Commit | Line | Data |
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e5a1845f NK |
1 | #include <fcntl.h> |
2 | #include <stdio.h> | |
3 | #include <errno.h> | |
4 | #include <string.h> | |
5 | #include <unistd.h> | |
6 | #include <inttypes.h> | |
7 | ||
8 | #include "symbol.h" | |
922d0e4d | 9 | #include "vdso.h" |
c506c96b | 10 | #include <symbol/kallsyms.h> |
e5a1845f NK |
11 | #include "debug.h" |
12 | ||
89fe808a | 13 | #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT |
e955d5c4 AH |
14 | static int elf_getphdrnum(Elf *elf, size_t *dst) |
15 | { | |
16 | GElf_Ehdr gehdr; | |
17 | GElf_Ehdr *ehdr; | |
18 | ||
19 | ehdr = gelf_getehdr(elf, &gehdr); | |
20 | if (!ehdr) | |
21 | return -1; | |
22 | ||
23 | *dst = ehdr->e_phnum; | |
24 | ||
25 | return 0; | |
26 | } | |
27 | #endif | |
28 | ||
e5a1845f NK |
29 | #ifndef NT_GNU_BUILD_ID |
30 | #define NT_GNU_BUILD_ID 3 | |
31 | #endif | |
32 | ||
33 | /** | |
34 | * elf_symtab__for_each_symbol - iterate thru all the symbols | |
35 | * | |
36 | * @syms: struct elf_symtab instance to iterate | |
37 | * @idx: uint32_t idx | |
38 | * @sym: GElf_Sym iterator | |
39 | */ | |
40 | #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \ | |
41 | for (idx = 0, gelf_getsym(syms, idx, &sym);\ | |
42 | idx < nr_syms; \ | |
43 | idx++, gelf_getsym(syms, idx, &sym)) | |
44 | ||
45 | static inline uint8_t elf_sym__type(const GElf_Sym *sym) | |
46 | { | |
47 | return GELF_ST_TYPE(sym->st_info); | |
48 | } | |
49 | ||
50 | static inline int elf_sym__is_function(const GElf_Sym *sym) | |
51 | { | |
a2f3b6bf AH |
52 | return (elf_sym__type(sym) == STT_FUNC || |
53 | elf_sym__type(sym) == STT_GNU_IFUNC) && | |
e5a1845f NK |
54 | sym->st_name != 0 && |
55 | sym->st_shndx != SHN_UNDEF; | |
56 | } | |
57 | ||
58 | static inline bool elf_sym__is_object(const GElf_Sym *sym) | |
59 | { | |
60 | return elf_sym__type(sym) == STT_OBJECT && | |
61 | sym->st_name != 0 && | |
62 | sym->st_shndx != SHN_UNDEF; | |
63 | } | |
64 | ||
65 | static inline int elf_sym__is_label(const GElf_Sym *sym) | |
66 | { | |
67 | return elf_sym__type(sym) == STT_NOTYPE && | |
68 | sym->st_name != 0 && | |
69 | sym->st_shndx != SHN_UNDEF && | |
70 | sym->st_shndx != SHN_ABS; | |
71 | } | |
72 | ||
73 | static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type) | |
74 | { | |
75 | switch (type) { | |
76 | case MAP__FUNCTION: | |
77 | return elf_sym__is_function(sym); | |
78 | case MAP__VARIABLE: | |
79 | return elf_sym__is_object(sym); | |
80 | default: | |
81 | return false; | |
82 | } | |
83 | } | |
84 | ||
85 | static inline const char *elf_sym__name(const GElf_Sym *sym, | |
86 | const Elf_Data *symstrs) | |
87 | { | |
88 | return symstrs->d_buf + sym->st_name; | |
89 | } | |
90 | ||
91 | static inline const char *elf_sec__name(const GElf_Shdr *shdr, | |
92 | const Elf_Data *secstrs) | |
93 | { | |
94 | return secstrs->d_buf + shdr->sh_name; | |
95 | } | |
96 | ||
97 | static inline int elf_sec__is_text(const GElf_Shdr *shdr, | |
98 | const Elf_Data *secstrs) | |
99 | { | |
100 | return strstr(elf_sec__name(shdr, secstrs), "text") != NULL; | |
101 | } | |
102 | ||
103 | static inline bool elf_sec__is_data(const GElf_Shdr *shdr, | |
104 | const Elf_Data *secstrs) | |
105 | { | |
106 | return strstr(elf_sec__name(shdr, secstrs), "data") != NULL; | |
107 | } | |
108 | ||
109 | static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs, | |
110 | enum map_type type) | |
111 | { | |
112 | switch (type) { | |
113 | case MAP__FUNCTION: | |
114 | return elf_sec__is_text(shdr, secstrs); | |
115 | case MAP__VARIABLE: | |
116 | return elf_sec__is_data(shdr, secstrs); | |
117 | default: | |
118 | return false; | |
119 | } | |
120 | } | |
121 | ||
122 | static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr) | |
123 | { | |
124 | Elf_Scn *sec = NULL; | |
125 | GElf_Shdr shdr; | |
126 | size_t cnt = 1; | |
127 | ||
128 | while ((sec = elf_nextscn(elf, sec)) != NULL) { | |
129 | gelf_getshdr(sec, &shdr); | |
130 | ||
131 | if ((addr >= shdr.sh_addr) && | |
132 | (addr < (shdr.sh_addr + shdr.sh_size))) | |
133 | return cnt; | |
134 | ||
135 | ++cnt; | |
136 | } | |
137 | ||
138 | return -1; | |
139 | } | |
140 | ||
99ca4233 MH |
141 | Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep, |
142 | GElf_Shdr *shp, const char *name, size_t *idx) | |
e5a1845f NK |
143 | { |
144 | Elf_Scn *sec = NULL; | |
145 | size_t cnt = 1; | |
146 | ||
49274654 CS |
147 | /* Elf is corrupted/truncated, avoid calling elf_strptr. */ |
148 | if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) | |
149 | return NULL; | |
150 | ||
e5a1845f NK |
151 | while ((sec = elf_nextscn(elf, sec)) != NULL) { |
152 | char *str; | |
153 | ||
154 | gelf_getshdr(sec, shp); | |
155 | str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name); | |
155b3a13 | 156 | if (str && !strcmp(name, str)) { |
e5a1845f NK |
157 | if (idx) |
158 | *idx = cnt; | |
155b3a13 | 159 | return sec; |
e5a1845f NK |
160 | } |
161 | ++cnt; | |
162 | } | |
163 | ||
155b3a13 | 164 | return NULL; |
e5a1845f NK |
165 | } |
166 | ||
167 | #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \ | |
168 | for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \ | |
169 | idx < nr_entries; \ | |
170 | ++idx, pos = gelf_getrel(reldata, idx, &pos_mem)) | |
171 | ||
172 | #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \ | |
173 | for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \ | |
174 | idx < nr_entries; \ | |
175 | ++idx, pos = gelf_getrela(reldata, idx, &pos_mem)) | |
176 | ||
177 | /* | |
178 | * We need to check if we have a .dynsym, so that we can handle the | |
179 | * .plt, synthesizing its symbols, that aren't on the symtabs (be it | |
180 | * .dynsym or .symtab). | |
181 | * And always look at the original dso, not at debuginfo packages, that | |
182 | * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS). | |
183 | */ | |
a44f605b | 184 | int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map, |
e5a1845f NK |
185 | symbol_filter_t filter) |
186 | { | |
187 | uint32_t nr_rel_entries, idx; | |
188 | GElf_Sym sym; | |
189 | u64 plt_offset; | |
190 | GElf_Shdr shdr_plt; | |
191 | struct symbol *f; | |
192 | GElf_Shdr shdr_rel_plt, shdr_dynsym; | |
193 | Elf_Data *reldata, *syms, *symstrs; | |
194 | Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym; | |
195 | size_t dynsym_idx; | |
196 | GElf_Ehdr ehdr; | |
197 | char sympltname[1024]; | |
198 | Elf *elf; | |
a44f605b | 199 | int nr = 0, symidx, err = 0; |
e5a1845f | 200 | |
f47b58b7 DA |
201 | if (!ss->dynsym) |
202 | return 0; | |
203 | ||
a44f605b CS |
204 | elf = ss->elf; |
205 | ehdr = ss->ehdr; | |
e5a1845f | 206 | |
a44f605b CS |
207 | scn_dynsym = ss->dynsym; |
208 | shdr_dynsym = ss->dynshdr; | |
209 | dynsym_idx = ss->dynsym_idx; | |
e5a1845f | 210 | |
e5a1845f NK |
211 | if (scn_dynsym == NULL) |
212 | goto out_elf_end; | |
213 | ||
214 | scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, | |
215 | ".rela.plt", NULL); | |
216 | if (scn_plt_rel == NULL) { | |
217 | scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, | |
218 | ".rel.plt", NULL); | |
219 | if (scn_plt_rel == NULL) | |
220 | goto out_elf_end; | |
221 | } | |
222 | ||
223 | err = -1; | |
224 | ||
225 | if (shdr_rel_plt.sh_link != dynsym_idx) | |
226 | goto out_elf_end; | |
227 | ||
228 | if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL) | |
229 | goto out_elf_end; | |
230 | ||
231 | /* | |
232 | * Fetch the relocation section to find the idxes to the GOT | |
233 | * and the symbols in the .dynsym they refer to. | |
234 | */ | |
235 | reldata = elf_getdata(scn_plt_rel, NULL); | |
236 | if (reldata == NULL) | |
237 | goto out_elf_end; | |
238 | ||
239 | syms = elf_getdata(scn_dynsym, NULL); | |
240 | if (syms == NULL) | |
241 | goto out_elf_end; | |
242 | ||
243 | scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link); | |
244 | if (scn_symstrs == NULL) | |
245 | goto out_elf_end; | |
246 | ||
247 | symstrs = elf_getdata(scn_symstrs, NULL); | |
248 | if (symstrs == NULL) | |
249 | goto out_elf_end; | |
250 | ||
52f9ddba CS |
251 | if (symstrs->d_size == 0) |
252 | goto out_elf_end; | |
253 | ||
e5a1845f NK |
254 | nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize; |
255 | plt_offset = shdr_plt.sh_offset; | |
256 | ||
257 | if (shdr_rel_plt.sh_type == SHT_RELA) { | |
258 | GElf_Rela pos_mem, *pos; | |
259 | ||
260 | elf_section__for_each_rela(reldata, pos, pos_mem, idx, | |
261 | nr_rel_entries) { | |
262 | symidx = GELF_R_SYM(pos->r_info); | |
263 | plt_offset += shdr_plt.sh_entsize; | |
264 | gelf_getsym(syms, symidx, &sym); | |
265 | snprintf(sympltname, sizeof(sympltname), | |
266 | "%s@plt", elf_sym__name(&sym, symstrs)); | |
267 | ||
268 | f = symbol__new(plt_offset, shdr_plt.sh_entsize, | |
269 | STB_GLOBAL, sympltname); | |
270 | if (!f) | |
271 | goto out_elf_end; | |
272 | ||
273 | if (filter && filter(map, f)) | |
274 | symbol__delete(f); | |
275 | else { | |
276 | symbols__insert(&dso->symbols[map->type], f); | |
277 | ++nr; | |
278 | } | |
279 | } | |
280 | } else if (shdr_rel_plt.sh_type == SHT_REL) { | |
281 | GElf_Rel pos_mem, *pos; | |
282 | elf_section__for_each_rel(reldata, pos, pos_mem, idx, | |
283 | nr_rel_entries) { | |
284 | symidx = GELF_R_SYM(pos->r_info); | |
285 | plt_offset += shdr_plt.sh_entsize; | |
286 | gelf_getsym(syms, symidx, &sym); | |
287 | snprintf(sympltname, sizeof(sympltname), | |
288 | "%s@plt", elf_sym__name(&sym, symstrs)); | |
289 | ||
290 | f = symbol__new(plt_offset, shdr_plt.sh_entsize, | |
291 | STB_GLOBAL, sympltname); | |
292 | if (!f) | |
293 | goto out_elf_end; | |
294 | ||
295 | if (filter && filter(map, f)) | |
296 | symbol__delete(f); | |
297 | else { | |
298 | symbols__insert(&dso->symbols[map->type], f); | |
299 | ++nr; | |
300 | } | |
301 | } | |
302 | } | |
303 | ||
304 | err = 0; | |
305 | out_elf_end: | |
e5a1845f NK |
306 | if (err == 0) |
307 | return nr; | |
e5a1845f NK |
308 | pr_debug("%s: problems reading %s PLT info.\n", |
309 | __func__, dso->long_name); | |
310 | return 0; | |
311 | } | |
312 | ||
313 | /* | |
314 | * Align offset to 4 bytes as needed for note name and descriptor data. | |
315 | */ | |
316 | #define NOTE_ALIGN(n) (((n) + 3) & -4U) | |
317 | ||
318 | static int elf_read_build_id(Elf *elf, void *bf, size_t size) | |
319 | { | |
320 | int err = -1; | |
321 | GElf_Ehdr ehdr; | |
322 | GElf_Shdr shdr; | |
323 | Elf_Data *data; | |
324 | Elf_Scn *sec; | |
325 | Elf_Kind ek; | |
326 | void *ptr; | |
327 | ||
328 | if (size < BUILD_ID_SIZE) | |
329 | goto out; | |
330 | ||
331 | ek = elf_kind(elf); | |
332 | if (ek != ELF_K_ELF) | |
333 | goto out; | |
334 | ||
335 | if (gelf_getehdr(elf, &ehdr) == NULL) { | |
336 | pr_err("%s: cannot get elf header.\n", __func__); | |
337 | goto out; | |
338 | } | |
339 | ||
340 | /* | |
341 | * Check following sections for notes: | |
342 | * '.note.gnu.build-id' | |
343 | * '.notes' | |
344 | * '.note' (VDSO specific) | |
345 | */ | |
346 | do { | |
347 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
348 | ".note.gnu.build-id", NULL); | |
349 | if (sec) | |
350 | break; | |
351 | ||
352 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
353 | ".notes", NULL); | |
354 | if (sec) | |
355 | break; | |
356 | ||
357 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
358 | ".note", NULL); | |
359 | if (sec) | |
360 | break; | |
361 | ||
362 | return err; | |
363 | ||
364 | } while (0); | |
365 | ||
366 | data = elf_getdata(sec, NULL); | |
367 | if (data == NULL) | |
368 | goto out; | |
369 | ||
370 | ptr = data->d_buf; | |
371 | while (ptr < (data->d_buf + data->d_size)) { | |
372 | GElf_Nhdr *nhdr = ptr; | |
373 | size_t namesz = NOTE_ALIGN(nhdr->n_namesz), | |
374 | descsz = NOTE_ALIGN(nhdr->n_descsz); | |
375 | const char *name; | |
376 | ||
377 | ptr += sizeof(*nhdr); | |
378 | name = ptr; | |
379 | ptr += namesz; | |
380 | if (nhdr->n_type == NT_GNU_BUILD_ID && | |
381 | nhdr->n_namesz == sizeof("GNU")) { | |
382 | if (memcmp(name, "GNU", sizeof("GNU")) == 0) { | |
383 | size_t sz = min(size, descsz); | |
384 | memcpy(bf, ptr, sz); | |
385 | memset(bf + sz, 0, size - sz); | |
386 | err = descsz; | |
387 | break; | |
388 | } | |
389 | } | |
390 | ptr += descsz; | |
391 | } | |
392 | ||
393 | out: | |
394 | return err; | |
395 | } | |
396 | ||
397 | int filename__read_build_id(const char *filename, void *bf, size_t size) | |
398 | { | |
399 | int fd, err = -1; | |
400 | Elf *elf; | |
401 | ||
402 | if (size < BUILD_ID_SIZE) | |
403 | goto out; | |
404 | ||
405 | fd = open(filename, O_RDONLY); | |
406 | if (fd < 0) | |
407 | goto out; | |
408 | ||
409 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
410 | if (elf == NULL) { | |
411 | pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename); | |
412 | goto out_close; | |
413 | } | |
414 | ||
415 | err = elf_read_build_id(elf, bf, size); | |
416 | ||
417 | elf_end(elf); | |
418 | out_close: | |
419 | close(fd); | |
420 | out: | |
421 | return err; | |
422 | } | |
423 | ||
424 | int sysfs__read_build_id(const char *filename, void *build_id, size_t size) | |
425 | { | |
426 | int fd, err = -1; | |
427 | ||
428 | if (size < BUILD_ID_SIZE) | |
429 | goto out; | |
430 | ||
431 | fd = open(filename, O_RDONLY); | |
432 | if (fd < 0) | |
433 | goto out; | |
434 | ||
435 | while (1) { | |
436 | char bf[BUFSIZ]; | |
437 | GElf_Nhdr nhdr; | |
438 | size_t namesz, descsz; | |
439 | ||
440 | if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr)) | |
441 | break; | |
442 | ||
443 | namesz = NOTE_ALIGN(nhdr.n_namesz); | |
444 | descsz = NOTE_ALIGN(nhdr.n_descsz); | |
445 | if (nhdr.n_type == NT_GNU_BUILD_ID && | |
446 | nhdr.n_namesz == sizeof("GNU")) { | |
447 | if (read(fd, bf, namesz) != (ssize_t)namesz) | |
448 | break; | |
449 | if (memcmp(bf, "GNU", sizeof("GNU")) == 0) { | |
450 | size_t sz = min(descsz, size); | |
451 | if (read(fd, build_id, sz) == (ssize_t)sz) { | |
452 | memset(build_id + sz, 0, size - sz); | |
453 | err = 0; | |
454 | break; | |
455 | } | |
456 | } else if (read(fd, bf, descsz) != (ssize_t)descsz) | |
457 | break; | |
458 | } else { | |
459 | int n = namesz + descsz; | |
460 | if (read(fd, bf, n) != n) | |
461 | break; | |
462 | } | |
463 | } | |
464 | close(fd); | |
465 | out: | |
466 | return err; | |
467 | } | |
468 | ||
469 | int filename__read_debuglink(const char *filename, char *debuglink, | |
470 | size_t size) | |
471 | { | |
472 | int fd, err = -1; | |
473 | Elf *elf; | |
474 | GElf_Ehdr ehdr; | |
475 | GElf_Shdr shdr; | |
476 | Elf_Data *data; | |
477 | Elf_Scn *sec; | |
478 | Elf_Kind ek; | |
479 | ||
480 | fd = open(filename, O_RDONLY); | |
481 | if (fd < 0) | |
482 | goto out; | |
483 | ||
484 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
485 | if (elf == NULL) { | |
486 | pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename); | |
487 | goto out_close; | |
488 | } | |
489 | ||
490 | ek = elf_kind(elf); | |
491 | if (ek != ELF_K_ELF) | |
784f3390 | 492 | goto out_elf_end; |
e5a1845f NK |
493 | |
494 | if (gelf_getehdr(elf, &ehdr) == NULL) { | |
495 | pr_err("%s: cannot get elf header.\n", __func__); | |
784f3390 | 496 | goto out_elf_end; |
e5a1845f NK |
497 | } |
498 | ||
499 | sec = elf_section_by_name(elf, &ehdr, &shdr, | |
500 | ".gnu_debuglink", NULL); | |
501 | if (sec == NULL) | |
784f3390 | 502 | goto out_elf_end; |
e5a1845f NK |
503 | |
504 | data = elf_getdata(sec, NULL); | |
505 | if (data == NULL) | |
784f3390 | 506 | goto out_elf_end; |
e5a1845f NK |
507 | |
508 | /* the start of this section is a zero-terminated string */ | |
509 | strncpy(debuglink, data->d_buf, size); | |
510 | ||
0d3dc5e8 SE |
511 | err = 0; |
512 | ||
784f3390 | 513 | out_elf_end: |
e5a1845f | 514 | elf_end(elf); |
e5a1845f NK |
515 | out_close: |
516 | close(fd); | |
517 | out: | |
518 | return err; | |
519 | } | |
520 | ||
521 | static int dso__swap_init(struct dso *dso, unsigned char eidata) | |
522 | { | |
523 | static unsigned int const endian = 1; | |
524 | ||
525 | dso->needs_swap = DSO_SWAP__NO; | |
526 | ||
527 | switch (eidata) { | |
528 | case ELFDATA2LSB: | |
529 | /* We are big endian, DSO is little endian. */ | |
530 | if (*(unsigned char const *)&endian != 1) | |
531 | dso->needs_swap = DSO_SWAP__YES; | |
532 | break; | |
533 | ||
534 | case ELFDATA2MSB: | |
535 | /* We are little endian, DSO is big endian. */ | |
536 | if (*(unsigned char const *)&endian != 0) | |
537 | dso->needs_swap = DSO_SWAP__YES; | |
538 | break; | |
539 | ||
540 | default: | |
541 | pr_err("unrecognized DSO data encoding %d\n", eidata); | |
542 | return -EINVAL; | |
543 | } | |
544 | ||
545 | return 0; | |
546 | } | |
547 | ||
3aafe5ae CS |
548 | bool symsrc__possibly_runtime(struct symsrc *ss) |
549 | { | |
550 | return ss->dynsym || ss->opdsec; | |
551 | } | |
552 | ||
d26cd12b CS |
553 | bool symsrc__has_symtab(struct symsrc *ss) |
554 | { | |
555 | return ss->symtab != NULL; | |
556 | } | |
b68e2f91 CS |
557 | |
558 | void symsrc__destroy(struct symsrc *ss) | |
559 | { | |
74cf249d | 560 | zfree(&ss->name); |
b68e2f91 CS |
561 | elf_end(ss->elf); |
562 | close(ss->fd); | |
563 | } | |
564 | ||
565 | int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, | |
566 | enum dso_binary_type type) | |
e5a1845f | 567 | { |
e5a1845f | 568 | int err = -1; |
e5a1845f | 569 | GElf_Ehdr ehdr; |
e5a1845f | 570 | Elf *elf; |
b68e2f91 CS |
571 | int fd; |
572 | ||
573 | fd = open(name, O_RDONLY); | |
574 | if (fd < 0) | |
575 | return -1; | |
e5a1845f NK |
576 | |
577 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
578 | if (elf == NULL) { | |
579 | pr_debug("%s: cannot read %s ELF file.\n", __func__, name); | |
580 | goto out_close; | |
581 | } | |
582 | ||
583 | if (gelf_getehdr(elf, &ehdr) == NULL) { | |
584 | pr_debug("%s: cannot get elf header.\n", __func__); | |
585 | goto out_elf_end; | |
586 | } | |
587 | ||
588 | if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) | |
589 | goto out_elf_end; | |
590 | ||
591 | /* Always reject images with a mismatched build-id: */ | |
592 | if (dso->has_build_id) { | |
593 | u8 build_id[BUILD_ID_SIZE]; | |
594 | ||
595 | if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) | |
596 | goto out_elf_end; | |
597 | ||
598 | if (!dso__build_id_equal(dso, build_id)) | |
599 | goto out_elf_end; | |
600 | } | |
601 | ||
c6d8f2a4 AH |
602 | ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64); |
603 | ||
b68e2f91 CS |
604 | ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab", |
605 | NULL); | |
606 | if (ss->symshdr.sh_type != SHT_SYMTAB) | |
607 | ss->symtab = NULL; | |
608 | ||
609 | ss->dynsym_idx = 0; | |
610 | ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym", | |
611 | &ss->dynsym_idx); | |
612 | if (ss->dynshdr.sh_type != SHT_DYNSYM) | |
613 | ss->dynsym = NULL; | |
614 | ||
615 | ss->opdidx = 0; | |
616 | ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd", | |
617 | &ss->opdidx); | |
618 | if (ss->opdshdr.sh_type != SHT_PROGBITS) | |
619 | ss->opdsec = NULL; | |
620 | ||
621 | if (dso->kernel == DSO_TYPE_USER) { | |
622 | GElf_Shdr shdr; | |
623 | ss->adjust_symbols = (ehdr.e_type == ET_EXEC || | |
0131c4ec | 624 | ehdr.e_type == ET_REL || |
51682dc7 | 625 | dso__is_vdso(dso) || |
b68e2f91 CS |
626 | elf_section_by_name(elf, &ehdr, &shdr, |
627 | ".gnu.prelink_undo", | |
628 | NULL) != NULL); | |
629 | } else { | |
0131c4ec AH |
630 | ss->adjust_symbols = ehdr.e_type == ET_EXEC || |
631 | ehdr.e_type == ET_REL; | |
b68e2f91 CS |
632 | } |
633 | ||
634 | ss->name = strdup(name); | |
635 | if (!ss->name) | |
636 | goto out_elf_end; | |
637 | ||
638 | ss->elf = elf; | |
639 | ss->fd = fd; | |
640 | ss->ehdr = ehdr; | |
641 | ss->type = type; | |
642 | ||
643 | return 0; | |
644 | ||
645 | out_elf_end: | |
646 | elf_end(elf); | |
647 | out_close: | |
648 | close(fd); | |
649 | return err; | |
650 | } | |
651 | ||
39b12f78 AH |
652 | /** |
653 | * ref_reloc_sym_not_found - has kernel relocation symbol been found. | |
654 | * @kmap: kernel maps and relocation reference symbol | |
655 | * | |
656 | * This function returns %true if we are dealing with the kernel maps and the | |
657 | * relocation reference symbol has not yet been found. Otherwise %false is | |
658 | * returned. | |
659 | */ | |
660 | static bool ref_reloc_sym_not_found(struct kmap *kmap) | |
661 | { | |
662 | return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name && | |
663 | !kmap->ref_reloc_sym->unrelocated_addr; | |
664 | } | |
665 | ||
666 | /** | |
667 | * ref_reloc - kernel relocation offset. | |
668 | * @kmap: kernel maps and relocation reference symbol | |
669 | * | |
670 | * This function returns the offset of kernel addresses as determined by using | |
671 | * the relocation reference symbol i.e. if the kernel has not been relocated | |
672 | * then the return value is zero. | |
673 | */ | |
674 | static u64 ref_reloc(struct kmap *kmap) | |
675 | { | |
676 | if (kmap && kmap->ref_reloc_sym && | |
677 | kmap->ref_reloc_sym->unrelocated_addr) | |
678 | return kmap->ref_reloc_sym->addr - | |
679 | kmap->ref_reloc_sym->unrelocated_addr; | |
680 | return 0; | |
681 | } | |
682 | ||
261360b6 CS |
683 | int dso__load_sym(struct dso *dso, struct map *map, |
684 | struct symsrc *syms_ss, struct symsrc *runtime_ss, | |
d26cd12b | 685 | symbol_filter_t filter, int kmodule) |
b68e2f91 CS |
686 | { |
687 | struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL; | |
688 | struct map *curr_map = map; | |
689 | struct dso *curr_dso = dso; | |
690 | Elf_Data *symstrs, *secstrs; | |
691 | uint32_t nr_syms; | |
692 | int err = -1; | |
693 | uint32_t idx; | |
694 | GElf_Ehdr ehdr; | |
261360b6 | 695 | GElf_Shdr shdr; |
b68e2f91 CS |
696 | Elf_Data *syms, *opddata = NULL; |
697 | GElf_Sym sym; | |
261360b6 | 698 | Elf_Scn *sec, *sec_strndx; |
b68e2f91 CS |
699 | Elf *elf; |
700 | int nr = 0; | |
39b12f78 | 701 | bool remap_kernel = false, adjust_kernel_syms = false; |
b68e2f91 | 702 | |
261360b6 | 703 | dso->symtab_type = syms_ss->type; |
c6d8f2a4 | 704 | dso->is_64_bit = syms_ss->is_64_bit; |
0131c4ec AH |
705 | dso->rel = syms_ss->ehdr.e_type == ET_REL; |
706 | ||
707 | /* | |
708 | * Modules may already have symbols from kallsyms, but those symbols | |
709 | * have the wrong values for the dso maps, so remove them. | |
710 | */ | |
711 | if (kmodule && syms_ss->symtab) | |
712 | symbols__delete(&dso->symbols[map->type]); | |
005f9294 | 713 | |
261360b6 CS |
714 | if (!syms_ss->symtab) { |
715 | syms_ss->symtab = syms_ss->dynsym; | |
716 | syms_ss->symshdr = syms_ss->dynshdr; | |
d26cd12b CS |
717 | } |
718 | ||
261360b6 CS |
719 | elf = syms_ss->elf; |
720 | ehdr = syms_ss->ehdr; | |
721 | sec = syms_ss->symtab; | |
722 | shdr = syms_ss->symshdr; | |
b68e2f91 | 723 | |
261360b6 CS |
724 | if (runtime_ss->opdsec) |
725 | opddata = elf_rawdata(runtime_ss->opdsec, NULL); | |
e5a1845f NK |
726 | |
727 | syms = elf_getdata(sec, NULL); | |
728 | if (syms == NULL) | |
729 | goto out_elf_end; | |
730 | ||
731 | sec = elf_getscn(elf, shdr.sh_link); | |
732 | if (sec == NULL) | |
733 | goto out_elf_end; | |
734 | ||
735 | symstrs = elf_getdata(sec, NULL); | |
736 | if (symstrs == NULL) | |
737 | goto out_elf_end; | |
738 | ||
739 | sec_strndx = elf_getscn(elf, ehdr.e_shstrndx); | |
740 | if (sec_strndx == NULL) | |
741 | goto out_elf_end; | |
742 | ||
743 | secstrs = elf_getdata(sec_strndx, NULL); | |
744 | if (secstrs == NULL) | |
745 | goto out_elf_end; | |
746 | ||
747 | nr_syms = shdr.sh_size / shdr.sh_entsize; | |
748 | ||
749 | memset(&sym, 0, sizeof(sym)); | |
39b12f78 AH |
750 | |
751 | /* | |
752 | * The kernel relocation symbol is needed in advance in order to adjust | |
753 | * kernel maps correctly. | |
754 | */ | |
755 | if (ref_reloc_sym_not_found(kmap)) { | |
756 | elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) { | |
757 | const char *elf_name = elf_sym__name(&sym, symstrs); | |
758 | ||
759 | if (strcmp(elf_name, kmap->ref_reloc_sym->name)) | |
760 | continue; | |
761 | kmap->ref_reloc_sym->unrelocated_addr = sym.st_value; | |
9176753d AH |
762 | map->reloc = kmap->ref_reloc_sym->addr - |
763 | kmap->ref_reloc_sym->unrelocated_addr; | |
39b12f78 AH |
764 | break; |
765 | } | |
766 | } | |
767 | ||
768 | dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap); | |
769 | /* | |
770 | * Initial kernel and module mappings do not map to the dso. For | |
771 | * function mappings, flag the fixups. | |
772 | */ | |
773 | if (map->type == MAP__FUNCTION && (dso->kernel || kmodule)) { | |
774 | remap_kernel = true; | |
775 | adjust_kernel_syms = dso->adjust_symbols; | |
776 | } | |
e5a1845f NK |
777 | elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) { |
778 | struct symbol *f; | |
779 | const char *elf_name = elf_sym__name(&sym, symstrs); | |
780 | char *demangled = NULL; | |
781 | int is_label = elf_sym__is_label(&sym); | |
782 | const char *section_name; | |
261360b6 | 783 | bool used_opd = false; |
e5a1845f | 784 | |
e5a1845f NK |
785 | if (!is_label && !elf_sym__is_a(&sym, map->type)) |
786 | continue; | |
787 | ||
788 | /* Reject ARM ELF "mapping symbols": these aren't unique and | |
789 | * don't identify functions, so will confuse the profile | |
790 | * output: */ | |
791 | if (ehdr.e_machine == EM_ARM) { | |
792 | if (!strcmp(elf_name, "$a") || | |
793 | !strcmp(elf_name, "$d") || | |
794 | !strcmp(elf_name, "$t")) | |
795 | continue; | |
796 | } | |
797 | ||
261360b6 CS |
798 | if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) { |
799 | u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr; | |
e5a1845f NK |
800 | u64 *opd = opddata->d_buf + offset; |
801 | sym.st_value = DSO__SWAP(dso, u64, *opd); | |
261360b6 CS |
802 | sym.st_shndx = elf_addr_to_index(runtime_ss->elf, |
803 | sym.st_value); | |
804 | used_opd = true; | |
e5a1845f | 805 | } |
3843b05d NK |
806 | /* |
807 | * When loading symbols in a data mapping, ABS symbols (which | |
808 | * has a value of SHN_ABS in its st_shndx) failed at | |
809 | * elf_getscn(). And it marks the loading as a failure so | |
810 | * already loaded symbols cannot be fixed up. | |
811 | * | |
812 | * I'm not sure what should be done. Just ignore them for now. | |
813 | * - Namhyung Kim | |
814 | */ | |
815 | if (sym.st_shndx == SHN_ABS) | |
816 | continue; | |
e5a1845f | 817 | |
261360b6 | 818 | sec = elf_getscn(runtime_ss->elf, sym.st_shndx); |
e5a1845f NK |
819 | if (!sec) |
820 | goto out_elf_end; | |
821 | ||
822 | gelf_getshdr(sec, &shdr); | |
823 | ||
824 | if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type)) | |
825 | continue; | |
826 | ||
827 | section_name = elf_sec__name(&shdr, secstrs); | |
828 | ||
829 | /* On ARM, symbols for thumb functions have 1 added to | |
830 | * the symbol address as a flag - remove it */ | |
831 | if ((ehdr.e_machine == EM_ARM) && | |
832 | (map->type == MAP__FUNCTION) && | |
833 | (sym.st_value & 1)) | |
834 | --sym.st_value; | |
835 | ||
39b12f78 | 836 | if (dso->kernel || kmodule) { |
e5a1845f NK |
837 | char dso_name[PATH_MAX]; |
838 | ||
39b12f78 AH |
839 | /* Adjust symbol to map to file offset */ |
840 | if (adjust_kernel_syms) | |
841 | sym.st_value -= shdr.sh_addr - shdr.sh_offset; | |
842 | ||
e5a1845f NK |
843 | if (strcmp(section_name, |
844 | (curr_dso->short_name + | |
845 | dso->short_name_len)) == 0) | |
846 | goto new_symbol; | |
847 | ||
848 | if (strcmp(section_name, ".text") == 0) { | |
39b12f78 AH |
849 | /* |
850 | * The initial kernel mapping is based on | |
851 | * kallsyms and identity maps. Overwrite it to | |
852 | * map to the kernel dso. | |
853 | */ | |
854 | if (remap_kernel && dso->kernel) { | |
855 | remap_kernel = false; | |
856 | map->start = shdr.sh_addr + | |
857 | ref_reloc(kmap); | |
858 | map->end = map->start + shdr.sh_size; | |
859 | map->pgoff = shdr.sh_offset; | |
860 | map->map_ip = map__map_ip; | |
861 | map->unmap_ip = map__unmap_ip; | |
862 | /* Ensure maps are correctly ordered */ | |
863 | map_groups__remove(kmap->kmaps, map); | |
864 | map_groups__insert(kmap->kmaps, map); | |
865 | } | |
866 | ||
0131c4ec AH |
867 | /* |
868 | * The initial module mapping is based on | |
869 | * /proc/modules mapped to offset zero. | |
870 | * Overwrite it to map to the module dso. | |
871 | */ | |
872 | if (remap_kernel && kmodule) { | |
873 | remap_kernel = false; | |
874 | map->pgoff = shdr.sh_offset; | |
875 | } | |
876 | ||
e5a1845f NK |
877 | curr_map = map; |
878 | curr_dso = dso; | |
879 | goto new_symbol; | |
880 | } | |
881 | ||
0131c4ec AH |
882 | if (!kmap) |
883 | goto new_symbol; | |
884 | ||
e5a1845f NK |
885 | snprintf(dso_name, sizeof(dso_name), |
886 | "%s%s", dso->short_name, section_name); | |
887 | ||
888 | curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name); | |
889 | if (curr_map == NULL) { | |
890 | u64 start = sym.st_value; | |
891 | ||
892 | if (kmodule) | |
893 | start += map->start + shdr.sh_offset; | |
894 | ||
895 | curr_dso = dso__new(dso_name); | |
896 | if (curr_dso == NULL) | |
897 | goto out_elf_end; | |
898 | curr_dso->kernel = dso->kernel; | |
899 | curr_dso->long_name = dso->long_name; | |
900 | curr_dso->long_name_len = dso->long_name_len; | |
901 | curr_map = map__new2(start, curr_dso, | |
902 | map->type); | |
903 | if (curr_map == NULL) { | |
904 | dso__delete(curr_dso); | |
905 | goto out_elf_end; | |
906 | } | |
39b12f78 AH |
907 | if (adjust_kernel_syms) { |
908 | curr_map->start = shdr.sh_addr + | |
909 | ref_reloc(kmap); | |
910 | curr_map->end = curr_map->start + | |
911 | shdr.sh_size; | |
912 | curr_map->pgoff = shdr.sh_offset; | |
913 | } else { | |
914 | curr_map->map_ip = identity__map_ip; | |
915 | curr_map->unmap_ip = identity__map_ip; | |
916 | } | |
e5a1845f NK |
917 | curr_dso->symtab_type = dso->symtab_type; |
918 | map_groups__insert(kmap->kmaps, curr_map); | |
919 | dsos__add(&dso->node, curr_dso); | |
920 | dso__set_loaded(curr_dso, map->type); | |
921 | } else | |
922 | curr_dso = curr_map->dso; | |
923 | ||
924 | goto new_symbol; | |
925 | } | |
926 | ||
261360b6 CS |
927 | if ((used_opd && runtime_ss->adjust_symbols) |
928 | || (!used_opd && syms_ss->adjust_symbols)) { | |
e5a1845f NK |
929 | pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " |
930 | "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__, | |
931 | (u64)sym.st_value, (u64)shdr.sh_addr, | |
932 | (u64)shdr.sh_offset); | |
933 | sym.st_value -= shdr.sh_addr - shdr.sh_offset; | |
934 | } | |
950b8354 | 935 | new_symbol: |
e5a1845f NK |
936 | /* |
937 | * We need to figure out if the object was created from C++ sources | |
938 | * DWARF DW_compile_unit has this, but we don't always have access | |
939 | * to it... | |
940 | */ | |
328ccdac | 941 | if (symbol_conf.demangle) { |
14951f22 | 942 | demangled = bfd_demangle(NULL, elf_name, |
328ccdac NK |
943 | DMGL_PARAMS | DMGL_ANSI); |
944 | if (demangled != NULL) | |
945 | elf_name = demangled; | |
946 | } | |
e5a1845f NK |
947 | f = symbol__new(sym.st_value, sym.st_size, |
948 | GELF_ST_BIND(sym.st_info), elf_name); | |
949 | free(demangled); | |
950 | if (!f) | |
951 | goto out_elf_end; | |
952 | ||
953 | if (filter && filter(curr_map, f)) | |
954 | symbol__delete(f); | |
955 | else { | |
956 | symbols__insert(&curr_dso->symbols[curr_map->type], f); | |
957 | nr++; | |
958 | } | |
959 | } | |
960 | ||
961 | /* | |
962 | * For misannotated, zeroed, ASM function sizes. | |
963 | */ | |
964 | if (nr > 0) { | |
965 | symbols__fixup_duplicate(&dso->symbols[map->type]); | |
966 | symbols__fixup_end(&dso->symbols[map->type]); | |
967 | if (kmap) { | |
968 | /* | |
969 | * We need to fixup this here too because we create new | |
970 | * maps here, for things like vsyscall sections. | |
971 | */ | |
972 | __map_groups__fixup_end(kmap->kmaps, map->type); | |
973 | } | |
974 | } | |
975 | err = nr; | |
976 | out_elf_end: | |
e5a1845f NK |
977 | return err; |
978 | } | |
979 | ||
8e0cf965 AH |
980 | static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data) |
981 | { | |
982 | GElf_Phdr phdr; | |
983 | size_t i, phdrnum; | |
984 | int err; | |
985 | u64 sz; | |
986 | ||
987 | if (elf_getphdrnum(elf, &phdrnum)) | |
988 | return -1; | |
989 | ||
990 | for (i = 0; i < phdrnum; i++) { | |
991 | if (gelf_getphdr(elf, i, &phdr) == NULL) | |
992 | return -1; | |
993 | if (phdr.p_type != PT_LOAD) | |
994 | continue; | |
995 | if (exe) { | |
996 | if (!(phdr.p_flags & PF_X)) | |
997 | continue; | |
998 | } else { | |
999 | if (!(phdr.p_flags & PF_R)) | |
1000 | continue; | |
1001 | } | |
1002 | sz = min(phdr.p_memsz, phdr.p_filesz); | |
1003 | if (!sz) | |
1004 | continue; | |
1005 | err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data); | |
1006 | if (err) | |
1007 | return err; | |
1008 | } | |
1009 | return 0; | |
1010 | } | |
1011 | ||
1012 | int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data, | |
1013 | bool *is_64_bit) | |
1014 | { | |
1015 | int err; | |
1016 | Elf *elf; | |
1017 | ||
1018 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
1019 | if (elf == NULL) | |
1020 | return -1; | |
1021 | ||
1022 | if (is_64_bit) | |
1023 | *is_64_bit = (gelf_getclass(elf) == ELFCLASS64); | |
1024 | ||
1025 | err = elf_read_maps(elf, exe, mapfn, data); | |
1026 | ||
1027 | elf_end(elf); | |
1028 | return err; | |
1029 | } | |
1030 | ||
afba19d9 AH |
1031 | static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len) |
1032 | { | |
1033 | ssize_t r; | |
1034 | size_t n; | |
1035 | int err = -1; | |
1036 | char *buf = malloc(page_size); | |
1037 | ||
1038 | if (buf == NULL) | |
1039 | return -1; | |
1040 | ||
1041 | if (lseek(to, to_offs, SEEK_SET) != to_offs) | |
1042 | goto out; | |
1043 | ||
1044 | if (lseek(from, from_offs, SEEK_SET) != from_offs) | |
1045 | goto out; | |
1046 | ||
1047 | while (len) { | |
1048 | n = page_size; | |
1049 | if (len < n) | |
1050 | n = len; | |
1051 | /* Use read because mmap won't work on proc files */ | |
1052 | r = read(from, buf, n); | |
1053 | if (r < 0) | |
1054 | goto out; | |
1055 | if (!r) | |
1056 | break; | |
1057 | n = r; | |
1058 | r = write(to, buf, n); | |
1059 | if (r < 0) | |
1060 | goto out; | |
1061 | if ((size_t)r != n) | |
1062 | goto out; | |
1063 | len -= n; | |
1064 | } | |
1065 | ||
1066 | err = 0; | |
1067 | out: | |
1068 | free(buf); | |
1069 | return err; | |
1070 | } | |
1071 | ||
1072 | struct kcore { | |
1073 | int fd; | |
1074 | int elfclass; | |
1075 | Elf *elf; | |
1076 | GElf_Ehdr ehdr; | |
1077 | }; | |
1078 | ||
1079 | static int kcore__open(struct kcore *kcore, const char *filename) | |
1080 | { | |
1081 | GElf_Ehdr *ehdr; | |
1082 | ||
1083 | kcore->fd = open(filename, O_RDONLY); | |
1084 | if (kcore->fd == -1) | |
1085 | return -1; | |
1086 | ||
1087 | kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL); | |
1088 | if (!kcore->elf) | |
1089 | goto out_close; | |
1090 | ||
1091 | kcore->elfclass = gelf_getclass(kcore->elf); | |
1092 | if (kcore->elfclass == ELFCLASSNONE) | |
1093 | goto out_end; | |
1094 | ||
1095 | ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr); | |
1096 | if (!ehdr) | |
1097 | goto out_end; | |
1098 | ||
1099 | return 0; | |
1100 | ||
1101 | out_end: | |
1102 | elf_end(kcore->elf); | |
1103 | out_close: | |
1104 | close(kcore->fd); | |
1105 | return -1; | |
1106 | } | |
1107 | ||
1108 | static int kcore__init(struct kcore *kcore, char *filename, int elfclass, | |
1109 | bool temp) | |
1110 | { | |
1111 | GElf_Ehdr *ehdr; | |
1112 | ||
1113 | kcore->elfclass = elfclass; | |
1114 | ||
1115 | if (temp) | |
1116 | kcore->fd = mkstemp(filename); | |
1117 | else | |
1118 | kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400); | |
1119 | if (kcore->fd == -1) | |
1120 | return -1; | |
1121 | ||
1122 | kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL); | |
1123 | if (!kcore->elf) | |
1124 | goto out_close; | |
1125 | ||
1126 | if (!gelf_newehdr(kcore->elf, elfclass)) | |
1127 | goto out_end; | |
1128 | ||
1129 | ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr); | |
1130 | if (!ehdr) | |
1131 | goto out_end; | |
1132 | ||
1133 | return 0; | |
1134 | ||
1135 | out_end: | |
1136 | elf_end(kcore->elf); | |
1137 | out_close: | |
1138 | close(kcore->fd); | |
1139 | unlink(filename); | |
1140 | return -1; | |
1141 | } | |
1142 | ||
1143 | static void kcore__close(struct kcore *kcore) | |
1144 | { | |
1145 | elf_end(kcore->elf); | |
1146 | close(kcore->fd); | |
1147 | } | |
1148 | ||
1149 | static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count) | |
1150 | { | |
1151 | GElf_Ehdr *ehdr = &to->ehdr; | |
1152 | GElf_Ehdr *kehdr = &from->ehdr; | |
1153 | ||
1154 | memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT); | |
1155 | ehdr->e_type = kehdr->e_type; | |
1156 | ehdr->e_machine = kehdr->e_machine; | |
1157 | ehdr->e_version = kehdr->e_version; | |
1158 | ehdr->e_entry = 0; | |
1159 | ehdr->e_shoff = 0; | |
1160 | ehdr->e_flags = kehdr->e_flags; | |
1161 | ehdr->e_phnum = count; | |
1162 | ehdr->e_shentsize = 0; | |
1163 | ehdr->e_shnum = 0; | |
1164 | ehdr->e_shstrndx = 0; | |
1165 | ||
1166 | if (from->elfclass == ELFCLASS32) { | |
1167 | ehdr->e_phoff = sizeof(Elf32_Ehdr); | |
1168 | ehdr->e_ehsize = sizeof(Elf32_Ehdr); | |
1169 | ehdr->e_phentsize = sizeof(Elf32_Phdr); | |
1170 | } else { | |
1171 | ehdr->e_phoff = sizeof(Elf64_Ehdr); | |
1172 | ehdr->e_ehsize = sizeof(Elf64_Ehdr); | |
1173 | ehdr->e_phentsize = sizeof(Elf64_Phdr); | |
1174 | } | |
1175 | ||
1176 | if (!gelf_update_ehdr(to->elf, ehdr)) | |
1177 | return -1; | |
1178 | ||
1179 | if (!gelf_newphdr(to->elf, count)) | |
1180 | return -1; | |
1181 | ||
1182 | return 0; | |
1183 | } | |
1184 | ||
1185 | static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset, | |
1186 | u64 addr, u64 len) | |
1187 | { | |
1188 | GElf_Phdr gphdr; | |
1189 | GElf_Phdr *phdr; | |
1190 | ||
1191 | phdr = gelf_getphdr(kcore->elf, idx, &gphdr); | |
1192 | if (!phdr) | |
1193 | return -1; | |
1194 | ||
1195 | phdr->p_type = PT_LOAD; | |
1196 | phdr->p_flags = PF_R | PF_W | PF_X; | |
1197 | phdr->p_offset = offset; | |
1198 | phdr->p_vaddr = addr; | |
1199 | phdr->p_paddr = 0; | |
1200 | phdr->p_filesz = len; | |
1201 | phdr->p_memsz = len; | |
1202 | phdr->p_align = page_size; | |
1203 | ||
1204 | if (!gelf_update_phdr(kcore->elf, idx, phdr)) | |
1205 | return -1; | |
1206 | ||
1207 | return 0; | |
1208 | } | |
1209 | ||
1210 | static off_t kcore__write(struct kcore *kcore) | |
1211 | { | |
1212 | return elf_update(kcore->elf, ELF_C_WRITE); | |
1213 | } | |
1214 | ||
fc1b691d AH |
1215 | struct phdr_data { |
1216 | off_t offset; | |
1217 | u64 addr; | |
1218 | u64 len; | |
1219 | }; | |
1220 | ||
1221 | struct kcore_copy_info { | |
1222 | u64 stext; | |
1223 | u64 etext; | |
1224 | u64 first_symbol; | |
1225 | u64 last_symbol; | |
1226 | u64 first_module; | |
1227 | u64 last_module_symbol; | |
1228 | struct phdr_data kernel_map; | |
1229 | struct phdr_data modules_map; | |
1230 | }; | |
1231 | ||
1232 | static int kcore_copy__process_kallsyms(void *arg, const char *name, char type, | |
1233 | u64 start) | |
1234 | { | |
1235 | struct kcore_copy_info *kci = arg; | |
1236 | ||
1237 | if (!symbol_type__is_a(type, MAP__FUNCTION)) | |
1238 | return 0; | |
1239 | ||
1240 | if (strchr(name, '[')) { | |
1241 | if (start > kci->last_module_symbol) | |
1242 | kci->last_module_symbol = start; | |
1243 | return 0; | |
1244 | } | |
1245 | ||
1246 | if (!kci->first_symbol || start < kci->first_symbol) | |
1247 | kci->first_symbol = start; | |
1248 | ||
1249 | if (!kci->last_symbol || start > kci->last_symbol) | |
1250 | kci->last_symbol = start; | |
1251 | ||
1252 | if (!strcmp(name, "_stext")) { | |
1253 | kci->stext = start; | |
1254 | return 0; | |
1255 | } | |
1256 | ||
1257 | if (!strcmp(name, "_etext")) { | |
1258 | kci->etext = start; | |
1259 | return 0; | |
1260 | } | |
1261 | ||
1262 | return 0; | |
1263 | } | |
1264 | ||
1265 | static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci, | |
1266 | const char *dir) | |
1267 | { | |
1268 | char kallsyms_filename[PATH_MAX]; | |
1269 | ||
1270 | scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir); | |
1271 | ||
1272 | if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms")) | |
1273 | return -1; | |
1274 | ||
1275 | if (kallsyms__parse(kallsyms_filename, kci, | |
1276 | kcore_copy__process_kallsyms) < 0) | |
1277 | return -1; | |
1278 | ||
1279 | return 0; | |
1280 | } | |
1281 | ||
1282 | static int kcore_copy__process_modules(void *arg, | |
1283 | const char *name __maybe_unused, | |
1284 | u64 start) | |
1285 | { | |
1286 | struct kcore_copy_info *kci = arg; | |
1287 | ||
1288 | if (!kci->first_module || start < kci->first_module) | |
1289 | kci->first_module = start; | |
1290 | ||
1291 | return 0; | |
1292 | } | |
1293 | ||
1294 | static int kcore_copy__parse_modules(struct kcore_copy_info *kci, | |
1295 | const char *dir) | |
1296 | { | |
1297 | char modules_filename[PATH_MAX]; | |
1298 | ||
1299 | scnprintf(modules_filename, PATH_MAX, "%s/modules", dir); | |
1300 | ||
1301 | if (symbol__restricted_filename(modules_filename, "/proc/modules")) | |
1302 | return -1; | |
1303 | ||
1304 | if (modules__parse(modules_filename, kci, | |
1305 | kcore_copy__process_modules) < 0) | |
1306 | return -1; | |
1307 | ||
1308 | return 0; | |
1309 | } | |
1310 | ||
1311 | static void kcore_copy__map(struct phdr_data *p, u64 start, u64 end, u64 pgoff, | |
1312 | u64 s, u64 e) | |
1313 | { | |
1314 | if (p->addr || s < start || s >= end) | |
1315 | return; | |
1316 | ||
1317 | p->addr = s; | |
1318 | p->offset = (s - start) + pgoff; | |
1319 | p->len = e < end ? e - s : end - s; | |
1320 | } | |
1321 | ||
1322 | static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data) | |
1323 | { | |
1324 | struct kcore_copy_info *kci = data; | |
1325 | u64 end = start + len; | |
1326 | ||
1327 | kcore_copy__map(&kci->kernel_map, start, end, pgoff, kci->stext, | |
1328 | kci->etext); | |
1329 | ||
1330 | kcore_copy__map(&kci->modules_map, start, end, pgoff, kci->first_module, | |
1331 | kci->last_module_symbol); | |
1332 | ||
1333 | return 0; | |
1334 | } | |
1335 | ||
1336 | static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf) | |
1337 | { | |
1338 | if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0) | |
1339 | return -1; | |
1340 | ||
1341 | return 0; | |
1342 | } | |
1343 | ||
1344 | static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir, | |
1345 | Elf *elf) | |
1346 | { | |
1347 | if (kcore_copy__parse_kallsyms(kci, dir)) | |
1348 | return -1; | |
1349 | ||
1350 | if (kcore_copy__parse_modules(kci, dir)) | |
1351 | return -1; | |
1352 | ||
1353 | if (kci->stext) | |
1354 | kci->stext = round_down(kci->stext, page_size); | |
1355 | else | |
1356 | kci->stext = round_down(kci->first_symbol, page_size); | |
1357 | ||
1358 | if (kci->etext) { | |
1359 | kci->etext = round_up(kci->etext, page_size); | |
1360 | } else if (kci->last_symbol) { | |
1361 | kci->etext = round_up(kci->last_symbol, page_size); | |
1362 | kci->etext += page_size; | |
1363 | } | |
1364 | ||
1365 | kci->first_module = round_down(kci->first_module, page_size); | |
1366 | ||
1367 | if (kci->last_module_symbol) { | |
1368 | kci->last_module_symbol = round_up(kci->last_module_symbol, | |
1369 | page_size); | |
1370 | kci->last_module_symbol += page_size; | |
1371 | } | |
1372 | ||
1373 | if (!kci->stext || !kci->etext) | |
1374 | return -1; | |
1375 | ||
1376 | if (kci->first_module && !kci->last_module_symbol) | |
1377 | return -1; | |
1378 | ||
1379 | return kcore_copy__read_maps(kci, elf); | |
1380 | } | |
1381 | ||
1382 | static int kcore_copy__copy_file(const char *from_dir, const char *to_dir, | |
1383 | const char *name) | |
1384 | { | |
1385 | char from_filename[PATH_MAX]; | |
1386 | char to_filename[PATH_MAX]; | |
1387 | ||
1388 | scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name); | |
1389 | scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name); | |
1390 | ||
1391 | return copyfile_mode(from_filename, to_filename, 0400); | |
1392 | } | |
1393 | ||
1394 | static int kcore_copy__unlink(const char *dir, const char *name) | |
1395 | { | |
1396 | char filename[PATH_MAX]; | |
1397 | ||
1398 | scnprintf(filename, PATH_MAX, "%s/%s", dir, name); | |
1399 | ||
1400 | return unlink(filename); | |
1401 | } | |
1402 | ||
1403 | static int kcore_copy__compare_fds(int from, int to) | |
1404 | { | |
1405 | char *buf_from; | |
1406 | char *buf_to; | |
1407 | ssize_t ret; | |
1408 | size_t len; | |
1409 | int err = -1; | |
1410 | ||
1411 | buf_from = malloc(page_size); | |
1412 | buf_to = malloc(page_size); | |
1413 | if (!buf_from || !buf_to) | |
1414 | goto out; | |
1415 | ||
1416 | while (1) { | |
1417 | /* Use read because mmap won't work on proc files */ | |
1418 | ret = read(from, buf_from, page_size); | |
1419 | if (ret < 0) | |
1420 | goto out; | |
1421 | ||
1422 | if (!ret) | |
1423 | break; | |
1424 | ||
1425 | len = ret; | |
1426 | ||
1427 | if (readn(to, buf_to, len) != (int)len) | |
1428 | goto out; | |
1429 | ||
1430 | if (memcmp(buf_from, buf_to, len)) | |
1431 | goto out; | |
1432 | } | |
1433 | ||
1434 | err = 0; | |
1435 | out: | |
1436 | free(buf_to); | |
1437 | free(buf_from); | |
1438 | return err; | |
1439 | } | |
1440 | ||
1441 | static int kcore_copy__compare_files(const char *from_filename, | |
1442 | const char *to_filename) | |
1443 | { | |
1444 | int from, to, err = -1; | |
1445 | ||
1446 | from = open(from_filename, O_RDONLY); | |
1447 | if (from < 0) | |
1448 | return -1; | |
1449 | ||
1450 | to = open(to_filename, O_RDONLY); | |
1451 | if (to < 0) | |
1452 | goto out_close_from; | |
1453 | ||
1454 | err = kcore_copy__compare_fds(from, to); | |
1455 | ||
1456 | close(to); | |
1457 | out_close_from: | |
1458 | close(from); | |
1459 | return err; | |
1460 | } | |
1461 | ||
1462 | static int kcore_copy__compare_file(const char *from_dir, const char *to_dir, | |
1463 | const char *name) | |
1464 | { | |
1465 | char from_filename[PATH_MAX]; | |
1466 | char to_filename[PATH_MAX]; | |
1467 | ||
1468 | scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name); | |
1469 | scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name); | |
1470 | ||
1471 | return kcore_copy__compare_files(from_filename, to_filename); | |
1472 | } | |
1473 | ||
1474 | /** | |
1475 | * kcore_copy - copy kallsyms, modules and kcore from one directory to another. | |
1476 | * @from_dir: from directory | |
1477 | * @to_dir: to directory | |
1478 | * | |
1479 | * This function copies kallsyms, modules and kcore files from one directory to | |
1480 | * another. kallsyms and modules are copied entirely. Only code segments are | |
1481 | * copied from kcore. It is assumed that two segments suffice: one for the | |
1482 | * kernel proper and one for all the modules. The code segments are determined | |
1483 | * from kallsyms and modules files. The kernel map starts at _stext or the | |
1484 | * lowest function symbol, and ends at _etext or the highest function symbol. | |
1485 | * The module map starts at the lowest module address and ends at the highest | |
1486 | * module symbol. Start addresses are rounded down to the nearest page. End | |
1487 | * addresses are rounded up to the nearest page. An extra page is added to the | |
1488 | * highest kernel symbol and highest module symbol to, hopefully, encompass that | |
1489 | * symbol too. Because it contains only code sections, the resulting kcore is | |
1490 | * unusual. One significant peculiarity is that the mapping (start -> pgoff) | |
1491 | * is not the same for the kernel map and the modules map. That happens because | |
1492 | * the data is copied adjacently whereas the original kcore has gaps. Finally, | |
1493 | * kallsyms and modules files are compared with their copies to check that | |
1494 | * modules have not been loaded or unloaded while the copies were taking place. | |
1495 | * | |
1496 | * Return: %0 on success, %-1 on failure. | |
1497 | */ | |
1498 | int kcore_copy(const char *from_dir, const char *to_dir) | |
1499 | { | |
1500 | struct kcore kcore; | |
1501 | struct kcore extract; | |
1502 | size_t count = 2; | |
1503 | int idx = 0, err = -1; | |
1504 | off_t offset = page_size, sz, modules_offset = 0; | |
1505 | struct kcore_copy_info kci = { .stext = 0, }; | |
1506 | char kcore_filename[PATH_MAX]; | |
1507 | char extract_filename[PATH_MAX]; | |
1508 | ||
1509 | if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms")) | |
1510 | return -1; | |
1511 | ||
1512 | if (kcore_copy__copy_file(from_dir, to_dir, "modules")) | |
1513 | goto out_unlink_kallsyms; | |
1514 | ||
1515 | scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir); | |
1516 | scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir); | |
1517 | ||
1518 | if (kcore__open(&kcore, kcore_filename)) | |
1519 | goto out_unlink_modules; | |
1520 | ||
1521 | if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf)) | |
1522 | goto out_kcore_close; | |
1523 | ||
1524 | if (kcore__init(&extract, extract_filename, kcore.elfclass, false)) | |
1525 | goto out_kcore_close; | |
1526 | ||
1527 | if (!kci.modules_map.addr) | |
1528 | count -= 1; | |
1529 | ||
1530 | if (kcore__copy_hdr(&kcore, &extract, count)) | |
1531 | goto out_extract_close; | |
1532 | ||
1533 | if (kcore__add_phdr(&extract, idx++, offset, kci.kernel_map.addr, | |
1534 | kci.kernel_map.len)) | |
1535 | goto out_extract_close; | |
1536 | ||
1537 | if (kci.modules_map.addr) { | |
1538 | modules_offset = offset + kci.kernel_map.len; | |
1539 | if (kcore__add_phdr(&extract, idx, modules_offset, | |
1540 | kci.modules_map.addr, kci.modules_map.len)) | |
1541 | goto out_extract_close; | |
1542 | } | |
1543 | ||
1544 | sz = kcore__write(&extract); | |
1545 | if (sz < 0 || sz > offset) | |
1546 | goto out_extract_close; | |
1547 | ||
1548 | if (copy_bytes(kcore.fd, kci.kernel_map.offset, extract.fd, offset, | |
1549 | kci.kernel_map.len)) | |
1550 | goto out_extract_close; | |
1551 | ||
1552 | if (modules_offset && copy_bytes(kcore.fd, kci.modules_map.offset, | |
1553 | extract.fd, modules_offset, | |
1554 | kci.modules_map.len)) | |
1555 | goto out_extract_close; | |
1556 | ||
1557 | if (kcore_copy__compare_file(from_dir, to_dir, "modules")) | |
1558 | goto out_extract_close; | |
1559 | ||
1560 | if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms")) | |
1561 | goto out_extract_close; | |
1562 | ||
1563 | err = 0; | |
1564 | ||
1565 | out_extract_close: | |
1566 | kcore__close(&extract); | |
1567 | if (err) | |
1568 | unlink(extract_filename); | |
1569 | out_kcore_close: | |
1570 | kcore__close(&kcore); | |
1571 | out_unlink_modules: | |
1572 | if (err) | |
1573 | kcore_copy__unlink(to_dir, "modules"); | |
1574 | out_unlink_kallsyms: | |
1575 | if (err) | |
1576 | kcore_copy__unlink(to_dir, "kallsyms"); | |
1577 | ||
1578 | return err; | |
1579 | } | |
1580 | ||
afba19d9 AH |
1581 | int kcore_extract__create(struct kcore_extract *kce) |
1582 | { | |
1583 | struct kcore kcore; | |
1584 | struct kcore extract; | |
1585 | size_t count = 1; | |
1586 | int idx = 0, err = -1; | |
1587 | off_t offset = page_size, sz; | |
1588 | ||
1589 | if (kcore__open(&kcore, kce->kcore_filename)) | |
1590 | return -1; | |
1591 | ||
1592 | strcpy(kce->extract_filename, PERF_KCORE_EXTRACT); | |
1593 | if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true)) | |
1594 | goto out_kcore_close; | |
1595 | ||
1596 | if (kcore__copy_hdr(&kcore, &extract, count)) | |
1597 | goto out_extract_close; | |
1598 | ||
1599 | if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len)) | |
1600 | goto out_extract_close; | |
1601 | ||
1602 | sz = kcore__write(&extract); | |
1603 | if (sz < 0 || sz > offset) | |
1604 | goto out_extract_close; | |
1605 | ||
1606 | if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len)) | |
1607 | goto out_extract_close; | |
1608 | ||
1609 | err = 0; | |
1610 | ||
1611 | out_extract_close: | |
1612 | kcore__close(&extract); | |
1613 | if (err) | |
1614 | unlink(kce->extract_filename); | |
1615 | out_kcore_close: | |
1616 | kcore__close(&kcore); | |
1617 | ||
1618 | return err; | |
1619 | } | |
1620 | ||
1621 | void kcore_extract__delete(struct kcore_extract *kce) | |
1622 | { | |
1623 | unlink(kce->extract_filename); | |
1624 | } | |
1625 | ||
e5a1845f NK |
1626 | void symbol__elf_init(void) |
1627 | { | |
1628 | elf_version(EV_CURRENT); | |
1629 | } |