]> Git Repo - J-linux.git/blob - tools/testing/selftests/bpf/prog_tests/recursive_attach.c
Merge tag 'vfs-6.13-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
[J-linux.git] / tools / testing / selftests / bpf / prog_tests / recursive_attach.c
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2023 Red Hat, Inc. */
3 #include <test_progs.h>
4 #include "fentry_recursive.skel.h"
5 #include "fentry_recursive_target.skel.h"
6 #include <bpf/btf.h>
7 #include "bpf/libbpf_internal.h"
8
9 /* Test recursive attachment of tracing progs with more than one nesting level
10  * is not possible. Create a chain of attachment, verify that the last prog
11  * will fail. Depending on the arguments, following cases are tested:
12  *
13  * - Recursive loading of tracing progs, without attaching (attach = false,
14  *   detach = false). The chain looks like this:
15  *       load target
16  *       load fentry1 -> target
17  *       load fentry2 -> fentry1 (fail)
18  *
19  * - Recursive attach of tracing progs (attach = true, detach = false). The
20  *   chain looks like this:
21  *       load target
22  *       load fentry1 -> target
23  *       attach fentry1 -> target
24  *       load fentry2 -> fentry1 (fail)
25  *
26  * - Recursive attach and detach of tracing progs (attach = true, detach =
27  *   true). This validates that attach_tracing_prog flag will be set throughout
28  *   the whole lifecycle of an fentry prog, independently from whether it's
29  *   detached. The chain looks like this:
30  *       load target
31  *       load fentry1 -> target
32  *       attach fentry1 -> target
33  *       detach fentry1
34  *       load fentry2 -> fentry1 (fail)
35  */
36 static void test_recursive_fentry_chain(bool attach, bool detach)
37 {
38         struct fentry_recursive_target *target_skel = NULL;
39         struct fentry_recursive *tracing_chain[2] = {};
40         struct bpf_program *prog;
41         int prev_fd, err;
42
43         target_skel = fentry_recursive_target__open_and_load();
44         if (!ASSERT_OK_PTR(target_skel, "fentry_recursive_target__open_and_load"))
45                 return;
46
47         /* Create an attachment chain with two fentry progs */
48         for (int i = 0; i < 2; i++) {
49                 tracing_chain[i] = fentry_recursive__open();
50                 if (!ASSERT_OK_PTR(tracing_chain[i], "fentry_recursive__open"))
51                         goto close_prog;
52
53                 /* The first prog in the chain is going to be attached to the target
54                  * fentry program, the second one to the previous in the chain.
55                  */
56                 prog = tracing_chain[i]->progs.recursive_attach;
57                 if (i == 0) {
58                         prev_fd = bpf_program__fd(target_skel->progs.test1);
59                         err = bpf_program__set_attach_target(prog, prev_fd, "test1");
60                 } else {
61                         prev_fd = bpf_program__fd(tracing_chain[i-1]->progs.recursive_attach);
62                         err = bpf_program__set_attach_target(prog, prev_fd, "recursive_attach");
63                 }
64
65                 if (!ASSERT_OK(err, "bpf_program__set_attach_target"))
66                         goto close_prog;
67
68                 err = fentry_recursive__load(tracing_chain[i]);
69                 /* The first attach should succeed, the second fail */
70                 if (i == 0) {
71                         if (!ASSERT_OK(err, "fentry_recursive__load"))
72                                 goto close_prog;
73
74                         if (attach) {
75                                 err = fentry_recursive__attach(tracing_chain[i]);
76                                 if (!ASSERT_OK(err, "fentry_recursive__attach"))
77                                         goto close_prog;
78                         }
79
80                         if (detach) {
81                                 /* Flag attach_tracing_prog should still be set, preventing
82                                  * attachment of the following prog.
83                                  */
84                                 fentry_recursive__detach(tracing_chain[i]);
85                         }
86                 } else {
87                         if (!ASSERT_ERR(err, "fentry_recursive__load"))
88                                 goto close_prog;
89                 }
90         }
91
92 close_prog:
93         fentry_recursive_target__destroy(target_skel);
94         for (int i = 0; i < 2; i++) {
95                 fentry_recursive__destroy(tracing_chain[i]);
96         }
97 }
98
99 void test_recursive_fentry(void)
100 {
101         if (test__start_subtest("attach"))
102                 test_recursive_fentry_chain(true, false);
103         if (test__start_subtest("load"))
104                 test_recursive_fentry_chain(false, false);
105         if (test__start_subtest("detach"))
106                 test_recursive_fentry_chain(true, true);
107 }
108
109 /* Test that a tracing prog reattachment (when we land in
110  * "prog->aux->dst_trampoline and tgt_prog is NULL" branch in
111  * bpf_tracing_prog_attach) does not lead to a crash due to missing attach_btf
112  */
113 void test_fentry_attach_btf_presence(void)
114 {
115         struct fentry_recursive_target *target_skel = NULL;
116         struct fentry_recursive *tracing_skel = NULL;
117         struct bpf_program *prog;
118         int err, link_fd, tgt_prog_fd;
119
120         target_skel = fentry_recursive_target__open_and_load();
121         if (!ASSERT_OK_PTR(target_skel, "fentry_recursive_target__open_and_load"))
122                 goto close_prog;
123
124         tracing_skel = fentry_recursive__open();
125         if (!ASSERT_OK_PTR(tracing_skel, "fentry_recursive__open"))
126                 goto close_prog;
127
128         prog = tracing_skel->progs.recursive_attach;
129         tgt_prog_fd = bpf_program__fd(target_skel->progs.fentry_target);
130         err = bpf_program__set_attach_target(prog, tgt_prog_fd, "fentry_target");
131         if (!ASSERT_OK(err, "bpf_program__set_attach_target"))
132                 goto close_prog;
133
134         err = fentry_recursive__load(tracing_skel);
135         if (!ASSERT_OK(err, "fentry_recursive__load"))
136                 goto close_prog;
137
138         tgt_prog_fd = bpf_program__fd(tracing_skel->progs.recursive_attach);
139         link_fd = bpf_link_create(tgt_prog_fd, 0, BPF_TRACE_FENTRY, NULL);
140         if (!ASSERT_GE(link_fd, 0, "link_fd"))
141                 goto close_prog;
142
143         fentry_recursive__detach(tracing_skel);
144
145         err = fentry_recursive__attach(tracing_skel);
146         ASSERT_ERR(err, "fentry_recursive__attach");
147
148 close_prog:
149         fentry_recursive_target__destroy(target_skel);
150         fentry_recursive__destroy(tracing_skel);
151 }
This page took 0.035391 seconds and 4 git commands to generate.