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// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <pthread.h>
#include <sched.h>
#include <sys/socket.h>
#include <test_progs.h>
#include "bpf/libbpf_internal.h"
#include "test_perf_branches.skel.h"
static void check_good_sample(struct test_perf_branches *skel)
{
int written_global = skel->bss->written_global_out;
int required_size = skel->bss->required_size_out;
int written_stack = skel->bss->written_stack_out;
int pbe_size = sizeof(struct perf_branch_entry);
int duration = 0;
if (CHECK(!skel->bss->valid, "output not valid",
"no valid sample from prog"))
return;
/*
* It's hard to validate the contents of the branch entries b/c it
* would require some kind of disassembler and also encoding the
* valid jump instructions for supported architectures. So just check
* the easy stuff for now.
*/
CHECK(required_size <= 0, "read_branches_size", "err %d\n", required_size);
CHECK(written_stack < 0, "read_branches_stack", "err %d\n", written_stack);
CHECK(written_stack % pbe_size != 0, "read_branches_stack",
"stack bytes written=%d not multiple of struct size=%d\n",
written_stack, pbe_size);
CHECK(written_global < 0, "read_branches_global", "err %d\n", written_global);
CHECK(written_global % pbe_size != 0, "read_branches_global",
"global bytes written=%d not multiple of struct size=%d\n",
written_global, pbe_size);
CHECK(written_global < written_stack, "read_branches_size",
"written_global=%d < written_stack=%d\n", written_global, written_stack);
}
static void check_bad_sample(struct test_perf_branches *skel)
{
int written_global = skel->bss->written_global_out;
int required_size = skel->bss->required_size_out;
int written_stack = skel->bss->written_stack_out;
int duration = 0;
if (CHECK(!skel->bss->valid, "output not valid",
"no valid sample from prog"))
return;
CHECK((required_size != -EINVAL && required_size != -ENOENT),
"read_branches_size", "err %d\n", required_size);
CHECK((written_stack != -EINVAL && written_stack != -ENOENT),
"read_branches_stack", "written %d\n", written_stack);
CHECK((written_global != -EINVAL && written_global != -ENOENT),
"read_branches_global", "written %d\n", written_global);
}
static void test_perf_branches_common(int perf_fd,
void (*cb)(struct test_perf_branches *))
{
struct test_perf_branches *skel;
int err, i, duration = 0;
bool detached = false;
struct bpf_link *link;
volatile int j = 0;
cpu_set_t cpu_set;
skel = test_perf_branches__open_and_load();
if (CHECK(!skel, "test_perf_branches_load",
"perf_branches skeleton failed\n"))
return;
/* attach perf_event */
link = bpf_program__attach_perf_event(skel->progs.perf_branches, perf_fd);
if (CHECK(IS_ERR(link), "attach_perf_event", "err %ld\n", PTR_ERR(link)))
goto out_destroy_skel;
/* generate some branches on cpu 0 */
CPU_ZERO(&cpu_set);
CPU_SET(0, &cpu_set);
err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);
if (CHECK(err, "set_affinity", "cpu #0, err %d\n", err))
goto out_destroy;
/* spin the loop for a while (random high number) */
for (i = 0; i < 1000000; ++i)
++j;
test_perf_branches__detach(skel);
detached = true;
cb(skel);
out_destroy:
bpf_link__destroy(link);
out_destroy_skel:
if (!detached)
test_perf_branches__detach(skel);
test_perf_branches__destroy(skel);
}
static void test_perf_branches_hw(void)
{
struct perf_event_attr attr = {0};
int duration = 0;
int pfd;
/* create perf event */
attr.size = sizeof(attr);
attr.type = PERF_TYPE_HARDWARE;
attr.config = PERF_COUNT_HW_CPU_CYCLES;
attr.freq = 1;
attr.sample_freq = 4000;
attr.sample_type = PERF_SAMPLE_BRANCH_STACK;
attr.branch_sample_type = PERF_SAMPLE_BRANCH_USER | PERF_SAMPLE_BRANCH_ANY;
pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);
/*
* Some setups don't support branch records (virtual machines, !x86),
* so skip test in this case.
*/
if (pfd == -1) {
if (errno == ENOENT || errno == EOPNOTSUPP) {
printf("%s:SKIP:no PERF_SAMPLE_BRANCH_STACK\n",
__func__);
test__skip();
return;
}
if (CHECK(pfd < 0, "perf_event_open", "err %d errno %d\n",
pfd, errno))
return;
}
test_perf_branches_common(pfd, check_good_sample);
close(pfd);
}
/*
* Tests negative case -- run bpf_read_branch_records() on improperly configured
* perf event.
*/
static void test_perf_branches_no_hw(void)
{
struct perf_event_attr attr = {0};
int duration = 0;
int pfd;
/* create perf event */
attr.size = sizeof(attr);
attr.type = PERF_TYPE_SOFTWARE;
attr.config = PERF_COUNT_SW_CPU_CLOCK;
attr.freq = 1;
attr.sample_freq = 4000;
pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);
if (CHECK(pfd < 0, "perf_event_open", "err %d\n", pfd))
return;
test_perf_branches_common(pfd, check_bad_sample);
close(pfd);
}
void test_perf_branches(void)
{
if (test__start_subtest("perf_branches_hw"))
test_perf_branches_hw();
if (test__start_subtest("perf_branches_no_hw"))
test_perf_branches_no_hw();
}
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