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 */
12static 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
41cleanup:
42	missed_kprobe__destroy(skel);
43}
44
45static __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 */
64static 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
89cleanup:
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 */
102static 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
126cleanup:
127	missed_tp_recursion__destroy(skel);
128}
129
130void 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