1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
3 
4 #include <test_progs.h>
5 #include "test_module_attach.skel.h"
6 
7 static int duration;
8 
9 static int trigger_module_test_read(int read_sz)
10 {
11 	int fd, err;
12 
13 	fd = open("/sys/kernel/bpf_testmod", O_RDONLY);
14 	err = -errno;
15 	if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err))
16 		return err;
17 
18 	read(fd, NULL, read_sz);
19 	close(fd);
20 
21 	return 0;
22 }
23 
24 static int trigger_module_test_write(int write_sz)
25 {
26 	int fd, err;
27 	char *buf = malloc(write_sz);
28 
29 	if (!buf)
30 		return -ENOMEM;
31 
32 	memset(buf, 'a', write_sz);
33 	buf[write_sz-1] = '\0';
34 
35 	fd = open("/sys/kernel/bpf_testmod", O_WRONLY);
36 	err = -errno;
37 	if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err)) {
38 		free(buf);
39 		return err;
40 	}
41 
42 	write(fd, buf, write_sz);
43 	close(fd);
44 	free(buf);
45 	return 0;
46 }
47 
48 static int delete_module(const char *name, int flags)
49 {
50 	return syscall(__NR_delete_module, name, flags);
51 }
52 
53 void test_module_attach(void)
54 {
55 	const int READ_SZ = 456;
56 	const int WRITE_SZ = 457;
57 	struct test_module_attach* skel;
58 	struct test_module_attach__bss *bss;
59 	struct bpf_link *link;
60 	int err;
61 
62 	skel = test_module_attach__open();
63 	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
64 		return;
65 
66 	err = bpf_program__set_attach_target(skel->progs.handle_fentry_manual,
67 					     0, "bpf_testmod_test_read");
68 	ASSERT_OK(err, "set_attach_target");
69 
70 	err = test_module_attach__load(skel);
71 	if (CHECK(err, "skel_load", "failed to load skeleton\n"))
72 		return;
73 
74 	bss = skel->bss;
75 
76 	err = test_module_attach__attach(skel);
77 	if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
78 		goto cleanup;
79 
80 	/* trigger tracepoint */
81 	ASSERT_OK(trigger_module_test_read(READ_SZ), "trigger_read");
82 	ASSERT_OK(trigger_module_test_write(WRITE_SZ), "trigger_write");
83 
84 	ASSERT_EQ(bss->raw_tp_read_sz, READ_SZ, "raw_tp");
85 	ASSERT_EQ(bss->raw_tp_bare_write_sz, WRITE_SZ, "raw_tp_bare");
86 	ASSERT_EQ(bss->tp_btf_read_sz, READ_SZ, "tp_btf");
87 	ASSERT_EQ(bss->fentry_read_sz, READ_SZ, "fentry");
88 	ASSERT_EQ(bss->fentry_manual_read_sz, READ_SZ, "fentry_manual");
89 	ASSERT_EQ(bss->fexit_read_sz, READ_SZ, "fexit");
90 	ASSERT_EQ(bss->fexit_ret, -EIO, "fexit_tet");
91 	ASSERT_EQ(bss->fmod_ret_read_sz, READ_SZ, "fmod_ret");
92 
93 	test_module_attach__detach(skel);
94 
95 	/* attach fentry/fexit and make sure it get's module reference */
96 	link = bpf_program__attach(skel->progs.handle_fentry);
97 	if (!ASSERT_OK_PTR(link, "attach_fentry"))
98 		goto cleanup;
99 
100 	ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module");
101 	bpf_link__destroy(link);
102 
103 	link = bpf_program__attach(skel->progs.handle_fexit);
104 	if (!ASSERT_OK_PTR(link, "attach_fexit"))
105 		goto cleanup;
106 
107 	ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module");
108 	bpf_link__destroy(link);
109 
110 cleanup:
111 	test_module_attach__destroy(skel);
112 }
113