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Commit | Line | Data |
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71ad0f5e JO |
1 | /* |
2 | * Post mortem Dwarf CFI based unwinding on top of regs and stack dumps. | |
3 | * | |
4 | * Lots of this code have been borrowed or heavily inspired from parts of | |
5 | * the libunwind 0.99 code which are (amongst other contributors I may have | |
6 | * forgotten): | |
7 | * | |
8 | * Copyright (C) 2002-2007 Hewlett-Packard Co | |
9 | * Contributed by David Mosberger-Tang <davidm@hpl.hp.com> | |
10 | * | |
11 | * And the bugs have been added by: | |
12 | * | |
13 | * Copyright (C) 2010, Frederic Weisbecker <fweisbec@gmail.com> | |
14 | * Copyright (C) 2012, Jiri Olsa <jolsa@redhat.com> | |
15 | * | |
16 | */ | |
17 | ||
18 | #include <elf.h> | |
19 | #include <gelf.h> | |
20 | #include <fcntl.h> | |
21 | #include <string.h> | |
22 | #include <unistd.h> | |
23 | #include <sys/mman.h> | |
24 | #include <linux/list.h> | |
19473e7b | 25 | #ifndef REMOTE_UNWIND_LIBUNWIND |
71ad0f5e JO |
26 | #include <libunwind.h> |
27 | #include <libunwind-ptrace.h> | |
19473e7b | 28 | #endif |
66f066d8 | 29 | #include "callchain.h" |
71ad0f5e JO |
30 | #include "thread.h" |
31 | #include "session.h" | |
32 | #include "perf_regs.h" | |
33 | #include "unwind.h" | |
99ca4233 | 34 | #include "symbol.h" |
71ad0f5e | 35 | #include "util.h" |
84f5d36f | 36 | #include "debug.h" |
e583d70c | 37 | #include "asm/bug.h" |
71ad0f5e JO |
38 | |
39 | extern int | |
40 | UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as, | |
41 | unw_word_t ip, | |
42 | unw_dyn_info_t *di, | |
43 | unw_proc_info_t *pi, | |
44 | int need_unwind_info, void *arg); | |
45 | ||
46 | #define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table) | |
47 | ||
ab255e72 JP |
48 | extern int |
49 | UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug, | |
50 | unw_word_t ip, | |
51 | unw_word_t segbase, | |
52 | const char *obj_name, unw_word_t start, | |
53 | unw_word_t end); | |
54 | ||
55 | #define dwarf_find_debug_frame UNW_OBJ(dwarf_find_debug_frame) | |
56 | ||
71ad0f5e JO |
57 | #define DW_EH_PE_FORMAT_MASK 0x0f /* format of the encoded value */ |
58 | #define DW_EH_PE_APPL_MASK 0x70 /* how the value is to be applied */ | |
59 | ||
60 | /* Pointer-encoding formats: */ | |
61 | #define DW_EH_PE_omit 0xff | |
62 | #define DW_EH_PE_ptr 0x00 /* pointer-sized unsigned value */ | |
63 | #define DW_EH_PE_udata4 0x03 /* unsigned 32-bit value */ | |
64 | #define DW_EH_PE_udata8 0x04 /* unsigned 64-bit value */ | |
65 | #define DW_EH_PE_sdata4 0x0b /* signed 32-bit value */ | |
66 | #define DW_EH_PE_sdata8 0x0c /* signed 64-bit value */ | |
67 | ||
68 | /* Pointer-encoding application: */ | |
69 | #define DW_EH_PE_absptr 0x00 /* absolute value */ | |
70 | #define DW_EH_PE_pcrel 0x10 /* rel. to addr. of encoded value */ | |
71 | ||
72 | /* | |
73 | * The following are not documented by LSB v1.3, yet they are used by | |
74 | * GCC, presumably they aren't documented by LSB since they aren't | |
75 | * used on Linux: | |
76 | */ | |
77 | #define DW_EH_PE_funcrel 0x40 /* start-of-procedure-relative */ | |
78 | #define DW_EH_PE_aligned 0x50 /* aligned pointer */ | |
79 | ||
80 | /* Flags intentionaly not handled, since they're not needed: | |
81 | * #define DW_EH_PE_indirect 0x80 | |
82 | * #define DW_EH_PE_uleb128 0x01 | |
83 | * #define DW_EH_PE_udata2 0x02 | |
84 | * #define DW_EH_PE_sleb128 0x09 | |
85 | * #define DW_EH_PE_sdata2 0x0a | |
86 | * #define DW_EH_PE_textrel 0x20 | |
87 | * #define DW_EH_PE_datarel 0x30 | |
88 | */ | |
89 | ||
90 | struct unwind_info { | |
91 | struct perf_sample *sample; | |
92 | struct machine *machine; | |
93 | struct thread *thread; | |
71ad0f5e JO |
94 | }; |
95 | ||
96 | #define dw_read(ptr, type, end) ({ \ | |
97 | type *__p = (type *) ptr; \ | |
98 | type __v; \ | |
99 | if ((__p + 1) > (type *) end) \ | |
100 | return -EINVAL; \ | |
101 | __v = *__p++; \ | |
102 | ptr = (typeof(ptr)) __p; \ | |
103 | __v; \ | |
104 | }) | |
105 | ||
106 | static int __dw_read_encoded_value(u8 **p, u8 *end, u64 *val, | |
107 | u8 encoding) | |
108 | { | |
109 | u8 *cur = *p; | |
110 | *val = 0; | |
111 | ||
112 | switch (encoding) { | |
113 | case DW_EH_PE_omit: | |
114 | *val = 0; | |
115 | goto out; | |
116 | case DW_EH_PE_ptr: | |
117 | *val = dw_read(cur, unsigned long, end); | |
118 | goto out; | |
119 | default: | |
120 | break; | |
121 | } | |
122 | ||
123 | switch (encoding & DW_EH_PE_APPL_MASK) { | |
124 | case DW_EH_PE_absptr: | |
125 | break; | |
126 | case DW_EH_PE_pcrel: | |
127 | *val = (unsigned long) cur; | |
128 | break; | |
129 | default: | |
130 | return -EINVAL; | |
131 | } | |
132 | ||
133 | if ((encoding & 0x07) == 0x00) | |
134 | encoding |= DW_EH_PE_udata4; | |
135 | ||
136 | switch (encoding & DW_EH_PE_FORMAT_MASK) { | |
137 | case DW_EH_PE_sdata4: | |
138 | *val += dw_read(cur, s32, end); | |
139 | break; | |
140 | case DW_EH_PE_udata4: | |
141 | *val += dw_read(cur, u32, end); | |
142 | break; | |
143 | case DW_EH_PE_sdata8: | |
144 | *val += dw_read(cur, s64, end); | |
145 | break; | |
146 | case DW_EH_PE_udata8: | |
147 | *val += dw_read(cur, u64, end); | |
148 | break; | |
149 | default: | |
150 | return -EINVAL; | |
151 | } | |
152 | ||
153 | out: | |
154 | *p = cur; | |
155 | return 0; | |
156 | } | |
157 | ||
158 | #define dw_read_encoded_value(ptr, end, enc) ({ \ | |
159 | u64 __v; \ | |
160 | if (__dw_read_encoded_value(&ptr, end, &__v, enc)) { \ | |
161 | return -EINVAL; \ | |
162 | } \ | |
163 | __v; \ | |
164 | }) | |
165 | ||
71ad0f5e JO |
166 | static u64 elf_section_offset(int fd, const char *name) |
167 | { | |
168 | Elf *elf; | |
169 | GElf_Ehdr ehdr; | |
170 | GElf_Shdr shdr; | |
171 | u64 offset = 0; | |
172 | ||
173 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
174 | if (elf == NULL) | |
175 | return 0; | |
176 | ||
177 | do { | |
178 | if (gelf_getehdr(elf, &ehdr) == NULL) | |
179 | break; | |
180 | ||
99ca4233 | 181 | if (!elf_section_by_name(elf, &ehdr, &shdr, name, NULL)) |
71ad0f5e JO |
182 | break; |
183 | ||
184 | offset = shdr.sh_offset; | |
185 | } while (0); | |
186 | ||
187 | elf_end(elf); | |
188 | return offset; | |
189 | } | |
190 | ||
b93b0967 WN |
191 | #ifndef NO_LIBUNWIND_DEBUG_FRAME |
192 | static int elf_is_exec(int fd, const char *name) | |
193 | { | |
194 | Elf *elf; | |
195 | GElf_Ehdr ehdr; | |
196 | int retval = 0; | |
197 | ||
198 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
199 | if (elf == NULL) | |
200 | return 0; | |
201 | if (gelf_getehdr(elf, &ehdr) == NULL) | |
202 | goto out; | |
203 | ||
204 | retval = (ehdr.e_type == ET_EXEC); | |
205 | ||
206 | out: | |
207 | elf_end(elf); | |
208 | pr_debug("unwind: elf_is_exec(%s): %d\n", name, retval); | |
209 | return retval; | |
210 | } | |
211 | #endif | |
212 | ||
71ad0f5e JO |
213 | struct table_entry { |
214 | u32 start_ip_offset; | |
215 | u32 fde_offset; | |
216 | }; | |
217 | ||
218 | struct eh_frame_hdr { | |
219 | unsigned char version; | |
220 | unsigned char eh_frame_ptr_enc; | |
221 | unsigned char fde_count_enc; | |
222 | unsigned char table_enc; | |
223 | ||
224 | /* | |
225 | * The rest of the header is variable-length and consists of the | |
226 | * following members: | |
227 | * | |
228 | * encoded_t eh_frame_ptr; | |
229 | * encoded_t fde_count; | |
230 | */ | |
231 | ||
232 | /* A single encoded pointer should not be more than 8 bytes. */ | |
233 | u64 enc[2]; | |
234 | ||
235 | /* | |
236 | * struct { | |
237 | * encoded_t start_ip; | |
238 | * encoded_t fde_addr; | |
239 | * } binary_search_table[fde_count]; | |
240 | */ | |
241 | char data[0]; | |
242 | } __packed; | |
243 | ||
244 | static int unwind_spec_ehframe(struct dso *dso, struct machine *machine, | |
245 | u64 offset, u64 *table_data, u64 *segbase, | |
246 | u64 *fde_count) | |
247 | { | |
248 | struct eh_frame_hdr hdr; | |
249 | u8 *enc = (u8 *) &hdr.enc; | |
250 | u8 *end = (u8 *) &hdr.data; | |
251 | ssize_t r; | |
252 | ||
253 | r = dso__data_read_offset(dso, machine, offset, | |
254 | (u8 *) &hdr, sizeof(hdr)); | |
255 | if (r != sizeof(hdr)) | |
256 | return -EINVAL; | |
257 | ||
258 | /* We dont need eh_frame_ptr, just skip it. */ | |
259 | dw_read_encoded_value(enc, end, hdr.eh_frame_ptr_enc); | |
260 | ||
261 | *fde_count = dw_read_encoded_value(enc, end, hdr.fde_count_enc); | |
262 | *segbase = offset; | |
263 | *table_data = (enc - (u8 *) &hdr) + offset; | |
264 | return 0; | |
265 | } | |
266 | ||
ab255e72 JP |
267 | static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine, |
268 | u64 *table_data, u64 *segbase, | |
269 | u64 *fde_count) | |
71ad0f5e JO |
270 | { |
271 | int ret = -EINVAL, fd; | |
303cb89a | 272 | u64 offset = dso->data.eh_frame_hdr_offset; |
71ad0f5e | 273 | |
f1f13af9 | 274 | if (offset == 0) { |
4bb11d01 | 275 | fd = dso__data_get_fd(dso, machine); |
f1f13af9 NK |
276 | if (fd < 0) |
277 | return -EINVAL; | |
71ad0f5e | 278 | |
f1f13af9 NK |
279 | /* Check the .eh_frame section for unwinding info */ |
280 | offset = elf_section_offset(fd, ".eh_frame_hdr"); | |
303cb89a | 281 | dso->data.eh_frame_hdr_offset = offset; |
4bb11d01 | 282 | dso__data_put_fd(dso); |
f1f13af9 | 283 | } |
71ad0f5e JO |
284 | |
285 | if (offset) | |
286 | ret = unwind_spec_ehframe(dso, machine, offset, | |
287 | table_data, segbase, | |
288 | fde_count); | |
289 | ||
71ad0f5e JO |
290 | return ret; |
291 | } | |
292 | ||
ab255e72 JP |
293 | #ifndef NO_LIBUNWIND_DEBUG_FRAME |
294 | static int read_unwind_spec_debug_frame(struct dso *dso, | |
295 | struct machine *machine, u64 *offset) | |
296 | { | |
f1f13af9 | 297 | int fd; |
303cb89a | 298 | u64 ofs = dso->data.debug_frame_offset; |
ab255e72 | 299 | |
f1f13af9 | 300 | if (ofs == 0) { |
4bb11d01 | 301 | fd = dso__data_get_fd(dso, machine); |
f1f13af9 NK |
302 | if (fd < 0) |
303 | return -EINVAL; | |
ab255e72 | 304 | |
f1f13af9 NK |
305 | /* Check the .debug_frame section for unwinding info */ |
306 | ofs = elf_section_offset(fd, ".debug_frame"); | |
303cb89a | 307 | dso->data.debug_frame_offset = ofs; |
4bb11d01 | 308 | dso__data_put_fd(dso); |
f1f13af9 | 309 | } |
ab255e72 | 310 | |
f1f13af9 | 311 | *offset = ofs; |
ab255e72 JP |
312 | if (*offset) |
313 | return 0; | |
314 | ||
315 | return -EINVAL; | |
316 | } | |
317 | #endif | |
318 | ||
71ad0f5e JO |
319 | static struct map *find_map(unw_word_t ip, struct unwind_info *ui) |
320 | { | |
321 | struct addr_location al; | |
322 | ||
bb871a9c | 323 | thread__find_addr_map(ui->thread, PERF_RECORD_MISC_USER, |
326f59bf | 324 | MAP__FUNCTION, ip, &al); |
0ddf5246 JO |
325 | if (!al.map) { |
326 | /* | |
327 | * We've seen cases (softice) where DWARF unwinder went | |
328 | * through non executable mmaps, which we need to lookup | |
329 | * in MAP__VARIABLE tree. | |
330 | */ | |
331 | thread__find_addr_map(ui->thread, PERF_RECORD_MISC_USER, | |
332 | MAP__VARIABLE, ip, &al); | |
333 | } | |
71ad0f5e JO |
334 | return al.map; |
335 | } | |
336 | ||
337 | static int | |
338 | find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi, | |
339 | int need_unwind_info, void *arg) | |
340 | { | |
341 | struct unwind_info *ui = arg; | |
342 | struct map *map; | |
343 | unw_dyn_info_t di; | |
344 | u64 table_data, segbase, fde_count; | |
8eac1d5e | 345 | int ret = -EINVAL; |
71ad0f5e JO |
346 | |
347 | map = find_map(ip, ui); | |
348 | if (!map || !map->dso) | |
349 | return -EINVAL; | |
350 | ||
351 | pr_debug("unwind: find_proc_info dso %s\n", map->dso->name); | |
352 | ||
ab255e72 JP |
353 | /* Check the .eh_frame section for unwinding info */ |
354 | if (!read_unwind_spec_eh_frame(map->dso, ui->machine, | |
355 | &table_data, &segbase, &fde_count)) { | |
356 | memset(&di, 0, sizeof(di)); | |
357 | di.format = UNW_INFO_FORMAT_REMOTE_TABLE; | |
358 | di.start_ip = map->start; | |
359 | di.end_ip = map->end; | |
360 | di.u.rti.segbase = map->start + segbase; | |
361 | di.u.rti.table_data = map->start + table_data; | |
362 | di.u.rti.table_len = fde_count * sizeof(struct table_entry) | |
363 | / sizeof(unw_word_t); | |
8eac1d5e RV |
364 | ret = dwarf_search_unwind_table(as, ip, &di, pi, |
365 | need_unwind_info, arg); | |
ab255e72 JP |
366 | } |
367 | ||
368 | #ifndef NO_LIBUNWIND_DEBUG_FRAME | |
369 | /* Check the .debug_frame section for unwinding info */ | |
8eac1d5e RV |
370 | if (ret < 0 && |
371 | !read_unwind_spec_debug_frame(map->dso, ui->machine, &segbase)) { | |
4bb11d01 | 372 | int fd = dso__data_get_fd(map->dso, ui->machine); |
b93b0967 WN |
373 | int is_exec = elf_is_exec(fd, map->dso->name); |
374 | unw_word_t base = is_exec ? 0 : map->start; | |
7ed4915a | 375 | const char *symfile; |
b93b0967 | 376 | |
4bb11d01 | 377 | if (fd >= 0) |
f005813a | 378 | dso__data_put_fd(map->dso); |
4bb11d01 | 379 | |
7ed4915a RV |
380 | symfile = map->dso->symsrc_filename ?: map->dso->name; |
381 | ||
ab255e72 | 382 | memset(&di, 0, sizeof(di)); |
7ed4915a | 383 | if (dwarf_find_debug_frame(0, &di, ip, base, symfile, |
d11416e7 JP |
384 | map->start, map->end)) |
385 | return dwarf_search_unwind_table(as, ip, &di, pi, | |
386 | need_unwind_info, arg); | |
ab255e72 JP |
387 | } |
388 | #endif | |
71ad0f5e | 389 | |
8eac1d5e | 390 | return ret; |
71ad0f5e JO |
391 | } |
392 | ||
1d037ca1 IT |
393 | static int access_fpreg(unw_addr_space_t __maybe_unused as, |
394 | unw_regnum_t __maybe_unused num, | |
395 | unw_fpreg_t __maybe_unused *val, | |
396 | int __maybe_unused __write, | |
397 | void __maybe_unused *arg) | |
71ad0f5e JO |
398 | { |
399 | pr_err("unwind: access_fpreg unsupported\n"); | |
400 | return -UNW_EINVAL; | |
401 | } | |
402 | ||
1d037ca1 IT |
403 | static int get_dyn_info_list_addr(unw_addr_space_t __maybe_unused as, |
404 | unw_word_t __maybe_unused *dil_addr, | |
405 | void __maybe_unused *arg) | |
71ad0f5e JO |
406 | { |
407 | return -UNW_ENOINFO; | |
408 | } | |
409 | ||
1d037ca1 IT |
410 | static int resume(unw_addr_space_t __maybe_unused as, |
411 | unw_cursor_t __maybe_unused *cu, | |
412 | void __maybe_unused *arg) | |
71ad0f5e JO |
413 | { |
414 | pr_err("unwind: resume unsupported\n"); | |
415 | return -UNW_EINVAL; | |
416 | } | |
417 | ||
418 | static int | |
1d037ca1 IT |
419 | get_proc_name(unw_addr_space_t __maybe_unused as, |
420 | unw_word_t __maybe_unused addr, | |
421 | char __maybe_unused *bufp, size_t __maybe_unused buf_len, | |
422 | unw_word_t __maybe_unused *offp, void __maybe_unused *arg) | |
71ad0f5e JO |
423 | { |
424 | pr_err("unwind: get_proc_name unsupported\n"); | |
425 | return -UNW_EINVAL; | |
426 | } | |
427 | ||
428 | static int access_dso_mem(struct unwind_info *ui, unw_word_t addr, | |
429 | unw_word_t *data) | |
430 | { | |
f22ed827 | 431 | struct map *map; |
71ad0f5e JO |
432 | ssize_t size; |
433 | ||
f22ed827 JO |
434 | map = find_map(addr, ui); |
435 | if (!map) { | |
71ad0f5e JO |
436 | pr_debug("unwind: no map for %lx\n", (unsigned long)addr); |
437 | return -1; | |
438 | } | |
439 | ||
f22ed827 | 440 | if (!map->dso) |
71ad0f5e JO |
441 | return -1; |
442 | ||
f22ed827 | 443 | size = dso__data_read_addr(map->dso, map, ui->machine, |
71ad0f5e JO |
444 | addr, (u8 *) data, sizeof(*data)); |
445 | ||
446 | return !(size == sizeof(*data)); | |
447 | } | |
448 | ||
1d037ca1 | 449 | static int access_mem(unw_addr_space_t __maybe_unused as, |
71ad0f5e JO |
450 | unw_word_t addr, unw_word_t *valp, |
451 | int __write, void *arg) | |
452 | { | |
453 | struct unwind_info *ui = arg; | |
454 | struct stack_dump *stack = &ui->sample->user_stack; | |
c9b951c4 | 455 | u64 start, end; |
71ad0f5e JO |
456 | int offset; |
457 | int ret; | |
458 | ||
459 | /* Don't support write, probably not needed. */ | |
460 | if (__write || !stack || !ui->sample->user_regs.regs) { | |
461 | *valp = 0; | |
462 | return 0; | |
463 | } | |
464 | ||
78ff1d6d HK |
465 | ret = perf_reg_value(&start, &ui->sample->user_regs, |
466 | LIBUNWIND__ARCH_REG_SP); | |
71ad0f5e JO |
467 | if (ret) |
468 | return ret; | |
469 | ||
470 | end = start + stack->size; | |
471 | ||
472 | /* Check overflow. */ | |
473 | if (addr + sizeof(unw_word_t) < addr) | |
474 | return -EINVAL; | |
475 | ||
476 | if (addr < start || addr + sizeof(unw_word_t) >= end) { | |
477 | ret = access_dso_mem(ui, addr, valp); | |
478 | if (ret) { | |
c9b951c4 JO |
479 | pr_debug("unwind: access_mem %p not inside range" |
480 | " 0x%" PRIx64 "-0x%" PRIx64 "\n", | |
186c6cfb | 481 | (void *) (uintptr_t) addr, start, end); |
71ad0f5e JO |
482 | *valp = 0; |
483 | return ret; | |
484 | } | |
485 | return 0; | |
486 | } | |
487 | ||
488 | offset = addr - start; | |
489 | *valp = *(unw_word_t *)&stack->data[offset]; | |
c9b951c4 | 490 | pr_debug("unwind: access_mem addr %p val %lx, offset %d\n", |
186c6cfb | 491 | (void *) (uintptr_t) addr, (unsigned long)*valp, offset); |
71ad0f5e JO |
492 | return 0; |
493 | } | |
494 | ||
1d037ca1 | 495 | static int access_reg(unw_addr_space_t __maybe_unused as, |
71ad0f5e JO |
496 | unw_regnum_t regnum, unw_word_t *valp, |
497 | int __write, void *arg) | |
498 | { | |
499 | struct unwind_info *ui = arg; | |
500 | int id, ret; | |
c9b951c4 | 501 | u64 val; |
71ad0f5e JO |
502 | |
503 | /* Don't support write, I suspect we don't need it. */ | |
504 | if (__write) { | |
505 | pr_err("unwind: access_reg w %d\n", regnum); | |
506 | return 0; | |
507 | } | |
508 | ||
509 | if (!ui->sample->user_regs.regs) { | |
510 | *valp = 0; | |
511 | return 0; | |
512 | } | |
513 | ||
eeb118c5 | 514 | id = LIBUNWIND__ARCH_REG_ID(regnum); |
71ad0f5e JO |
515 | if (id < 0) |
516 | return -EINVAL; | |
517 | ||
c9b951c4 | 518 | ret = perf_reg_value(&val, &ui->sample->user_regs, id); |
71ad0f5e JO |
519 | if (ret) { |
520 | pr_err("unwind: can't read reg %d\n", regnum); | |
521 | return ret; | |
522 | } | |
523 | ||
c9b951c4 | 524 | *valp = (unw_word_t) val; |
71ad0f5e JO |
525 | pr_debug("unwind: reg %d, val %lx\n", regnum, (unsigned long)*valp); |
526 | return 0; | |
527 | } | |
528 | ||
1d037ca1 IT |
529 | static void put_unwind_info(unw_addr_space_t __maybe_unused as, |
530 | unw_proc_info_t *pi __maybe_unused, | |
531 | void *arg __maybe_unused) | |
71ad0f5e JO |
532 | { |
533 | pr_debug("unwind: put_unwind_info called\n"); | |
534 | } | |
535 | ||
bb871a9c | 536 | static int entry(u64 ip, struct thread *thread, |
71ad0f5e JO |
537 | unwind_entry_cb_t cb, void *arg) |
538 | { | |
539 | struct unwind_entry e; | |
540 | struct addr_location al; | |
541 | ||
bb871a9c | 542 | thread__find_addr_location(thread, PERF_RECORD_MISC_USER, |
61710bde | 543 | MAP__FUNCTION, ip, &al); |
71ad0f5e | 544 | |
67540759 | 545 | e.ip = al.addr; |
71ad0f5e JO |
546 | e.map = al.map; |
547 | e.sym = al.sym; | |
548 | ||
549 | pr_debug("unwind: %s:ip = 0x%" PRIx64 " (0x%" PRIx64 ")\n", | |
550 | al.sym ? al.sym->name : "''", | |
551 | ip, | |
552 | al.map ? al.map->map_ip(al.map, ip) : (u64) 0); | |
553 | ||
554 | return cb(&e, arg); | |
555 | } | |
556 | ||
557 | static void display_error(int err) | |
558 | { | |
559 | switch (err) { | |
560 | case UNW_EINVAL: | |
561 | pr_err("unwind: Only supports local.\n"); | |
562 | break; | |
563 | case UNW_EUNSPEC: | |
564 | pr_err("unwind: Unspecified error.\n"); | |
565 | break; | |
566 | case UNW_EBADREG: | |
567 | pr_err("unwind: Register unavailable.\n"); | |
568 | break; | |
569 | default: | |
570 | break; | |
571 | } | |
572 | } | |
573 | ||
574 | static unw_accessors_t accessors = { | |
575 | .find_proc_info = find_proc_info, | |
576 | .put_unwind_info = put_unwind_info, | |
577 | .get_dyn_info_list_addr = get_dyn_info_list_addr, | |
578 | .access_mem = access_mem, | |
579 | .access_reg = access_reg, | |
580 | .access_fpreg = access_fpreg, | |
581 | .resume = resume, | |
582 | .get_proc_name = get_proc_name, | |
583 | }; | |
584 | ||
f83c0415 | 585 | static int _unwind__prepare_access(struct thread *thread) |
71ad0f5e | 586 | { |
66f066d8 NK |
587 | if (callchain_param.record_mode != CALLCHAIN_DWARF) |
588 | return 0; | |
71ad0f5e | 589 | |
e583d70c JO |
590 | thread->addr_space = unw_create_addr_space(&accessors, 0); |
591 | if (!thread->addr_space) { | |
71ad0f5e JO |
592 | pr_err("unwind: Can't create unwind address space.\n"); |
593 | return -ENOMEM; | |
594 | } | |
595 | ||
e583d70c | 596 | unw_set_caching_policy(thread->addr_space, UNW_CACHE_GLOBAL); |
66f066d8 NK |
597 | return 0; |
598 | } | |
599 | ||
f83c0415 | 600 | static void _unwind__flush_access(struct thread *thread) |
380b5143 | 601 | { |
380b5143 NK |
602 | if (callchain_param.record_mode != CALLCHAIN_DWARF) |
603 | return; | |
604 | ||
e583d70c | 605 | unw_flush_cache(thread->addr_space, 0, 0); |
380b5143 NK |
606 | } |
607 | ||
f83c0415 | 608 | static void _unwind__finish_access(struct thread *thread) |
66f066d8 | 609 | { |
66f066d8 NK |
610 | if (callchain_param.record_mode != CALLCHAIN_DWARF) |
611 | return; | |
612 | ||
e583d70c | 613 | unw_destroy_addr_space(thread->addr_space); |
66f066d8 NK |
614 | } |
615 | ||
616 | static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb, | |
617 | void *arg, int max_stack) | |
618 | { | |
b26b218a | 619 | u64 val; |
cb1dc22d | 620 | unw_word_t ips[max_stack]; |
66f066d8 NK |
621 | unw_addr_space_t addr_space; |
622 | unw_cursor_t c; | |
cb1dc22d | 623 | int ret, i = 0; |
66f066d8 | 624 | |
78ff1d6d HK |
625 | ret = perf_reg_value(&val, &ui->sample->user_regs, |
626 | LIBUNWIND__ARCH_REG_IP); | |
b26b218a JO |
627 | if (ret) |
628 | return ret; | |
629 | ||
cb1dc22d | 630 | ips[i++] = (unw_word_t) val; |
b26b218a | 631 | |
cb1dc22d JO |
632 | /* |
633 | * If we need more than one entry, do the DWARF | |
634 | * unwind itself. | |
635 | */ | |
636 | if (max_stack - 1 > 0) { | |
e583d70c JO |
637 | WARN_ONCE(!ui->thread, "WARNING: ui->thread is NULL"); |
638 | addr_space = ui->thread->addr_space; | |
639 | ||
cb1dc22d JO |
640 | if (addr_space == NULL) |
641 | return -1; | |
642 | ||
643 | ret = unw_init_remote(&c, addr_space, ui); | |
644 | if (ret) | |
645 | display_error(ret); | |
646 | ||
647 | while (!ret && (unw_step(&c) > 0) && i < max_stack) { | |
648 | unw_get_reg(&c, UNW_REG_IP, &ips[i]); | |
649 | ++i; | |
650 | } | |
66f066d8 | 651 | |
cb1dc22d JO |
652 | max_stack = i; |
653 | } | |
71ad0f5e | 654 | |
cb1dc22d JO |
655 | /* |
656 | * Display what we got based on the order setup. | |
657 | */ | |
658 | for (i = 0; i < max_stack && !ret; i++) { | |
659 | int j = i; | |
71ad0f5e | 660 | |
cb1dc22d JO |
661 | if (callchain_param.order == ORDER_CALLER) |
662 | j = max_stack - i - 1; | |
663 | ret = ips[j] ? entry(ips[j], ui->thread, cb, arg) : 0; | |
71ad0f5e JO |
664 | } |
665 | ||
71ad0f5e JO |
666 | return ret; |
667 | } | |
668 | ||
f83c0415 | 669 | static int _unwind__get_entries(unwind_entry_cb_t cb, void *arg, |
dd8c17a5 | 670 | struct thread *thread, |
352ea45a | 671 | struct perf_sample *data, int max_stack) |
71ad0f5e | 672 | { |
71ad0f5e JO |
673 | struct unwind_info ui = { |
674 | .sample = data, | |
71ad0f5e | 675 | .thread = thread, |
dd8c17a5 | 676 | .machine = thread->mg->machine, |
71ad0f5e | 677 | }; |
71ad0f5e JO |
678 | |
679 | if (!data->user_regs.regs) | |
680 | return -EINVAL; | |
681 | ||
b26b218a JO |
682 | if (max_stack <= 0) |
683 | return -EINVAL; | |
71ad0f5e | 684 | |
b26b218a | 685 | return get_entries(&ui, cb, arg, max_stack); |
71ad0f5e | 686 | } |
f83c0415 HK |
687 | |
688 | static struct unwind_libunwind_ops | |
689 | _unwind_libunwind_ops = { | |
690 | .prepare_access = _unwind__prepare_access, | |
691 | .flush_access = _unwind__flush_access, | |
692 | .finish_access = _unwind__finish_access, | |
693 | .get_entries = _unwind__get_entries, | |
694 | }; | |
695 | ||
19473e7b | 696 | #ifndef REMOTE_UNWIND_LIBUNWIND |
f83c0415 HK |
697 | struct unwind_libunwind_ops * |
698 | local_unwind_libunwind_ops = &_unwind_libunwind_ops; | |
19473e7b | 699 | #endif |