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 "bpf/libbpf_internal.h" 8 #include "test_perf_branches.skel.h" 9 10 static 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 it 24 * would require some kind of disassembler and also encoding the 25 * valid jump instructions for supported architectures. So just check 26 * 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 41 static 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 60 static 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 (CHECK(IS_ERR(link), "attach_perf_event", "err %ld\n", PTR_ERR(link))) 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); 94 out_destroy: 95 bpf_link__destroy(link); 96 out_destroy_skel: 97 if (!detached) 98 test_perf_branches__detach(skel); 99 test_perf_branches__destroy(skel); 100 } 101 102 static 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 = 4000; 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 == -1) { 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 configured 141 * perf event. 142 */ 143 static 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 = 4000; 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 } 163 164 void 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