u64 addr, u64 len)
1298{
1299 GElf_Phdr gphdr;
1300 GElf_Phdr *phdr;
1301
1302 phdr = gelf_getphdr(kcore->elf, idx, &gphdr);
1303 if (!phdr)
1304 return -1;
1305
1306 phdr->p_type = PT_LOAD;
1307 phdr->p_flags = PF_R | PF_W | PF_X;
1308 phdr->p_offset = offset;
1309 phdr->p_vaddr = addr;
1310 phdr->p_paddr = 0;
1311 phdr->p_filesz = len;
1312 phdr->p_memsz = len;
1313 phdr->p_align = page_size;
1314
1315 if (!gelf_update_phdr(kcore->elf, idx, phdr))
1316 return -1;
1317
1318 return 0;
1319}
1320
1321static off_t kcore__write(struct kcore *kcore)
1322{
1323 return elf_update(kcore->elf, ELF_C_WRITE);
1324}
1325
fc1b691d
AH		 1326struct phdr_data {
1327 off_t offset;
1328 u64 addr;
1329 u64 len;
1330};
1331
1332struct kcore_copy_info {
1333 u64 stext;
1334 u64 etext;
1335 u64 first_symbol;
1336 u64 last_symbol;
1337 u64 first_module;
1338 u64 last_module_symbol;
1339 struct phdr_data kernel_map;
1340 struct phdr_data modules_map;
1341};
1342
1343static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
1344 u64 start)
1345{
1346 struct kcore_copy_info *kci = arg;
1347
1348 if (!symbol_type__is_a(type, MAP__FUNCTION))
1349 return 0;
1350
1351 if (strchr(name, '[')) {
1352 if (start > kci->last_module_symbol)
1353 kci->last_module_symbol = start;
1354 return 0;
1355 }
1356
1357 if (!kci->first_symbol || start < kci->first_symbol)
1358 kci->first_symbol = start;
1359
1360 if (!kci->last_symbol || start > kci->last_symbol)
1361 kci->last_symbol = start;
1362
1363 if (!strcmp(name, "_stext")) {
1364 kci->stext = start;
1365 return 0;
1366 }
1367
1368 if (!strcmp(name, "_etext")) {
1369 kci->etext = start;
1370 return 0;
1371 }
1372
1373 return 0;
1374}
1375
1376static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
1377 const char *dir)
1378{
1379 char kallsyms_filename[PATH_MAX];
1380
1381 scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
1382
1383 if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
1384 return -1;
1385
1386 if (kallsyms__parse(kallsyms_filename, kci,
1387 kcore_copy__process_kallsyms) < 0)
1388 return -1;
1389
1390 return 0;
1391}
1392
1393static int kcore_copy__process_modules(void *arg,
1394 const char *name __maybe_unused,
1395 u64 start)
1396{
1397 struct kcore_copy_info *kci = arg;
1398
1399 if (!kci->first_module || start < kci->first_module)
1400 kci->first_module = start;
1401
1402 return 0;
1403}
1404
1405static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
1406 const char *dir)
1407{
1408 char modules_filename[PATH_MAX];
1409
1410 scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
1411
1412 if (symbol__restricted_filename(modules_filename, "/proc/modules"))
1413 return -1;
1414
1415 if (modules__parse(modules_filename, kci,
1416 kcore_copy__process_modules) < 0)
1417 return -1;
1418
1419 return 0;
1420}
1421
1422static void kcore_copy__map(struct phdr_data *p, u64 start, u64 end, u64 pgoff,
1423 u64 s, u64 e)
1424{
1425 if (p->addr || s < start || s >= end)
1426 return;
1427
1428 p->addr = s;
1429 p->offset = (s - start) + pgoff;
1430 p->len = e < end ? e - s : end - s;
1431}
1432
1433static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
1434{
1435 struct kcore_copy_info *kci = data;
1436 u64 end = start + len;
1437
1438 kcore_copy__map(&kci->kernel_map, start, end, pgoff, kci->stext,
1439 kci->etext);
1440
1441 kcore_copy__map(&kci->modules_map, start, end, pgoff, kci->first_module,
1442 kci->last_module_symbol);
1443
1444 return 0;
1445}
1446
1447static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
1448{
1449 if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
1450 return -1;
1451
1452 return 0;
1453}
1454
1455static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
1456 Elf *elf)
1457{
1458 if (kcore_copy__parse_kallsyms(kci, dir))
1459 return -1;
1460
1461 if (kcore_copy__parse_modules(kci, dir))
1462 return -1;
1463
1464 if (kci->stext)
1465 kci->stext = round_down(kci->stext, page_size);
1466 else
1467 kci->stext = round_down(kci->first_symbol, page_size);
1468
1469 if (kci->etext) {
1470 kci->etext = round_up(kci->etext, page_size);
1471 } else if (kci->last_symbol) {
1472 kci->etext = round_up(kci->last_symbol, page_size);
1473 kci->etext += page_size;
1474 }
1475
1476 kci->first_module = round_down(kci->first_module, page_size);
1477
1478 if (kci->last_module_symbol) {
1479 kci->last_module_symbol = round_up(kci->last_module_symbol,
1480 page_size);
1481 kci->last_module_symbol += page_size;
1482 }
1483
1484 if (!kci->stext || !kci->etext)
1485 return -1;
1486
1487 if (kci->first_module && !kci->last_module_symbol)
1488 return -1;
1489
1490 return kcore_copy__read_maps(kci, elf);
1491}
1492
1493static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
1494 const char *name)
1495{
1496 char from_filename[PATH_MAX];
1497 char to_filename[PATH_MAX];
1498
1499 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1500 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1501
1502 return copyfile_mode(from_filename, to_filename, 0400);
1503}
1504
1505static int kcore_copy__unlink(const char *dir, const char *name)
1506{
1507 char filename[PATH_MAX];
1508
1509 scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
1510
1511 return unlink(filename);
1512}
1513
1514static int kcore_copy__compare_fds(int from, int to)
1515{
1516 char *buf_from;
1517 char *buf_to;
1518 ssize_t ret;
1519 size_t len;
1520 int err = -1;
1521
1522 buf_from = malloc(page_size);
1523 buf_to = malloc(page_size);
1524 if (!buf_from || !buf_to)
1525 goto out;
1526
1527 while (1) {
1528 /* Use read because mmap won't work on proc files */
1529 ret = read(from, buf_from, page_size);
1530 if (ret < 0)
1531 goto out;
1532
1533 if (!ret)
1534 break;
1535
1536 len = ret;
1537
1538 if (readn(to, buf_to, len) != (int)len)
1539 goto out;
1540
1541 if (memcmp(buf_from, buf_to, len))
1542 goto out;
1543 }
1544
1545 err = 0;
1546out:
1547 free(buf_to);
1548 free(buf_from);
1549 return err;
1550}
1551
1552static int kcore_copy__compare_files(const char *from_filename,
1553 const char *to_filename)
1554{
1555 int from, to, err = -1;
1556
1557 from = open(from_filename, O_RDONLY);
1558 if (from < 0)
1559 return -1;
1560
1561 to = open(to_filename, O_RDONLY);
1562 if (to < 0)
1563 goto out_close_from;
1564
1565 err = kcore_copy__compare_fds(from, to);
1566
1567 close(to);
1568out_close_from:
1569 close(from);
1570 return err;
1571}
1572
1573static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
1574 const char *name)
1575{
1576 char from_filename[PATH_MAX];
1577 char to_filename[PATH_MAX];
1578
1579 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1580 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1581
1582 return kcore_copy__compare_files(from_filename, to_filename);
1583}
1584
1585/**
1586 * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
1587 * @from_dir: from directory
1588 * @to_dir: to directory
1589 *
1590 * This function copies kallsyms, modules and kcore files from one directory to
1591 * another. kallsyms and modules are copied entirely. Only code segments are
1592 * copied from kcore. It is assumed that two segments suffice: one for the
1593 * kernel proper and one for all the modules. The code segments are determined
1594 * from kallsyms and modules files. The kernel map starts at _stext or the
1595 * lowest function symbol, and ends at _etext or the highest function symbol.
1596 * The module map starts at the lowest module address and ends at the highest
1597 * module symbol. Start addresses are rounded down to the nearest page. End
1598 * addresses are rounded up to the nearest page. An extra page is added to the
1599 * highest kernel symbol and highest module symbol to, hopefully, encompass that
1600 * symbol too. Because it contains only code sections, the resulting kcore is
1601 * unusual. One significant peculiarity is that the mapping (start -> pgoff)
1602 * is not the same for the kernel map and the modules map. That happens because
1603 * the data is copied adjacently whereas the original kcore has gaps. Finally,
1604 * kallsyms and modules files are compared with their copies to check that
1605 * modules have not been loaded or unloaded while the copies were taking place.
1606 *
1607 * Return: %0 on success, %-1 on failure.
1608 */
1609int kcore_copy(const char *from_dir, const char *to_dir)
1610{
1611 struct kcore kcore;
1612 struct kcore extract;
1613 size_t count = 2;
1614 int idx = 0, err = -1;
1615 off_t offset = page_size, sz, modules_offset = 0;
1616 struct kcore_copy_info kci = { .stext = 0, };
1617 char kcore_filename[PATH_MAX];
1618 char extract_filename[PATH_MAX];
1619
1620 if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
1621 return -1;
1622
1623 if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
1624 goto out_unlink_kallsyms;
1625
1626 scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
1627 scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
1628
1629 if (kcore__open(&kcore, kcore_filename))
1630 goto out_unlink_modules;
1631
1632 if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
1633 goto out_kcore_close;
1634
1635 if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
1636 goto out_kcore_close;
1637
1638 if (!kci.modules_map.addr)
1639 count -= 1;
1640
1641 if (kcore__copy_hdr(&kcore, &extract, count))
1642 goto out_extract_close;
1643
1644 if (kcore__add_phdr(&extract, idx++, offset, kci.kernel_map.addr,
1645 kci.kernel_map.len))
1646 goto out_extract_close;
1647
1648 if (kci.modules_map.addr) {
1649 modules_offset = offset + kci.kernel_map.len;
1650 if (kcore__add_phdr(&extract, idx, modules_offset,
1651 kci.modules_map.addr, kci.modules_map.len))
1652 goto out_extract_close;
1653 }
1654
1655 sz = kcore__write(&extract);
1656 if (sz < 0 || sz > offset)
1657 goto out_extract_close;
1658
1659 if (copy_bytes(kcore.fd, kci.kernel_map.offset, extract.fd, offset,
1660 kci.kernel_map.len))
1661 goto out_extract_close;
1662
1663 if (modules_offset && copy_bytes(kcore.fd, kci.modules_map.offset,
1664 extract.fd, modules_offset,
1665 kci.modules_map.len))
1666 goto out_extract_close;
1667
1668 if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
1669 goto out_extract_close;
1670
1671 if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
1672 goto out_extract_close;
1673
1674 err = 0;
1675
1676out_extract_close:
1677 kcore__close(&extract);
1678 if (err)
1679 unlink(extract_filename);
1680out_kcore_close:
1681 kcore__close(&kcore);
1682out_unlink_modules:
1683 if (err)
1684 kcore_copy__unlink(to_dir, "modules");
1685out_unlink_kallsyms:
1686 if (err)
1687 kcore_copy__unlink(to_dir, "kallsyms");
1688
1689 return err;
1690}
1691
afba19d9
AH		 1692int kcore_extract__create(struct kcore_extract *kce)
1693{
1694 struct kcore kcore;
1695 struct kcore extract;
1696 size_t count = 1;
1697 int idx = 0, err = -1;
1698 off_t offset = page_size, sz;
1699
1700 if (kcore__open(&kcore, kce->kcore_filename))
1701 return -1;
1702
1703 strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
1704 if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
1705 goto out_kcore_close;
1706
1707 if (kcore__copy_hdr(&kcore, &extract, count))
1708 goto out_extract_close;
1709
1710 if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
1711 goto out_extract_close;
1712
1713 sz = kcore__write(&extract);
1714 if (sz < 0 || sz > offset)
1715 goto out_extract_close;
1716
1717 if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
1718 goto out_extract_close;
1719
1720 err = 0;
1721
1722out_extract_close:
1723 kcore__close(&extract);
1724 if (err)
1725 unlink(kce->extract_filename);
1726out_kcore_close:
1727 kcore__close(&kcore);
1728
1729 return err;
1730}
1731
1732void kcore_extract__delete(struct kcore_extract *kce)
1733{
1734 unlink(kce->extract_filename);
1735}
1736
e5a1845f
NK		 1737void symbol__elf_init(void)
1738{
1739 elf_version(EV_CURRENT);
1740}
Linux kernel - Deliverables
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