Commit | Line | Data |
---|---|---|
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> | |
25 | #include <libunwind.h> | |
26 | #include <libunwind-ptrace.h> | |
66f066d8 | 27 | #include "callchain.h" |
71ad0f5e JO |
28 | #include "thread.h" |
29 | #include "session.h" | |
30 | #include "perf_regs.h" | |
31 | #include "unwind.h" | |
99ca4233 | 32 | #include "symbol.h" |
71ad0f5e | 33 | #include "util.h" |
84f5d36f | 34 | #include "debug.h" |
e583d70c | 35 | #include "asm/bug.h" |
71ad0f5e JO |
36 | |
37 | extern int | |
38 | UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as, | |
39 | unw_word_t ip, | |
40 | unw_dyn_info_t *di, | |
41 | unw_proc_info_t *pi, | |
42 | int need_unwind_info, void *arg); | |
43 | ||
44 | #define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table) | |
45 | ||
ab255e72 JP |
46 | extern int |
47 | UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug, | |
48 | unw_word_t ip, | |
49 | unw_word_t segbase, | |
50 | const char *obj_name, unw_word_t start, | |
51 | unw_word_t end); | |
52 | ||
53 | #define dwarf_find_debug_frame UNW_OBJ(dwarf_find_debug_frame) | |
54 | ||
71ad0f5e JO |
55 | #define DW_EH_PE_FORMAT_MASK 0x0f /* format of the encoded value */ |
56 | #define DW_EH_PE_APPL_MASK 0x70 /* how the value is to be applied */ | |
57 | ||
58 | /* Pointer-encoding formats: */ | |
59 | #define DW_EH_PE_omit 0xff | |
60 | #define DW_EH_PE_ptr 0x00 /* pointer-sized unsigned value */ | |
61 | #define DW_EH_PE_udata4 0x03 /* unsigned 32-bit value */ | |
62 | #define DW_EH_PE_udata8 0x04 /* unsigned 64-bit value */ | |
63 | #define DW_EH_PE_sdata4 0x0b /* signed 32-bit value */ | |
64 | #define DW_EH_PE_sdata8 0x0c /* signed 64-bit value */ | |
65 | ||
66 | /* Pointer-encoding application: */ | |
67 | #define DW_EH_PE_absptr 0x00 /* absolute value */ | |
68 | #define DW_EH_PE_pcrel 0x10 /* rel. to addr. of encoded value */ | |
69 | ||
70 | /* | |
71 | * The following are not documented by LSB v1.3, yet they are used by | |
72 | * GCC, presumably they aren't documented by LSB since they aren't | |
73 | * used on Linux: | |
74 | */ | |
75 | #define DW_EH_PE_funcrel 0x40 /* start-of-procedure-relative */ | |
76 | #define DW_EH_PE_aligned 0x50 /* aligned pointer */ | |
77 | ||
78 | /* Flags intentionaly not handled, since they're not needed: | |
79 | * #define DW_EH_PE_indirect 0x80 | |
80 | * #define DW_EH_PE_uleb128 0x01 | |
81 | * #define DW_EH_PE_udata2 0x02 | |
82 | * #define DW_EH_PE_sleb128 0x09 | |
83 | * #define DW_EH_PE_sdata2 0x0a | |
84 | * #define DW_EH_PE_textrel 0x20 | |
85 | * #define DW_EH_PE_datarel 0x30 | |
86 | */ | |
87 | ||
88 | struct unwind_info { | |
89 | struct perf_sample *sample; | |
90 | struct machine *machine; | |
91 | struct thread *thread; | |
71ad0f5e JO |
92 | }; |
93 | ||
94 | #define dw_read(ptr, type, end) ({ \ | |
95 | type *__p = (type *) ptr; \ | |
96 | type __v; \ | |
97 | if ((__p + 1) > (type *) end) \ | |
98 | return -EINVAL; \ | |
99 | __v = *__p++; \ | |
100 | ptr = (typeof(ptr)) __p; \ | |
101 | __v; \ | |
102 | }) | |
103 | ||
104 | static int __dw_read_encoded_value(u8 **p, u8 *end, u64 *val, | |
105 | u8 encoding) | |
106 | { | |
107 | u8 *cur = *p; | |
108 | *val = 0; | |
109 | ||
110 | switch (encoding) { | |
111 | case DW_EH_PE_omit: | |
112 | *val = 0; | |
113 | goto out; | |
114 | case DW_EH_PE_ptr: | |
115 | *val = dw_read(cur, unsigned long, end); | |
116 | goto out; | |
117 | default: | |
118 | break; | |
119 | } | |
120 | ||
121 | switch (encoding & DW_EH_PE_APPL_MASK) { | |
122 | case DW_EH_PE_absptr: | |
123 | break; | |
124 | case DW_EH_PE_pcrel: | |
125 | *val = (unsigned long) cur; | |
126 | break; | |
127 | default: | |
128 | return -EINVAL; | |
129 | } | |
130 | ||
131 | if ((encoding & 0x07) == 0x00) | |
132 | encoding |= DW_EH_PE_udata4; | |
133 | ||
134 | switch (encoding & DW_EH_PE_FORMAT_MASK) { | |
135 | case DW_EH_PE_sdata4: | |
136 | *val += dw_read(cur, s32, end); | |
137 | break; | |
138 | case DW_EH_PE_udata4: | |
139 | *val += dw_read(cur, u32, end); | |
140 | break; | |
141 | case DW_EH_PE_sdata8: | |
142 | *val += dw_read(cur, s64, end); | |
143 | break; | |
144 | case DW_EH_PE_udata8: | |
145 | *val += dw_read(cur, u64, end); | |
146 | break; | |
147 | default: | |
148 | return -EINVAL; | |
149 | } | |
150 | ||
151 | out: | |
152 | *p = cur; | |
153 | return 0; | |
154 | } | |
155 | ||
156 | #define dw_read_encoded_value(ptr, end, enc) ({ \ | |
157 | u64 __v; \ | |
158 | if (__dw_read_encoded_value(&ptr, end, &__v, enc)) { \ | |
159 | return -EINVAL; \ | |
160 | } \ | |
161 | __v; \ | |
162 | }) | |
163 | ||
71ad0f5e JO |
164 | static u64 elf_section_offset(int fd, const char *name) |
165 | { | |
166 | Elf *elf; | |
167 | GElf_Ehdr ehdr; | |
168 | GElf_Shdr shdr; | |
169 | u64 offset = 0; | |
170 | ||
171 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
172 | if (elf == NULL) | |
173 | return 0; | |
174 | ||
175 | do { | |
176 | if (gelf_getehdr(elf, &ehdr) == NULL) | |
177 | break; | |
178 | ||
99ca4233 | 179 | if (!elf_section_by_name(elf, &ehdr, &shdr, name, NULL)) |
71ad0f5e JO |
180 | break; |
181 | ||
182 | offset = shdr.sh_offset; | |
183 | } while (0); | |
184 | ||
185 | elf_end(elf); | |
186 | return offset; | |
187 | } | |
188 | ||
b93b0967 WN |
189 | #ifndef NO_LIBUNWIND_DEBUG_FRAME |
190 | static int elf_is_exec(int fd, const char *name) | |
191 | { | |
192 | Elf *elf; | |
193 | GElf_Ehdr ehdr; | |
194 | int retval = 0; | |
195 | ||
196 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); | |
197 | if (elf == NULL) | |
198 | return 0; | |
199 | if (gelf_getehdr(elf, &ehdr) == NULL) | |
200 | goto out; | |
201 | ||
202 | retval = (ehdr.e_type == ET_EXEC); | |
203 | ||
204 | out: | |
205 | elf_end(elf); | |
206 | pr_debug("unwind: elf_is_exec(%s): %d\n", name, retval); | |
207 | return retval; | |
208 | } | |
209 | #endif | |
210 | ||
71ad0f5e JO |
211 | struct table_entry { |
212 | u32 start_ip_offset; | |
213 | u32 fde_offset; | |
214 | }; | |
215 | ||
216 | struct eh_frame_hdr { | |
217 | unsigned char version; | |
218 | unsigned char eh_frame_ptr_enc; | |
219 | unsigned char fde_count_enc; | |
220 | unsigned char table_enc; | |
221 | ||
222 | /* | |
223 | * The rest of the header is variable-length and consists of the | |
224 | * following members: | |
225 | * | |
226 | * encoded_t eh_frame_ptr; | |
227 | * encoded_t fde_count; | |
228 | */ | |
229 | ||
230 | /* A single encoded pointer should not be more than 8 bytes. */ | |
231 | u64 enc[2]; | |
232 | ||
233 | /* | |
234 | * struct { | |
235 | * encoded_t start_ip; | |
236 | * encoded_t fde_addr; | |
237 | * } binary_search_table[fde_count]; | |
238 | */ | |
239 | char data[0]; | |
240 | } __packed; | |
241 | ||
242 | static int unwind_spec_ehframe(struct dso *dso, struct machine *machine, | |
243 | u64 offset, u64 *table_data, u64 *segbase, | |
244 | u64 *fde_count) | |
245 | { | |
246 | struct eh_frame_hdr hdr; | |
247 | u8 *enc = (u8 *) &hdr.enc; | |
248 | u8 *end = (u8 *) &hdr.data; | |
249 | ssize_t r; | |
250 | ||
251 | r = dso__data_read_offset(dso, machine, offset, | |
252 | (u8 *) &hdr, sizeof(hdr)); | |
253 | if (r != sizeof(hdr)) | |
254 | return -EINVAL; | |
255 | ||
256 | /* We dont need eh_frame_ptr, just skip it. */ | |
257 | dw_read_encoded_value(enc, end, hdr.eh_frame_ptr_enc); | |
258 | ||
259 | *fde_count = dw_read_encoded_value(enc, end, hdr.fde_count_enc); | |
260 | *segbase = offset; | |
261 | *table_data = (enc - (u8 *) &hdr) + offset; | |
262 | return 0; | |
263 | } | |
264 | ||
ab255e72 JP |
265 | static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine, |
266 | u64 *table_data, u64 *segbase, | |
267 | u64 *fde_count) | |
71ad0f5e JO |
268 | { |
269 | int ret = -EINVAL, fd; | |
303cb89a | 270 | u64 offset = dso->data.eh_frame_hdr_offset; |
71ad0f5e | 271 | |
f1f13af9 | 272 | if (offset == 0) { |
4bb11d01 | 273 | fd = dso__data_get_fd(dso, machine); |
f1f13af9 NK |
274 | if (fd < 0) |
275 | return -EINVAL; | |
71ad0f5e | 276 | |
f1f13af9 NK |
277 | /* Check the .eh_frame section for unwinding info */ |
278 | offset = elf_section_offset(fd, ".eh_frame_hdr"); | |
303cb89a | 279 | dso->data.eh_frame_hdr_offset = offset; |
4bb11d01 | 280 | dso__data_put_fd(dso); |
f1f13af9 | 281 | } |
71ad0f5e JO |
282 | |
283 | if (offset) | |
284 | ret = unwind_spec_ehframe(dso, machine, offset, | |
285 | table_data, segbase, | |
286 | fde_count); | |
287 | ||
71ad0f5e JO |
288 | return ret; |
289 | } | |
290 | ||
ab255e72 JP |
291 | #ifndef NO_LIBUNWIND_DEBUG_FRAME |
292 | static int read_unwind_spec_debug_frame(struct dso *dso, | |
293 | struct machine *machine, u64 *offset) | |
294 | { | |
f1f13af9 | 295 | int fd; |
303cb89a | 296 | u64 ofs = dso->data.debug_frame_offset; |
ab255e72 | 297 | |
f1f13af9 | 298 | if (ofs == 0) { |
4bb11d01 | 299 | fd = dso__data_get_fd(dso, machine); |
f1f13af9 NK |
300 | if (fd < 0) |
301 | return -EINVAL; | |
ab255e72 | 302 | |
f1f13af9 NK |
303 | /* Check the .debug_frame section for unwinding info */ |
304 | ofs = elf_section_offset(fd, ".debug_frame"); | |
303cb89a | 305 | dso->data.debug_frame_offset = ofs; |
4bb11d01 | 306 | dso__data_put_fd(dso); |
f1f13af9 | 307 | } |
ab255e72 | 308 | |
f1f13af9 | 309 | *offset = ofs; |
ab255e72 JP |
310 | if (*offset) |
311 | return 0; | |
312 | ||
313 | return -EINVAL; | |
314 | } | |
315 | #endif | |
316 | ||
71ad0f5e JO |
317 | static struct map *find_map(unw_word_t ip, struct unwind_info *ui) |
318 | { | |
319 | struct addr_location al; | |
320 | ||
bb871a9c | 321 | thread__find_addr_map(ui->thread, PERF_RECORD_MISC_USER, |
326f59bf | 322 | MAP__FUNCTION, ip, &al); |
0ddf5246 JO |
323 | if (!al.map) { |
324 | /* | |
325 | * We've seen cases (softice) where DWARF unwinder went | |
326 | * through non executable mmaps, which we need to lookup | |
327 | * in MAP__VARIABLE tree. | |
328 | */ | |
329 | thread__find_addr_map(ui->thread, PERF_RECORD_MISC_USER, | |
330 | MAP__VARIABLE, ip, &al); | |
331 | } | |
71ad0f5e JO |
332 | return al.map; |
333 | } | |
334 | ||
335 | static int | |
336 | find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi, | |
337 | int need_unwind_info, void *arg) | |
338 | { | |
339 | struct unwind_info *ui = arg; | |
340 | struct map *map; | |
341 | unw_dyn_info_t di; | |
342 | u64 table_data, segbase, fde_count; | |
8eac1d5e | 343 | int ret = -EINVAL; |
71ad0f5e JO |
344 | |
345 | map = find_map(ip, ui); | |
346 | if (!map || !map->dso) | |
347 | return -EINVAL; | |
348 | ||
349 | pr_debug("unwind: find_proc_info dso %s\n", map->dso->name); | |
350 | ||
ab255e72 JP |
351 | /* Check the .eh_frame section for unwinding info */ |
352 | if (!read_unwind_spec_eh_frame(map->dso, ui->machine, | |
353 | &table_data, &segbase, &fde_count)) { | |
354 | memset(&di, 0, sizeof(di)); | |
355 | di.format = UNW_INFO_FORMAT_REMOTE_TABLE; | |
356 | di.start_ip = map->start; | |
357 | di.end_ip = map->end; | |
358 | di.u.rti.segbase = map->start + segbase; | |
359 | di.u.rti.table_data = map->start + table_data; | |
360 | di.u.rti.table_len = fde_count * sizeof(struct table_entry) | |
361 | / sizeof(unw_word_t); | |
8eac1d5e RV |
362 | ret = dwarf_search_unwind_table(as, ip, &di, pi, |
363 | need_unwind_info, arg); | |
ab255e72 JP |
364 | } |
365 | ||
366 | #ifndef NO_LIBUNWIND_DEBUG_FRAME | |
367 | /* Check the .debug_frame section for unwinding info */ | |
8eac1d5e RV |
368 | if (ret < 0 && |
369 | !read_unwind_spec_debug_frame(map->dso, ui->machine, &segbase)) { | |
4bb11d01 | 370 | int fd = dso__data_get_fd(map->dso, ui->machine); |
b93b0967 WN |
371 | int is_exec = elf_is_exec(fd, map->dso->name); |
372 | unw_word_t base = is_exec ? 0 : map->start; | |
7ed4915a | 373 | const char *symfile; |
b93b0967 | 374 | |
4bb11d01 | 375 | if (fd >= 0) |
f005813a | 376 | dso__data_put_fd(map->dso); |
4bb11d01 | 377 | |
7ed4915a RV |
378 | symfile = map->dso->symsrc_filename ?: map->dso->name; |
379 | ||
ab255e72 | 380 | memset(&di, 0, sizeof(di)); |
7ed4915a | 381 | if (dwarf_find_debug_frame(0, &di, ip, base, symfile, |
d11416e7 JP |
382 | map->start, map->end)) |
383 | return dwarf_search_unwind_table(as, ip, &di, pi, | |
384 | need_unwind_info, arg); | |
ab255e72 JP |
385 | } |
386 | #endif | |
71ad0f5e | 387 | |
8eac1d5e | 388 | return ret; |
71ad0f5e JO |
389 | } |
390 | ||
1d037ca1 IT |
391 | static int access_fpreg(unw_addr_space_t __maybe_unused as, |
392 | unw_regnum_t __maybe_unused num, | |
393 | unw_fpreg_t __maybe_unused *val, | |
394 | int __maybe_unused __write, | |
395 | void __maybe_unused *arg) | |
71ad0f5e JO |
396 | { |
397 | pr_err("unwind: access_fpreg unsupported\n"); | |
398 | return -UNW_EINVAL; | |
399 | } | |
400 | ||
1d037ca1 IT |
401 | static int get_dyn_info_list_addr(unw_addr_space_t __maybe_unused as, |
402 | unw_word_t __maybe_unused *dil_addr, | |
403 | void __maybe_unused *arg) | |
71ad0f5e JO |
404 | { |
405 | return -UNW_ENOINFO; | |
406 | } | |
407 | ||
1d037ca1 IT |
408 | static int resume(unw_addr_space_t __maybe_unused as, |
409 | unw_cursor_t __maybe_unused *cu, | |
410 | void __maybe_unused *arg) | |
71ad0f5e JO |
411 | { |
412 | pr_err("unwind: resume unsupported\n"); | |
413 | return -UNW_EINVAL; | |
414 | } | |
415 | ||
416 | static int | |
1d037ca1 IT |
417 | get_proc_name(unw_addr_space_t __maybe_unused as, |
418 | unw_word_t __maybe_unused addr, | |
419 | char __maybe_unused *bufp, size_t __maybe_unused buf_len, | |
420 | unw_word_t __maybe_unused *offp, void __maybe_unused *arg) | |
71ad0f5e JO |
421 | { |
422 | pr_err("unwind: get_proc_name unsupported\n"); | |
423 | return -UNW_EINVAL; | |
424 | } | |
425 | ||
426 | static int access_dso_mem(struct unwind_info *ui, unw_word_t addr, | |
427 | unw_word_t *data) | |
428 | { | |
f22ed827 | 429 | struct map *map; |
71ad0f5e JO |
430 | ssize_t size; |
431 | ||
f22ed827 JO |
432 | map = find_map(addr, ui); |
433 | if (!map) { | |
71ad0f5e JO |
434 | pr_debug("unwind: no map for %lx\n", (unsigned long)addr); |
435 | return -1; | |
436 | } | |
437 | ||
f22ed827 | 438 | if (!map->dso) |
71ad0f5e JO |
439 | return -1; |
440 | ||
f22ed827 | 441 | size = dso__data_read_addr(map->dso, map, ui->machine, |
71ad0f5e JO |
442 | addr, (u8 *) data, sizeof(*data)); |
443 | ||
444 | return !(size == sizeof(*data)); | |
445 | } | |
446 | ||
1d037ca1 | 447 | static int access_mem(unw_addr_space_t __maybe_unused as, |
71ad0f5e JO |
448 | unw_word_t addr, unw_word_t *valp, |
449 | int __write, void *arg) | |
450 | { | |
451 | struct unwind_info *ui = arg; | |
452 | struct stack_dump *stack = &ui->sample->user_stack; | |
c9b951c4 | 453 | u64 start, end; |
71ad0f5e JO |
454 | int offset; |
455 | int ret; | |
456 | ||
457 | /* Don't support write, probably not needed. */ | |
458 | if (__write || !stack || !ui->sample->user_regs.regs) { | |
459 | *valp = 0; | |
460 | return 0; | |
461 | } | |
462 | ||
c9b951c4 | 463 | ret = perf_reg_value(&start, &ui->sample->user_regs, PERF_REG_SP); |
71ad0f5e JO |
464 | if (ret) |
465 | return ret; | |
466 | ||
467 | end = start + stack->size; | |
468 | ||
469 | /* Check overflow. */ | |
470 | if (addr + sizeof(unw_word_t) < addr) | |
471 | return -EINVAL; | |
472 | ||
473 | if (addr < start || addr + sizeof(unw_word_t) >= end) { | |
474 | ret = access_dso_mem(ui, addr, valp); | |
475 | if (ret) { | |
c9b951c4 JO |
476 | pr_debug("unwind: access_mem %p not inside range" |
477 | " 0x%" PRIx64 "-0x%" PRIx64 "\n", | |
186c6cfb | 478 | (void *) (uintptr_t) addr, start, end); |
71ad0f5e JO |
479 | *valp = 0; |
480 | return ret; | |
481 | } | |
482 | return 0; | |
483 | } | |
484 | ||
485 | offset = addr - start; | |
486 | *valp = *(unw_word_t *)&stack->data[offset]; | |
c9b951c4 | 487 | pr_debug("unwind: access_mem addr %p val %lx, offset %d\n", |
186c6cfb | 488 | (void *) (uintptr_t) addr, (unsigned long)*valp, offset); |
71ad0f5e JO |
489 | return 0; |
490 | } | |
491 | ||
1d037ca1 | 492 | static int access_reg(unw_addr_space_t __maybe_unused as, |
71ad0f5e JO |
493 | unw_regnum_t regnum, unw_word_t *valp, |
494 | int __write, void *arg) | |
495 | { | |
496 | struct unwind_info *ui = arg; | |
497 | int id, ret; | |
c9b951c4 | 498 | u64 val; |
71ad0f5e JO |
499 | |
500 | /* Don't support write, I suspect we don't need it. */ | |
501 | if (__write) { | |
502 | pr_err("unwind: access_reg w %d\n", regnum); | |
503 | return 0; | |
504 | } | |
505 | ||
506 | if (!ui->sample->user_regs.regs) { | |
507 | *valp = 0; | |
508 | return 0; | |
509 | } | |
510 | ||
ea3da69d | 511 | id = libunwind__arch_reg_id(regnum); |
71ad0f5e JO |
512 | if (id < 0) |
513 | return -EINVAL; | |
514 | ||
c9b951c4 | 515 | ret = perf_reg_value(&val, &ui->sample->user_regs, id); |
71ad0f5e JO |
516 | if (ret) { |
517 | pr_err("unwind: can't read reg %d\n", regnum); | |
518 | return ret; | |
519 | } | |
520 | ||
c9b951c4 | 521 | *valp = (unw_word_t) val; |
71ad0f5e JO |
522 | pr_debug("unwind: reg %d, val %lx\n", regnum, (unsigned long)*valp); |
523 | return 0; | |
524 | } | |
525 | ||
1d037ca1 IT |
526 | static void put_unwind_info(unw_addr_space_t __maybe_unused as, |
527 | unw_proc_info_t *pi __maybe_unused, | |
528 | void *arg __maybe_unused) | |
71ad0f5e JO |
529 | { |
530 | pr_debug("unwind: put_unwind_info called\n"); | |
531 | } | |
532 | ||
bb871a9c | 533 | static int entry(u64 ip, struct thread *thread, |
71ad0f5e JO |
534 | unwind_entry_cb_t cb, void *arg) |
535 | { | |
536 | struct unwind_entry e; | |
537 | struct addr_location al; | |
538 | ||
bb871a9c | 539 | thread__find_addr_location(thread, PERF_RECORD_MISC_USER, |
61710bde | 540 | MAP__FUNCTION, ip, &al); |
71ad0f5e JO |
541 | |
542 | e.ip = ip; | |
543 | e.map = al.map; | |
544 | e.sym = al.sym; | |
545 | ||
546 | pr_debug("unwind: %s:ip = 0x%" PRIx64 " (0x%" PRIx64 ")\n", | |
547 | al.sym ? al.sym->name : "''", | |
548 | ip, | |
549 | al.map ? al.map->map_ip(al.map, ip) : (u64) 0); | |
550 | ||
551 | return cb(&e, arg); | |
552 | } | |
553 | ||
554 | static void display_error(int err) | |
555 | { | |
556 | switch (err) { | |
557 | case UNW_EINVAL: | |
558 | pr_err("unwind: Only supports local.\n"); | |
559 | break; | |
560 | case UNW_EUNSPEC: | |
561 | pr_err("unwind: Unspecified error.\n"); | |
562 | break; | |
563 | case UNW_EBADREG: | |
564 | pr_err("unwind: Register unavailable.\n"); | |
565 | break; | |
566 | default: | |
567 | break; | |
568 | } | |
569 | } | |
570 | ||
571 | static unw_accessors_t accessors = { | |
572 | .find_proc_info = find_proc_info, | |
573 | .put_unwind_info = put_unwind_info, | |
574 | .get_dyn_info_list_addr = get_dyn_info_list_addr, | |
575 | .access_mem = access_mem, | |
576 | .access_reg = access_reg, | |
577 | .access_fpreg = access_fpreg, | |
578 | .resume = resume, | |
579 | .get_proc_name = get_proc_name, | |
580 | }; | |
581 | ||
66f066d8 | 582 | int unwind__prepare_access(struct thread *thread) |
71ad0f5e | 583 | { |
66f066d8 NK |
584 | if (callchain_param.record_mode != CALLCHAIN_DWARF) |
585 | return 0; | |
71ad0f5e | 586 | |
e583d70c JO |
587 | thread->addr_space = unw_create_addr_space(&accessors, 0); |
588 | if (!thread->addr_space) { | |
71ad0f5e JO |
589 | pr_err("unwind: Can't create unwind address space.\n"); |
590 | return -ENOMEM; | |
591 | } | |
592 | ||
e583d70c | 593 | unw_set_caching_policy(thread->addr_space, UNW_CACHE_GLOBAL); |
66f066d8 NK |
594 | return 0; |
595 | } | |
596 | ||
380b5143 NK |
597 | void unwind__flush_access(struct thread *thread) |
598 | { | |
380b5143 NK |
599 | if (callchain_param.record_mode != CALLCHAIN_DWARF) |
600 | return; | |
601 | ||
e583d70c | 602 | unw_flush_cache(thread->addr_space, 0, 0); |
380b5143 NK |
603 | } |
604 | ||
66f066d8 NK |
605 | void unwind__finish_access(struct thread *thread) |
606 | { | |
66f066d8 NK |
607 | if (callchain_param.record_mode != CALLCHAIN_DWARF) |
608 | return; | |
609 | ||
e583d70c | 610 | unw_destroy_addr_space(thread->addr_space); |
66f066d8 NK |
611 | } |
612 | ||
613 | static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb, | |
614 | void *arg, int max_stack) | |
615 | { | |
b26b218a | 616 | u64 val; |
cb1dc22d | 617 | unw_word_t ips[max_stack]; |
66f066d8 NK |
618 | unw_addr_space_t addr_space; |
619 | unw_cursor_t c; | |
cb1dc22d | 620 | int ret, i = 0; |
66f066d8 | 621 | |
b26b218a JO |
622 | ret = perf_reg_value(&val, &ui->sample->user_regs, PERF_REG_IP); |
623 | if (ret) | |
624 | return ret; | |
625 | ||
cb1dc22d | 626 | ips[i++] = (unw_word_t) val; |
b26b218a | 627 | |
cb1dc22d JO |
628 | /* |
629 | * If we need more than one entry, do the DWARF | |
630 | * unwind itself. | |
631 | */ | |
632 | if (max_stack - 1 > 0) { | |
e583d70c JO |
633 | WARN_ONCE(!ui->thread, "WARNING: ui->thread is NULL"); |
634 | addr_space = ui->thread->addr_space; | |
635 | ||
cb1dc22d JO |
636 | if (addr_space == NULL) |
637 | return -1; | |
638 | ||
639 | ret = unw_init_remote(&c, addr_space, ui); | |
640 | if (ret) | |
641 | display_error(ret); | |
642 | ||
643 | while (!ret && (unw_step(&c) > 0) && i < max_stack) { | |
644 | unw_get_reg(&c, UNW_REG_IP, &ips[i]); | |
645 | ++i; | |
646 | } | |
66f066d8 | 647 | |
cb1dc22d JO |
648 | max_stack = i; |
649 | } | |
71ad0f5e | 650 | |
cb1dc22d JO |
651 | /* |
652 | * Display what we got based on the order setup. | |
653 | */ | |
654 | for (i = 0; i < max_stack && !ret; i++) { | |
655 | int j = i; | |
71ad0f5e | 656 | |
cb1dc22d JO |
657 | if (callchain_param.order == ORDER_CALLER) |
658 | j = max_stack - i - 1; | |
659 | ret = ips[j] ? entry(ips[j], ui->thread, cb, arg) : 0; | |
71ad0f5e JO |
660 | } |
661 | ||
71ad0f5e JO |
662 | return ret; |
663 | } | |
664 | ||
665 | int unwind__get_entries(unwind_entry_cb_t cb, void *arg, | |
dd8c17a5 | 666 | struct thread *thread, |
352ea45a | 667 | struct perf_sample *data, int max_stack) |
71ad0f5e | 668 | { |
71ad0f5e JO |
669 | struct unwind_info ui = { |
670 | .sample = data, | |
71ad0f5e | 671 | .thread = thread, |
dd8c17a5 | 672 | .machine = thread->mg->machine, |
71ad0f5e | 673 | }; |
71ad0f5e JO |
674 | |
675 | if (!data->user_regs.regs) | |
676 | return -EINVAL; | |
677 | ||
b26b218a JO |
678 | if (max_stack <= 0) |
679 | return -EINVAL; | |
71ad0f5e | 680 | |
b26b218a | 681 | return get_entries(&ui, cb, arg, max_stack); |
71ad0f5e | 682 | } |