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1// SPDX-License-Identifier: GPL-2.0
2#include <fcntl.h>
3#include <stdio.h>
4#include <errno.h>
5#include <stdlib.h>
6#include <string.h>
7#include <unistd.h>
8#include <inttypes.h>
9
10#include "dso.h"
11#include "map.h"
12#include "maps.h"
13#include "symbol.h"
14#include "symsrc.h"
15#include "demangle-java.h"
16#include "demangle-rust.h"
17#include "machine.h"
18#include "vdso.h"
19#include "debug.h"
20#include "util/copyfile.h"
21#include <linux/ctype.h>
22#include <linux/kernel.h>
23#include <linux/zalloc.h>
24#include <symbol/kallsyms.h>
25#include <internal/lib.h>
26
27#ifndef EM_AARCH64
28#define EM_AARCH64 183 /* ARM 64 bit */
29#endif
30
31#ifndef ELF32_ST_VISIBILITY
32#define ELF32_ST_VISIBILITY(o) ((o) & 0x03)
33#endif
34
35/* For ELF64 the definitions are the same. */
36#ifndef ELF64_ST_VISIBILITY
37#define ELF64_ST_VISIBILITY(o) ELF32_ST_VISIBILITY (o)
38#endif
39
40/* How to extract information held in the st_other field. */
41#ifndef GELF_ST_VISIBILITY
42#define GELF_ST_VISIBILITY(val) ELF64_ST_VISIBILITY (val)
43#endif
44
45typedef Elf64_Nhdr GElf_Nhdr;
46
47#ifndef DMGL_PARAMS
48#define DMGL_NO_OPTS 0 /* For readability... */
49#define DMGL_PARAMS (1 << 0) /* Include function args */
50#define DMGL_ANSI (1 << 1) /* Include const, volatile, etc */
51#endif
52
53#ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
54extern char *cplus_demangle(const char *, int);
55
56static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
57{
58 return cplus_demangle(c, i);
59}
60#else
61#ifdef NO_DEMANGLE
62static inline char *bfd_demangle(void __maybe_unused *v,
63 const char __maybe_unused *c,
64 int __maybe_unused i)
65{
66 return NULL;
67}
68#else
69#define PACKAGE 'perf'
70#include <bfd.h>
71#endif
72#endif
73
74#ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
75static int elf_getphdrnum(Elf *elf, size_t *dst)
76{
77 GElf_Ehdr gehdr;
78 GElf_Ehdr *ehdr;
79
80 ehdr = gelf_getehdr(elf, &gehdr);
81 if (!ehdr)
82 return -1;
83
84 *dst = ehdr->e_phnum;
85
86 return 0;
87}
88#endif
89
90#ifndef HAVE_ELF_GETSHDRSTRNDX_SUPPORT
91static int elf_getshdrstrndx(Elf *elf __maybe_unused, size_t *dst __maybe_unused)
92{
93 pr_err("%s: update your libelf to > 0.140, this one lacks elf_getshdrstrndx().\n", __func__);
94 return -1;
95}
96#endif
97
98#ifndef NT_GNU_BUILD_ID
99#define NT_GNU_BUILD_ID 3
100#endif
101
102/**
103 * elf_symtab__for_each_symbol - iterate thru all the symbols
104 *
105 * @syms: struct elf_symtab instance to iterate
106 * @idx: uint32_t idx
107 * @sym: GElf_Sym iterator
108 */
109#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
110 for (idx = 0, gelf_getsym(syms, idx, &sym);\
111 idx < nr_syms; \
112 idx++, gelf_getsym(syms, idx, &sym))
113
114static inline uint8_t elf_sym__type(const GElf_Sym *sym)
115{
116 return GELF_ST_TYPE(sym->st_info);
117}
118
119static inline uint8_t elf_sym__visibility(const GElf_Sym *sym)
120{
121 return GELF_ST_VISIBILITY(sym->st_other);
122}
123
124#ifndef STT_GNU_IFUNC
125#define STT_GNU_IFUNC 10
126#endif
127
128static inline int elf_sym__is_function(const GElf_Sym *sym)
129{
130 return (elf_sym__type(sym) == STT_FUNC ||
131 elf_sym__type(sym) == STT_GNU_IFUNC) &&
132 sym->st_name != 0 &&
133 sym->st_shndx != SHN_UNDEF;
134}
135
136static inline bool elf_sym__is_object(const GElf_Sym *sym)
137{
138 return elf_sym__type(sym) == STT_OBJECT &&
139 sym->st_name != 0 &&
140 sym->st_shndx != SHN_UNDEF;
141}
142
143static inline int elf_sym__is_label(const GElf_Sym *sym)
144{
145 return elf_sym__type(sym) == STT_NOTYPE &&
146 sym->st_name != 0 &&
147 sym->st_shndx != SHN_UNDEF &&
148 sym->st_shndx != SHN_ABS &&
149 elf_sym__visibility(sym) != STV_HIDDEN &&
150 elf_sym__visibility(sym) != STV_INTERNAL;
151}
152
153static bool elf_sym__filter(GElf_Sym *sym)
154{
155 return elf_sym__is_function(sym) || elf_sym__is_object(sym);
156}
157
158static inline const char *elf_sym__name(const GElf_Sym *sym,
159 const Elf_Data *symstrs)
160{
161 return symstrs->d_buf + sym->st_name;
162}
163
164static inline const char *elf_sec__name(const GElf_Shdr *shdr,
165 const Elf_Data *secstrs)
166{
167 return secstrs->d_buf + shdr->sh_name;
168}
169
170static inline int elf_sec__is_text(const GElf_Shdr *shdr,
171 const Elf_Data *secstrs)
172{
173 return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
174}
175
176static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
177 const Elf_Data *secstrs)
178{
179 return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
180}
181
182static bool elf_sec__filter(GElf_Shdr *shdr, Elf_Data *secstrs)
183{
184 return elf_sec__is_text(shdr, secstrs) ||
185 elf_sec__is_data(shdr, secstrs);
186}
187
188static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
189{
190 Elf_Scn *sec = NULL;
191 GElf_Shdr shdr;
192 size_t cnt = 1;
193
194 while ((sec = elf_nextscn(elf, sec)) != NULL) {
195 gelf_getshdr(sec, &shdr);
196
197 if ((addr >= shdr.sh_addr) &&
198 (addr < (shdr.sh_addr + shdr.sh_size)))
199 return cnt;
200
201 ++cnt;
202 }
203
204 return -1;
205}
206
207Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
208 GElf_Shdr *shp, const char *name, size_t *idx)
209{
210 Elf_Scn *sec = NULL;
211 size_t cnt = 1;
212
213 /* Elf is corrupted/truncated, avoid calling elf_strptr. */
214 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
215 return NULL;
216
217 while ((sec = elf_nextscn(elf, sec)) != NULL) {
218 char *str;
219
220 gelf_getshdr(sec, shp);
221 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
222 if (str && !strcmp(name, str)) {
223 if (idx)
224 *idx = cnt;
225 return sec;
226 }
227 ++cnt;
228 }
229
230 return NULL;
231}
232
233static bool want_demangle(bool is_kernel_sym)
234{
235 return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
236}
237
238static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
239{
240 int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
241 char *demangled = NULL;
242
243 /*
244 * We need to figure out if the object was created from C++ sources
245 * DWARF DW_compile_unit has this, but we don't always have access
246 * to it...
247 */
248 if (!want_demangle(dso->kernel || kmodule))
249 return demangled;
250
251 demangled = bfd_demangle(NULL, elf_name, demangle_flags);
252 if (demangled == NULL)
253 demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
254 else if (rust_is_mangled(demangled))
255 /*
256 * Input to Rust demangling is the BFD-demangled
257 * name which it Rust-demangles in place.
258 */
259 rust_demangle_sym(demangled);
260
261 return demangled;
262}
263
264#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
265 for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
266 idx < nr_entries; \
267 ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
268
269#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
270 for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
271 idx < nr_entries; \
272 ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
273
274/*
275 * We need to check if we have a .dynsym, so that we can handle the
276 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
277 * .dynsym or .symtab).
278 * And always look at the original dso, not at debuginfo packages, that
279 * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
280 */
281int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)
282{
283 uint32_t nr_rel_entries, idx;
284 GElf_Sym sym;
285 u64 plt_offset, plt_header_size, plt_entry_size;
286 GElf_Shdr shdr_plt;
287 struct symbol *f;
288 GElf_Shdr shdr_rel_plt, shdr_dynsym;
289 Elf_Data *reldata, *syms, *symstrs;
290 Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
291 size_t dynsym_idx;
292 GElf_Ehdr ehdr;
293 char sympltname[1024];
294 Elf *elf;
295 int nr = 0, symidx, err = 0;
296
297 if (!ss->dynsym)
298 return 0;
299
300 elf = ss->elf;
301 ehdr = ss->ehdr;
302
303 scn_dynsym = ss->dynsym;
304 shdr_dynsym = ss->dynshdr;
305 dynsym_idx = ss->dynsym_idx;
306
307 if (scn_dynsym == NULL)
308 goto out_elf_end;
309
310 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
311 ".rela.plt", NULL);
312 if (scn_plt_rel == NULL) {
313 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
314 ".rel.plt", NULL);
315 if (scn_plt_rel == NULL)
316 goto out_elf_end;
317 }
318
319 err = -1;
320
321 if (shdr_rel_plt.sh_link != dynsym_idx)
322 goto out_elf_end;
323
324 if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
325 goto out_elf_end;
326
327 /*
328 * Fetch the relocation section to find the idxes to the GOT
329 * and the symbols in the .dynsym they refer to.
330 */
331 reldata = elf_getdata(scn_plt_rel, NULL);
332 if (reldata == NULL)
333 goto out_elf_end;
334
335 syms = elf_getdata(scn_dynsym, NULL);
336 if (syms == NULL)
337 goto out_elf_end;
338
339 scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
340 if (scn_symstrs == NULL)
341 goto out_elf_end;
342
343 symstrs = elf_getdata(scn_symstrs, NULL);
344 if (symstrs == NULL)
345 goto out_elf_end;
346
347 if (symstrs->d_size == 0)
348 goto out_elf_end;
349
350 nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
351 plt_offset = shdr_plt.sh_offset;
352 switch (ehdr.e_machine) {
353 case EM_ARM:
354 plt_header_size = 20;
355 plt_entry_size = 12;
356 break;
357
358 case EM_AARCH64:
359 plt_header_size = 32;
360 plt_entry_size = 16;
361 break;
362
363 case EM_SPARC:
364 plt_header_size = 48;
365 plt_entry_size = 12;
366 break;
367
368 case EM_SPARCV9:
369 plt_header_size = 128;
370 plt_entry_size = 32;
371 break;
372
373 default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/xtensa need to be checked */
374 plt_header_size = shdr_plt.sh_entsize;
375 plt_entry_size = shdr_plt.sh_entsize;
376 break;
377 }
378 plt_offset += plt_header_size;
379
380 if (shdr_rel_plt.sh_type == SHT_RELA) {
381 GElf_Rela pos_mem, *pos;
382
383 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
384 nr_rel_entries) {
385 const char *elf_name = NULL;
386 char *demangled = NULL;
387 symidx = GELF_R_SYM(pos->r_info);
388 gelf_getsym(syms, symidx, &sym);
389
390 elf_name = elf_sym__name(&sym, symstrs);
391 demangled = demangle_sym(dso, 0, elf_name);
392 if (demangled != NULL)
393 elf_name = demangled;
394 snprintf(sympltname, sizeof(sympltname),
395 "%s@plt", elf_name);
396 free(demangled);
397
398 f = symbol__new(plt_offset, plt_entry_size,
399 STB_GLOBAL, STT_FUNC, sympltname);
400 if (!f)
401 goto out_elf_end;
402
403 plt_offset += plt_entry_size;
404 symbols__insert(&dso->symbols, f);
405 ++nr;
406 }
407 } else if (shdr_rel_plt.sh_type == SHT_REL) {
408 GElf_Rel pos_mem, *pos;
409 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
410 nr_rel_entries) {
411 const char *elf_name = NULL;
412 char *demangled = NULL;
413 symidx = GELF_R_SYM(pos->r_info);
414 gelf_getsym(syms, symidx, &sym);
415
416 elf_name = elf_sym__name(&sym, symstrs);
417 demangled = demangle_sym(dso, 0, elf_name);
418 if (demangled != NULL)
419 elf_name = demangled;
420 snprintf(sympltname, sizeof(sympltname),
421 "%s@plt", elf_name);
422 free(demangled);
423
424 f = symbol__new(plt_offset, plt_entry_size,
425 STB_GLOBAL, STT_FUNC, sympltname);
426 if (!f)
427 goto out_elf_end;
428
429 plt_offset += plt_entry_size;
430 symbols__insert(&dso->symbols, f);
431 ++nr;
432 }
433 }
434
435 err = 0;
436out_elf_end:
437 if (err == 0)
438 return nr;
439 pr_debug("%s: problems reading %s PLT info.\n",
440 __func__, dso->long_name);
441 return 0;
442}
443
444char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
445{
446 return demangle_sym(dso, kmodule, elf_name);
447}
448
449/*
450 * Align offset to 4 bytes as needed for note name and descriptor data.
451 */
452#define NOTE_ALIGN(n) (((n) + 3) & -4U)
453
454static int elf_read_build_id(Elf *elf, void *bf, size_t size)
455{
456 int err = -1;
457 GElf_Ehdr ehdr;
458 GElf_Shdr shdr;
459 Elf_Data *data;
460 Elf_Scn *sec;
461 Elf_Kind ek;
462 void *ptr;
463
464 if (size < BUILD_ID_SIZE)
465 goto out;
466
467 ek = elf_kind(elf);
468 if (ek != ELF_K_ELF)
469 goto out;
470
471 if (gelf_getehdr(elf, &ehdr) == NULL) {
472 pr_err("%s: cannot get elf header.\n", __func__);
473 goto out;
474 }
475
476 /*
477 * Check following sections for notes:
478 * '.note.gnu.build-id'
479 * '.notes'
480 * '.note' (VDSO specific)
481 */
482 do {
483 sec = elf_section_by_name(elf, &ehdr, &shdr,
484 ".note.gnu.build-id", NULL);
485 if (sec)
486 break;
487
488 sec = elf_section_by_name(elf, &ehdr, &shdr,
489 ".notes", NULL);
490 if (sec)
491 break;
492
493 sec = elf_section_by_name(elf, &ehdr, &shdr,
494 ".note", NULL);
495 if (sec)
496 break;
497
498 return err;
499
500 } while (0);
501
502 data = elf_getdata(sec, NULL);
503 if (data == NULL)
504 goto out;
505
506 ptr = data->d_buf;
507 while (ptr < (data->d_buf + data->d_size)) {
508 GElf_Nhdr *nhdr = ptr;
509 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
510 descsz = NOTE_ALIGN(nhdr->n_descsz);
511 const char *name;
512
513 ptr += sizeof(*nhdr);
514 name = ptr;
515 ptr += namesz;
516 if (nhdr->n_type == NT_GNU_BUILD_ID &&
517 nhdr->n_namesz == sizeof("GNU")) {
518 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
519 size_t sz = min(size, descsz);
520 memcpy(bf, ptr, sz);
521 memset(bf + sz, 0, size - sz);
522 err = descsz;
523 break;
524 }
525 }
526 ptr += descsz;
527 }
528
529out:
530 return err;
531}
532
533int filename__read_build_id(const char *filename, void *bf, size_t size)
534{
535 int fd, err = -1;
536 Elf *elf;
537
538 if (size < BUILD_ID_SIZE)
539 goto out;
540
541 fd = open(filename, O_RDONLY);
542 if (fd < 0)
543 goto out;
544
545 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
546 if (elf == NULL) {
547 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
548 goto out_close;
549 }
550
551 err = elf_read_build_id(elf, bf, size);
552
553 elf_end(elf);
554out_close:
555 close(fd);
556out:
557 return err;
558}
559
560int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
561{
562 int fd, err = -1;
563
564 if (size < BUILD_ID_SIZE)
565 goto out;
566
567 fd = open(filename, O_RDONLY);
568 if (fd < 0)
569 goto out;
570
571 while (1) {
572 char bf[BUFSIZ];
573 GElf_Nhdr nhdr;
574 size_t namesz, descsz;
575
576 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
577 break;
578
579 namesz = NOTE_ALIGN(nhdr.n_namesz);
580 descsz = NOTE_ALIGN(nhdr.n_descsz);
581 if (nhdr.n_type == NT_GNU_BUILD_ID &&
582 nhdr.n_namesz == sizeof("GNU")) {
583 if (read(fd, bf, namesz) != (ssize_t)namesz)
584 break;
585 if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
586 size_t sz = min(descsz, size);
587 if (read(fd, build_id, sz) == (ssize_t)sz) {
588 memset(build_id + sz, 0, size - sz);
589 err = 0;
590 break;
591 }
592 } else if (read(fd, bf, descsz) != (ssize_t)descsz)
593 break;
594 } else {
595 int n = namesz + descsz;
596
597 if (n > (int)sizeof(bf)) {
598 n = sizeof(bf);
599 pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
600 __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
601 }
602 if (read(fd, bf, n) != n)
603 break;
604 }
605 }
606 close(fd);
607out:
608 return err;
609}
610
611int filename__read_debuglink(const char *filename, char *debuglink,
612 size_t size)
613{
614 int fd, err = -1;
615 Elf *elf;
616 GElf_Ehdr ehdr;
617 GElf_Shdr shdr;
618 Elf_Data *data;
619 Elf_Scn *sec;
620 Elf_Kind ek;
621
622 fd = open(filename, O_RDONLY);
623 if (fd < 0)
624 goto out;
625
626 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
627 if (elf == NULL) {
628 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
629 goto out_close;
630 }
631
632 ek = elf_kind(elf);
633 if (ek != ELF_K_ELF)
634 goto out_elf_end;
635
636 if (gelf_getehdr(elf, &ehdr) == NULL) {
637 pr_err("%s: cannot get elf header.\n", __func__);
638 goto out_elf_end;
639 }
640
641 sec = elf_section_by_name(elf, &ehdr, &shdr,
642 ".gnu_debuglink", NULL);
643 if (sec == NULL)
644 goto out_elf_end;
645
646 data = elf_getdata(sec, NULL);
647 if (data == NULL)
648 goto out_elf_end;
649
650 /* the start of this section is a zero-terminated string */
651 strncpy(debuglink, data->d_buf, size);
652
653 err = 0;
654
655out_elf_end:
656 elf_end(elf);
657out_close:
658 close(fd);
659out:
660 return err;
661}
662
663static int dso__swap_init(struct dso *dso, unsigned char eidata)
664{
665 static unsigned int const endian = 1;
666
667 dso->needs_swap = DSO_SWAP__NO;
668
669 switch (eidata) {
670 case ELFDATA2LSB:
671 /* We are big endian, DSO is little endian. */
672 if (*(unsigned char const *)&endian != 1)
673 dso->needs_swap = DSO_SWAP__YES;
674 break;
675
676 case ELFDATA2MSB:
677 /* We are little endian, DSO is big endian. */
678 if (*(unsigned char const *)&endian != 0)
679 dso->needs_swap = DSO_SWAP__YES;
680 break;
681
682 default:
683 pr_err("unrecognized DSO data encoding %d\n", eidata);
684 return -EINVAL;
685 }
686
687 return 0;
688}
689
690bool symsrc__possibly_runtime(struct symsrc *ss)
691{
692 return ss->dynsym || ss->opdsec;
693}
694
695bool symsrc__has_symtab(struct symsrc *ss)
696{
697 return ss->symtab != NULL;
698}
699
700void symsrc__destroy(struct symsrc *ss)
701{
702 zfree(&ss->name);
703 elf_end(ss->elf);
704 close(ss->fd);
705}
706
707bool elf__needs_adjust_symbols(GElf_Ehdr ehdr)
708{
709 /*
710 * Usually vmlinux is an ELF file with type ET_EXEC for most
711 * architectures; except Arm64 kernel is linked with option
712 * '-share', so need to check type ET_DYN.
713 */
714 return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL ||
715 ehdr.e_type == ET_DYN;
716}
717
718int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
719 enum dso_binary_type type)
720{
721 GElf_Ehdr ehdr;
722 Elf *elf;
723 int fd;
724
725 if (dso__needs_decompress(dso)) {
726 fd = dso__decompress_kmodule_fd(dso, name);
727 if (fd < 0)
728 return -1;
729
730 type = dso->symtab_type;
731 } else {
732 fd = open(name, O_RDONLY);
733 if (fd < 0) {
734 dso->load_errno = errno;
735 return -1;
736 }
737 }
738
739 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
740 if (elf == NULL) {
741 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
742 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
743 goto out_close;
744 }
745
746 if (gelf_getehdr(elf, &ehdr) == NULL) {
747 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
748 pr_debug("%s: cannot get elf header.\n", __func__);
749 goto out_elf_end;
750 }
751
752 if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) {
753 dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR;
754 goto out_elf_end;
755 }
756
757 /* Always reject images with a mismatched build-id: */
758 if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
759 u8 build_id[BUILD_ID_SIZE];
760
761 if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) {
762 dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
763 goto out_elf_end;
764 }
765
766 if (!dso__build_id_equal(dso, build_id)) {
767 pr_debug("%s: build id mismatch for %s.\n", __func__, name);
768 dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
769 goto out_elf_end;
770 }
771 }
772
773 ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
774
775 ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
776 NULL);
777 if (ss->symshdr.sh_type != SHT_SYMTAB)
778 ss->symtab = NULL;
779
780 ss->dynsym_idx = 0;
781 ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
782 &ss->dynsym_idx);
783 if (ss->dynshdr.sh_type != SHT_DYNSYM)
784 ss->dynsym = NULL;
785
786 ss->opdidx = 0;
787 ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
788 &ss->opdidx);
789 if (ss->opdshdr.sh_type != SHT_PROGBITS)
790 ss->opdsec = NULL;
791
792 if (dso->kernel == DSO_SPACE__USER)
793 ss->adjust_symbols = true;
794 else
795 ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);
796
797 ss->name = strdup(name);
798 if (!ss->name) {
799 dso->load_errno = errno;
800 goto out_elf_end;
801 }
802
803 ss->elf = elf;
804 ss->fd = fd;
805 ss->ehdr = ehdr;
806 ss->type = type;
807
808 return 0;
809
810out_elf_end:
811 elf_end(elf);
812out_close:
813 close(fd);
814 return -1;
815}
816
817/**
818 * ref_reloc_sym_not_found - has kernel relocation symbol been found.
819 * @kmap: kernel maps and relocation reference symbol
820 *
821 * This function returns %true if we are dealing with the kernel maps and the
822 * relocation reference symbol has not yet been found. Otherwise %false is
823 * returned.
824 */
825static bool ref_reloc_sym_not_found(struct kmap *kmap)
826{
827 return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
828 !kmap->ref_reloc_sym->unrelocated_addr;
829}
830
831/**
832 * ref_reloc - kernel relocation offset.
833 * @kmap: kernel maps and relocation reference symbol
834 *
835 * This function returns the offset of kernel addresses as determined by using
836 * the relocation reference symbol i.e. if the kernel has not been relocated
837 * then the return value is zero.
838 */
839static u64 ref_reloc(struct kmap *kmap)
840{
841 if (kmap && kmap->ref_reloc_sym &&
842 kmap->ref_reloc_sym->unrelocated_addr)
843 return kmap->ref_reloc_sym->addr -
844 kmap->ref_reloc_sym->unrelocated_addr;
845 return 0;
846}
847
848void __weak arch__sym_update(struct symbol *s __maybe_unused,
849 GElf_Sym *sym __maybe_unused) { }
850
851static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
852 GElf_Sym *sym, GElf_Shdr *shdr,
853 struct maps *kmaps, struct kmap *kmap,
854 struct dso **curr_dsop, struct map **curr_mapp,
855 const char *section_name,
856 bool adjust_kernel_syms, bool kmodule, bool *remap_kernel)
857{
858 struct dso *curr_dso = *curr_dsop;
859 struct map *curr_map;
860 char dso_name[PATH_MAX];
861
862 /* Adjust symbol to map to file offset */
863 if (adjust_kernel_syms)
864 sym->st_value -= shdr->sh_addr - shdr->sh_offset;
865
866 if (strcmp(section_name, (curr_dso->short_name + dso->short_name_len)) == 0)
867 return 0;
868
869 if (strcmp(section_name, ".text") == 0) {
870 /*
871 * The initial kernel mapping is based on
872 * kallsyms and identity maps. Overwrite it to
873 * map to the kernel dso.
874 */
875 if (*remap_kernel && dso->kernel && !kmodule) {
876 *remap_kernel = false;
877 map->start = shdr->sh_addr + ref_reloc(kmap);
878 map->end = map->start + shdr->sh_size;
879 map->pgoff = shdr->sh_offset;
880 map->map_ip = map__map_ip;
881 map->unmap_ip = map__unmap_ip;
882 /* Ensure maps are correctly ordered */
883 if (kmaps) {
884 map__get(map);
885 maps__remove(kmaps, map);
886 maps__insert(kmaps, map);
887 map__put(map);
888 }
889 }
890
891 /*
892 * The initial module mapping is based on
893 * /proc/modules mapped to offset zero.
894 * Overwrite it to map to the module dso.
895 */
896 if (*remap_kernel && kmodule) {
897 *remap_kernel = false;
898 map->pgoff = shdr->sh_offset;
899 }
900
901 *curr_mapp = map;
902 *curr_dsop = dso;
903 return 0;
904 }
905
906 if (!kmap)
907 return 0;
908
909 snprintf(dso_name, sizeof(dso_name), "%s%s", dso->short_name, section_name);
910
911 curr_map = maps__find_by_name(kmaps, dso_name);
912 if (curr_map == NULL) {
913 u64 start = sym->st_value;
914
915 if (kmodule)
916 start += map->start + shdr->sh_offset;
917
918 curr_dso = dso__new(dso_name);
919 if (curr_dso == NULL)
920 return -1;
921 curr_dso->kernel = dso->kernel;
922 curr_dso->long_name = dso->long_name;
923 curr_dso->long_name_len = dso->long_name_len;
924 curr_map = map__new2(start, curr_dso);
925 dso__put(curr_dso);
926 if (curr_map == NULL)
927 return -1;
928
929 if (curr_dso->kernel)
930 map__kmap(curr_map)->kmaps = kmaps;
931
932 if (adjust_kernel_syms) {
933 curr_map->start = shdr->sh_addr + ref_reloc(kmap);
934 curr_map->end = curr_map->start + shdr->sh_size;
935 curr_map->pgoff = shdr->sh_offset;
936 } else {
937 curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
938 }
939 curr_dso->symtab_type = dso->symtab_type;
940 maps__insert(kmaps, curr_map);
941 /*
942 * Add it before we drop the referece to curr_map, i.e. while
943 * we still are sure to have a reference to this DSO via
944 * *curr_map->dso.
945 */
946 dsos__add(&kmaps->machine->dsos, curr_dso);
947 /* kmaps already got it */
948 map__put(curr_map);
949 dso__set_loaded(curr_dso);
950 *curr_mapp = curr_map;
951 *curr_dsop = curr_dso;
952 } else
953 *curr_dsop = curr_map->dso;
954
955 return 0;
956}
957
958int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
959 struct symsrc *runtime_ss, int kmodule)
960{
961 struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
962 struct maps *kmaps = kmap ? map__kmaps(map) : NULL;
963 struct map *curr_map = map;
964 struct dso *curr_dso = dso;
965 Elf_Data *symstrs, *secstrs;
966 uint32_t nr_syms;
967 int err = -1;
968 uint32_t idx;
969 GElf_Ehdr ehdr;
970 GElf_Shdr shdr;
971 GElf_Shdr tshdr;
972 Elf_Data *syms, *opddata = NULL;
973 GElf_Sym sym;
974 Elf_Scn *sec, *sec_strndx;
975 Elf *elf;
976 int nr = 0;
977 bool remap_kernel = false, adjust_kernel_syms = false;
978
979 if (kmap && !kmaps)
980 return -1;
981
982 dso->symtab_type = syms_ss->type;
983 dso->is_64_bit = syms_ss->is_64_bit;
984 dso->rel = syms_ss->ehdr.e_type == ET_REL;
985
986 /*
987 * Modules may already have symbols from kallsyms, but those symbols
988 * have the wrong values for the dso maps, so remove them.
989 */
990 if (kmodule && syms_ss->symtab)
991 symbols__delete(&dso->symbols);
992
993 if (!syms_ss->symtab) {
994 /*
995 * If the vmlinux is stripped, fail so we will fall back
996 * to using kallsyms. The vmlinux runtime symbols aren't
997 * of much use.
998 */
999 if (dso->kernel)
1000 goto out_elf_end;
1001
1002 syms_ss->symtab = syms_ss->dynsym;
1003 syms_ss->symshdr = syms_ss->dynshdr;
1004 }
1005
1006 elf = syms_ss->elf;
1007 ehdr = syms_ss->ehdr;
1008 sec = syms_ss->symtab;
1009 shdr = syms_ss->symshdr;
1010
1011 if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr,
1012 ".text", NULL))
1013 dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;
1014
1015 if (runtime_ss->opdsec)
1016 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
1017
1018 syms = elf_getdata(sec, NULL);
1019 if (syms == NULL)
1020 goto out_elf_end;
1021
1022 sec = elf_getscn(elf, shdr.sh_link);
1023 if (sec == NULL)
1024 goto out_elf_end;
1025
1026 symstrs = elf_getdata(sec, NULL);
1027 if (symstrs == NULL)
1028 goto out_elf_end;
1029
1030 sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
1031 if (sec_strndx == NULL)
1032 goto out_elf_end;
1033
1034 secstrs = elf_getdata(sec_strndx, NULL);
1035 if (secstrs == NULL)
1036 goto out_elf_end;
1037
1038 nr_syms = shdr.sh_size / shdr.sh_entsize;
1039
1040 memset(&sym, 0, sizeof(sym));
1041
1042 /*
1043 * The kernel relocation symbol is needed in advance in order to adjust
1044 * kernel maps correctly.
1045 */
1046 if (ref_reloc_sym_not_found(kmap)) {
1047 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
1048 const char *elf_name = elf_sym__name(&sym, symstrs);
1049
1050 if (strcmp(elf_name, kmap->ref_reloc_sym->name))
1051 continue;
1052 kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
1053 map->reloc = kmap->ref_reloc_sym->addr -
1054 kmap->ref_reloc_sym->unrelocated_addr;
1055 break;
1056 }
1057 }
1058
1059 /*
1060 * Handle any relocation of vdso necessary because older kernels
1061 * attempted to prelink vdso to its virtual address.
1062 */
1063 if (dso__is_vdso(dso))
1064 map->reloc = map->start - dso->text_offset;
1065
1066 dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
1067 /*
1068 * Initial kernel and module mappings do not map to the dso.
1069 * Flag the fixups.
1070 */
1071 if (dso->kernel) {
1072 remap_kernel = true;
1073 adjust_kernel_syms = dso->adjust_symbols;
1074 }
1075 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
1076 struct symbol *f;
1077 const char *elf_name = elf_sym__name(&sym, symstrs);
1078 char *demangled = NULL;
1079 int is_label = elf_sym__is_label(&sym);
1080 const char *section_name;
1081 bool used_opd = false;
1082
1083 if (!is_label && !elf_sym__filter(&sym))
1084 continue;
1085
1086 /* Reject ARM ELF "mapping symbols": these aren't unique and
1087 * don't identify functions, so will confuse the profile
1088 * output: */
1089 if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
1090 if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
1091 && (elf_name[2] == '\0' || elf_name[2] == '.'))
1092 continue;
1093 }
1094
1095 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
1096 u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
1097 u64 *opd = opddata->d_buf + offset;
1098 sym.st_value = DSO__SWAP(dso, u64, *opd);
1099 sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
1100 sym.st_value);
1101 used_opd = true;
1102 }
1103 /*
1104 * When loading symbols in a data mapping, ABS symbols (which
1105 * has a value of SHN_ABS in its st_shndx) failed at
1106 * elf_getscn(). And it marks the loading as a failure so
1107 * already loaded symbols cannot be fixed up.
1108 *
1109 * I'm not sure what should be done. Just ignore them for now.
1110 * - Namhyung Kim
1111 */
1112 if (sym.st_shndx == SHN_ABS)
1113 continue;
1114
1115 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
1116 if (!sec)
1117 goto out_elf_end;
1118
1119 gelf_getshdr(sec, &shdr);
1120
1121 if (is_label && !elf_sec__filter(&shdr, secstrs))
1122 continue;
1123
1124 section_name = elf_sec__name(&shdr, secstrs);
1125
1126 /* On ARM, symbols for thumb functions have 1 added to
1127 * the symbol address as a flag - remove it */
1128 if ((ehdr.e_machine == EM_ARM) &&
1129 (GELF_ST_TYPE(sym.st_info) == STT_FUNC) &&
1130 (sym.st_value & 1))
1131 --sym.st_value;
1132
1133 if (dso->kernel) {
1134 if (dso__process_kernel_symbol(dso, map, &sym, &shdr, kmaps, kmap, &curr_dso, &curr_map,
1135 section_name, adjust_kernel_syms, kmodule, &remap_kernel))
1136 goto out_elf_end;
1137 } else if ((used_opd && runtime_ss->adjust_symbols) ||
1138 (!used_opd && syms_ss->adjust_symbols)) {
1139 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1140 "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
1141 (u64)sym.st_value, (u64)shdr.sh_addr,
1142 (u64)shdr.sh_offset);
1143 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1144 }
1145
1146 demangled = demangle_sym(dso, kmodule, elf_name);
1147 if (demangled != NULL)
1148 elf_name = demangled;
1149
1150 f = symbol__new(sym.st_value, sym.st_size,
1151 GELF_ST_BIND(sym.st_info),
1152 GELF_ST_TYPE(sym.st_info), elf_name);
1153 free(demangled);
1154 if (!f)
1155 goto out_elf_end;
1156
1157 arch__sym_update(f, &sym);
1158
1159 __symbols__insert(&curr_dso->symbols, f, dso->kernel);
1160 nr++;
1161 }
1162
1163 /*
1164 * For misannotated, zeroed, ASM function sizes.
1165 */
1166 if (nr > 0) {
1167 symbols__fixup_end(&dso->symbols);
1168 symbols__fixup_duplicate(&dso->symbols);
1169 if (kmap) {
1170 /*
1171 * We need to fixup this here too because we create new
1172 * maps here, for things like vsyscall sections.
1173 */
1174 maps__fixup_end(kmaps);
1175 }
1176 }
1177 err = nr;
1178out_elf_end:
1179 return err;
1180}
1181
1182static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
1183{
1184 GElf_Phdr phdr;
1185 size_t i, phdrnum;
1186 int err;
1187 u64 sz;
1188
1189 if (elf_getphdrnum(elf, &phdrnum))
1190 return -1;
1191
1192 for (i = 0; i < phdrnum; i++) {
1193 if (gelf_getphdr(elf, i, &phdr) == NULL)
1194 return -1;
1195 if (phdr.p_type != PT_LOAD)
1196 continue;
1197 if (exe) {
1198 if (!(phdr.p_flags & PF_X))
1199 continue;
1200 } else {
1201 if (!(phdr.p_flags & PF_R))
1202 continue;
1203 }
1204 sz = min(phdr.p_memsz, phdr.p_filesz);
1205 if (!sz)
1206 continue;
1207 err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
1208 if (err)
1209 return err;
1210 }
1211 return 0;
1212}
1213
1214int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
1215 bool *is_64_bit)
1216{
1217 int err;
1218 Elf *elf;
1219
1220 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1221 if (elf == NULL)
1222 return -1;
1223
1224 if (is_64_bit)
1225 *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
1226
1227 err = elf_read_maps(elf, exe, mapfn, data);
1228
1229 elf_end(elf);
1230 return err;
1231}
1232
1233enum dso_type dso__type_fd(int fd)
1234{
1235 enum dso_type dso_type = DSO__TYPE_UNKNOWN;
1236 GElf_Ehdr ehdr;
1237 Elf_Kind ek;
1238 Elf *elf;
1239
1240 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1241 if (elf == NULL)
1242 goto out;
1243
1244 ek = elf_kind(elf);
1245 if (ek != ELF_K_ELF)
1246 goto out_end;
1247
1248 if (gelf_getclass(elf) == ELFCLASS64) {
1249 dso_type = DSO__TYPE_64BIT;
1250 goto out_end;
1251 }
1252
1253 if (gelf_getehdr(elf, &ehdr) == NULL)
1254 goto out_end;
1255
1256 if (ehdr.e_machine == EM_X86_64)
1257 dso_type = DSO__TYPE_X32BIT;
1258 else
1259 dso_type = DSO__TYPE_32BIT;
1260out_end:
1261 elf_end(elf);
1262out:
1263 return dso_type;
1264}
1265
1266static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
1267{
1268 ssize_t r;
1269 size_t n;
1270 int err = -1;
1271 char *buf = malloc(page_size);
1272
1273 if (buf == NULL)
1274 return -1;
1275
1276 if (lseek(to, to_offs, SEEK_SET) != to_offs)
1277 goto out;
1278
1279 if (lseek(from, from_offs, SEEK_SET) != from_offs)
1280 goto out;
1281
1282 while (len) {
1283 n = page_size;
1284 if (len < n)
1285 n = len;
1286 /* Use read because mmap won't work on proc files */
1287 r = read(from, buf, n);
1288 if (r < 0)
1289 goto out;
1290 if (!r)
1291 break;
1292 n = r;
1293 r = write(to, buf, n);
1294 if (r < 0)
1295 goto out;
1296 if ((size_t)r != n)
1297 goto out;
1298 len -= n;
1299 }
1300
1301 err = 0;
1302out:
1303 free(buf);
1304 return err;
1305}
1306
1307struct kcore {
1308 int fd;
1309 int elfclass;
1310 Elf *elf;
1311 GElf_Ehdr ehdr;
1312};
1313
1314static int kcore__open(struct kcore *kcore, const char *filename)
1315{
1316 GElf_Ehdr *ehdr;
1317
1318 kcore->fd = open(filename, O_RDONLY);
1319 if (kcore->fd == -1)
1320 return -1;
1321
1322 kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
1323 if (!kcore->elf)
1324 goto out_close;
1325
1326 kcore->elfclass = gelf_getclass(kcore->elf);
1327 if (kcore->elfclass == ELFCLASSNONE)
1328 goto out_end;
1329
1330 ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1331 if (!ehdr)
1332 goto out_end;
1333
1334 return 0;
1335
1336out_end:
1337 elf_end(kcore->elf);
1338out_close:
1339 close(kcore->fd);
1340 return -1;
1341}
1342
1343static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
1344 bool temp)
1345{
1346 kcore->elfclass = elfclass;
1347
1348 if (temp)
1349 kcore->fd = mkstemp(filename);
1350 else
1351 kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
1352 if (kcore->fd == -1)
1353 return -1;
1354
1355 kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
1356 if (!kcore->elf)
1357 goto out_close;
1358
1359 if (!gelf_newehdr(kcore->elf, elfclass))
1360 goto out_end;
1361
1362 memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr));
1363
1364 return 0;
1365
1366out_end:
1367 elf_end(kcore->elf);
1368out_close:
1369 close(kcore->fd);
1370 unlink(filename);
1371 return -1;
1372}
1373
1374static void kcore__close(struct kcore *kcore)
1375{
1376 elf_end(kcore->elf);
1377 close(kcore->fd);
1378}
1379
1380static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
1381{
1382 GElf_Ehdr *ehdr = &to->ehdr;
1383 GElf_Ehdr *kehdr = &from->ehdr;
1384
1385 memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
1386 ehdr->e_type = kehdr->e_type;
1387 ehdr->e_machine = kehdr->e_machine;
1388 ehdr->e_version = kehdr->e_version;
1389 ehdr->e_entry = 0;
1390 ehdr->e_shoff = 0;
1391 ehdr->e_flags = kehdr->e_flags;
1392 ehdr->e_phnum = count;
1393 ehdr->e_shentsize = 0;
1394 ehdr->e_shnum = 0;
1395 ehdr->e_shstrndx = 0;
1396
1397 if (from->elfclass == ELFCLASS32) {
1398 ehdr->e_phoff = sizeof(Elf32_Ehdr);
1399 ehdr->e_ehsize = sizeof(Elf32_Ehdr);
1400 ehdr->e_phentsize = sizeof(Elf32_Phdr);
1401 } else {
1402 ehdr->e_phoff = sizeof(Elf64_Ehdr);
1403 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1404 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1405 }
1406
1407 if (!gelf_update_ehdr(to->elf, ehdr))
1408 return -1;
1409
1410 if (!gelf_newphdr(to->elf, count))
1411 return -1;
1412
1413 return 0;
1414}
1415
1416static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
1417 u64 addr, u64 len)
1418{
1419 GElf_Phdr phdr = {
1420 .p_type = PT_LOAD,
1421 .p_flags = PF_R | PF_W | PF_X,
1422 .p_offset = offset,
1423 .p_vaddr = addr,
1424 .p_paddr = 0,
1425 .p_filesz = len,
1426 .p_memsz = len,
1427 .p_align = page_size,
1428 };
1429
1430 if (!gelf_update_phdr(kcore->elf, idx, &phdr))
1431 return -1;
1432
1433 return 0;
1434}
1435
1436static off_t kcore__write(struct kcore *kcore)
1437{
1438 return elf_update(kcore->elf, ELF_C_WRITE);
1439}
1440
1441struct phdr_data {
1442 off_t offset;
1443 off_t rel;
1444 u64 addr;
1445 u64 len;
1446 struct list_head node;
1447 struct phdr_data *remaps;
1448};
1449
1450struct sym_data {
1451 u64 addr;
1452 struct list_head node;
1453};
1454
1455struct kcore_copy_info {
1456 u64 stext;
1457 u64 etext;
1458 u64 first_symbol;
1459 u64 last_symbol;
1460 u64 first_module;
1461 u64 first_module_symbol;
1462 u64 last_module_symbol;
1463 size_t phnum;
1464 struct list_head phdrs;
1465 struct list_head syms;
1466};
1467
1468#define kcore_copy__for_each_phdr(k, p) \
1469 list_for_each_entry((p), &(k)->phdrs, node)
1470
1471static struct phdr_data *phdr_data__new(u64 addr, u64 len, off_t offset)
1472{
1473 struct phdr_data *p = zalloc(sizeof(*p));
1474
1475 if (p) {
1476 p->addr = addr;
1477 p->len = len;
1478 p->offset = offset;
1479 }
1480
1481 return p;
1482}
1483
1484static struct phdr_data *kcore_copy_info__addnew(struct kcore_copy_info *kci,
1485 u64 addr, u64 len,
1486 off_t offset)
1487{
1488 struct phdr_data *p = phdr_data__new(addr, len, offset);
1489
1490 if (p)
1491 list_add_tail(&p->node, &kci->phdrs);
1492
1493 return p;
1494}
1495
1496static void kcore_copy__free_phdrs(struct kcore_copy_info *kci)
1497{
1498 struct phdr_data *p, *tmp;
1499
1500 list_for_each_entry_safe(p, tmp, &kci->phdrs, node) {
1501 list_del_init(&p->node);
1502 free(p);
1503 }
1504}
1505
1506static struct sym_data *kcore_copy__new_sym(struct kcore_copy_info *kci,
1507 u64 addr)
1508{
1509 struct sym_data *s = zalloc(sizeof(*s));
1510
1511 if (s) {
1512 s->addr = addr;
1513 list_add_tail(&s->node, &kci->syms);
1514 }
1515
1516 return s;
1517}
1518
1519static void kcore_copy__free_syms(struct kcore_copy_info *kci)
1520{
1521 struct sym_data *s, *tmp;
1522
1523 list_for_each_entry_safe(s, tmp, &kci->syms, node) {
1524 list_del_init(&s->node);
1525 free(s);
1526 }
1527}
1528
1529static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
1530 u64 start)
1531{
1532 struct kcore_copy_info *kci = arg;
1533
1534 if (!kallsyms__is_function(type))
1535 return 0;
1536
1537 if (strchr(name, '[')) {
1538 if (!kci->first_module_symbol || start < kci->first_module_symbol)
1539 kci->first_module_symbol = start;
1540 if (start > kci->last_module_symbol)
1541 kci->last_module_symbol = start;
1542 return 0;
1543 }
1544
1545 if (!kci->first_symbol || start < kci->first_symbol)
1546 kci->first_symbol = start;
1547
1548 if (!kci->last_symbol || start > kci->last_symbol)
1549 kci->last_symbol = start;
1550
1551 if (!strcmp(name, "_stext")) {
1552 kci->stext = start;
1553 return 0;
1554 }
1555
1556 if (!strcmp(name, "_etext")) {
1557 kci->etext = start;
1558 return 0;
1559 }
1560
1561 if (is_entry_trampoline(name) && !kcore_copy__new_sym(kci, start))
1562 return -1;
1563
1564 return 0;
1565}
1566
1567static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
1568 const char *dir)
1569{
1570 char kallsyms_filename[PATH_MAX];
1571
1572 scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
1573
1574 if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
1575 return -1;
1576
1577 if (kallsyms__parse(kallsyms_filename, kci,
1578 kcore_copy__process_kallsyms) < 0)
1579 return -1;
1580
1581 return 0;
1582}
1583
1584static int kcore_copy__process_modules(void *arg,
1585 const char *name __maybe_unused,
1586 u64 start, u64 size __maybe_unused)
1587{
1588 struct kcore_copy_info *kci = arg;
1589
1590 if (!kci->first_module || start < kci->first_module)
1591 kci->first_module = start;
1592
1593 return 0;
1594}
1595
1596static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
1597 const char *dir)
1598{
1599 char modules_filename[PATH_MAX];
1600
1601 scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
1602
1603 if (symbol__restricted_filename(modules_filename, "/proc/modules"))
1604 return -1;
1605
1606 if (modules__parse(modules_filename, kci,
1607 kcore_copy__process_modules) < 0)
1608 return -1;
1609
1610 return 0;
1611}
1612
1613static int kcore_copy__map(struct kcore_copy_info *kci, u64 start, u64 end,
1614 u64 pgoff, u64 s, u64 e)
1615{
1616 u64 len, offset;
1617
1618 if (s < start || s >= end)
1619 return 0;
1620
1621 offset = (s - start) + pgoff;
1622 len = e < end ? e - s : end - s;
1623
1624 return kcore_copy_info__addnew(kci, s, len, offset) ? 0 : -1;
1625}
1626
1627static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
1628{
1629 struct kcore_copy_info *kci = data;
1630 u64 end = start + len;
1631 struct sym_data *sdat;
1632
1633 if (kcore_copy__map(kci, start, end, pgoff, kci->stext, kci->etext))
1634 return -1;
1635
1636 if (kcore_copy__map(kci, start, end, pgoff, kci->first_module,
1637 kci->last_module_symbol))
1638 return -1;
1639
1640 list_for_each_entry(sdat, &kci->syms, node) {
1641 u64 s = round_down(sdat->addr, page_size);
1642
1643 if (kcore_copy__map(kci, start, end, pgoff, s, s + len))
1644 return -1;
1645 }
1646
1647 return 0;
1648}
1649
1650static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
1651{
1652 if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
1653 return -1;
1654
1655 return 0;
1656}
1657
1658static void kcore_copy__find_remaps(struct kcore_copy_info *kci)
1659{
1660 struct phdr_data *p, *k = NULL;
1661 u64 kend;
1662
1663 if (!kci->stext)
1664 return;
1665
1666 /* Find phdr that corresponds to the kernel map (contains stext) */
1667 kcore_copy__for_each_phdr(kci, p) {
1668 u64 pend = p->addr + p->len - 1;
1669
1670 if (p->addr <= kci->stext && pend >= kci->stext) {
1671 k = p;
1672 break;
1673 }
1674 }
1675
1676 if (!k)
1677 return;
1678
1679 kend = k->offset + k->len;
1680
1681 /* Find phdrs that remap the kernel */
1682 kcore_copy__for_each_phdr(kci, p) {
1683 u64 pend = p->offset + p->len;
1684
1685 if (p == k)
1686 continue;
1687
1688 if (p->offset >= k->offset && pend <= kend)
1689 p->remaps = k;
1690 }
1691}
1692
1693static void kcore_copy__layout(struct kcore_copy_info *kci)
1694{
1695 struct phdr_data *p;
1696 off_t rel = 0;
1697
1698 kcore_copy__find_remaps(kci);
1699
1700 kcore_copy__for_each_phdr(kci, p) {
1701 if (!p->remaps) {
1702 p->rel = rel;
1703 rel += p->len;
1704 }
1705 kci->phnum += 1;
1706 }
1707
1708 kcore_copy__for_each_phdr(kci, p) {
1709 struct phdr_data *k = p->remaps;
1710
1711 if (k)
1712 p->rel = p->offset - k->offset + k->rel;
1713 }
1714}
1715
1716static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
1717 Elf *elf)
1718{
1719 if (kcore_copy__parse_kallsyms(kci, dir))
1720 return -1;
1721
1722 if (kcore_copy__parse_modules(kci, dir))
1723 return -1;
1724
1725 if (kci->stext)
1726 kci->stext = round_down(kci->stext, page_size);
1727 else
1728 kci->stext = round_down(kci->first_symbol, page_size);
1729
1730 if (kci->etext) {
1731 kci->etext = round_up(kci->etext, page_size);
1732 } else if (kci->last_symbol) {
1733 kci->etext = round_up(kci->last_symbol, page_size);
1734 kci->etext += page_size;
1735 }
1736
1737 if (kci->first_module_symbol &&
1738 (!kci->first_module || kci->first_module_symbol < kci->first_module))
1739 kci->first_module = kci->first_module_symbol;
1740
1741 kci->first_module = round_down(kci->first_module, page_size);
1742
1743 if (kci->last_module_symbol) {
1744 kci->last_module_symbol = round_up(kci->last_module_symbol,
1745 page_size);
1746 kci->last_module_symbol += page_size;
1747 }
1748
1749 if (!kci->stext || !kci->etext)
1750 return -1;
1751
1752 if (kci->first_module && !kci->last_module_symbol)
1753 return -1;
1754
1755 if (kcore_copy__read_maps(kci, elf))
1756 return -1;
1757
1758 kcore_copy__layout(kci);
1759
1760 return 0;
1761}
1762
1763static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
1764 const char *name)
1765{
1766 char from_filename[PATH_MAX];
1767 char to_filename[PATH_MAX];
1768
1769 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1770 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1771
1772 return copyfile_mode(from_filename, to_filename, 0400);
1773}
1774
1775static int kcore_copy__unlink(const char *dir, const char *name)
1776{
1777 char filename[PATH_MAX];
1778
1779 scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
1780
1781 return unlink(filename);
1782}
1783
1784static int kcore_copy__compare_fds(int from, int to)
1785{
1786 char *buf_from;
1787 char *buf_to;
1788 ssize_t ret;
1789 size_t len;
1790 int err = -1;
1791
1792 buf_from = malloc(page_size);
1793 buf_to = malloc(page_size);
1794 if (!buf_from || !buf_to)
1795 goto out;
1796
1797 while (1) {
1798 /* Use read because mmap won't work on proc files */
1799 ret = read(from, buf_from, page_size);
1800 if (ret < 0)
1801 goto out;
1802
1803 if (!ret)
1804 break;
1805
1806 len = ret;
1807
1808 if (readn(to, buf_to, len) != (int)len)
1809 goto out;
1810
1811 if (memcmp(buf_from, buf_to, len))
1812 goto out;
1813 }
1814
1815 err = 0;
1816out:
1817 free(buf_to);
1818 free(buf_from);
1819 return err;
1820}
1821
1822static int kcore_copy__compare_files(const char *from_filename,
1823 const char *to_filename)
1824{
1825 int from, to, err = -1;
1826
1827 from = open(from_filename, O_RDONLY);
1828 if (from < 0)
1829 return -1;
1830
1831 to = open(to_filename, O_RDONLY);
1832 if (to < 0)
1833 goto out_close_from;
1834
1835 err = kcore_copy__compare_fds(from, to);
1836
1837 close(to);
1838out_close_from:
1839 close(from);
1840 return err;
1841}
1842
1843static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
1844 const char *name)
1845{
1846 char from_filename[PATH_MAX];
1847 char to_filename[PATH_MAX];
1848
1849 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1850 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1851
1852 return kcore_copy__compare_files(from_filename, to_filename);
1853}
1854
1855/**
1856 * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
1857 * @from_dir: from directory
1858 * @to_dir: to directory
1859 *
1860 * This function copies kallsyms, modules and kcore files from one directory to
1861 * another. kallsyms and modules are copied entirely. Only code segments are
1862 * copied from kcore. It is assumed that two segments suffice: one for the
1863 * kernel proper and one for all the modules. The code segments are determined
1864 * from kallsyms and modules files. The kernel map starts at _stext or the
1865 * lowest function symbol, and ends at _etext or the highest function symbol.
1866 * The module map starts at the lowest module address and ends at the highest
1867 * module symbol. Start addresses are rounded down to the nearest page. End
1868 * addresses are rounded up to the nearest page. An extra page is added to the
1869 * highest kernel symbol and highest module symbol to, hopefully, encompass that
1870 * symbol too. Because it contains only code sections, the resulting kcore is
1871 * unusual. One significant peculiarity is that the mapping (start -> pgoff)
1872 * is not the same for the kernel map and the modules map. That happens because
1873 * the data is copied adjacently whereas the original kcore has gaps. Finally,
1874 * kallsyms and modules files are compared with their copies to check that
1875 * modules have not been loaded or unloaded while the copies were taking place.
1876 *
1877 * Return: %0 on success, %-1 on failure.
1878 */
1879int kcore_copy(const char *from_dir, const char *to_dir)
1880{
1881 struct kcore kcore;
1882 struct kcore extract;
1883 int idx = 0, err = -1;
1884 off_t offset, sz;
1885 struct kcore_copy_info kci = { .stext = 0, };
1886 char kcore_filename[PATH_MAX];
1887 char extract_filename[PATH_MAX];
1888 struct phdr_data *p;
1889
1890 INIT_LIST_HEAD(&kci.phdrs);
1891 INIT_LIST_HEAD(&kci.syms);
1892
1893 if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
1894 return -1;
1895
1896 if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
1897 goto out_unlink_kallsyms;
1898
1899 scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
1900 scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
1901
1902 if (kcore__open(&kcore, kcore_filename))
1903 goto out_unlink_modules;
1904
1905 if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
1906 goto out_kcore_close;
1907
1908 if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
1909 goto out_kcore_close;
1910
1911 if (kcore__copy_hdr(&kcore, &extract, kci.phnum))
1912 goto out_extract_close;
1913
1914 offset = gelf_fsize(extract.elf, ELF_T_EHDR, 1, EV_CURRENT) +
1915 gelf_fsize(extract.elf, ELF_T_PHDR, kci.phnum, EV_CURRENT);
1916 offset = round_up(offset, page_size);
1917
1918 kcore_copy__for_each_phdr(&kci, p) {
1919 off_t offs = p->rel + offset;
1920
1921 if (kcore__add_phdr(&extract, idx++, offs, p->addr, p->len))
1922 goto out_extract_close;
1923 }
1924
1925 sz = kcore__write(&extract);
1926 if (sz < 0 || sz > offset)
1927 goto out_extract_close;
1928
1929 kcore_copy__for_each_phdr(&kci, p) {
1930 off_t offs = p->rel + offset;
1931
1932 if (p->remaps)
1933 continue;
1934 if (copy_bytes(kcore.fd, p->offset, extract.fd, offs, p->len))
1935 goto out_extract_close;
1936 }
1937
1938 if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
1939 goto out_extract_close;
1940
1941 if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
1942 goto out_extract_close;
1943
1944 err = 0;
1945
1946out_extract_close:
1947 kcore__close(&extract);
1948 if (err)
1949 unlink(extract_filename);
1950out_kcore_close:
1951 kcore__close(&kcore);
1952out_unlink_modules:
1953 if (err)
1954 kcore_copy__unlink(to_dir, "modules");
1955out_unlink_kallsyms:
1956 if (err)
1957 kcore_copy__unlink(to_dir, "kallsyms");
1958
1959 kcore_copy__free_phdrs(&kci);
1960 kcore_copy__free_syms(&kci);
1961
1962 return err;
1963}
1964
1965int kcore_extract__create(struct kcore_extract *kce)
1966{
1967 struct kcore kcore;
1968 struct kcore extract;
1969 size_t count = 1;
1970 int idx = 0, err = -1;
1971 off_t offset = page_size, sz;
1972
1973 if (kcore__open(&kcore, kce->kcore_filename))
1974 return -1;
1975
1976 strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
1977 if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
1978 goto out_kcore_close;
1979
1980 if (kcore__copy_hdr(&kcore, &extract, count))
1981 goto out_extract_close;
1982
1983 if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
1984 goto out_extract_close;
1985
1986 sz = kcore__write(&extract);
1987 if (sz < 0 || sz > offset)
1988 goto out_extract_close;
1989
1990 if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
1991 goto out_extract_close;
1992
1993 err = 0;
1994
1995out_extract_close:
1996 kcore__close(&extract);
1997 if (err)
1998 unlink(kce->extract_filename);
1999out_kcore_close:
2000 kcore__close(&kcore);
2001
2002 return err;
2003}
2004
2005void kcore_extract__delete(struct kcore_extract *kce)
2006{
2007 unlink(kce->extract_filename);
2008}
2009
2010#ifdef HAVE_GELF_GETNOTE_SUPPORT
2011
2012static void sdt_adjust_loc(struct sdt_note *tmp, GElf_Addr base_off)
2013{
2014 if (!base_off)
2015 return;
2016
2017 if (tmp->bit32)
2018 tmp->addr.a32[SDT_NOTE_IDX_LOC] =
2019 tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off -
2020 tmp->addr.a32[SDT_NOTE_IDX_BASE];
2021 else
2022 tmp->addr.a64[SDT_NOTE_IDX_LOC] =
2023 tmp->addr.a64[SDT_NOTE_IDX_LOC] + base_off -
2024 tmp->addr.a64[SDT_NOTE_IDX_BASE];
2025}
2026
2027static void sdt_adjust_refctr(struct sdt_note *tmp, GElf_Addr base_addr,
2028 GElf_Addr base_off)
2029{
2030 if (!base_off)
2031 return;
2032
2033 if (tmp->bit32 && tmp->addr.a32[SDT_NOTE_IDX_REFCTR])
2034 tmp->addr.a32[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
2035 else if (tmp->addr.a64[SDT_NOTE_IDX_REFCTR])
2036 tmp->addr.a64[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
2037}
2038
2039/**
2040 * populate_sdt_note : Parse raw data and identify SDT note
2041 * @elf: elf of the opened file
2042 * @data: raw data of a section with description offset applied
2043 * @len: note description size
2044 * @type: type of the note
2045 * @sdt_notes: List to add the SDT note
2046 *
2047 * Responsible for parsing the @data in section .note.stapsdt in @elf and
2048 * if its an SDT note, it appends to @sdt_notes list.
2049 */
2050static int populate_sdt_note(Elf **elf, const char *data, size_t len,
2051 struct list_head *sdt_notes)
2052{
2053 const char *provider, *name, *args;
2054 struct sdt_note *tmp = NULL;
2055 GElf_Ehdr ehdr;
2056 GElf_Shdr shdr;
2057 int ret = -EINVAL;
2058
2059 union {
2060 Elf64_Addr a64[NR_ADDR];
2061 Elf32_Addr a32[NR_ADDR];
2062 } buf;
2063
2064 Elf_Data dst = {
2065 .d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT,
2066 .d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT),
2067 .d_off = 0, .d_align = 0
2068 };
2069 Elf_Data src = {
2070 .d_buf = (void *) data, .d_type = ELF_T_ADDR,
2071 .d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0,
2072 .d_align = 0
2073 };
2074
2075 tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note));
2076 if (!tmp) {
2077 ret = -ENOMEM;
2078 goto out_err;
2079 }
2080
2081 INIT_LIST_HEAD(&tmp->note_list);
2082
2083 if (len < dst.d_size + 3)
2084 goto out_free_note;
2085
2086 /* Translation from file representation to memory representation */
2087 if (gelf_xlatetom(*elf, &dst, &src,
2088 elf_getident(*elf, NULL)[EI_DATA]) == NULL) {
2089 pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1));
2090 goto out_free_note;
2091 }
2092
2093 /* Populate the fields of sdt_note */
2094 provider = data + dst.d_size;
2095
2096 name = (const char *)memchr(provider, '\0', data + len - provider);
2097 if (name++ == NULL)
2098 goto out_free_note;
2099
2100 tmp->provider = strdup(provider);
2101 if (!tmp->provider) {
2102 ret = -ENOMEM;
2103 goto out_free_note;
2104 }
2105 tmp->name = strdup(name);
2106 if (!tmp->name) {
2107 ret = -ENOMEM;
2108 goto out_free_prov;
2109 }
2110
2111 args = memchr(name, '\0', data + len - name);
2112
2113 /*
2114 * There is no argument if:
2115 * - We reached the end of the note;
2116 * - There is not enough room to hold a potential string;
2117 * - The argument string is empty or just contains ':'.
2118 */
2119 if (args == NULL || data + len - args < 2 ||
2120 args[1] == ':' || args[1] == '\0')
2121 tmp->args = NULL;
2122 else {
2123 tmp->args = strdup(++args);
2124 if (!tmp->args) {
2125 ret = -ENOMEM;
2126 goto out_free_name;
2127 }
2128 }
2129
2130 if (gelf_getclass(*elf) == ELFCLASS32) {
2131 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
2132 tmp->bit32 = true;
2133 } else {
2134 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr));
2135 tmp->bit32 = false;
2136 }
2137
2138 if (!gelf_getehdr(*elf, &ehdr)) {
2139 pr_debug("%s : cannot get elf header.\n", __func__);
2140 ret = -EBADF;
2141 goto out_free_args;
2142 }
2143
2144 /* Adjust the prelink effect :
2145 * Find out the .stapsdt.base section.
2146 * This scn will help us to handle prelinking (if present).
2147 * Compare the retrieved file offset of the base section with the
2148 * base address in the description of the SDT note. If its different,
2149 * then accordingly, adjust the note location.
2150 */
2151 if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL))
2152 sdt_adjust_loc(tmp, shdr.sh_offset);
2153
2154 /* Adjust reference counter offset */
2155 if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_PROBES_SCN, NULL))
2156 sdt_adjust_refctr(tmp, shdr.sh_addr, shdr.sh_offset);
2157
2158 list_add_tail(&tmp->note_list, sdt_notes);
2159 return 0;
2160
2161out_free_args:
2162 zfree(&tmp->args);
2163out_free_name:
2164 zfree(&tmp->name);
2165out_free_prov:
2166 zfree(&tmp->provider);
2167out_free_note:
2168 free(tmp);
2169out_err:
2170 return ret;
2171}
2172
2173/**
2174 * construct_sdt_notes_list : constructs a list of SDT notes
2175 * @elf : elf to look into
2176 * @sdt_notes : empty list_head
2177 *
2178 * Scans the sections in 'elf' for the section
2179 * .note.stapsdt. It, then calls populate_sdt_note to find
2180 * out the SDT events and populates the 'sdt_notes'.
2181 */
2182static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes)
2183{
2184 GElf_Ehdr ehdr;
2185 Elf_Scn *scn = NULL;
2186 Elf_Data *data;
2187 GElf_Shdr shdr;
2188 size_t shstrndx, next;
2189 GElf_Nhdr nhdr;
2190 size_t name_off, desc_off, offset;
2191 int ret = 0;
2192
2193 if (gelf_getehdr(elf, &ehdr) == NULL) {
2194 ret = -EBADF;
2195 goto out_ret;
2196 }
2197 if (elf_getshdrstrndx(elf, &shstrndx) != 0) {
2198 ret = -EBADF;
2199 goto out_ret;
2200 }
2201
2202 /* Look for the required section */
2203 scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL);
2204 if (!scn) {
2205 ret = -ENOENT;
2206 goto out_ret;
2207 }
2208
2209 if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) {
2210 ret = -ENOENT;
2211 goto out_ret;
2212 }
2213
2214 data = elf_getdata(scn, NULL);
2215
2216 /* Get the SDT notes */
2217 for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
2218 &desc_off)) > 0; offset = next) {
2219 if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) &&
2220 !memcmp(data->d_buf + name_off, SDT_NOTE_NAME,
2221 sizeof(SDT_NOTE_NAME))) {
2222 /* Check the type of the note */
2223 if (nhdr.n_type != SDT_NOTE_TYPE)
2224 goto out_ret;
2225
2226 ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off),
2227 nhdr.n_descsz, sdt_notes);
2228 if (ret < 0)
2229 goto out_ret;
2230 }
2231 }
2232 if (list_empty(sdt_notes))
2233 ret = -ENOENT;
2234
2235out_ret:
2236 return ret;
2237}
2238
2239/**
2240 * get_sdt_note_list : Wrapper to construct a list of sdt notes
2241 * @head : empty list_head
2242 * @target : file to find SDT notes from
2243 *
2244 * This opens the file, initializes
2245 * the ELF and then calls construct_sdt_notes_list.
2246 */
2247int get_sdt_note_list(struct list_head *head, const char *target)
2248{
2249 Elf *elf;
2250 int fd, ret;
2251
2252 fd = open(target, O_RDONLY);
2253 if (fd < 0)
2254 return -EBADF;
2255
2256 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
2257 if (!elf) {
2258 ret = -EBADF;
2259 goto out_close;
2260 }
2261 ret = construct_sdt_notes_list(elf, head);
2262 elf_end(elf);
2263out_close:
2264 close(fd);
2265 return ret;
2266}
2267
2268/**
2269 * cleanup_sdt_note_list : free the sdt notes' list
2270 * @sdt_notes: sdt notes' list
2271 *
2272 * Free up the SDT notes in @sdt_notes.
2273 * Returns the number of SDT notes free'd.
2274 */
2275int cleanup_sdt_note_list(struct list_head *sdt_notes)
2276{
2277 struct sdt_note *tmp, *pos;
2278 int nr_free = 0;
2279
2280 list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
2281 list_del_init(&pos->note_list);
2282 zfree(&pos->name);
2283 zfree(&pos->provider);
2284 free(pos);
2285 nr_free++;
2286 }
2287 return nr_free;
2288}
2289
2290/**
2291 * sdt_notes__get_count: Counts the number of sdt events
2292 * @start: list_head to sdt_notes list
2293 *
2294 * Returns the number of SDT notes in a list
2295 */
2296int sdt_notes__get_count(struct list_head *start)
2297{
2298 struct sdt_note *sdt_ptr;
2299 int count = 0;
2300
2301 list_for_each_entry(sdt_ptr, start, note_list)
2302 count++;
2303 return count;
2304}
2305#endif
2306
2307void symbol__elf_init(void)
2308{
2309 elf_version(EV_CURRENT);
2310}