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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
14static struct {
15 __u32 batch_iters;
16} args = {
17 .batch_iters = 100,
18};
19
20enum {
21 ARG_TRIG_BATCH_ITERS = 7000,
22};
23
24static 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
30static 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
51const 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 */
62static struct trigger_ctx {
63 struct trigger_bench *skel;
64 bool usermode_counters;
65 int driver_prog_fd;
66} ctx;
67
68static struct counter base_hits[MAX_BUCKETS];
69
70static __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
85static 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
95static 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
103static 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
117static 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
127static 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
135static 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
152static 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
163static 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
174static void trigger_syscall_count_setup(void)
175{
176 ctx.usermode_counters = true;
177}
178
179/* Batched, staying mostly in-kernel triggering setups */
180static 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
190static 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
198static 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
206static 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
214static 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
222static 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
230static 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
261static 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
276static 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
291static 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
299static 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
311static 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
323static 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
368static 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
377static void *uprobe_producer_nop(void *input)
378{
379 while (true)
380 uprobe_target_nop();
381 return NULL;
382}
383
384static void *uprobe_producer_push(void *input)
385{
386 while (true)
387 uprobe_target_push();
388 return NULL;
389}
390
391static 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_nop10(void)
400{
401 asm volatile (".byte 0x66, 0x2e, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00");
402}
403
404static void *uprobe_producer_nop10(void *input)
405{
406 while (true)
407 uprobe_target_nop10();
408 return NULL;
409}
410
411void usdt_1(void);
412void usdt_2(void);
413
414static void *uprobe_producer_usdt_nop(void *input)
415{
416 while (true)
417 usdt_1();
418 return NULL;
419}
420
421static void *uprobe_producer_usdt_nop10(void *input)
422{
423 while (true)
424 usdt_2();
425 return NULL;
426}
427#endif
428
429static void usetup(bool use_retprobe, bool use_multi, void *target_addr)
430{
431 size_t uprobe_offset;
432 struct bpf_link *link;
433 int err;
434
435 setup_libbpf();
436
437 ctx.skel = trigger_bench__open();
438 if (!ctx.skel) {
439 fprintf(stderr, "failed to open skeleton\n");
440 exit(1);
441 }
442
443 if (use_multi)
444 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_uprobe_multi, true);
445 else
446 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_uprobe, true);
447
448 err = trigger_bench__load(ctx.skel);
449 if (err) {
450 fprintf(stderr, "failed to load skeleton\n");
451 exit(1);
452 }
453
454 uprobe_offset = get_uprobe_offset(target_addr);
455 if (use_multi) {
456 LIBBPF_OPTS(bpf_uprobe_multi_opts, opts,
457 .retprobe = use_retprobe,
458 .cnt = 1,
459 .offsets = &uprobe_offset,
460 );
461 link = bpf_program__attach_uprobe_multi(
462 ctx.skel->progs.bench_trigger_uprobe_multi,
463 -1 /* all PIDs */, "/proc/self/exe", NULL, &opts);
464 ctx.skel->links.bench_trigger_uprobe_multi = link;
465 } else {
466 link = bpf_program__attach_uprobe(ctx.skel->progs.bench_trigger_uprobe,
467 use_retprobe,
468 -1 /* all PIDs */,
469 "/proc/self/exe",
470 uprobe_offset);
471 ctx.skel->links.bench_trigger_uprobe = link;
472 }
473 if (!link) {
474 fprintf(stderr, "failed to attach %s!\n", use_multi ? "multi-uprobe" : "uprobe");
475 exit(1);
476 }
477}
478
479static void usermode_count_setup(void)
480{
481 ctx.usermode_counters = true;
482}
483
484static void uprobe_nop_setup(void)
485{
486 usetup(false, false /* !use_multi */, &uprobe_target_nop);
487}
488
489static void uretprobe_nop_setup(void)
490{
491 usetup(true, false /* !use_multi */, &uprobe_target_nop);
492}
493
494static void uprobe_push_setup(void)
495{
496 usetup(false, false /* !use_multi */, &uprobe_target_push);
497}
498
499static void uretprobe_push_setup(void)
500{
501 usetup(true, false /* !use_multi */, &uprobe_target_push);
502}
503
504static void uprobe_ret_setup(void)
505{
506 usetup(false, false /* !use_multi */, &uprobe_target_ret);
507}
508
509static void uretprobe_ret_setup(void)
510{
511 usetup(true, false /* !use_multi */, &uprobe_target_ret);
512}
513
514static void uprobe_multi_nop_setup(void)
515{
516 usetup(false, true /* use_multi */, &uprobe_target_nop);
517}
518
519static void uretprobe_multi_nop_setup(void)
520{
521 usetup(true, true /* use_multi */, &uprobe_target_nop);
522}
523
524static void uprobe_multi_push_setup(void)
525{
526 usetup(false, true /* use_multi */, &uprobe_target_push);
527}
528
529static void uretprobe_multi_push_setup(void)
530{
531 usetup(true, true /* use_multi */, &uprobe_target_push);
532}
533
534static void uprobe_multi_ret_setup(void)
535{
536 usetup(false, true /* use_multi */, &uprobe_target_ret);
537}
538
539static void uretprobe_multi_ret_setup(void)
540{
541 usetup(true, true /* use_multi */, &uprobe_target_ret);
542}
543
544#ifdef __x86_64__
545static void uprobe_nop10_setup(void)
546{
547 usetup(false, false /* !use_multi */, &uprobe_target_nop10);
548}
549
550static void uretprobe_nop10_setup(void)
551{
552 usetup(true, false /* !use_multi */, &uprobe_target_nop10);
553}
554
555static void uprobe_multi_nop10_setup(void)
556{
557 usetup(false, true /* use_multi */, &uprobe_target_nop10);
558}
559
560static void uretprobe_multi_nop10_setup(void)
561{
562 usetup(true, true /* use_multi */, &uprobe_target_nop10);
563}
564
565static void usdt_setup(const char *name)
566{
567 struct bpf_link *link;
568 int err;
569
570 setup_libbpf();
571
572 ctx.skel = trigger_bench__open();
573 if (!ctx.skel) {
574 fprintf(stderr, "failed to open skeleton\n");
575 exit(1);
576 }
577
578 bpf_program__set_autoload(ctx.skel->progs.bench_trigger_usdt, true);
579
580 err = trigger_bench__load(ctx.skel);
581 if (err) {
582 fprintf(stderr, "failed to load skeleton\n");
583 exit(1);
584 }
585
586 link = bpf_program__attach_usdt(ctx.skel->progs.bench_trigger_usdt,
587 0 /*self*/, "/proc/self/exe",
588 "optimized_attach", name, NULL);
589 if (libbpf_get_error(link)) {
590 fprintf(stderr, "failed to attach optimized_attach:%s usdt probe\n", name);
591 exit(1);
592 }
593 ctx.skel->links.bench_trigger_usdt = link;
594}
595
596static void usdt_nop_setup(void)
597{
598 usdt_setup("usdt_1");
599}
600
601static void usdt_nop10_setup(void)
602{
603 usdt_setup("usdt_2");
604}
605#endif
606
607const struct bench bench_trig_syscall_count = {
608 .name = "trig-syscall-count",
609 .validate = trigger_validate,
610 .setup = trigger_syscall_count_setup,
611 .producer_thread = trigger_producer,
612 .measure = trigger_measure,
613 .report_progress = hits_drops_report_progress,
614 .report_final = hits_drops_report_final,
615};
616
617/* batched (staying mostly in kernel) kprobe/fentry benchmarks */
618#define BENCH_TRIG_KERNEL(KIND, NAME) \
619const struct bench bench_trig_##KIND = { \
620 .name = "trig-" NAME, \
621 .setup = trigger_##KIND##_setup, \
622 .producer_thread = trigger_producer_batch, \
623 .measure = trigger_measure, \
624 .report_progress = hits_drops_report_progress, \
625 .report_final = hits_drops_report_final, \
626 .argp = &bench_trigger_batch_argp, \
627}
628
629BENCH_TRIG_KERNEL(kernel_count, "kernel-count");
630BENCH_TRIG_KERNEL(kprobe, "kprobe");
631BENCH_TRIG_KERNEL(kretprobe, "kretprobe");
632BENCH_TRIG_KERNEL(kprobe_multi, "kprobe-multi");
633BENCH_TRIG_KERNEL(kretprobe_multi, "kretprobe-multi");
634BENCH_TRIG_KERNEL(fentry, "fentry");
635BENCH_TRIG_KERNEL(kprobe_multi_all, "kprobe-multi-all");
636BENCH_TRIG_KERNEL(kretprobe_multi_all, "kretprobe-multi-all");
637BENCH_TRIG_KERNEL(fexit, "fexit");
638BENCH_TRIG_KERNEL(fmodret, "fmodret");
639BENCH_TRIG_KERNEL(tp, "tp");
640BENCH_TRIG_KERNEL(rawtp, "rawtp");
641
642/* uprobe benchmarks */
643#define BENCH_TRIG_USERMODE(KIND, PRODUCER, NAME) \
644const struct bench bench_trig_##KIND = { \
645 .name = "trig-" NAME, \
646 .validate = trigger_validate, \
647 .setup = KIND##_setup, \
648 .producer_thread = uprobe_producer_##PRODUCER, \
649 .measure = trigger_measure, \
650 .report_progress = hits_drops_report_progress, \
651 .report_final = hits_drops_report_final, \
652}
653
654BENCH_TRIG_USERMODE(usermode_count, count, "usermode-count");
655BENCH_TRIG_USERMODE(uprobe_nop, nop, "uprobe-nop");
656BENCH_TRIG_USERMODE(uprobe_push, push, "uprobe-push");
657BENCH_TRIG_USERMODE(uprobe_ret, ret, "uprobe-ret");
658BENCH_TRIG_USERMODE(uretprobe_nop, nop, "uretprobe-nop");
659BENCH_TRIG_USERMODE(uretprobe_push, push, "uretprobe-push");
660BENCH_TRIG_USERMODE(uretprobe_ret, ret, "uretprobe-ret");
661BENCH_TRIG_USERMODE(uprobe_multi_nop, nop, "uprobe-multi-nop");
662BENCH_TRIG_USERMODE(uprobe_multi_push, push, "uprobe-multi-push");
663BENCH_TRIG_USERMODE(uprobe_multi_ret, ret, "uprobe-multi-ret");
664BENCH_TRIG_USERMODE(uretprobe_multi_nop, nop, "uretprobe-multi-nop");
665BENCH_TRIG_USERMODE(uretprobe_multi_push, push, "uretprobe-multi-push");
666BENCH_TRIG_USERMODE(uretprobe_multi_ret, ret, "uretprobe-multi-ret");
667#ifdef __x86_64__
668BENCH_TRIG_USERMODE(uprobe_nop10, nop10, "uprobe-nop10");
669BENCH_TRIG_USERMODE(uretprobe_nop10, nop10, "uretprobe-nop10");
670BENCH_TRIG_USERMODE(uprobe_multi_nop10, nop10, "uprobe-multi-nop10");
671BENCH_TRIG_USERMODE(uretprobe_multi_nop10, nop10, "uretprobe-multi-nop10");
672BENCH_TRIG_USERMODE(usdt_nop, usdt_nop, "usdt-nop");
673BENCH_TRIG_USERMODE(usdt_nop10, usdt_nop10, "usdt-nop10");
674#endif