xref: /linux/tools/testing/selftests/bpf/progs/kprobe_multi_session.c (revision 39daa09d34ada1bc7227d68def63e0a2105b5496)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bpf.h>
3 #include <bpf/bpf_helpers.h>
4 #include <bpf/bpf_tracing.h>
5 #include <stdbool.h>
6 #include "bpf_kfuncs.h"
7 #include "bpf_misc.h"
8 
9 char _license[] SEC("license") = "GPL";
10 
11 extern const void bpf_fentry_test1 __ksym;
12 extern const void bpf_fentry_test2 __ksym;
13 extern const void bpf_fentry_test3 __ksym;
14 extern const void bpf_fentry_test4 __ksym;
15 extern const void bpf_fentry_test5 __ksym;
16 extern const void bpf_fentry_test6 __ksym;
17 extern const void bpf_fentry_test7 __ksym;
18 extern const void bpf_fentry_test8 __ksym;
19 
20 int pid = 0;
21 
22 __u64 kprobe_session_result[8];
23 
24 static int session_check(void *ctx)
25 {
26 	unsigned int i;
27 	__u64 addr;
28 	const void *kfuncs[] = {
29 		&bpf_fentry_test1,
30 		&bpf_fentry_test2,
31 		&bpf_fentry_test3,
32 		&bpf_fentry_test4,
33 		&bpf_fentry_test5,
34 		&bpf_fentry_test6,
35 		&bpf_fentry_test7,
36 		&bpf_fentry_test8,
37 	};
38 
39 	if (bpf_get_current_pid_tgid() >> 32 != pid)
40 		return 1;
41 
42 	addr = bpf_get_func_ip(ctx);
43 
44 	for (i = 0; i < ARRAY_SIZE(kfuncs); i++) {
45 		if (kfuncs[i] == (void *) addr) {
46 			kprobe_session_result[i]++;
47 			break;
48 		}
49 	}
50 
51 	/*
52 	 * Force probes for function bpf_fentry_test[5-8] not to
53 	 * install and execute the return probe
54 	 */
55 	if (((const void *) addr == &bpf_fentry_test5) ||
56 	    ((const void *) addr == &bpf_fentry_test6) ||
57 	    ((const void *) addr == &bpf_fentry_test7) ||
58 	    ((const void *) addr == &bpf_fentry_test8))
59 		return 1;
60 
61 	return 0;
62 }
63 
64 /*
65  * No tests in here, just to trigger 'bpf_fentry_test*'
66  * through tracing test_run
67  */
68 SEC("fentry/bpf_modify_return_test")
69 int BPF_PROG(trigger)
70 {
71 	return 0;
72 }
73 
74 SEC("kprobe.session/bpf_fentry_test*")
75 int test_kprobe(struct pt_regs *ctx)
76 {
77 	return session_check(ctx);
78 }
79