171 lines · c
1// SPDX-License-Identifier: GPL-2.02#define _GNU_SOURCE3#include <pthread.h>4#include <sched.h>5#include <sys/socket.h>6#include <test_progs.h>7#include "bpf/libbpf_internal.h"8#include "test_perf_branches.skel.h"9 10static void check_good_sample(struct test_perf_branches *skel)11{12 int written_global = skel->bss->written_global_out;13 int required_size = skel->bss->required_size_out;14 int written_stack = skel->bss->written_stack_out;15 int pbe_size = sizeof(struct perf_branch_entry);16 int duration = 0;17 18 if (CHECK(!skel->bss->valid, "output not valid",19 "no valid sample from prog"))20 return;21 22 /*23 * It's hard to validate the contents of the branch entries b/c it24 * would require some kind of disassembler and also encoding the25 * valid jump instructions for supported architectures. So just check26 * the easy stuff for now.27 */28 CHECK(required_size <= 0, "read_branches_size", "err %d\n", required_size);29 CHECK(written_stack < 0, "read_branches_stack", "err %d\n", written_stack);30 CHECK(written_stack % pbe_size != 0, "read_branches_stack",31 "stack bytes written=%d not multiple of struct size=%d\n",32 written_stack, pbe_size);33 CHECK(written_global < 0, "read_branches_global", "err %d\n", written_global);34 CHECK(written_global % pbe_size != 0, "read_branches_global",35 "global bytes written=%d not multiple of struct size=%d\n",36 written_global, pbe_size);37 CHECK(written_global < written_stack, "read_branches_size",38 "written_global=%d < written_stack=%d\n", written_global, written_stack);39}40 41static void check_bad_sample(struct test_perf_branches *skel)42{43 int written_global = skel->bss->written_global_out;44 int required_size = skel->bss->required_size_out;45 int written_stack = skel->bss->written_stack_out;46 int duration = 0;47 48 if (CHECK(!skel->bss->valid, "output not valid",49 "no valid sample from prog"))50 return;51 52 CHECK((required_size != -EINVAL && required_size != -ENOENT),53 "read_branches_size", "err %d\n", required_size);54 CHECK((written_stack != -EINVAL && written_stack != -ENOENT),55 "read_branches_stack", "written %d\n", written_stack);56 CHECK((written_global != -EINVAL && written_global != -ENOENT),57 "read_branches_global", "written %d\n", written_global);58}59 60static void test_perf_branches_common(int perf_fd,61 void (*cb)(struct test_perf_branches *))62{63 struct test_perf_branches *skel;64 int err, i, duration = 0;65 bool detached = false;66 struct bpf_link *link;67 volatile int j = 0;68 cpu_set_t cpu_set;69 70 skel = test_perf_branches__open_and_load();71 if (CHECK(!skel, "test_perf_branches_load",72 "perf_branches skeleton failed\n"))73 return;74 75 /* attach perf_event */76 link = bpf_program__attach_perf_event(skel->progs.perf_branches, perf_fd);77 if (!ASSERT_OK_PTR(link, "attach_perf_event"))78 goto out_destroy_skel;79 80 /* generate some branches on cpu 0 */81 CPU_ZERO(&cpu_set);82 CPU_SET(0, &cpu_set);83 err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);84 if (CHECK(err, "set_affinity", "cpu #0, err %d\n", err))85 goto out_destroy;86 /* spin the loop for a while (random high number) */87 for (i = 0; i < 1000000; ++i)88 ++j;89 90 test_perf_branches__detach(skel);91 detached = true;92 93 cb(skel);94out_destroy:95 bpf_link__destroy(link);96out_destroy_skel:97 if (!detached)98 test_perf_branches__detach(skel);99 test_perf_branches__destroy(skel);100}101 102static void test_perf_branches_hw(void)103{104 struct perf_event_attr attr = {0};105 int duration = 0;106 int pfd;107 108 /* create perf event */109 attr.size = sizeof(attr);110 attr.type = PERF_TYPE_HARDWARE;111 attr.config = PERF_COUNT_HW_CPU_CYCLES;112 attr.freq = 1;113 attr.sample_freq = 1000;114 attr.sample_type = PERF_SAMPLE_BRANCH_STACK;115 attr.branch_sample_type = PERF_SAMPLE_BRANCH_USER | PERF_SAMPLE_BRANCH_ANY;116 pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);117 118 /*119 * Some setups don't support branch records (virtual machines, !x86),120 * so skip test in this case.121 */122 if (pfd < 0) {123 if (errno == ENOENT || errno == EOPNOTSUPP) {124 printf("%s:SKIP:no PERF_SAMPLE_BRANCH_STACK\n",125 __func__);126 test__skip();127 return;128 }129 if (CHECK(pfd < 0, "perf_event_open", "err %d errno %d\n",130 pfd, errno))131 return;132 }133 134 test_perf_branches_common(pfd, check_good_sample);135 136 close(pfd);137}138 139/*140 * Tests negative case -- run bpf_read_branch_records() on improperly configured141 * perf event.142 */143static void test_perf_branches_no_hw(void)144{145 struct perf_event_attr attr = {0};146 int duration = 0;147 int pfd;148 149 /* create perf event */150 attr.size = sizeof(attr);151 attr.type = PERF_TYPE_SOFTWARE;152 attr.config = PERF_COUNT_SW_CPU_CLOCK;153 attr.freq = 1;154 attr.sample_freq = 1000;155 pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);156 if (CHECK(pfd < 0, "perf_event_open", "err %d\n", pfd))157 return;158 159 test_perf_branches_common(pfd, check_bad_sample);160 161 close(pfd);162}163 164void test_perf_branches(void)165{166 if (test__start_subtest("perf_branches_hw"))167 test_perf_branches_hw();168 if (test__start_subtest("perf_branches_no_hw"))169 test_perf_branches_no_hw();170}171