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