diff options
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/ringbuf.c')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/ringbuf.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf.c b/tools/testing/selftests/bpf/prog_tests/ringbuf.c new file mode 100644 index 000000000000..2bba908dfa63 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/ringbuf.c @@ -0,0 +1,211 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#include <linux/compiler.h> +#include <asm/barrier.h> +#include <test_progs.h> +#include <sys/mman.h> +#include <sys/epoll.h> +#include <time.h> +#include <sched.h> +#include <signal.h> +#include <pthread.h> +#include <sys/sysinfo.h> +#include <linux/perf_event.h> +#include <linux/ring_buffer.h> +#include "test_ringbuf.skel.h" + +#define EDONE 7777 + +static int duration = 0; + +struct sample { + int pid; + int seq; + long value; + char comm[16]; +}; + +static volatile int sample_cnt; + +static int process_sample(void *ctx, void *data, size_t len) +{ + struct sample *s = data; + + sample_cnt++; + + switch (s->seq) { + case 0: + CHECK(s->value != 333, "sample1_value", "exp %ld, got %ld\n", + 333L, s->value); + return 0; + case 1: + CHECK(s->value != 777, "sample2_value", "exp %ld, got %ld\n", + 777L, s->value); + return -EDONE; + default: + /* we don't care about the rest */ + return 0; + } +} + +static struct test_ringbuf *skel; +static struct ring_buffer *ringbuf; + +static void trigger_samples() +{ + skel->bss->dropped = 0; + skel->bss->total = 0; + skel->bss->discarded = 0; + + /* trigger exactly two samples */ + skel->bss->value = 333; + syscall(__NR_getpgid); + skel->bss->value = 777; + syscall(__NR_getpgid); +} + +static void *poll_thread(void *input) +{ + long timeout = (long)input; + + return (void *)(long)ring_buffer__poll(ringbuf, timeout); +} + +void test_ringbuf(void) +{ + const size_t rec_sz = BPF_RINGBUF_HDR_SZ + sizeof(struct sample); + pthread_t thread; + long bg_ret = -1; + int err; + + skel = test_ringbuf__open_and_load(); + if (CHECK(!skel, "skel_open_load", "skeleton open&load failed\n")) + return; + + /* only trigger BPF program for current process */ + skel->bss->pid = getpid(); + + ringbuf = ring_buffer__new(bpf_map__fd(skel->maps.ringbuf), + process_sample, NULL, NULL); + if (CHECK(!ringbuf, "ringbuf_create", "failed to create ringbuf\n")) + goto cleanup; + + err = test_ringbuf__attach(skel); + if (CHECK(err, "skel_attach", "skeleton attachment failed: %d\n", err)) + goto cleanup; + + trigger_samples(); + + /* 2 submitted + 1 discarded records */ + CHECK(skel->bss->avail_data != 3 * rec_sz, + "err_avail_size", "exp %ld, got %ld\n", + 3L * rec_sz, skel->bss->avail_data); + CHECK(skel->bss->ring_size != 4096, + "err_ring_size", "exp %ld, got %ld\n", + 4096L, skel->bss->ring_size); + CHECK(skel->bss->cons_pos != 0, + "err_cons_pos", "exp %ld, got %ld\n", + 0L, skel->bss->cons_pos); + CHECK(skel->bss->prod_pos != 3 * rec_sz, + "err_prod_pos", "exp %ld, got %ld\n", + 3L * rec_sz, skel->bss->prod_pos); + + /* poll for samples */ + err = ring_buffer__poll(ringbuf, -1); + + /* -EDONE is used as an indicator that we are done */ + if (CHECK(err != -EDONE, "err_done", "done err: %d\n", err)) + goto cleanup; + + /* we expect extra polling to return nothing */ + err = ring_buffer__poll(ringbuf, 0); + if (CHECK(err != 0, "extra_samples", "poll result: %d\n", err)) + goto cleanup; + + CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n", + 0L, skel->bss->dropped); + CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n", + 2L, skel->bss->total); + CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n", + 1L, skel->bss->discarded); + + /* now validate consumer position is updated and returned */ + trigger_samples(); + CHECK(skel->bss->cons_pos != 3 * rec_sz, + "err_cons_pos", "exp %ld, got %ld\n", + 3L * rec_sz, skel->bss->cons_pos); + err = ring_buffer__poll(ringbuf, -1); + CHECK(err <= 0, "poll_err", "err %d\n", err); + + /* start poll in background w/ long timeout */ + err = pthread_create(&thread, NULL, poll_thread, (void *)(long)10000); + if (CHECK(err, "bg_poll", "pthread_create failed: %d\n", err)) + goto cleanup; + + /* turn off notifications now */ + skel->bss->flags = BPF_RB_NO_WAKEUP; + + /* give background thread a bit of a time */ + usleep(50000); + trigger_samples(); + /* sleeping arbitrarily is bad, but no better way to know that + * epoll_wait() **DID NOT** unblock in background thread + */ + usleep(50000); + /* background poll should still be blocked */ + err = pthread_tryjoin_np(thread, (void **)&bg_ret); + if (CHECK(err != EBUSY, "try_join", "err %d\n", err)) + goto cleanup; + + /* BPF side did everything right */ + CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n", + 0L, skel->bss->dropped); + CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n", + 2L, skel->bss->total); + CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n", + 1L, skel->bss->discarded); + + /* clear flags to return to "adaptive" notification mode */ + skel->bss->flags = 0; + + /* produce new samples, no notification should be triggered, because + * consumer is now behind + */ + trigger_samples(); + + /* background poll should still be blocked */ + err = pthread_tryjoin_np(thread, (void **)&bg_ret); + if (CHECK(err != EBUSY, "try_join", "err %d\n", err)) + goto cleanup; + + /* now force notifications */ + skel->bss->flags = BPF_RB_FORCE_WAKEUP; + sample_cnt = 0; + trigger_samples(); + + /* now we should get a pending notification */ + usleep(50000); + err = pthread_tryjoin_np(thread, (void **)&bg_ret); + if (CHECK(err, "join_bg", "err %d\n", err)) + goto cleanup; + + if (CHECK(bg_ret != 1, "bg_ret", "epoll_wait result: %ld", bg_ret)) + goto cleanup; + + /* 3 rounds, 2 samples each */ + CHECK(sample_cnt != 6, "wrong_sample_cnt", + "expected to see %d samples, got %d\n", 6, sample_cnt); + + /* BPF side did everything right */ + CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n", + 0L, skel->bss->dropped); + CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n", + 2L, skel->bss->total); + CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n", + 1L, skel->bss->discarded); + + test_ringbuf__detach(skel); +cleanup: + ring_buffer__free(ringbuf); + test_ringbuf__destroy(skel); +} |