1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2020 Facebook */ 3 #define _GNU_SOURCE 4 #include <argp.h> 5 #include <unistd.h> 6 #include <stdint.h> 7 #include "bpf_util.h" 8 #include "bench.h" 9 #include "trigger_bench.skel.h" 10 #include "trace_helpers.h" 11 12 #define MAX_TRIG_BATCH_ITERS 1000 13 14 static struct { 15 __u32 batch_iters; 16 } args = { 17 .batch_iters = 100, 18 }; 19 20 enum { 21 ARG_TRIG_BATCH_ITERS = 7000, 22 }; 23 24 static const struct argp_option opts[] = { 25 { "trig-batch-iters", ARG_TRIG_BATCH_ITERS, "BATCH_ITER_CNT", 0, 26 "Number of in-kernel iterations per one driver test run"}, 27 {}, 28 }; 29 30 static error_t parse_arg(int key, char *arg, struct argp_state *state) 31 { 32 long ret; 33 34 switch (key) { 35 case ARG_TRIG_BATCH_ITERS: 36 ret = strtol(arg, NULL, 10); 37 if (ret < 1 || ret > MAX_TRIG_BATCH_ITERS) { 38 fprintf(stderr, "invalid --trig-batch-iters value (should be between %d and %d)\n", 39 1, MAX_TRIG_BATCH_ITERS); 40 argp_usage(state); 41 } 42 args.batch_iters = ret; 43 break; 44 default: 45 return ARGP_ERR_UNKNOWN; 46 } 47 48 return 0; 49 } 50 51 const struct argp bench_trigger_batch_argp = { 52 .options = opts, 53 .parser = parse_arg, 54 }; 55 56 /* adjust slot shift in inc_hits() if changing */ 57 #define MAX_BUCKETS 256 58 59 #pragma GCC diagnostic ignored "-Wattributes" 60 61 /* BPF triggering benchmarks */ 62 static struct trigger_ctx { 63 struct trigger_bench *skel; 64 bool usermode_counters; 65 int driver_prog_fd; 66 } ctx; 67 68 static struct counter base_hits[MAX_BUCKETS]; 69 70 static __always_inline void inc_counter(struct counter *counters) 71 { 72 static __thread int tid = 0; 73 unsigned slot; 74 75 if (unlikely(tid == 0)) 76 tid = sys_gettid(); 77 78 /* multiplicative hashing, it's fast */ 79 slot = 2654435769U * tid; 80 slot >>= 24; 81 82 atomic_inc(&base_hits[slot].value); /* use highest byte as an index */ 83 } 84 85 static long sum_and_reset_counters(struct counter *counters) 86 { 87 int i; 88 long sum = 0; 89 90 for (i = 0; i < MAX_BUCKETS; i++) 91 sum += atomic_swap(&counters[i].value, 0); 92 return sum; 93 } 94 95 static void trigger_validate(void) 96 { 97 if (env.consumer_cnt != 0) { 98 fprintf(stderr, "benchmark doesn't support consumer!\n"); 99 exit(1); 100 } 101 } 102 103 static void *trigger_producer(void *input) 104 { 105 if (ctx.usermode_counters) { 106 while (true) { 107 (void)syscall(__NR_getpgid); 108 inc_counter(base_hits); 109 } 110 } else { 111 while (true) 112 (void)syscall(__NR_getpgid); 113 } 114 return NULL; 115 } 116 117 static void *trigger_producer_batch(void *input) 118 { 119 int fd = ctx.driver_prog_fd ?: bpf_program__fd(ctx.skel->progs.trigger_driver); 120 121 while (true) 122 bpf_prog_test_run_opts(fd, NULL); 123 124 return NULL; 125 } 126 127 static void trigger_measure(struct bench_res *res) 128 { 129 if (ctx.usermode_counters) 130 res->hits = sum_and_reset_counters(base_hits); 131 else 132 res->hits = sum_and_reset_counters(ctx.skel->bss->hits); 133 } 134 135 static void setup_ctx(void) 136 { 137 setup_libbpf(); 138 139 ctx.skel = trigger_bench__open(); 140 if (!ctx.skel) { 141 fprintf(stderr, "failed to open skeleton\n"); 142 exit(1); 143 } 144 145 /* default "driver" BPF program */ 146 bpf_program__set_autoload(ctx.skel->progs.trigger_driver, true); 147 148 ctx.skel->rodata->batch_iters = args.batch_iters; 149 } 150 151 static void load_ctx(void) 152 { 153 int err; 154 155 err = trigger_bench__load(ctx.skel); 156 if (err) { 157 fprintf(stderr, "failed to open skeleton\n"); 158 exit(1); 159 } 160 } 161 162 static void attach_bpf(struct bpf_program *prog) 163 { 164 struct bpf_link *link; 165 166 link = bpf_program__attach(prog); 167 if (!link) { 168 fprintf(stderr, "failed to attach program!\n"); 169 exit(1); 170 } 171 } 172 173 static void trigger_syscall_count_setup(void) 174 { 175 ctx.usermode_counters = true; 176 } 177 178 /* Batched, staying mostly in-kernel triggering setups */ 179 static void trigger_kernel_count_setup(void) 180 { 181 setup_ctx(); 182 bpf_program__set_autoload(ctx.skel->progs.trigger_driver, false); 183 bpf_program__set_autoload(ctx.skel->progs.trigger_count, true); 184 load_ctx(); 185 /* override driver program */ 186 ctx.driver_prog_fd = bpf_program__fd(ctx.skel->progs.trigger_count); 187 } 188 189 static void trigger_kprobe_setup(void) 190 { 191 setup_ctx(); 192 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_kprobe, true); 193 load_ctx(); 194 attach_bpf(ctx.skel->progs.bench_trigger_kprobe); 195 } 196 197 static void trigger_kretprobe_setup(void) 198 { 199 setup_ctx(); 200 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_kretprobe, true); 201 load_ctx(); 202 attach_bpf(ctx.skel->progs.bench_trigger_kretprobe); 203 } 204 205 static void trigger_kprobe_multi_setup(void) 206 { 207 setup_ctx(); 208 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_kprobe_multi, true); 209 load_ctx(); 210 attach_bpf(ctx.skel->progs.bench_trigger_kprobe_multi); 211 } 212 213 static void trigger_kretprobe_multi_setup(void) 214 { 215 setup_ctx(); 216 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_kretprobe_multi, true); 217 load_ctx(); 218 attach_bpf(ctx.skel->progs.bench_trigger_kretprobe_multi); 219 } 220 221 static void trigger_fentry_setup(void) 222 { 223 setup_ctx(); 224 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_fentry, true); 225 load_ctx(); 226 attach_bpf(ctx.skel->progs.bench_trigger_fentry); 227 } 228 229 static void attach_ksyms_all(struct bpf_program *empty, bool kretprobe) 230 { 231 LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); 232 char **syms = NULL; 233 size_t cnt = 0; 234 235 /* Some recursive functions will be skipped in 236 * bpf_get_ksyms -> skip_entry, as they can introduce sufficient 237 * overhead. However, it's difficut to skip all the recursive 238 * functions for a debug kernel. 239 * 240 * So, don't run the kprobe-multi-all and kretprobe-multi-all on 241 * a debug kernel. 242 */ 243 if (bpf_get_ksyms(&syms, &cnt, true)) { 244 fprintf(stderr, "failed to get ksyms\n"); 245 exit(1); 246 } 247 248 opts.syms = (const char **) syms; 249 opts.cnt = cnt; 250 opts.retprobe = kretprobe; 251 /* attach empty to all the kernel functions except bpf_get_numa_node_id. */ 252 if (!bpf_program__attach_kprobe_multi_opts(empty, NULL, &opts)) { 253 fprintf(stderr, "failed to attach bpf_program__attach_kprobe_multi_opts to all\n"); 254 exit(1); 255 } 256 } 257 258 static void trigger_kprobe_multi_all_setup(void) 259 { 260 struct bpf_program *prog, *empty; 261 262 setup_ctx(); 263 empty = ctx.skel->progs.bench_kprobe_multi_empty; 264 prog = ctx.skel->progs.bench_trigger_kprobe_multi; 265 bpf_program__set_autoload(empty, true); 266 bpf_program__set_autoload(prog, true); 267 load_ctx(); 268 269 attach_ksyms_all(empty, false); 270 attach_bpf(prog); 271 } 272 273 static void trigger_kretprobe_multi_all_setup(void) 274 { 275 struct bpf_program *prog, *empty; 276 277 setup_ctx(); 278 empty = ctx.skel->progs.bench_kretprobe_multi_empty; 279 prog = ctx.skel->progs.bench_trigger_kretprobe_multi; 280 bpf_program__set_autoload(empty, true); 281 bpf_program__set_autoload(prog, true); 282 load_ctx(); 283 284 attach_ksyms_all(empty, true); 285 attach_bpf(prog); 286 } 287 288 static void trigger_fexit_setup(void) 289 { 290 setup_ctx(); 291 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_fexit, true); 292 load_ctx(); 293 attach_bpf(ctx.skel->progs.bench_trigger_fexit); 294 } 295 296 static void trigger_fmodret_setup(void) 297 { 298 setup_ctx(); 299 bpf_program__set_autoload(ctx.skel->progs.trigger_driver, false); 300 bpf_program__set_autoload(ctx.skel->progs.trigger_driver_kfunc, true); 301 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_fmodret, true); 302 load_ctx(); 303 /* override driver program */ 304 ctx.driver_prog_fd = bpf_program__fd(ctx.skel->progs.trigger_driver_kfunc); 305 attach_bpf(ctx.skel->progs.bench_trigger_fmodret); 306 } 307 308 static void trigger_tp_setup(void) 309 { 310 setup_ctx(); 311 bpf_program__set_autoload(ctx.skel->progs.trigger_driver, false); 312 bpf_program__set_autoload(ctx.skel->progs.trigger_driver_kfunc, true); 313 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_tp, true); 314 load_ctx(); 315 /* override driver program */ 316 ctx.driver_prog_fd = bpf_program__fd(ctx.skel->progs.trigger_driver_kfunc); 317 attach_bpf(ctx.skel->progs.bench_trigger_tp); 318 } 319 320 static void trigger_rawtp_setup(void) 321 { 322 setup_ctx(); 323 bpf_program__set_autoload(ctx.skel->progs.trigger_driver, false); 324 bpf_program__set_autoload(ctx.skel->progs.trigger_driver_kfunc, true); 325 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_rawtp, true); 326 load_ctx(); 327 /* override driver program */ 328 ctx.driver_prog_fd = bpf_program__fd(ctx.skel->progs.trigger_driver_kfunc); 329 attach_bpf(ctx.skel->progs.bench_trigger_rawtp); 330 } 331 332 /* make sure call is not inlined and not avoided by compiler, so __weak and 333 * inline asm volatile in the body of the function 334 * 335 * There is a performance difference between uprobing at nop location vs other 336 * instructions. So use two different targets, one of which starts with nop 337 * and another doesn't. 338 * 339 * GCC doesn't generate stack setup preamble for these functions due to them 340 * having no input arguments and doing nothing in the body. 341 */ 342 __nocf_check __weak void uprobe_target_nop(void) 343 { 344 asm volatile ("nop"); 345 } 346 347 __weak void opaque_noop_func(void) 348 { 349 } 350 351 __nocf_check __weak int uprobe_target_push(void) 352 { 353 /* overhead of function call is negligible compared to uprobe 354 * triggering, so this shouldn't affect benchmark results much 355 */ 356 opaque_noop_func(); 357 return 1; 358 } 359 360 __nocf_check __weak void uprobe_target_ret(void) 361 { 362 asm volatile (""); 363 } 364 365 static void *uprobe_producer_count(void *input) 366 { 367 while (true) { 368 uprobe_target_nop(); 369 inc_counter(base_hits); 370 } 371 return NULL; 372 } 373 374 static void *uprobe_producer_nop(void *input) 375 { 376 while (true) 377 uprobe_target_nop(); 378 return NULL; 379 } 380 381 static void *uprobe_producer_push(void *input) 382 { 383 while (true) 384 uprobe_target_push(); 385 return NULL; 386 } 387 388 static void *uprobe_producer_ret(void *input) 389 { 390 while (true) 391 uprobe_target_ret(); 392 return NULL; 393 } 394 395 #ifdef __x86_64__ 396 __nocf_check __weak void uprobe_target_nop5(void) 397 { 398 asm volatile (".byte 0x0f, 0x1f, 0x44, 0x00, 0x00"); 399 } 400 401 static void *uprobe_producer_nop5(void *input) 402 { 403 while (true) 404 uprobe_target_nop5(); 405 return NULL; 406 } 407 #endif 408 409 static void usetup(bool use_retprobe, bool use_multi, void *target_addr) 410 { 411 size_t uprobe_offset; 412 struct bpf_link *link; 413 int err; 414 415 setup_libbpf(); 416 417 ctx.skel = trigger_bench__open(); 418 if (!ctx.skel) { 419 fprintf(stderr, "failed to open skeleton\n"); 420 exit(1); 421 } 422 423 if (use_multi) 424 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_uprobe_multi, true); 425 else 426 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_uprobe, true); 427 428 err = trigger_bench__load(ctx.skel); 429 if (err) { 430 fprintf(stderr, "failed to load skeleton\n"); 431 exit(1); 432 } 433 434 uprobe_offset = get_uprobe_offset(target_addr); 435 if (use_multi) { 436 LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, 437 .retprobe = use_retprobe, 438 .cnt = 1, 439 .offsets = &uprobe_offset, 440 ); 441 link = bpf_program__attach_uprobe_multi( 442 ctx.skel->progs.bench_trigger_uprobe_multi, 443 -1 /* all PIDs */, "/proc/self/exe", NULL, &opts); 444 ctx.skel->links.bench_trigger_uprobe_multi = link; 445 } else { 446 link = bpf_program__attach_uprobe(ctx.skel->progs.bench_trigger_uprobe, 447 use_retprobe, 448 -1 /* all PIDs */, 449 "/proc/self/exe", 450 uprobe_offset); 451 ctx.skel->links.bench_trigger_uprobe = link; 452 } 453 if (!link) { 454 fprintf(stderr, "failed to attach %s!\n", use_multi ? "multi-uprobe" : "uprobe"); 455 exit(1); 456 } 457 } 458 459 static void usermode_count_setup(void) 460 { 461 ctx.usermode_counters = true; 462 } 463 464 static void uprobe_nop_setup(void) 465 { 466 usetup(false, false /* !use_multi */, &uprobe_target_nop); 467 } 468 469 static void uretprobe_nop_setup(void) 470 { 471 usetup(true, false /* !use_multi */, &uprobe_target_nop); 472 } 473 474 static void uprobe_push_setup(void) 475 { 476 usetup(false, false /* !use_multi */, &uprobe_target_push); 477 } 478 479 static void uretprobe_push_setup(void) 480 { 481 usetup(true, false /* !use_multi */, &uprobe_target_push); 482 } 483 484 static void uprobe_ret_setup(void) 485 { 486 usetup(false, false /* !use_multi */, &uprobe_target_ret); 487 } 488 489 static void uretprobe_ret_setup(void) 490 { 491 usetup(true, false /* !use_multi */, &uprobe_target_ret); 492 } 493 494 static void uprobe_multi_nop_setup(void) 495 { 496 usetup(false, true /* use_multi */, &uprobe_target_nop); 497 } 498 499 static void uretprobe_multi_nop_setup(void) 500 { 501 usetup(true, true /* use_multi */, &uprobe_target_nop); 502 } 503 504 static void uprobe_multi_push_setup(void) 505 { 506 usetup(false, true /* use_multi */, &uprobe_target_push); 507 } 508 509 static void uretprobe_multi_push_setup(void) 510 { 511 usetup(true, true /* use_multi */, &uprobe_target_push); 512 } 513 514 static void uprobe_multi_ret_setup(void) 515 { 516 usetup(false, true /* use_multi */, &uprobe_target_ret); 517 } 518 519 static void uretprobe_multi_ret_setup(void) 520 { 521 usetup(true, true /* use_multi */, &uprobe_target_ret); 522 } 523 524 #ifdef __x86_64__ 525 static void uprobe_nop5_setup(void) 526 { 527 usetup(false, false /* !use_multi */, &uprobe_target_nop5); 528 } 529 530 static void uretprobe_nop5_setup(void) 531 { 532 usetup(true, false /* !use_multi */, &uprobe_target_nop5); 533 } 534 535 static void uprobe_multi_nop5_setup(void) 536 { 537 usetup(false, true /* use_multi */, &uprobe_target_nop5); 538 } 539 540 static void uretprobe_multi_nop5_setup(void) 541 { 542 usetup(true, true /* use_multi */, &uprobe_target_nop5); 543 } 544 #endif 545 546 const struct bench bench_trig_syscall_count = { 547 .name = "trig-syscall-count", 548 .validate = trigger_validate, 549 .setup = trigger_syscall_count_setup, 550 .producer_thread = trigger_producer, 551 .measure = trigger_measure, 552 .report_progress = hits_drops_report_progress, 553 .report_final = hits_drops_report_final, 554 }; 555 556 /* batched (staying mostly in kernel) kprobe/fentry benchmarks */ 557 #define BENCH_TRIG_KERNEL(KIND, NAME) \ 558 const struct bench bench_trig_##KIND = { \ 559 .name = "trig-" NAME, \ 560 .setup = trigger_##KIND##_setup, \ 561 .producer_thread = trigger_producer_batch, \ 562 .measure = trigger_measure, \ 563 .report_progress = hits_drops_report_progress, \ 564 .report_final = hits_drops_report_final, \ 565 .argp = &bench_trigger_batch_argp, \ 566 } 567 568 BENCH_TRIG_KERNEL(kernel_count, "kernel-count"); 569 BENCH_TRIG_KERNEL(kprobe, "kprobe"); 570 BENCH_TRIG_KERNEL(kretprobe, "kretprobe"); 571 BENCH_TRIG_KERNEL(kprobe_multi, "kprobe-multi"); 572 BENCH_TRIG_KERNEL(kretprobe_multi, "kretprobe-multi"); 573 BENCH_TRIG_KERNEL(fentry, "fentry"); 574 BENCH_TRIG_KERNEL(kprobe_multi_all, "kprobe-multi-all"); 575 BENCH_TRIG_KERNEL(kretprobe_multi_all, "kretprobe-multi-all"); 576 BENCH_TRIG_KERNEL(fexit, "fexit"); 577 BENCH_TRIG_KERNEL(fmodret, "fmodret"); 578 BENCH_TRIG_KERNEL(tp, "tp"); 579 BENCH_TRIG_KERNEL(rawtp, "rawtp"); 580 581 /* uprobe benchmarks */ 582 #define BENCH_TRIG_USERMODE(KIND, PRODUCER, NAME) \ 583 const struct bench bench_trig_##KIND = { \ 584 .name = "trig-" NAME, \ 585 .validate = trigger_validate, \ 586 .setup = KIND##_setup, \ 587 .producer_thread = uprobe_producer_##PRODUCER, \ 588 .measure = trigger_measure, \ 589 .report_progress = hits_drops_report_progress, \ 590 .report_final = hits_drops_report_final, \ 591 } 592 593 BENCH_TRIG_USERMODE(usermode_count, count, "usermode-count"); 594 BENCH_TRIG_USERMODE(uprobe_nop, nop, "uprobe-nop"); 595 BENCH_TRIG_USERMODE(uprobe_push, push, "uprobe-push"); 596 BENCH_TRIG_USERMODE(uprobe_ret, ret, "uprobe-ret"); 597 BENCH_TRIG_USERMODE(uretprobe_nop, nop, "uretprobe-nop"); 598 BENCH_TRIG_USERMODE(uretprobe_push, push, "uretprobe-push"); 599 BENCH_TRIG_USERMODE(uretprobe_ret, ret, "uretprobe-ret"); 600 BENCH_TRIG_USERMODE(uprobe_multi_nop, nop, "uprobe-multi-nop"); 601 BENCH_TRIG_USERMODE(uprobe_multi_push, push, "uprobe-multi-push"); 602 BENCH_TRIG_USERMODE(uprobe_multi_ret, ret, "uprobe-multi-ret"); 603 BENCH_TRIG_USERMODE(uretprobe_multi_nop, nop, "uretprobe-multi-nop"); 604 BENCH_TRIG_USERMODE(uretprobe_multi_push, push, "uretprobe-multi-push"); 605 BENCH_TRIG_USERMODE(uretprobe_multi_ret, ret, "uretprobe-multi-ret"); 606 #ifdef __x86_64__ 607 BENCH_TRIG_USERMODE(uprobe_nop5, nop5, "uprobe-nop5"); 608 BENCH_TRIG_USERMODE(uretprobe_nop5, nop5, "uretprobe-nop5"); 609 BENCH_TRIG_USERMODE(uprobe_multi_nop5, nop5, "uprobe-multi-nop5"); 610 BENCH_TRIG_USERMODE(uretprobe_multi_nop5, nop5, "uretprobe-multi-nop5"); 611 #endif 612