diff options
Diffstat (limited to '')
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/perf_buffer.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/perf_buffer.c b/tools/testing/selftests/bpf/prog_tests/perf_buffer.c new file mode 100644 index 000000000..8d7547540 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/perf_buffer.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#include <pthread.h> +#include <sched.h> +#include <sys/socket.h> +#include <test_progs.h> +#include "test_perf_buffer.skel.h" +#include "bpf/libbpf_internal.h" + +static int duration; + +/* AddressSanitizer sometimes crashes due to data dereference below, due to + * this being mmap()'ed memory. Disable instrumentation with + * no_sanitize_address attribute + */ +__attribute__((no_sanitize_address)) +static void on_sample(void *ctx, int cpu, void *data, __u32 size) +{ + int cpu_data = *(int *)data, duration = 0; + cpu_set_t *cpu_seen = ctx; + + if (cpu_data != cpu) + CHECK(cpu_data != cpu, "check_cpu_data", + "cpu_data %d != cpu %d\n", cpu_data, cpu); + + CPU_SET(cpu, cpu_seen); +} + +int trigger_on_cpu(int cpu) +{ + cpu_set_t cpu_set; + int err; + + CPU_ZERO(&cpu_set); + CPU_SET(cpu, &cpu_set); + + err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set); + if (err && CHECK(err, "set_affinity", "cpu #%d, err %d\n", cpu, err)) + return err; + + usleep(1); + + return 0; +} + +void test_perf_buffer(void) +{ + int err, on_len, nr_on_cpus = 0, nr_cpus, i; + struct perf_buffer_opts pb_opts = {}; + struct test_perf_buffer *skel; + cpu_set_t cpu_seen; + struct perf_buffer *pb; + int last_fd = -1, fd; + bool *online; + + nr_cpus = libbpf_num_possible_cpus(); + if (CHECK(nr_cpus < 0, "nr_cpus", "err %d\n", nr_cpus)) + return; + + err = parse_cpu_mask_file("/sys/devices/system/cpu/online", + &online, &on_len); + if (CHECK(err, "nr_on_cpus", "err %d\n", err)) + return; + + for (i = 0; i < on_len; i++) + if (online[i]) + nr_on_cpus++; + + /* load program */ + skel = test_perf_buffer__open_and_load(); + if (CHECK(!skel, "skel_load", "skeleton open/load failed\n")) + goto out_close; + + /* attach probe */ + err = test_perf_buffer__attach(skel); + if (CHECK(err, "attach_kprobe", "err %d\n", err)) + goto out_close; + + /* set up perf buffer */ + pb_opts.sample_cb = on_sample; + pb_opts.ctx = &cpu_seen; + pb = perf_buffer__new(bpf_map__fd(skel->maps.perf_buf_map), 1, &pb_opts); + if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb))) + goto out_close; + + CHECK(perf_buffer__epoll_fd(pb) < 0, "epoll_fd", + "bad fd: %d\n", perf_buffer__epoll_fd(pb)); + + /* trigger kprobe on every CPU */ + CPU_ZERO(&cpu_seen); + for (i = 0; i < nr_cpus; i++) { + if (i >= on_len || !online[i]) { + printf("skipping offline CPU #%d\n", i); + continue; + } + + if (trigger_on_cpu(i)) + goto out_close; + } + + /* read perf buffer */ + err = perf_buffer__poll(pb, 100); + if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err)) + goto out_free_pb; + + if (CHECK(CPU_COUNT(&cpu_seen) != nr_on_cpus, "seen_cpu_cnt", + "expect %d, seen %d\n", nr_on_cpus, CPU_COUNT(&cpu_seen))) + goto out_free_pb; + + if (CHECK(perf_buffer__buffer_cnt(pb) != nr_on_cpus, "buf_cnt", + "got %zu, expected %d\n", perf_buffer__buffer_cnt(pb), nr_on_cpus)) + goto out_close; + + for (i = 0; i < nr_cpus; i++) { + if (i >= on_len || !online[i]) + continue; + + fd = perf_buffer__buffer_fd(pb, i); + CHECK(fd < 0 || last_fd == fd, "fd_check", "last fd %d == fd %d\n", last_fd, fd); + last_fd = fd; + + err = perf_buffer__consume_buffer(pb, i); + if (CHECK(err, "drain_buf", "cpu %d, err %d\n", i, err)) + goto out_close; + + CPU_CLR(i, &cpu_seen); + if (trigger_on_cpu(i)) + goto out_close; + + err = perf_buffer__consume_buffer(pb, i); + if (CHECK(err, "consume_buf", "cpu %d, err %d\n", i, err)) + goto out_close; + + if (CHECK(!CPU_ISSET(i, &cpu_seen), "cpu_seen", "cpu %d not seen\n", i)) + goto out_close; + } + +out_free_pb: + perf_buffer__free(pb); +out_close: + test_perf_buffer__destroy(skel); + free(online); +} |