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 ctx.skel->rodata->stacktrace = env.stacktrace; 150 } 151 152 static void load_ctx(void) 153 { 154 int err; 155 156 err = trigger_bench__load(ctx.skel); 157 if (err) { 158 fprintf(stderr, "failed to open skeleton\n"); 159 exit(1); 160 } 161 } 162 163 static void attach_bpf(struct bpf_program *prog) 164 { 165 struct bpf_link *link; 166 167 link = bpf_program__attach(prog); 168 if (!link) { 169 fprintf(stderr, "failed to attach program!\n"); 170 exit(1); 171 } 172 } 173 174 static void trigger_syscall_count_setup(void) 175 { 176 ctx.usermode_counters = true; 177 } 178 179 /* Batched, staying mostly in-kernel triggering setups */ 180 static void trigger_kernel_count_setup(void) 181 { 182 setup_ctx(); 183 bpf_program__set_autoload(ctx.skel->progs.trigger_driver, false); 184 bpf_program__set_autoload(ctx.skel->progs.trigger_kernel_count, true); 185 load_ctx(); 186 /* override driver program */ 187 ctx.driver_prog_fd = bpf_program__fd(ctx.skel->progs.trigger_kernel_count); 188 } 189 190 static void trigger_kprobe_setup(void) 191 { 192 setup_ctx(); 193 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_kprobe, true); 194 load_ctx(); 195 attach_bpf(ctx.skel->progs.bench_trigger_kprobe); 196 } 197 198 static void trigger_kretprobe_setup(void) 199 { 200 setup_ctx(); 201 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_kretprobe, true); 202 load_ctx(); 203 attach_bpf(ctx.skel->progs.bench_trigger_kretprobe); 204 } 205 206 static void trigger_kprobe_multi_setup(void) 207 { 208 setup_ctx(); 209 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_kprobe_multi, true); 210 load_ctx(); 211 attach_bpf(ctx.skel->progs.bench_trigger_kprobe_multi); 212 } 213 214 static void trigger_kretprobe_multi_setup(void) 215 { 216 setup_ctx(); 217 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_kretprobe_multi, true); 218 load_ctx(); 219 attach_bpf(ctx.skel->progs.bench_trigger_kretprobe_multi); 220 } 221 222 static void trigger_fentry_setup(void) 223 { 224 setup_ctx(); 225 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_fentry, true); 226 load_ctx(); 227 attach_bpf(ctx.skel->progs.bench_trigger_fentry); 228 } 229 230 static void attach_ksyms_all(struct bpf_program *empty, bool kretprobe) 231 { 232 LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); 233 struct bpf_link *link = NULL; 234 struct ksyms *ksyms = NULL; 235 236 /* Some recursive functions will be skipped in 237 * bpf_get_ksyms -> skip_entry, as they can introduce sufficient 238 * overhead. However, it's difficut to skip all the recursive 239 * functions for a debug kernel. 240 * 241 * So, don't run the kprobe-multi-all and kretprobe-multi-all on 242 * a debug kernel. 243 */ 244 if (bpf_get_ksyms(&ksyms, true)) { 245 fprintf(stderr, "failed to get ksyms\n"); 246 exit(1); 247 } 248 249 opts.syms = (const char **)ksyms->filtered_syms; 250 opts.cnt = ksyms->filtered_cnt; 251 opts.retprobe = kretprobe; 252 /* attach empty to all the kernel functions except bpf_get_numa_node_id. */ 253 link = bpf_program__attach_kprobe_multi_opts(empty, NULL, &opts); 254 free_kallsyms_local(ksyms); 255 if (!link) { 256 fprintf(stderr, "failed to attach bpf_program__attach_kprobe_multi_opts to all\n"); 257 exit(1); 258 } 259 } 260 261 static void trigger_kprobe_multi_all_setup(void) 262 { 263 struct bpf_program *prog, *empty; 264 265 setup_ctx(); 266 empty = ctx.skel->progs.bench_kprobe_multi_empty; 267 prog = ctx.skel->progs.bench_trigger_kprobe_multi; 268 bpf_program__set_autoload(empty, true); 269 bpf_program__set_autoload(prog, true); 270 load_ctx(); 271 272 attach_ksyms_all(empty, false); 273 attach_bpf(prog); 274 } 275 276 static void trigger_kretprobe_multi_all_setup(void) 277 { 278 struct bpf_program *prog, *empty; 279 280 setup_ctx(); 281 empty = ctx.skel->progs.bench_kretprobe_multi_empty; 282 prog = ctx.skel->progs.bench_trigger_kretprobe_multi; 283 bpf_program__set_autoload(empty, true); 284 bpf_program__set_autoload(prog, true); 285 load_ctx(); 286 287 attach_ksyms_all(empty, true); 288 attach_bpf(prog); 289 } 290 291 static void trigger_fexit_setup(void) 292 { 293 setup_ctx(); 294 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_fexit, true); 295 load_ctx(); 296 attach_bpf(ctx.skel->progs.bench_trigger_fexit); 297 } 298 299 static void trigger_fmodret_setup(void) 300 { 301 setup_ctx(); 302 bpf_program__set_autoload(ctx.skel->progs.trigger_driver, false); 303 bpf_program__set_autoload(ctx.skel->progs.trigger_driver_kfunc, true); 304 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_fmodret, true); 305 load_ctx(); 306 /* override driver program */ 307 ctx.driver_prog_fd = bpf_program__fd(ctx.skel->progs.trigger_driver_kfunc); 308 attach_bpf(ctx.skel->progs.bench_trigger_fmodret); 309 } 310 311 static void trigger_tp_setup(void) 312 { 313 setup_ctx(); 314 bpf_program__set_autoload(ctx.skel->progs.trigger_driver, false); 315 bpf_program__set_autoload(ctx.skel->progs.trigger_driver_kfunc, true); 316 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_tp, true); 317 load_ctx(); 318 /* override driver program */ 319 ctx.driver_prog_fd = bpf_program__fd(ctx.skel->progs.trigger_driver_kfunc); 320 attach_bpf(ctx.skel->progs.bench_trigger_tp); 321 } 322 323 static void trigger_rawtp_setup(void) 324 { 325 setup_ctx(); 326 bpf_program__set_autoload(ctx.skel->progs.trigger_driver, false); 327 bpf_program__set_autoload(ctx.skel->progs.trigger_driver_kfunc, true); 328 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_rawtp, true); 329 load_ctx(); 330 /* override driver program */ 331 ctx.driver_prog_fd = bpf_program__fd(ctx.skel->progs.trigger_driver_kfunc); 332 attach_bpf(ctx.skel->progs.bench_trigger_rawtp); 333 } 334 335 /* make sure call is not inlined and not avoided by compiler, so __weak and 336 * inline asm volatile in the body of the function 337 * 338 * There is a performance difference between uprobing at nop location vs other 339 * instructions. So use two different targets, one of which starts with nop 340 * and another doesn't. 341 * 342 * GCC doesn't generate stack setup preamble for these functions due to them 343 * having no input arguments and doing nothing in the body. 344 */ 345 __nocf_check __weak void uprobe_target_nop(void) 346 { 347 asm volatile ("nop"); 348 } 349 350 __weak void opaque_noop_func(void) 351 { 352 } 353 354 __nocf_check __weak int uprobe_target_push(void) 355 { 356 /* overhead of function call is negligible compared to uprobe 357 * triggering, so this shouldn't affect benchmark results much 358 */ 359 opaque_noop_func(); 360 return 1; 361 } 362 363 __nocf_check __weak void uprobe_target_ret(void) 364 { 365 asm volatile (""); 366 } 367 368 static void *uprobe_producer_count(void *input) 369 { 370 while (true) { 371 uprobe_target_nop(); 372 inc_counter(base_hits); 373 } 374 return NULL; 375 } 376 377 static void *uprobe_producer_nop(void *input) 378 { 379 while (true) 380 uprobe_target_nop(); 381 return NULL; 382 } 383 384 static void *uprobe_producer_push(void *input) 385 { 386 while (true) 387 uprobe_target_push(); 388 return NULL; 389 } 390 391 static void *uprobe_producer_ret(void *input) 392 { 393 while (true) 394 uprobe_target_ret(); 395 return NULL; 396 } 397 398 #ifdef __x86_64__ 399 __nocf_check __weak void uprobe_target_nop5(void) 400 { 401 asm volatile (".byte 0x0f, 0x1f, 0x44, 0x00, 0x00"); 402 } 403 404 static void *uprobe_producer_nop5(void *input) 405 { 406 while (true) 407 uprobe_target_nop5(); 408 return NULL; 409 } 410 #endif 411 412 static void usetup(bool use_retprobe, bool use_multi, void *target_addr) 413 { 414 size_t uprobe_offset; 415 struct bpf_link *link; 416 int err; 417 418 setup_libbpf(); 419 420 ctx.skel = trigger_bench__open(); 421 if (!ctx.skel) { 422 fprintf(stderr, "failed to open skeleton\n"); 423 exit(1); 424 } 425 426 if (use_multi) 427 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_uprobe_multi, true); 428 else 429 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_uprobe, true); 430 431 err = trigger_bench__load(ctx.skel); 432 if (err) { 433 fprintf(stderr, "failed to load skeleton\n"); 434 exit(1); 435 } 436 437 uprobe_offset = get_uprobe_offset(target_addr); 438 if (use_multi) { 439 LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, 440 .retprobe = use_retprobe, 441 .cnt = 1, 442 .offsets = &uprobe_offset, 443 ); 444 link = bpf_program__attach_uprobe_multi( 445 ctx.skel->progs.bench_trigger_uprobe_multi, 446 -1 /* all PIDs */, "/proc/self/exe", NULL, &opts); 447 ctx.skel->links.bench_trigger_uprobe_multi = link; 448 } else { 449 link = bpf_program__attach_uprobe(ctx.skel->progs.bench_trigger_uprobe, 450 use_retprobe, 451 -1 /* all PIDs */, 452 "/proc/self/exe", 453 uprobe_offset); 454 ctx.skel->links.bench_trigger_uprobe = link; 455 } 456 if (!link) { 457 fprintf(stderr, "failed to attach %s!\n", use_multi ? "multi-uprobe" : "uprobe"); 458 exit(1); 459 } 460 } 461 462 static void usermode_count_setup(void) 463 { 464 ctx.usermode_counters = true; 465 } 466 467 static void uprobe_nop_setup(void) 468 { 469 usetup(false, false /* !use_multi */, &uprobe_target_nop); 470 } 471 472 static void uretprobe_nop_setup(void) 473 { 474 usetup(true, false /* !use_multi */, &uprobe_target_nop); 475 } 476 477 static void uprobe_push_setup(void) 478 { 479 usetup(false, false /* !use_multi */, &uprobe_target_push); 480 } 481 482 static void uretprobe_push_setup(void) 483 { 484 usetup(true, false /* !use_multi */, &uprobe_target_push); 485 } 486 487 static void uprobe_ret_setup(void) 488 { 489 usetup(false, false /* !use_multi */, &uprobe_target_ret); 490 } 491 492 static void uretprobe_ret_setup(void) 493 { 494 usetup(true, false /* !use_multi */, &uprobe_target_ret); 495 } 496 497 static void uprobe_multi_nop_setup(void) 498 { 499 usetup(false, true /* use_multi */, &uprobe_target_nop); 500 } 501 502 static void uretprobe_multi_nop_setup(void) 503 { 504 usetup(true, true /* use_multi */, &uprobe_target_nop); 505 } 506 507 static void uprobe_multi_push_setup(void) 508 { 509 usetup(false, true /* use_multi */, &uprobe_target_push); 510 } 511 512 static void uretprobe_multi_push_setup(void) 513 { 514 usetup(true, true /* use_multi */, &uprobe_target_push); 515 } 516 517 static void uprobe_multi_ret_setup(void) 518 { 519 usetup(false, true /* use_multi */, &uprobe_target_ret); 520 } 521 522 static void uretprobe_multi_ret_setup(void) 523 { 524 usetup(true, true /* use_multi */, &uprobe_target_ret); 525 } 526 527 #ifdef __x86_64__ 528 static void uprobe_nop5_setup(void) 529 { 530 usetup(false, false /* !use_multi */, &uprobe_target_nop5); 531 } 532 533 static void uretprobe_nop5_setup(void) 534 { 535 usetup(true, false /* !use_multi */, &uprobe_target_nop5); 536 } 537 538 static void uprobe_multi_nop5_setup(void) 539 { 540 usetup(false, true /* use_multi */, &uprobe_target_nop5); 541 } 542 543 static void uretprobe_multi_nop5_setup(void) 544 { 545 usetup(true, true /* use_multi */, &uprobe_target_nop5); 546 } 547 #endif 548 549 const struct bench bench_trig_syscall_count = { 550 .name = "trig-syscall-count", 551 .validate = trigger_validate, 552 .setup = trigger_syscall_count_setup, 553 .producer_thread = trigger_producer, 554 .measure = trigger_measure, 555 .report_progress = hits_drops_report_progress, 556 .report_final = hits_drops_report_final, 557 }; 558 559 /* batched (staying mostly in kernel) kprobe/fentry benchmarks */ 560 #define BENCH_TRIG_KERNEL(KIND, NAME) \ 561 const struct bench bench_trig_##KIND = { \ 562 .name = "trig-" NAME, \ 563 .setup = trigger_##KIND##_setup, \ 564 .producer_thread = trigger_producer_batch, \ 565 .measure = trigger_measure, \ 566 .report_progress = hits_drops_report_progress, \ 567 .report_final = hits_drops_report_final, \ 568 .argp = &bench_trigger_batch_argp, \ 569 } 570 571 BENCH_TRIG_KERNEL(kernel_count, "kernel-count"); 572 BENCH_TRIG_KERNEL(kprobe, "kprobe"); 573 BENCH_TRIG_KERNEL(kretprobe, "kretprobe"); 574 BENCH_TRIG_KERNEL(kprobe_multi, "kprobe-multi"); 575 BENCH_TRIG_KERNEL(kretprobe_multi, "kretprobe-multi"); 576 BENCH_TRIG_KERNEL(fentry, "fentry"); 577 BENCH_TRIG_KERNEL(kprobe_multi_all, "kprobe-multi-all"); 578 BENCH_TRIG_KERNEL(kretprobe_multi_all, "kretprobe-multi-all"); 579 BENCH_TRIG_KERNEL(fexit, "fexit"); 580 BENCH_TRIG_KERNEL(fmodret, "fmodret"); 581 BENCH_TRIG_KERNEL(tp, "tp"); 582 BENCH_TRIG_KERNEL(rawtp, "rawtp"); 583 584 /* uprobe benchmarks */ 585 #define BENCH_TRIG_USERMODE(KIND, PRODUCER, NAME) \ 586 const struct bench bench_trig_##KIND = { \ 587 .name = "trig-" NAME, \ 588 .validate = trigger_validate, \ 589 .setup = KIND##_setup, \ 590 .producer_thread = uprobe_producer_##PRODUCER, \ 591 .measure = trigger_measure, \ 592 .report_progress = hits_drops_report_progress, \ 593 .report_final = hits_drops_report_final, \ 594 } 595 596 BENCH_TRIG_USERMODE(usermode_count, count, "usermode-count"); 597 BENCH_TRIG_USERMODE(uprobe_nop, nop, "uprobe-nop"); 598 BENCH_TRIG_USERMODE(uprobe_push, push, "uprobe-push"); 599 BENCH_TRIG_USERMODE(uprobe_ret, ret, "uprobe-ret"); 600 BENCH_TRIG_USERMODE(uretprobe_nop, nop, "uretprobe-nop"); 601 BENCH_TRIG_USERMODE(uretprobe_push, push, "uretprobe-push"); 602 BENCH_TRIG_USERMODE(uretprobe_ret, ret, "uretprobe-ret"); 603 BENCH_TRIG_USERMODE(uprobe_multi_nop, nop, "uprobe-multi-nop"); 604 BENCH_TRIG_USERMODE(uprobe_multi_push, push, "uprobe-multi-push"); 605 BENCH_TRIG_USERMODE(uprobe_multi_ret, ret, "uprobe-multi-ret"); 606 BENCH_TRIG_USERMODE(uretprobe_multi_nop, nop, "uretprobe-multi-nop"); 607 BENCH_TRIG_USERMODE(uretprobe_multi_push, push, "uretprobe-multi-push"); 608 BENCH_TRIG_USERMODE(uretprobe_multi_ret, ret, "uretprobe-multi-ret"); 609 #ifdef __x86_64__ 610 BENCH_TRIG_USERMODE(uprobe_nop5, nop5, "uprobe-nop5"); 611 BENCH_TRIG_USERMODE(uretprobe_nop5, nop5, "uretprobe-nop5"); 612 BENCH_TRIG_USERMODE(uprobe_multi_nop5, nop5, "uprobe-multi-nop5"); 613 BENCH_TRIG_USERMODE(uretprobe_multi_nop5, nop5, "uretprobe-multi-nop5"); 614 #endif 615