1 // SPDX-License-Identifier: GPL-2.0 2 #include <test_progs.h> 3 #include "missed_kprobe.skel.h" 4 #include "missed_kprobe_recursion.skel.h" 5 #include "missed_tp_recursion.skel.h" 6 7 /* 8 * Putting kprobe on bpf_fentry_test1 that calls bpf_kfunc_common_test 9 * kfunc, which has also kprobe on. The latter won't get triggered due 10 * to kprobe recursion check and kprobe missed counter is incremented. 11 */ 12 static void test_missed_perf_kprobe(void) 13 { 14 LIBBPF_OPTS(bpf_test_run_opts, topts); 15 struct bpf_link_info info = {}; 16 struct missed_kprobe *skel; 17 __u32 len = sizeof(info); 18 int err, prog_fd; 19 20 skel = missed_kprobe__open_and_load(); 21 if (!ASSERT_OK_PTR(skel, "missed_kprobe__open_and_load")) 22 goto cleanup; 23 24 err = missed_kprobe__attach(skel); 25 if (!ASSERT_OK(err, "missed_kprobe__attach")) 26 goto cleanup; 27 28 prog_fd = bpf_program__fd(skel->progs.trigger); 29 err = bpf_prog_test_run_opts(prog_fd, &topts); 30 ASSERT_OK(err, "test_run"); 31 ASSERT_EQ(topts.retval, 0, "test_run"); 32 33 err = bpf_link_get_info_by_fd(bpf_link__fd(skel->links.test2), &info, &len); 34 if (!ASSERT_OK(err, "bpf_link_get_info_by_fd")) 35 goto cleanup; 36 37 ASSERT_EQ(info.type, BPF_LINK_TYPE_PERF_EVENT, "info.type"); 38 ASSERT_EQ(info.perf_event.type, BPF_PERF_EVENT_KPROBE, "info.perf_event.type"); 39 ASSERT_EQ(info.perf_event.kprobe.missed, 1, "info.perf_event.kprobe.missed"); 40 41 cleanup: 42 missed_kprobe__destroy(skel); 43 } 44 45 static __u64 get_missed_count(int fd) 46 { 47 struct bpf_prog_info info = {}; 48 __u32 len = sizeof(info); 49 int err; 50 51 err = bpf_prog_get_info_by_fd(fd, &info, &len); 52 if (!ASSERT_OK(err, "bpf_prog_get_info_by_fd")) 53 return (__u64) -1; 54 return info.recursion_misses; 55 } 56 57 /* 58 * Putting kprobe.multi on bpf_fentry_test1 that calls bpf_kfunc_common_test 59 * kfunc which has 3 perf event kprobes and 1 kprobe.multi attached. 60 * 61 * Because fprobe (kprobe.multi attach layear) does not have strict recursion 62 * check the kprobe's bpf_prog_active check is hit for test2-5. 63 */ 64 static void test_missed_kprobe_recursion(void) 65 { 66 LIBBPF_OPTS(bpf_test_run_opts, topts); 67 struct missed_kprobe_recursion *skel; 68 int err, prog_fd; 69 70 skel = missed_kprobe_recursion__open_and_load(); 71 if (!ASSERT_OK_PTR(skel, "missed_kprobe_recursion__open_and_load")) 72 goto cleanup; 73 74 err = missed_kprobe_recursion__attach(skel); 75 if (!ASSERT_OK(err, "missed_kprobe_recursion__attach")) 76 goto cleanup; 77 78 prog_fd = bpf_program__fd(skel->progs.trigger); 79 err = bpf_prog_test_run_opts(prog_fd, &topts); 80 ASSERT_OK(err, "test_run"); 81 ASSERT_EQ(topts.retval, 0, "test_run"); 82 83 ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test1)), 0, "test1_recursion_misses"); 84 ASSERT_GE(get_missed_count(bpf_program__fd(skel->progs.test2)), 1, "test2_recursion_misses"); 85 ASSERT_GE(get_missed_count(bpf_program__fd(skel->progs.test3)), 1, "test3_recursion_misses"); 86 ASSERT_GE(get_missed_count(bpf_program__fd(skel->progs.test4)), 1, "test4_recursion_misses"); 87 ASSERT_GE(get_missed_count(bpf_program__fd(skel->progs.test5)), 1, "test5_recursion_misses"); 88 89 cleanup: 90 missed_kprobe_recursion__destroy(skel); 91 } 92 93 /* 94 * Putting kprobe on bpf_fentry_test1 that calls bpf_printk and invokes 95 * bpf_trace_printk tracepoint. The bpf_trace_printk tracepoint has test[234] 96 * programs attached to it. 97 * 98 * Because kprobe execution goes through bpf_prog_active check, programs 99 * attached to the tracepoint will fail the recursion check and increment 100 * the recursion_misses stats. 101 */ 102 static void test_missed_tp_recursion(void) 103 { 104 LIBBPF_OPTS(bpf_test_run_opts, topts); 105 struct missed_tp_recursion *skel; 106 int err, prog_fd; 107 108 skel = missed_tp_recursion__open_and_load(); 109 if (!ASSERT_OK_PTR(skel, "missed_tp_recursion__open_and_load")) 110 goto cleanup; 111 112 err = missed_tp_recursion__attach(skel); 113 if (!ASSERT_OK(err, "missed_tp_recursion__attach")) 114 goto cleanup; 115 116 prog_fd = bpf_program__fd(skel->progs.trigger); 117 err = bpf_prog_test_run_opts(prog_fd, &topts); 118 ASSERT_OK(err, "test_run"); 119 ASSERT_EQ(topts.retval, 0, "test_run"); 120 121 ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test1)), 0, "test1_recursion_misses"); 122 ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test2)), 1, "test2_recursion_misses"); 123 ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test3)), 1, "test3_recursion_misses"); 124 ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test4)), 1, "test4_recursion_misses"); 125 126 cleanup: 127 missed_tp_recursion__destroy(skel); 128 } 129 130 void test_missed(void) 131 { 132 if (test__start_subtest("perf_kprobe")) 133 test_missed_perf_kprobe(); 134 if (test__start_subtest("kprobe_recursion")) 135 test_missed_kprobe_recursion(); 136 if (test__start_subtest("tp_recursion")) 137 test_missed_tp_recursion(); 138 } 139