Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 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> |
| 27 | #include "thread.h" |
| 28 | #include "session.h" |
| 29 | #include "perf_regs.h" |
| 30 | #include "unwind.h" |
Masami Hiramatsu | 99ca423 | 2014-01-16 09:39:49 +0000 | [diff] [blame] | 31 | #include "symbol.h" |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 32 | #include "util.h" |
| 33 | |
| 34 | extern int |
| 35 | UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as, |
| 36 | unw_word_t ip, |
| 37 | unw_dyn_info_t *di, |
| 38 | unw_proc_info_t *pi, |
| 39 | int need_unwind_info, void *arg); |
| 40 | |
| 41 | #define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table) |
| 42 | |
Jean Pihet | ab255e7 | 2013-09-26 12:36:38 +0100 | [diff] [blame] | 43 | extern int |
| 44 | UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug, |
| 45 | unw_word_t ip, |
| 46 | unw_word_t segbase, |
| 47 | const char *obj_name, unw_word_t start, |
| 48 | unw_word_t end); |
| 49 | |
| 50 | #define dwarf_find_debug_frame UNW_OBJ(dwarf_find_debug_frame) |
| 51 | |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 52 | #define DW_EH_PE_FORMAT_MASK 0x0f /* format of the encoded value */ |
| 53 | #define DW_EH_PE_APPL_MASK 0x70 /* how the value is to be applied */ |
| 54 | |
| 55 | /* Pointer-encoding formats: */ |
| 56 | #define DW_EH_PE_omit 0xff |
| 57 | #define DW_EH_PE_ptr 0x00 /* pointer-sized unsigned value */ |
| 58 | #define DW_EH_PE_udata4 0x03 /* unsigned 32-bit value */ |
| 59 | #define DW_EH_PE_udata8 0x04 /* unsigned 64-bit value */ |
| 60 | #define DW_EH_PE_sdata4 0x0b /* signed 32-bit value */ |
| 61 | #define DW_EH_PE_sdata8 0x0c /* signed 64-bit value */ |
| 62 | |
| 63 | /* Pointer-encoding application: */ |
| 64 | #define DW_EH_PE_absptr 0x00 /* absolute value */ |
| 65 | #define DW_EH_PE_pcrel 0x10 /* rel. to addr. of encoded value */ |
| 66 | |
| 67 | /* |
| 68 | * The following are not documented by LSB v1.3, yet they are used by |
| 69 | * GCC, presumably they aren't documented by LSB since they aren't |
| 70 | * used on Linux: |
| 71 | */ |
| 72 | #define DW_EH_PE_funcrel 0x40 /* start-of-procedure-relative */ |
| 73 | #define DW_EH_PE_aligned 0x50 /* aligned pointer */ |
| 74 | |
| 75 | /* Flags intentionaly not handled, since they're not needed: |
| 76 | * #define DW_EH_PE_indirect 0x80 |
| 77 | * #define DW_EH_PE_uleb128 0x01 |
| 78 | * #define DW_EH_PE_udata2 0x02 |
| 79 | * #define DW_EH_PE_sleb128 0x09 |
| 80 | * #define DW_EH_PE_sdata2 0x0a |
| 81 | * #define DW_EH_PE_textrel 0x20 |
| 82 | * #define DW_EH_PE_datarel 0x30 |
| 83 | */ |
| 84 | |
| 85 | struct unwind_info { |
| 86 | struct perf_sample *sample; |
| 87 | struct machine *machine; |
| 88 | struct thread *thread; |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 89 | }; |
| 90 | |
| 91 | #define dw_read(ptr, type, end) ({ \ |
| 92 | type *__p = (type *) ptr; \ |
| 93 | type __v; \ |
| 94 | if ((__p + 1) > (type *) end) \ |
| 95 | return -EINVAL; \ |
| 96 | __v = *__p++; \ |
| 97 | ptr = (typeof(ptr)) __p; \ |
| 98 | __v; \ |
| 99 | }) |
| 100 | |
| 101 | static int __dw_read_encoded_value(u8 **p, u8 *end, u64 *val, |
| 102 | u8 encoding) |
| 103 | { |
| 104 | u8 *cur = *p; |
| 105 | *val = 0; |
| 106 | |
| 107 | switch (encoding) { |
| 108 | case DW_EH_PE_omit: |
| 109 | *val = 0; |
| 110 | goto out; |
| 111 | case DW_EH_PE_ptr: |
| 112 | *val = dw_read(cur, unsigned long, end); |
| 113 | goto out; |
| 114 | default: |
| 115 | break; |
| 116 | } |
| 117 | |
| 118 | switch (encoding & DW_EH_PE_APPL_MASK) { |
| 119 | case DW_EH_PE_absptr: |
| 120 | break; |
| 121 | case DW_EH_PE_pcrel: |
| 122 | *val = (unsigned long) cur; |
| 123 | break; |
| 124 | default: |
| 125 | return -EINVAL; |
| 126 | } |
| 127 | |
| 128 | if ((encoding & 0x07) == 0x00) |
| 129 | encoding |= DW_EH_PE_udata4; |
| 130 | |
| 131 | switch (encoding & DW_EH_PE_FORMAT_MASK) { |
| 132 | case DW_EH_PE_sdata4: |
| 133 | *val += dw_read(cur, s32, end); |
| 134 | break; |
| 135 | case DW_EH_PE_udata4: |
| 136 | *val += dw_read(cur, u32, end); |
| 137 | break; |
| 138 | case DW_EH_PE_sdata8: |
| 139 | *val += dw_read(cur, s64, end); |
| 140 | break; |
| 141 | case DW_EH_PE_udata8: |
| 142 | *val += dw_read(cur, u64, end); |
| 143 | break; |
| 144 | default: |
| 145 | return -EINVAL; |
| 146 | } |
| 147 | |
| 148 | out: |
| 149 | *p = cur; |
| 150 | return 0; |
| 151 | } |
| 152 | |
| 153 | #define dw_read_encoded_value(ptr, end, enc) ({ \ |
| 154 | u64 __v; \ |
| 155 | if (__dw_read_encoded_value(&ptr, end, &__v, enc)) { \ |
| 156 | return -EINVAL; \ |
| 157 | } \ |
| 158 | __v; \ |
| 159 | }) |
| 160 | |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 161 | static u64 elf_section_offset(int fd, const char *name) |
| 162 | { |
| 163 | Elf *elf; |
| 164 | GElf_Ehdr ehdr; |
| 165 | GElf_Shdr shdr; |
| 166 | u64 offset = 0; |
| 167 | |
| 168 | elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); |
| 169 | if (elf == NULL) |
| 170 | return 0; |
| 171 | |
| 172 | do { |
| 173 | if (gelf_getehdr(elf, &ehdr) == NULL) |
| 174 | break; |
| 175 | |
Masami Hiramatsu | 99ca423 | 2014-01-16 09:39:49 +0000 | [diff] [blame] | 176 | if (!elf_section_by_name(elf, &ehdr, &shdr, name, NULL)) |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 177 | break; |
| 178 | |
| 179 | offset = shdr.sh_offset; |
| 180 | } while (0); |
| 181 | |
| 182 | elf_end(elf); |
| 183 | return offset; |
| 184 | } |
| 185 | |
| 186 | struct table_entry { |
| 187 | u32 start_ip_offset; |
| 188 | u32 fde_offset; |
| 189 | }; |
| 190 | |
| 191 | struct eh_frame_hdr { |
| 192 | unsigned char version; |
| 193 | unsigned char eh_frame_ptr_enc; |
| 194 | unsigned char fde_count_enc; |
| 195 | unsigned char table_enc; |
| 196 | |
| 197 | /* |
| 198 | * The rest of the header is variable-length and consists of the |
| 199 | * following members: |
| 200 | * |
| 201 | * encoded_t eh_frame_ptr; |
| 202 | * encoded_t fde_count; |
| 203 | */ |
| 204 | |
| 205 | /* A single encoded pointer should not be more than 8 bytes. */ |
| 206 | u64 enc[2]; |
| 207 | |
| 208 | /* |
| 209 | * struct { |
| 210 | * encoded_t start_ip; |
| 211 | * encoded_t fde_addr; |
| 212 | * } binary_search_table[fde_count]; |
| 213 | */ |
| 214 | char data[0]; |
| 215 | } __packed; |
| 216 | |
| 217 | static int unwind_spec_ehframe(struct dso *dso, struct machine *machine, |
| 218 | u64 offset, u64 *table_data, u64 *segbase, |
| 219 | u64 *fde_count) |
| 220 | { |
| 221 | struct eh_frame_hdr hdr; |
| 222 | u8 *enc = (u8 *) &hdr.enc; |
| 223 | u8 *end = (u8 *) &hdr.data; |
| 224 | ssize_t r; |
| 225 | |
| 226 | r = dso__data_read_offset(dso, machine, offset, |
| 227 | (u8 *) &hdr, sizeof(hdr)); |
| 228 | if (r != sizeof(hdr)) |
| 229 | return -EINVAL; |
| 230 | |
| 231 | /* We dont need eh_frame_ptr, just skip it. */ |
| 232 | dw_read_encoded_value(enc, end, hdr.eh_frame_ptr_enc); |
| 233 | |
| 234 | *fde_count = dw_read_encoded_value(enc, end, hdr.fde_count_enc); |
| 235 | *segbase = offset; |
| 236 | *table_data = (enc - (u8 *) &hdr) + offset; |
| 237 | return 0; |
| 238 | } |
| 239 | |
Jean Pihet | ab255e7 | 2013-09-26 12:36:38 +0100 | [diff] [blame] | 240 | static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine, |
| 241 | u64 *table_data, u64 *segbase, |
| 242 | u64 *fde_count) |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 243 | { |
| 244 | int ret = -EINVAL, fd; |
| 245 | u64 offset; |
| 246 | |
| 247 | fd = dso__data_fd(dso, machine); |
| 248 | if (fd < 0) |
| 249 | return -EINVAL; |
| 250 | |
Jean Pihet | ab255e7 | 2013-09-26 12:36:38 +0100 | [diff] [blame] | 251 | /* Check the .eh_frame section for unwinding info */ |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 252 | offset = elf_section_offset(fd, ".eh_frame_hdr"); |
| 253 | close(fd); |
| 254 | |
| 255 | if (offset) |
| 256 | ret = unwind_spec_ehframe(dso, machine, offset, |
| 257 | table_data, segbase, |
| 258 | fde_count); |
| 259 | |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 260 | return ret; |
| 261 | } |
| 262 | |
Jean Pihet | ab255e7 | 2013-09-26 12:36:38 +0100 | [diff] [blame] | 263 | #ifndef NO_LIBUNWIND_DEBUG_FRAME |
| 264 | static int read_unwind_spec_debug_frame(struct dso *dso, |
| 265 | struct machine *machine, u64 *offset) |
| 266 | { |
| 267 | int fd = dso__data_fd(dso, machine); |
| 268 | |
| 269 | if (fd < 0) |
| 270 | return -EINVAL; |
| 271 | |
| 272 | /* Check the .debug_frame section for unwinding info */ |
| 273 | *offset = elf_section_offset(fd, ".debug_frame"); |
| 274 | close(fd); |
| 275 | |
| 276 | if (*offset) |
| 277 | return 0; |
| 278 | |
| 279 | return -EINVAL; |
| 280 | } |
| 281 | #endif |
| 282 | |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 283 | static struct map *find_map(unw_word_t ip, struct unwind_info *ui) |
| 284 | { |
| 285 | struct addr_location al; |
| 286 | |
| 287 | thread__find_addr_map(ui->thread, ui->machine, PERF_RECORD_MISC_USER, |
Adrian Hunter | 326f59b | 2013-08-08 14:32:27 +0300 | [diff] [blame] | 288 | MAP__FUNCTION, ip, &al); |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 289 | return al.map; |
| 290 | } |
| 291 | |
| 292 | static int |
| 293 | find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi, |
| 294 | int need_unwind_info, void *arg) |
| 295 | { |
| 296 | struct unwind_info *ui = arg; |
| 297 | struct map *map; |
| 298 | unw_dyn_info_t di; |
| 299 | u64 table_data, segbase, fde_count; |
| 300 | |
| 301 | map = find_map(ip, ui); |
| 302 | if (!map || !map->dso) |
| 303 | return -EINVAL; |
| 304 | |
| 305 | pr_debug("unwind: find_proc_info dso %s\n", map->dso->name); |
| 306 | |
Jean Pihet | ab255e7 | 2013-09-26 12:36:38 +0100 | [diff] [blame] | 307 | /* Check the .eh_frame section for unwinding info */ |
| 308 | if (!read_unwind_spec_eh_frame(map->dso, ui->machine, |
| 309 | &table_data, &segbase, &fde_count)) { |
| 310 | memset(&di, 0, sizeof(di)); |
| 311 | di.format = UNW_INFO_FORMAT_REMOTE_TABLE; |
| 312 | di.start_ip = map->start; |
| 313 | di.end_ip = map->end; |
| 314 | di.u.rti.segbase = map->start + segbase; |
| 315 | di.u.rti.table_data = map->start + table_data; |
| 316 | di.u.rti.table_len = fde_count * sizeof(struct table_entry) |
| 317 | / sizeof(unw_word_t); |
| 318 | return dwarf_search_unwind_table(as, ip, &di, pi, |
| 319 | need_unwind_info, arg); |
| 320 | } |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 321 | |
Jean Pihet | ab255e7 | 2013-09-26 12:36:38 +0100 | [diff] [blame] | 322 | #ifndef NO_LIBUNWIND_DEBUG_FRAME |
| 323 | /* Check the .debug_frame section for unwinding info */ |
| 324 | if (!read_unwind_spec_debug_frame(map->dso, ui->machine, &segbase)) { |
| 325 | memset(&di, 0, sizeof(di)); |
Jean Pihet | d11416e | 2013-12-16 17:43:14 +0100 | [diff] [blame] | 326 | if (dwarf_find_debug_frame(0, &di, ip, 0, map->dso->name, |
| 327 | map->start, map->end)) |
| 328 | return dwarf_search_unwind_table(as, ip, &di, pi, |
| 329 | need_unwind_info, arg); |
Jean Pihet | ab255e7 | 2013-09-26 12:36:38 +0100 | [diff] [blame] | 330 | } |
| 331 | #endif |
| 332 | |
| 333 | return -EINVAL; |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 334 | } |
| 335 | |
Irina Tirdea | 1d037ca | 2012-09-11 01:15:03 +0300 | [diff] [blame] | 336 | static int access_fpreg(unw_addr_space_t __maybe_unused as, |
| 337 | unw_regnum_t __maybe_unused num, |
| 338 | unw_fpreg_t __maybe_unused *val, |
| 339 | int __maybe_unused __write, |
| 340 | void __maybe_unused *arg) |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 341 | { |
| 342 | pr_err("unwind: access_fpreg unsupported\n"); |
| 343 | return -UNW_EINVAL; |
| 344 | } |
| 345 | |
Irina Tirdea | 1d037ca | 2012-09-11 01:15:03 +0300 | [diff] [blame] | 346 | static int get_dyn_info_list_addr(unw_addr_space_t __maybe_unused as, |
| 347 | unw_word_t __maybe_unused *dil_addr, |
| 348 | void __maybe_unused *arg) |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 349 | { |
| 350 | return -UNW_ENOINFO; |
| 351 | } |
| 352 | |
Irina Tirdea | 1d037ca | 2012-09-11 01:15:03 +0300 | [diff] [blame] | 353 | static int resume(unw_addr_space_t __maybe_unused as, |
| 354 | unw_cursor_t __maybe_unused *cu, |
| 355 | void __maybe_unused *arg) |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 356 | { |
| 357 | pr_err("unwind: resume unsupported\n"); |
| 358 | return -UNW_EINVAL; |
| 359 | } |
| 360 | |
| 361 | static int |
Irina Tirdea | 1d037ca | 2012-09-11 01:15:03 +0300 | [diff] [blame] | 362 | get_proc_name(unw_addr_space_t __maybe_unused as, |
| 363 | unw_word_t __maybe_unused addr, |
| 364 | char __maybe_unused *bufp, size_t __maybe_unused buf_len, |
| 365 | unw_word_t __maybe_unused *offp, void __maybe_unused *arg) |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 366 | { |
| 367 | pr_err("unwind: get_proc_name unsupported\n"); |
| 368 | return -UNW_EINVAL; |
| 369 | } |
| 370 | |
| 371 | static int access_dso_mem(struct unwind_info *ui, unw_word_t addr, |
| 372 | unw_word_t *data) |
| 373 | { |
| 374 | struct addr_location al; |
| 375 | ssize_t size; |
| 376 | |
| 377 | thread__find_addr_map(ui->thread, ui->machine, PERF_RECORD_MISC_USER, |
Adrian Hunter | 326f59b | 2013-08-08 14:32:27 +0300 | [diff] [blame] | 378 | MAP__FUNCTION, addr, &al); |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 379 | if (!al.map) { |
| 380 | pr_debug("unwind: no map for %lx\n", (unsigned long)addr); |
| 381 | return -1; |
| 382 | } |
| 383 | |
| 384 | if (!al.map->dso) |
| 385 | return -1; |
| 386 | |
| 387 | size = dso__data_read_addr(al.map->dso, al.map, ui->machine, |
| 388 | addr, (u8 *) data, sizeof(*data)); |
| 389 | |
| 390 | return !(size == sizeof(*data)); |
| 391 | } |
| 392 | |
Irina Tirdea | 1d037ca | 2012-09-11 01:15:03 +0300 | [diff] [blame] | 393 | static int access_mem(unw_addr_space_t __maybe_unused as, |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 394 | unw_word_t addr, unw_word_t *valp, |
| 395 | int __write, void *arg) |
| 396 | { |
| 397 | struct unwind_info *ui = arg; |
| 398 | struct stack_dump *stack = &ui->sample->user_stack; |
Jiri Olsa | c9b951c | 2014-01-07 13:47:29 +0100 | [diff] [blame] | 399 | u64 start, end; |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 400 | int offset; |
| 401 | int ret; |
| 402 | |
| 403 | /* Don't support write, probably not needed. */ |
| 404 | if (__write || !stack || !ui->sample->user_regs.regs) { |
| 405 | *valp = 0; |
| 406 | return 0; |
| 407 | } |
| 408 | |
Jiri Olsa | c9b951c | 2014-01-07 13:47:29 +0100 | [diff] [blame] | 409 | ret = perf_reg_value(&start, &ui->sample->user_regs, PERF_REG_SP); |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 410 | if (ret) |
| 411 | return ret; |
| 412 | |
| 413 | end = start + stack->size; |
| 414 | |
| 415 | /* Check overflow. */ |
| 416 | if (addr + sizeof(unw_word_t) < addr) |
| 417 | return -EINVAL; |
| 418 | |
| 419 | if (addr < start || addr + sizeof(unw_word_t) >= end) { |
| 420 | ret = access_dso_mem(ui, addr, valp); |
| 421 | if (ret) { |
Jiri Olsa | c9b951c | 2014-01-07 13:47:29 +0100 | [diff] [blame] | 422 | pr_debug("unwind: access_mem %p not inside range" |
| 423 | " 0x%" PRIx64 "-0x%" PRIx64 "\n", |
| 424 | (void *) addr, start, end); |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 425 | *valp = 0; |
| 426 | return ret; |
| 427 | } |
| 428 | return 0; |
| 429 | } |
| 430 | |
| 431 | offset = addr - start; |
| 432 | *valp = *(unw_word_t *)&stack->data[offset]; |
Jiri Olsa | c9b951c | 2014-01-07 13:47:29 +0100 | [diff] [blame] | 433 | pr_debug("unwind: access_mem addr %p val %lx, offset %d\n", |
| 434 | (void *) addr, (unsigned long)*valp, offset); |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 435 | return 0; |
| 436 | } |
| 437 | |
Irina Tirdea | 1d037ca | 2012-09-11 01:15:03 +0300 | [diff] [blame] | 438 | static int access_reg(unw_addr_space_t __maybe_unused as, |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 439 | unw_regnum_t regnum, unw_word_t *valp, |
| 440 | int __write, void *arg) |
| 441 | { |
| 442 | struct unwind_info *ui = arg; |
| 443 | int id, ret; |
Jiri Olsa | c9b951c | 2014-01-07 13:47:29 +0100 | [diff] [blame] | 444 | u64 val; |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 445 | |
| 446 | /* Don't support write, I suspect we don't need it. */ |
| 447 | if (__write) { |
| 448 | pr_err("unwind: access_reg w %d\n", regnum); |
| 449 | return 0; |
| 450 | } |
| 451 | |
| 452 | if (!ui->sample->user_regs.regs) { |
| 453 | *valp = 0; |
| 454 | return 0; |
| 455 | } |
| 456 | |
Jiri Olsa | ea3da69 | 2014-01-07 13:47:27 +0100 | [diff] [blame] | 457 | id = libunwind__arch_reg_id(regnum); |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 458 | if (id < 0) |
| 459 | return -EINVAL; |
| 460 | |
Jiri Olsa | c9b951c | 2014-01-07 13:47:29 +0100 | [diff] [blame] | 461 | ret = perf_reg_value(&val, &ui->sample->user_regs, id); |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 462 | if (ret) { |
| 463 | pr_err("unwind: can't read reg %d\n", regnum); |
| 464 | return ret; |
| 465 | } |
| 466 | |
Jiri Olsa | c9b951c | 2014-01-07 13:47:29 +0100 | [diff] [blame] | 467 | *valp = (unw_word_t) val; |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 468 | pr_debug("unwind: reg %d, val %lx\n", regnum, (unsigned long)*valp); |
| 469 | return 0; |
| 470 | } |
| 471 | |
Irina Tirdea | 1d037ca | 2012-09-11 01:15:03 +0300 | [diff] [blame] | 472 | static void put_unwind_info(unw_addr_space_t __maybe_unused as, |
| 473 | unw_proc_info_t *pi __maybe_unused, |
| 474 | void *arg __maybe_unused) |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 475 | { |
| 476 | pr_debug("unwind: put_unwind_info called\n"); |
| 477 | } |
| 478 | |
| 479 | static int entry(u64 ip, struct thread *thread, struct machine *machine, |
| 480 | unwind_entry_cb_t cb, void *arg) |
| 481 | { |
| 482 | struct unwind_entry e; |
| 483 | struct addr_location al; |
| 484 | |
| 485 | thread__find_addr_location(thread, machine, |
| 486 | PERF_RECORD_MISC_USER, |
Adrian Hunter | 61710bd | 2013-08-08 14:32:26 +0300 | [diff] [blame] | 487 | MAP__FUNCTION, ip, &al); |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 488 | |
| 489 | e.ip = ip; |
| 490 | e.map = al.map; |
| 491 | e.sym = al.sym; |
| 492 | |
| 493 | pr_debug("unwind: %s:ip = 0x%" PRIx64 " (0x%" PRIx64 ")\n", |
| 494 | al.sym ? al.sym->name : "''", |
| 495 | ip, |
| 496 | al.map ? al.map->map_ip(al.map, ip) : (u64) 0); |
| 497 | |
| 498 | return cb(&e, arg); |
| 499 | } |
| 500 | |
| 501 | static void display_error(int err) |
| 502 | { |
| 503 | switch (err) { |
| 504 | case UNW_EINVAL: |
| 505 | pr_err("unwind: Only supports local.\n"); |
| 506 | break; |
| 507 | case UNW_EUNSPEC: |
| 508 | pr_err("unwind: Unspecified error.\n"); |
| 509 | break; |
| 510 | case UNW_EBADREG: |
| 511 | pr_err("unwind: Register unavailable.\n"); |
| 512 | break; |
| 513 | default: |
| 514 | break; |
| 515 | } |
| 516 | } |
| 517 | |
| 518 | static unw_accessors_t accessors = { |
| 519 | .find_proc_info = find_proc_info, |
| 520 | .put_unwind_info = put_unwind_info, |
| 521 | .get_dyn_info_list_addr = get_dyn_info_list_addr, |
| 522 | .access_mem = access_mem, |
| 523 | .access_reg = access_reg, |
| 524 | .access_fpreg = access_fpreg, |
| 525 | .resume = resume, |
| 526 | .get_proc_name = get_proc_name, |
| 527 | }; |
| 528 | |
| 529 | static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb, |
Arnaldo Carvalho de Melo | 37676af | 2013-11-13 17:40:36 -0300 | [diff] [blame] | 530 | void *arg, int max_stack) |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 531 | { |
| 532 | unw_addr_space_t addr_space; |
| 533 | unw_cursor_t c; |
| 534 | int ret; |
| 535 | |
| 536 | addr_space = unw_create_addr_space(&accessors, 0); |
| 537 | if (!addr_space) { |
| 538 | pr_err("unwind: Can't create unwind address space.\n"); |
| 539 | return -ENOMEM; |
| 540 | } |
| 541 | |
| 542 | ret = unw_init_remote(&c, addr_space, ui); |
| 543 | if (ret) |
| 544 | display_error(ret); |
| 545 | |
Arnaldo Carvalho de Melo | 37676af | 2013-11-13 17:40:36 -0300 | [diff] [blame] | 546 | while (!ret && (unw_step(&c) > 0) && max_stack--) { |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 547 | unw_word_t ip; |
| 548 | |
| 549 | unw_get_reg(&c, UNW_REG_IP, &ip); |
Jiri Olsa | 1cf0382 | 2014-01-07 13:47:24 +0100 | [diff] [blame] | 550 | ret = ip ? entry(ip, ui->thread, ui->machine, cb, arg) : 0; |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 551 | } |
| 552 | |
| 553 | unw_destroy_addr_space(addr_space); |
| 554 | return ret; |
| 555 | } |
| 556 | |
| 557 | int unwind__get_entries(unwind_entry_cb_t cb, void *arg, |
| 558 | struct machine *machine, struct thread *thread, |
Jiri Olsa | 352ea45 | 2014-01-07 13:47:25 +0100 | [diff] [blame] | 559 | struct perf_sample *data, int max_stack) |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 560 | { |
Jiri Olsa | c9b951c | 2014-01-07 13:47:29 +0100 | [diff] [blame] | 561 | u64 ip; |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 562 | struct unwind_info ui = { |
| 563 | .sample = data, |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 564 | .thread = thread, |
| 565 | .machine = machine, |
| 566 | }; |
| 567 | int ret; |
| 568 | |
| 569 | if (!data->user_regs.regs) |
| 570 | return -EINVAL; |
| 571 | |
Jiri Olsa | c9b951c | 2014-01-07 13:47:29 +0100 | [diff] [blame] | 572 | ret = perf_reg_value(&ip, &data->user_regs, PERF_REG_IP); |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 573 | if (ret) |
| 574 | return ret; |
| 575 | |
| 576 | ret = entry(ip, thread, machine, cb, arg); |
| 577 | if (ret) |
| 578 | return -ENOMEM; |
| 579 | |
Jiri Olsa | b42dc32d | 2014-01-07 13:47:23 +0100 | [diff] [blame] | 580 | return --max_stack > 0 ? get_entries(&ui, cb, arg, max_stack) : 0; |
Jiri Olsa | 71ad0f5 | 2012-08-07 15:20:46 +0200 | [diff] [blame] | 581 | } |