Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 1 | /* |
| 2 | * jvmti_agent.c: JVMTI agent interface |
| 3 | * |
| 4 | * Adapted from the Oprofile code in opagent.c: |
| 5 | * This library is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU Lesser General Public |
| 7 | * License as published by the Free Software Foundation; either |
| 8 | * version 2.1 of the License, or (at your option) any later version. |
| 9 | * |
| 10 | * This library is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * Lesser General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU Lesser General Public |
| 16 | * License along with this library; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 18 | * |
| 19 | * Copyright 2007 OProfile authors |
| 20 | * Jens Wilke |
| 21 | * Daniel Hansel |
| 22 | * Copyright IBM Corporation 2007 |
| 23 | */ |
| 24 | #include <sys/types.h> |
| 25 | #include <sys/stat.h> /* for mkdir() */ |
| 26 | #include <stdio.h> |
| 27 | #include <errno.h> |
| 28 | #include <string.h> |
| 29 | #include <stdlib.h> |
| 30 | #include <stdint.h> |
| 31 | #include <limits.h> |
| 32 | #include <fcntl.h> |
| 33 | #include <unistd.h> |
| 34 | #include <time.h> |
| 35 | #include <sys/mman.h> |
| 36 | #include <syscall.h> /* for gettid() */ |
| 37 | #include <err.h> |
| 38 | |
| 39 | #include "jvmti_agent.h" |
| 40 | #include "../util/jitdump.h" |
| 41 | |
| 42 | #define JIT_LANG "java" |
| 43 | |
| 44 | static char jit_path[PATH_MAX]; |
| 45 | static void *marker_addr; |
| 46 | |
| 47 | /* |
| 48 | * padding buffer |
| 49 | */ |
| 50 | static const char pad_bytes[7]; |
| 51 | |
| 52 | static inline pid_t gettid(void) |
| 53 | { |
| 54 | return (pid_t)syscall(__NR_gettid); |
| 55 | } |
| 56 | |
| 57 | static int get_e_machine(struct jitheader *hdr) |
| 58 | { |
| 59 | ssize_t sret; |
| 60 | char id[16]; |
| 61 | int fd, ret = -1; |
| 62 | int m = -1; |
| 63 | struct { |
| 64 | uint16_t e_type; |
| 65 | uint16_t e_machine; |
| 66 | } info; |
| 67 | |
| 68 | fd = open("/proc/self/exe", O_RDONLY); |
| 69 | if (fd == -1) |
| 70 | return -1; |
| 71 | |
| 72 | sret = read(fd, id, sizeof(id)); |
| 73 | if (sret != sizeof(id)) |
| 74 | goto error; |
| 75 | |
| 76 | /* check ELF signature */ |
| 77 | if (id[0] != 0x7f || id[1] != 'E' || id[2] != 'L' || id[3] != 'F') |
| 78 | goto error; |
| 79 | |
| 80 | sret = read(fd, &info, sizeof(info)); |
| 81 | if (sret != sizeof(info)) |
| 82 | goto error; |
| 83 | |
| 84 | m = info.e_machine; |
| 85 | if (m < 0) |
| 86 | m = 0; /* ELF EM_NONE */ |
| 87 | |
| 88 | hdr->elf_mach = m; |
| 89 | ret = 0; |
| 90 | error: |
| 91 | close(fd); |
| 92 | return ret; |
| 93 | } |
| 94 | |
Adrian Hunter | 2a28e23 | 2016-03-08 10:38:50 +0200 | [diff] [blame] | 95 | static int use_arch_timestamp; |
| 96 | |
| 97 | static inline uint64_t |
| 98 | get_arch_timestamp(void) |
| 99 | { |
| 100 | #if defined(__i386__) || defined(__x86_64__) |
| 101 | unsigned int low, high; |
| 102 | |
| 103 | asm volatile("rdtsc" : "=a" (low), "=d" (high)); |
| 104 | |
| 105 | return low | ((uint64_t)high) << 32; |
| 106 | #else |
| 107 | return 0; |
| 108 | #endif |
| 109 | } |
| 110 | |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 111 | #define NSEC_PER_SEC 1000000000 |
| 112 | static int perf_clk_id = CLOCK_MONOTONIC; |
| 113 | |
| 114 | static inline uint64_t |
| 115 | timespec_to_ns(const struct timespec *ts) |
| 116 | { |
| 117 | return ((uint64_t) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec; |
| 118 | } |
| 119 | |
| 120 | static inline uint64_t |
| 121 | perf_get_timestamp(void) |
| 122 | { |
| 123 | struct timespec ts; |
| 124 | int ret; |
| 125 | |
Adrian Hunter | 2a28e23 | 2016-03-08 10:38:50 +0200 | [diff] [blame] | 126 | if (use_arch_timestamp) |
| 127 | return get_arch_timestamp(); |
| 128 | |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 129 | ret = clock_gettime(perf_clk_id, &ts); |
| 130 | if (ret) |
| 131 | return 0; |
| 132 | |
| 133 | return timespec_to_ns(&ts); |
| 134 | } |
| 135 | |
| 136 | static int |
| 137 | debug_cache_init(void) |
| 138 | { |
| 139 | char str[32]; |
| 140 | char *base, *p; |
| 141 | struct tm tm; |
| 142 | time_t t; |
| 143 | int ret; |
| 144 | |
| 145 | time(&t); |
| 146 | localtime_r(&t, &tm); |
| 147 | |
| 148 | base = getenv("JITDUMPDIR"); |
| 149 | if (!base) |
| 150 | base = getenv("HOME"); |
| 151 | if (!base) |
| 152 | base = "."; |
| 153 | |
| 154 | strftime(str, sizeof(str), JIT_LANG"-jit-%Y%m%d", &tm); |
| 155 | |
| 156 | snprintf(jit_path, PATH_MAX - 1, "%s/.debug/", base); |
| 157 | |
| 158 | ret = mkdir(jit_path, 0755); |
| 159 | if (ret == -1) { |
| 160 | if (errno != EEXIST) { |
| 161 | warn("jvmti: cannot create jit cache dir %s", jit_path); |
| 162 | return -1; |
| 163 | } |
| 164 | } |
| 165 | |
| 166 | snprintf(jit_path, PATH_MAX - 1, "%s/.debug/jit", base); |
| 167 | ret = mkdir(jit_path, 0755); |
| 168 | if (ret == -1) { |
| 169 | if (errno != EEXIST) { |
| 170 | warn("cannot create jit cache dir %s", jit_path); |
| 171 | return -1; |
| 172 | } |
| 173 | } |
| 174 | |
| 175 | snprintf(jit_path, PATH_MAX - 1, "%s/.debug/jit/%s.XXXXXXXX", base, str); |
| 176 | |
| 177 | p = mkdtemp(jit_path); |
| 178 | if (p != jit_path) { |
| 179 | warn("cannot create jit cache dir %s", jit_path); |
| 180 | return -1; |
| 181 | } |
| 182 | |
| 183 | return 0; |
| 184 | } |
| 185 | |
| 186 | static int |
| 187 | perf_open_marker_file(int fd) |
| 188 | { |
| 189 | long pgsz; |
| 190 | |
| 191 | pgsz = sysconf(_SC_PAGESIZE); |
| 192 | if (pgsz == -1) |
| 193 | return -1; |
| 194 | |
| 195 | /* |
| 196 | * we mmap the jitdump to create an MMAP RECORD in perf.data file. |
| 197 | * The mmap is captured either live (perf record running when we mmap) |
| 198 | * or in deferred mode, via /proc/PID/maps |
| 199 | * the MMAP record is used as a marker of a jitdump file for more meta |
| 200 | * data info about the jitted code. Perf report/annotate detect this |
| 201 | * special filename and process the jitdump file. |
| 202 | * |
| 203 | * mapping must be PROT_EXEC to ensure it is captured by perf record |
| 204 | * even when not using -d option |
| 205 | */ |
| 206 | marker_addr = mmap(NULL, pgsz, PROT_READ|PROT_EXEC, MAP_PRIVATE, fd, 0); |
| 207 | return (marker_addr == MAP_FAILED) ? -1 : 0; |
| 208 | } |
| 209 | |
| 210 | static void |
| 211 | perf_close_marker_file(void) |
| 212 | { |
| 213 | long pgsz; |
| 214 | |
| 215 | if (!marker_addr) |
| 216 | return; |
| 217 | |
| 218 | pgsz = sysconf(_SC_PAGESIZE); |
| 219 | if (pgsz == -1) |
| 220 | return; |
| 221 | |
| 222 | munmap(marker_addr, pgsz); |
| 223 | } |
| 224 | |
Adrian Hunter | 2a28e23 | 2016-03-08 10:38:50 +0200 | [diff] [blame] | 225 | static void |
| 226 | init_arch_timestamp(void) |
| 227 | { |
| 228 | char *str = getenv("JITDUMP_USE_ARCH_TIMESTAMP"); |
| 229 | |
| 230 | if (!str || !*str || !strcmp(str, "0")) |
| 231 | return; |
| 232 | |
| 233 | use_arch_timestamp = 1; |
| 234 | } |
| 235 | |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 236 | void *jvmti_open(void) |
| 237 | { |
| 238 | int pad_cnt; |
| 239 | char dump_path[PATH_MAX]; |
| 240 | struct jitheader header; |
| 241 | int fd; |
| 242 | FILE *fp; |
| 243 | |
Adrian Hunter | 2a28e23 | 2016-03-08 10:38:50 +0200 | [diff] [blame] | 244 | init_arch_timestamp(); |
| 245 | |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 246 | /* |
| 247 | * check if clockid is supported |
| 248 | */ |
Adrian Hunter | 2a28e23 | 2016-03-08 10:38:50 +0200 | [diff] [blame] | 249 | if (!perf_get_timestamp()) { |
| 250 | if (use_arch_timestamp) |
| 251 | warnx("jvmti: arch timestamp not supported"); |
| 252 | else |
| 253 | warnx("jvmti: kernel does not support %d clock id", perf_clk_id); |
| 254 | } |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 255 | |
| 256 | memset(&header, 0, sizeof(header)); |
| 257 | |
| 258 | debug_cache_init(); |
| 259 | |
| 260 | /* |
| 261 | * jitdump file name |
| 262 | */ |
| 263 | snprintf(dump_path, PATH_MAX, "%s/jit-%i.dump", jit_path, getpid()); |
| 264 | |
| 265 | fd = open(dump_path, O_CREAT|O_TRUNC|O_RDWR, 0666); |
| 266 | if (fd == -1) |
| 267 | return NULL; |
| 268 | |
| 269 | /* |
| 270 | * create perf.data maker for the jitdump file |
| 271 | */ |
| 272 | if (perf_open_marker_file(fd)) { |
| 273 | warnx("jvmti: failed to create marker file"); |
| 274 | return NULL; |
| 275 | } |
| 276 | |
| 277 | fp = fdopen(fd, "w+"); |
| 278 | if (!fp) { |
| 279 | warn("jvmti: cannot create %s", dump_path); |
| 280 | close(fd); |
| 281 | goto error; |
| 282 | } |
| 283 | |
| 284 | warnx("jvmti: jitdump in %s", dump_path); |
| 285 | |
| 286 | if (get_e_machine(&header)) { |
| 287 | warn("get_e_machine failed\n"); |
| 288 | goto error; |
| 289 | } |
| 290 | |
| 291 | header.magic = JITHEADER_MAGIC; |
| 292 | header.version = JITHEADER_VERSION; |
| 293 | header.total_size = sizeof(header); |
| 294 | header.pid = getpid(); |
| 295 | |
| 296 | /* calculate amount of padding '\0' */ |
| 297 | pad_cnt = PADDING_8ALIGNED(header.total_size); |
| 298 | header.total_size += pad_cnt; |
| 299 | |
| 300 | header.timestamp = perf_get_timestamp(); |
| 301 | |
Adrian Hunter | 2a28e23 | 2016-03-08 10:38:50 +0200 | [diff] [blame] | 302 | if (use_arch_timestamp) |
| 303 | header.flags |= JITDUMP_FLAGS_ARCH_TIMESTAMP; |
| 304 | |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 305 | if (!fwrite(&header, sizeof(header), 1, fp)) { |
| 306 | warn("jvmti: cannot write dumpfile header"); |
| 307 | goto error; |
| 308 | } |
| 309 | |
| 310 | /* write padding '\0' if necessary */ |
| 311 | if (pad_cnt && !fwrite(pad_bytes, pad_cnt, 1, fp)) { |
| 312 | warn("jvmti: cannot write dumpfile header padding"); |
| 313 | goto error; |
| 314 | } |
| 315 | |
| 316 | return fp; |
| 317 | error: |
| 318 | fclose(fp); |
| 319 | return NULL; |
| 320 | } |
| 321 | |
| 322 | int |
| 323 | jvmti_close(void *agent) |
| 324 | { |
| 325 | struct jr_code_close rec; |
| 326 | FILE *fp = agent; |
| 327 | |
| 328 | if (!fp) { |
| 329 | warnx("jvmti: incalid fd in close_agent"); |
| 330 | return -1; |
| 331 | } |
| 332 | |
| 333 | rec.p.id = JIT_CODE_CLOSE; |
| 334 | rec.p.total_size = sizeof(rec); |
| 335 | |
| 336 | rec.p.timestamp = perf_get_timestamp(); |
| 337 | |
| 338 | if (!fwrite(&rec, sizeof(rec), 1, fp)) |
| 339 | return -1; |
| 340 | |
| 341 | fclose(fp); |
| 342 | |
| 343 | fp = NULL; |
| 344 | |
| 345 | perf_close_marker_file(); |
| 346 | |
| 347 | return 0; |
| 348 | } |
| 349 | |
| 350 | int |
| 351 | jvmti_write_code(void *agent, char const *sym, |
| 352 | uint64_t vma, void const *code, unsigned int const size) |
| 353 | { |
| 354 | static int code_generation = 1; |
| 355 | struct jr_code_load rec; |
| 356 | size_t sym_len; |
| 357 | size_t padding_count; |
| 358 | FILE *fp = agent; |
| 359 | int ret = -1; |
| 360 | |
| 361 | /* don't care about 0 length function, no samples */ |
| 362 | if (size == 0) |
| 363 | return 0; |
| 364 | |
| 365 | if (!fp) { |
| 366 | warnx("jvmti: invalid fd in write_native_code"); |
| 367 | return -1; |
| 368 | } |
| 369 | |
| 370 | sym_len = strlen(sym) + 1; |
| 371 | |
| 372 | rec.p.id = JIT_CODE_LOAD; |
| 373 | rec.p.total_size = sizeof(rec) + sym_len; |
| 374 | padding_count = PADDING_8ALIGNED(rec.p.total_size); |
| 375 | rec.p. total_size += padding_count; |
| 376 | rec.p.timestamp = perf_get_timestamp(); |
| 377 | |
| 378 | rec.code_size = size; |
| 379 | rec.vma = vma; |
| 380 | rec.code_addr = vma; |
| 381 | rec.pid = getpid(); |
| 382 | rec.tid = gettid(); |
| 383 | |
| 384 | if (code) |
| 385 | rec.p.total_size += size; |
| 386 | |
| 387 | /* |
| 388 | * If JVM is multi-threaded, nultiple concurrent calls to agent |
| 389 | * may be possible, so protect file writes |
| 390 | */ |
| 391 | flockfile(fp); |
| 392 | |
| 393 | /* |
| 394 | * get code index inside lock to avoid race condition |
| 395 | */ |
| 396 | rec.code_index = code_generation++; |
| 397 | |
| 398 | ret = fwrite_unlocked(&rec, sizeof(rec), 1, fp); |
| 399 | fwrite_unlocked(sym, sym_len, 1, fp); |
| 400 | |
| 401 | if (padding_count) |
| 402 | fwrite_unlocked(pad_bytes, padding_count, 1, fp); |
| 403 | |
| 404 | if (code) |
| 405 | fwrite_unlocked(code, size, 1, fp); |
| 406 | |
| 407 | funlockfile(fp); |
| 408 | |
| 409 | ret = 0; |
| 410 | |
| 411 | return ret; |
| 412 | } |
| 413 | |
| 414 | int |
| 415 | jvmti_write_debug_info(void *agent, uint64_t code, const char *file, |
Stephane Eranian | 598b7c6 | 2015-11-30 10:02:23 +0100 | [diff] [blame] | 416 | jvmti_line_info_t *li, int nr_lines) |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 417 | { |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 418 | struct jr_code_debug_info rec; |
| 419 | size_t sret, len, size, flen; |
| 420 | size_t padding_count; |
Stephane Eranian | 598b7c6 | 2015-11-30 10:02:23 +0100 | [diff] [blame] | 421 | uint64_t addr; |
| 422 | const char *fn = file; |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 423 | FILE *fp = agent; |
| 424 | int i; |
| 425 | |
| 426 | /* |
| 427 | * no entry to write |
| 428 | */ |
Stephane Eranian | 598b7c6 | 2015-11-30 10:02:23 +0100 | [diff] [blame] | 429 | if (!nr_lines) |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 430 | return 0; |
| 431 | |
| 432 | if (!fp) { |
| 433 | warnx("jvmti: invalid fd in write_debug_info"); |
| 434 | return -1; |
| 435 | } |
| 436 | |
| 437 | flen = strlen(file) + 1; |
| 438 | |
| 439 | rec.p.id = JIT_CODE_DEBUG_INFO; |
| 440 | size = sizeof(rec); |
| 441 | rec.p.timestamp = perf_get_timestamp(); |
| 442 | rec.code_addr = (uint64_t)(uintptr_t)code; |
Stephane Eranian | 598b7c6 | 2015-11-30 10:02:23 +0100 | [diff] [blame] | 443 | rec.nr_entry = nr_lines; |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 444 | |
| 445 | /* |
| 446 | * on disk source line info layout: |
| 447 | * uint64_t : addr |
| 448 | * int : line number |
Stephane Eranian | 598b7c6 | 2015-11-30 10:02:23 +0100 | [diff] [blame] | 449 | * int : column discriminator |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 450 | * file[] : source file name |
| 451 | * padding : pad to multiple of 8 bytes |
| 452 | */ |
Stephane Eranian | 598b7c6 | 2015-11-30 10:02:23 +0100 | [diff] [blame] | 453 | size += nr_lines * sizeof(struct debug_entry); |
| 454 | size += flen * nr_lines; |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 455 | /* |
| 456 | * pad to 8 bytes |
| 457 | */ |
| 458 | padding_count = PADDING_8ALIGNED(size); |
| 459 | |
| 460 | rec.p.total_size = size + padding_count; |
| 461 | |
| 462 | /* |
| 463 | * If JVM is multi-threaded, nultiple concurrent calls to agent |
| 464 | * may be possible, so protect file writes |
| 465 | */ |
| 466 | flockfile(fp); |
| 467 | |
| 468 | sret = fwrite_unlocked(&rec, sizeof(rec), 1, fp); |
| 469 | if (sret != 1) |
| 470 | goto error; |
| 471 | |
Stephane Eranian | 598b7c6 | 2015-11-30 10:02:23 +0100 | [diff] [blame] | 472 | for (i = 0; i < nr_lines; i++) { |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 473 | |
Stephane Eranian | 598b7c6 | 2015-11-30 10:02:23 +0100 | [diff] [blame] | 474 | addr = (uint64_t)li[i].pc; |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 475 | len = sizeof(addr); |
| 476 | sret = fwrite_unlocked(&addr, len, 1, fp); |
| 477 | if (sret != 1) |
| 478 | goto error; |
| 479 | |
Stephane Eranian | 598b7c6 | 2015-11-30 10:02:23 +0100 | [diff] [blame] | 480 | len = sizeof(li[0].line_number); |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 481 | sret = fwrite_unlocked(&li[i].line_number, len, 1, fp); |
| 482 | if (sret != 1) |
| 483 | goto error; |
| 484 | |
Stephane Eranian | 598b7c6 | 2015-11-30 10:02:23 +0100 | [diff] [blame] | 485 | len = sizeof(li[0].discrim); |
| 486 | sret = fwrite_unlocked(&li[i].discrim, len, 1, fp); |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 487 | if (sret != 1) |
| 488 | goto error; |
| 489 | |
Stephane Eranian | 598b7c6 | 2015-11-30 10:02:23 +0100 | [diff] [blame] | 490 | sret = fwrite_unlocked(fn, flen, 1, fp); |
| 491 | if (sret != 1) |
| 492 | goto error; |
Stephane Eranian | 209045a | 2015-11-30 10:02:22 +0100 | [diff] [blame] | 493 | } |
| 494 | if (padding_count) |
| 495 | sret = fwrite_unlocked(pad_bytes, padding_count, 1, fp); |
| 496 | if (sret != 1) |
| 497 | goto error; |
| 498 | |
| 499 | funlockfile(fp); |
| 500 | return 0; |
| 501 | error: |
| 502 | funlockfile(fp); |
| 503 | return -1; |
| 504 | } |