114 lines
2.9 KiB
C
114 lines
2.9 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 "libbpf_internal.h"
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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, prog_fd, on_len, nr_on_cpus = 0, nr_cpus, i, duration = 0;
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const char *prog_name = "kprobe/sys_nanosleep";
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const char *file = "./test_perf_buffer.o";
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struct perf_buffer_opts pb_opts = {};
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struct bpf_map *perf_buf_map;
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cpu_set_t cpu_set, cpu_seen;
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struct bpf_program *prog;
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struct bpf_object *obj;
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struct perf_buffer *pb;
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struct bpf_link *link;
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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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err = bpf_prog_load(file, BPF_PROG_TYPE_KPROBE, &obj, &prog_fd);
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if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno)) {
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obj = NULL;
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goto out_close;
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}
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prog = bpf_object__find_program_by_title(obj, prog_name);
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if (CHECK(!prog, "find_probe", "prog '%s' not found\n", prog_name))
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goto out_close;
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/* load map */
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perf_buf_map = bpf_object__find_map_by_name(obj, "perf_buf_map");
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if (CHECK(!perf_buf_map, "find_perf_buf_map", "not found\n"))
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goto out_close;
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/* attach kprobe */
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link = bpf_program__attach_kprobe(prog, false /* retprobe */,
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SYS_NANOSLEEP_KPROBE_NAME);
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if (CHECK(IS_ERR(link), "attach_kprobe", "err %ld\n", PTR_ERR(link)))
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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(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_detach;
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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_detach;
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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_detach:
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bpf_link__destroy(link);
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out_close:
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bpf_object__close(obj);
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free(online);
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}
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