6984cbc6df
Switch perf_buffer test to use skeleton to avoid use of bpf_prog_load() and make test a bit more succinct. Also switch BPF program to use tracepoint instead of kprobe, as that allows to support older kernels, which had tracepoint support before kprobe support in the form that libbpf expects (i.e., libbpf expects /sys/bus/event_source/devices/kprobe/type, which doesn't always exist on old kernels). Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200708015318.3827358-7-andriin@fb.com
101 lines
2.5 KiB
C
101 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#define _GNU_SOURCE
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#include <pthread.h>
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#include <sched.h>
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#include <sys/socket.h>
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#include <test_progs.h>
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#include "test_perf_buffer.skel.h"
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#include "bpf/libbpf_internal.h"
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/* AddressSanitizer sometimes crashes due to data dereference below, due to
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* this being mmap()'ed memory. Disable instrumentation with
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* no_sanitize_address attribute
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*/
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__attribute__((no_sanitize_address))
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static void on_sample(void *ctx, int cpu, void *data, __u32 size)
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{
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int cpu_data = *(int *)data, duration = 0;
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cpu_set_t *cpu_seen = ctx;
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if (cpu_data != cpu)
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CHECK(cpu_data != cpu, "check_cpu_data",
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"cpu_data %d != cpu %d\n", cpu_data, cpu);
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CPU_SET(cpu, cpu_seen);
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}
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void test_perf_buffer(void)
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{
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int err, on_len, nr_on_cpus = 0, nr_cpus, i, duration = 0;
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struct perf_buffer_opts pb_opts = {};
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struct test_perf_buffer *skel;
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cpu_set_t cpu_set, cpu_seen;
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struct perf_buffer *pb;
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bool *online;
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nr_cpus = libbpf_num_possible_cpus();
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if (CHECK(nr_cpus < 0, "nr_cpus", "err %d\n", nr_cpus))
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return;
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err = parse_cpu_mask_file("/sys/devices/system/cpu/online",
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&online, &on_len);
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if (CHECK(err, "nr_on_cpus", "err %d\n", err))
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return;
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for (i = 0; i < on_len; i++)
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if (online[i])
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nr_on_cpus++;
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/* load program */
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skel = test_perf_buffer__open_and_load();
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if (CHECK(!skel, "skel_load", "skeleton open/load failed\n"))
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goto out_close;
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/* attach probe */
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err = test_perf_buffer__attach(skel);
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if (CHECK(err, "attach_kprobe", "err %d\n", err))
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goto out_close;
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/* set up perf buffer */
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pb_opts.sample_cb = on_sample;
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pb_opts.ctx = &cpu_seen;
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pb = perf_buffer__new(bpf_map__fd(skel->maps.perf_buf_map), 1, &pb_opts);
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if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb)))
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goto out_close;
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/* trigger kprobe on every CPU */
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CPU_ZERO(&cpu_seen);
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for (i = 0; i < nr_cpus; i++) {
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if (i >= on_len || !online[i]) {
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printf("skipping offline CPU #%d\n", i);
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continue;
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}
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CPU_ZERO(&cpu_set);
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CPU_SET(i, &cpu_set);
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err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set),
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&cpu_set);
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if (err && CHECK(err, "set_affinity", "cpu #%d, err %d\n",
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i, err))
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goto out_close;
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usleep(1);
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}
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/* read perf buffer */
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err = perf_buffer__poll(pb, 100);
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if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
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goto out_free_pb;
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if (CHECK(CPU_COUNT(&cpu_seen) != nr_on_cpus, "seen_cpu_cnt",
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"expect %d, seen %d\n", nr_on_cpus, CPU_COUNT(&cpu_seen)))
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goto out_free_pb;
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out_free_pb:
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perf_buffer__free(pb);
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out_close:
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test_perf_buffer__destroy(skel);
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free(online);
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}
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