1// SPDX-License-Identifier: GPL-2.0
  2#define _GNU_SOURCE
  3#include <pthread.h>
  4#include <sched.h>
  5#include <sys/socket.h>
  6#include <test_progs.h>
  7#include "test_perf_buffer.skel.h"
  8#include "bpf/libbpf_internal.h"
  9
 10static int duration;
 11
 12/* AddressSanitizer sometimes crashes due to data dereference below, due to
 13 * this being mmap()'ed memory. Disable instrumentation with
 14 * no_sanitize_address attribute
 15 */
 16__attribute__((no_sanitize_address))
 17static void on_sample(void *ctx, int cpu, void *data, __u32 size)
 18{
 19	int cpu_data = *(int *)data, duration = 0;
 20	cpu_set_t *cpu_seen = ctx;
 21
 22	if (cpu_data != cpu)
 23		CHECK(cpu_data != cpu, "check_cpu_data",
 24		      "cpu_data %d != cpu %d\n", cpu_data, cpu);
 25
 26	CPU_SET(cpu, cpu_seen);
 27}
 28
 29int trigger_on_cpu(int cpu)
 30{
 31	cpu_set_t cpu_set;
 32	int err;
 33
 34	CPU_ZERO(&cpu_set);
 35	CPU_SET(cpu, &cpu_set);
 36
 37	err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);
 38	if (err && CHECK(err, "set_affinity", "cpu #%d, err %d\n", cpu, err))
 39		return err;
 40
 41	usleep(1);
 42
 43	return 0;
 44}
 45
 46void serial_test_perf_buffer(void)
 47{
 48	int err, on_len, nr_on_cpus = 0, nr_cpus, i, j;
 49	int zero = 0, my_pid = getpid();
 50	struct test_perf_buffer *skel;
 51	cpu_set_t cpu_seen;
 52	struct perf_buffer *pb;
 53	int last_fd = -1, fd;
 54	bool *online;
 55
 56	nr_cpus = libbpf_num_possible_cpus();
 57	if (CHECK(nr_cpus < 0, "nr_cpus", "err %d\n", nr_cpus))
 58		return;
 59
 60	err = parse_cpu_mask_file("/sys/devices/system/cpu/online",
 61				  &online, &on_len);
 62	if (CHECK(err, "nr_on_cpus", "err %d\n", err))
 63		return;
 64
 65	for (i = 0; i < on_len; i++)
 66		if (online[i])
 67			nr_on_cpus++;
 68
 69	/* load program */
 70	skel = test_perf_buffer__open_and_load();
 71	if (CHECK(!skel, "skel_load", "skeleton open/load failed\n"))
 72		goto out_close;
 73
 74	err = bpf_map_update_elem(bpf_map__fd(skel->maps.my_pid_map), &zero, &my_pid, 0);
 75	if (!ASSERT_OK(err, "my_pid_update"))
 76		goto out_close;
 77
 78	/* attach probe */
 79	err = test_perf_buffer__attach(skel);
 80	if (CHECK(err, "attach_kprobe", "err %d\n", err))
 81		goto out_close;
 82
 83	/* set up perf buffer */
 84	pb = perf_buffer__new(bpf_map__fd(skel->maps.perf_buf_map), 1,
 85			      on_sample, NULL, &cpu_seen, NULL);
 86	if (!ASSERT_OK_PTR(pb, "perf_buf__new"))
 87		goto out_close;
 88
 89	CHECK(perf_buffer__epoll_fd(pb) < 0, "epoll_fd",
 90	      "bad fd: %d\n", perf_buffer__epoll_fd(pb));
 91
 92	/* trigger kprobe on every CPU */
 93	CPU_ZERO(&cpu_seen);
 94	for (i = 0; i < nr_cpus; i++) {
 95		if (i >= on_len || !online[i]) {
 96			printf("skipping offline CPU #%d\n", i);
 97			continue;
 98		}
 99
100		if (trigger_on_cpu(i))
101			goto out_close;
102	}
103
104	/* read perf buffer */
105	err = perf_buffer__poll(pb, 100);
106	if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
107		goto out_free_pb;
108
109	if (CHECK(CPU_COUNT(&cpu_seen) != nr_on_cpus, "seen_cpu_cnt",
110		  "expect %d, seen %d\n", nr_on_cpus, CPU_COUNT(&cpu_seen)))
111		goto out_free_pb;
112
113	if (CHECK(perf_buffer__buffer_cnt(pb) != nr_on_cpus, "buf_cnt",
114		  "got %zu, expected %d\n", perf_buffer__buffer_cnt(pb), nr_on_cpus))
115		goto out_close;
116
117	for (i = 0, j = 0; i < nr_cpus; i++) {
118		if (i >= on_len || !online[i])
119			continue;
120
121		fd = perf_buffer__buffer_fd(pb, j);
122		CHECK(fd < 0 || last_fd == fd, "fd_check", "last fd %d == fd %d\n", last_fd, fd);
123		last_fd = fd;
124
125		err = perf_buffer__consume_buffer(pb, j);
126		if (CHECK(err, "drain_buf", "cpu %d, err %d\n", i, err))
127			goto out_close;
128
129		CPU_CLR(i, &cpu_seen);
130		if (trigger_on_cpu(i))
131			goto out_close;
132
133		err = perf_buffer__consume_buffer(pb, j);
134		if (CHECK(err, "consume_buf", "cpu %d, err %d\n", j, err))
135			goto out_close;
136
137		if (CHECK(!CPU_ISSET(i, &cpu_seen), "cpu_seen", "cpu %d not seen\n", i))
138			goto out_close;
139		j++;
140	}
141
142out_free_pb:
143	perf_buffer__free(pb);
144out_close:
145	test_perf_buffer__destroy(skel);
146	free(online);
147}