diff options
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/perf_branches.c')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/perf_branches.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/perf_branches.c b/tools/testing/selftests/bpf/prog_tests/perf_branches.c new file mode 100644 index 000000000000..e35c444902a7 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/perf_branches.c @@ -0,0 +1,170 @@ +// 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(); +} |