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(counters: 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(counters: base_hits);
131 else
132 res->hits = sum_and_reset_counters(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}
150
151static 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
162static 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
173static void trigger_syscall_count_setup(void)
174{
175 ctx.usermode_counters = true;
176}
177
178/* Batched, staying mostly in-kernel triggering setups */
179static 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_kernel_count, true);
184 load_ctx();
185 /* override driver program */
186 ctx.driver_prog_fd = bpf_program__fd(ctx.skel->progs.trigger_kernel_count);
187}
188
189static 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(prog: ctx.skel->progs.bench_trigger_kprobe);
195}
196
197static 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(prog: ctx.skel->progs.bench_trigger_kretprobe);
203}
204
205static 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(prog: ctx.skel->progs.bench_trigger_kprobe_multi);
211}
212
213static 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(prog: ctx.skel->progs.bench_trigger_kretprobe_multi);
219}
220
221static 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(prog: ctx.skel->progs.bench_trigger_fentry);
227}
228
229static 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
258static 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
273static 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
288static 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(prog: ctx.skel->progs.bench_trigger_fexit);
294}
295
296static 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(prog: ctx.skel->progs.bench_trigger_fmodret);
306}
307
308static 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(prog: ctx.skel->progs.bench_trigger_tp);
318}
319
320static 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(prog: 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
365static void *uprobe_producer_count(void *input)
366{
367 while (true) {
368 uprobe_target_nop();
369 inc_counter(counters: base_hits);
370 }
371 return NULL;
372}
373
374static void *uprobe_producer_nop(void *input)
375{
376 while (true)
377 uprobe_target_nop();
378 return NULL;
379}
380
381static void *uprobe_producer_push(void *input)
382{
383 while (true)
384 uprobe_target_push();
385 return NULL;
386}
387
388static 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
401static void *uprobe_producer_nop5(void *input)
402{
403 while (true)
404 uprobe_target_nop5();
405 return NULL;
406}
407#endif
408
409static 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
459static void usermode_count_setup(void)
460{
461 ctx.usermode_counters = true;
462}
463
464static void uprobe_nop_setup(void)
465{
466 usetup(false, false /* !use_multi */, &uprobe_target_nop);
467}
468
469static void uretprobe_nop_setup(void)
470{
471 usetup(true, false /* !use_multi */, &uprobe_target_nop);
472}
473
474static void uprobe_push_setup(void)
475{
476 usetup(false, false /* !use_multi */, &uprobe_target_push);
477}
478
479static void uretprobe_push_setup(void)
480{
481 usetup(true, false /* !use_multi */, &uprobe_target_push);
482}
483
484static void uprobe_ret_setup(void)
485{
486 usetup(false, false /* !use_multi */, &uprobe_target_ret);
487}
488
489static void uretprobe_ret_setup(void)
490{
491 usetup(true, false /* !use_multi */, &uprobe_target_ret);
492}
493
494static void uprobe_multi_nop_setup(void)
495{
496 usetup(false, true /* use_multi */, &uprobe_target_nop);
497}
498
499static void uretprobe_multi_nop_setup(void)
500{
501 usetup(true, true /* use_multi */, &uprobe_target_nop);
502}
503
504static void uprobe_multi_push_setup(void)
505{
506 usetup(false, true /* use_multi */, &uprobe_target_push);
507}
508
509static void uretprobe_multi_push_setup(void)
510{
511 usetup(true, true /* use_multi */, &uprobe_target_push);
512}
513
514static void uprobe_multi_ret_setup(void)
515{
516 usetup(false, true /* use_multi */, &uprobe_target_ret);
517}
518
519static void uretprobe_multi_ret_setup(void)
520{
521 usetup(true, true /* use_multi */, &uprobe_target_ret);
522}
523
524#ifdef __x86_64__
525static void uprobe_nop5_setup(void)
526{
527 usetup(false, false /* !use_multi */, &uprobe_target_nop5);
528}
529
530static void uretprobe_nop5_setup(void)
531{
532 usetup(true, false /* !use_multi */, &uprobe_target_nop5);
533}
534
535static void uprobe_multi_nop5_setup(void)
536{
537 usetup(false, true /* use_multi */, &uprobe_target_nop5);
538}
539
540static void uretprobe_multi_nop5_setup(void)
541{
542 usetup(true, true /* use_multi */, &uprobe_target_nop5);
543}
544#endif
545
546const 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) \
558const 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
568BENCH_TRIG_KERNEL(kernel_count, "kernel-count");
569BENCH_TRIG_KERNEL(kprobe, "kprobe");
570BENCH_TRIG_KERNEL(kretprobe, "kretprobe");
571BENCH_TRIG_KERNEL(kprobe_multi, "kprobe-multi");
572BENCH_TRIG_KERNEL(kretprobe_multi, "kretprobe-multi");
573BENCH_TRIG_KERNEL(fentry, "fentry");
574BENCH_TRIG_KERNEL(kprobe_multi_all, "kprobe-multi-all");
575BENCH_TRIG_KERNEL(kretprobe_multi_all, "kretprobe-multi-all");
576BENCH_TRIG_KERNEL(fexit, "fexit");
577BENCH_TRIG_KERNEL(fmodret, "fmodret");
578BENCH_TRIG_KERNEL(tp, "tp");
579BENCH_TRIG_KERNEL(rawtp, "rawtp");
580
581/* uprobe benchmarks */
582#define BENCH_TRIG_USERMODE(KIND, PRODUCER, NAME) \
583const 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
593BENCH_TRIG_USERMODE(usermode_count, count, "usermode-count");
594BENCH_TRIG_USERMODE(uprobe_nop, nop, "uprobe-nop");
595BENCH_TRIG_USERMODE(uprobe_push, push, "uprobe-push");
596BENCH_TRIG_USERMODE(uprobe_ret, ret, "uprobe-ret");
597BENCH_TRIG_USERMODE(uretprobe_nop, nop, "uretprobe-nop");
598BENCH_TRIG_USERMODE(uretprobe_push, push, "uretprobe-push");
599BENCH_TRIG_USERMODE(uretprobe_ret, ret, "uretprobe-ret");
600BENCH_TRIG_USERMODE(uprobe_multi_nop, nop, "uprobe-multi-nop");
601BENCH_TRIG_USERMODE(uprobe_multi_push, push, "uprobe-multi-push");
602BENCH_TRIG_USERMODE(uprobe_multi_ret, ret, "uprobe-multi-ret");
603BENCH_TRIG_USERMODE(uretprobe_multi_nop, nop, "uretprobe-multi-nop");
604BENCH_TRIG_USERMODE(uretprobe_multi_push, push, "uretprobe-multi-push");
605BENCH_TRIG_USERMODE(uretprobe_multi_ret, ret, "uretprobe-multi-ret");
606#ifdef __x86_64__
607BENCH_TRIG_USERMODE(uprobe_nop5, nop5, "uprobe-nop5");
608BENCH_TRIG_USERMODE(uretprobe_nop5, nop5, "uretprobe-nop5");
609BENCH_TRIG_USERMODE(uprobe_multi_nop5, nop5, "uprobe-multi-nop5");
610BENCH_TRIG_USERMODE(uretprobe_multi_nop5, nop5, "uretprobe-multi-nop5");
611#endif
612

source code of linux/tools/testing/selftests/bpf/benchs/bench_trigger.c