xref: /linux/tools/testing/selftests/bpf/prog_tests/kfunc_call.c (revision 3a39d672e7f48b8d6b91a09afa4b55352773b4b5)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2021 Facebook */
3 #include <test_progs.h>
4 #include <network_helpers.h>
5 #include "kfunc_call_fail.skel.h"
6 #include "kfunc_call_test.skel.h"
7 #include "kfunc_call_test.lskel.h"
8 #include "kfunc_call_test_subprog.skel.h"
9 #include "kfunc_call_test_subprog.lskel.h"
10 #include "kfunc_call_destructive.skel.h"
11 
12 #include "cap_helpers.h"
13 
14 static size_t log_buf_sz = 1048576; /* 1 MB */
15 static char obj_log_buf[1048576];
16 
17 enum kfunc_test_type {
18 	tc_test = 0,
19 	syscall_test,
20 	syscall_null_ctx_test,
21 };
22 
23 struct kfunc_test_params {
24 	const char *prog_name;
25 	unsigned long lskel_prog_desc_offset;
26 	int retval;
27 	enum kfunc_test_type test_type;
28 	const char *expected_err_msg;
29 };
30 
31 #define __BPF_TEST_SUCCESS(name, __retval, type) \
32 	{ \
33 	  .prog_name = #name, \
34 	  .lskel_prog_desc_offset = offsetof(struct kfunc_call_test_lskel, progs.name), \
35 	  .retval = __retval, \
36 	  .test_type = type, \
37 	  .expected_err_msg = NULL, \
38 	}
39 
40 #define __BPF_TEST_FAIL(name, __retval, type, error_msg) \
41 	{ \
42 	  .prog_name = #name, \
43 	  .lskel_prog_desc_offset = 0 /* unused when test is failing */, \
44 	  .retval = __retval, \
45 	  .test_type = type, \
46 	  .expected_err_msg = error_msg, \
47 	}
48 
49 #define TC_TEST(name, retval) __BPF_TEST_SUCCESS(name, retval, tc_test)
50 #define SYSCALL_TEST(name, retval) __BPF_TEST_SUCCESS(name, retval, syscall_test)
51 #define SYSCALL_NULL_CTX_TEST(name, retval) __BPF_TEST_SUCCESS(name, retval, syscall_null_ctx_test)
52 
53 #define TC_FAIL(name, retval, error_msg) __BPF_TEST_FAIL(name, retval, tc_test, error_msg)
54 #define SYSCALL_NULL_CTX_FAIL(name, retval, error_msg) \
55 	__BPF_TEST_FAIL(name, retval, syscall_null_ctx_test, error_msg)
56 
57 static struct kfunc_test_params kfunc_tests[] = {
58 	/* failure cases:
59 	 * if retval is 0 -> the program will fail to load and the error message is an error
60 	 * if retval is not 0 -> the program can be loaded but running it will gives the
61 	 *                       provided return value. The error message is thus the one
62 	 *                       from a successful load
63 	 */
64 	SYSCALL_NULL_CTX_FAIL(kfunc_syscall_test_fail, -EINVAL, "processed 4 insns"),
65 	SYSCALL_NULL_CTX_FAIL(kfunc_syscall_test_null_fail, -EINVAL, "processed 4 insns"),
66 	TC_FAIL(kfunc_call_test_get_mem_fail_rdonly, 0, "R0 cannot write into rdonly_mem"),
67 	TC_FAIL(kfunc_call_test_get_mem_fail_use_after_free, 0, "invalid mem access 'scalar'"),
68 	TC_FAIL(kfunc_call_test_get_mem_fail_oob, 0, "min value is outside of the allowed memory range"),
69 	TC_FAIL(kfunc_call_test_get_mem_fail_not_const, 0, "is not a const"),
70 	TC_FAIL(kfunc_call_test_mem_acquire_fail, 0, "acquire kernel function does not return PTR_TO_BTF_ID"),
71 	TC_FAIL(kfunc_call_test_pointer_arg_type_mismatch, 0, "arg#0 expected pointer to ctx, but got scalar"),
72 
73 	/* success cases */
74 	TC_TEST(kfunc_call_test1, 12),
75 	TC_TEST(kfunc_call_test2, 3),
76 	TC_TEST(kfunc_call_test4, -1234),
77 	TC_TEST(kfunc_call_test_ref_btf_id, 0),
78 	TC_TEST(kfunc_call_test_get_mem, 42),
79 	SYSCALL_TEST(kfunc_syscall_test, 0),
80 	SYSCALL_NULL_CTX_TEST(kfunc_syscall_test_null, 0),
81 	TC_TEST(kfunc_call_test_static_unused_arg, 0),
82 	TC_TEST(kfunc_call_ctx, 0),
83 };
84 
85 struct syscall_test_args {
86 	__u8 data[16];
87 	size_t size;
88 };
89 
verify_success(struct kfunc_test_params * param)90 static void verify_success(struct kfunc_test_params *param)
91 {
92 	struct kfunc_call_test_lskel *lskel = NULL;
93 	LIBBPF_OPTS(bpf_test_run_opts, topts);
94 	struct bpf_prog_desc *lskel_prog;
95 	struct kfunc_call_test *skel;
96 	struct bpf_program *prog;
97 	int prog_fd, err;
98 	struct syscall_test_args args = {
99 		.size = 10,
100 	};
101 
102 	switch (param->test_type) {
103 	case syscall_test:
104 		topts.ctx_in = &args;
105 		topts.ctx_size_in = sizeof(args);
106 		/* fallthrough */
107 	case syscall_null_ctx_test:
108 		break;
109 	case tc_test:
110 		topts.data_in = &pkt_v4;
111 		topts.data_size_in = sizeof(pkt_v4);
112 		topts.repeat = 1;
113 		break;
114 	}
115 
116 	/* first test with normal libbpf */
117 	skel = kfunc_call_test__open_and_load();
118 	if (!ASSERT_OK_PTR(skel, "skel"))
119 		return;
120 
121 	prog = bpf_object__find_program_by_name(skel->obj, param->prog_name);
122 	if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
123 		goto cleanup;
124 
125 	prog_fd = bpf_program__fd(prog);
126 	err = bpf_prog_test_run_opts(prog_fd, &topts);
127 	if (!ASSERT_OK(err, param->prog_name))
128 		goto cleanup;
129 
130 	if (!ASSERT_EQ(topts.retval, param->retval, "retval"))
131 		goto cleanup;
132 
133 	/* second test with light skeletons */
134 	lskel = kfunc_call_test_lskel__open_and_load();
135 	if (!ASSERT_OK_PTR(lskel, "lskel"))
136 		goto cleanup;
137 
138 	lskel_prog = (struct bpf_prog_desc *)((char *)lskel + param->lskel_prog_desc_offset);
139 
140 	prog_fd = lskel_prog->prog_fd;
141 	err = bpf_prog_test_run_opts(prog_fd, &topts);
142 	if (!ASSERT_OK(err, param->prog_name))
143 		goto cleanup;
144 
145 	ASSERT_EQ(topts.retval, param->retval, "retval");
146 
147 cleanup:
148 	kfunc_call_test__destroy(skel);
149 	if (lskel)
150 		kfunc_call_test_lskel__destroy(lskel);
151 }
152 
verify_fail(struct kfunc_test_params * param)153 static void verify_fail(struct kfunc_test_params *param)
154 {
155 	LIBBPF_OPTS(bpf_object_open_opts, opts);
156 	LIBBPF_OPTS(bpf_test_run_opts, topts);
157 	struct bpf_program *prog;
158 	struct kfunc_call_fail *skel;
159 	int prog_fd, err;
160 	struct syscall_test_args args = {
161 		.size = 10,
162 	};
163 
164 	opts.kernel_log_buf = obj_log_buf;
165 	opts.kernel_log_size = log_buf_sz;
166 	opts.kernel_log_level = 1;
167 
168 	switch (param->test_type) {
169 	case syscall_test:
170 		topts.ctx_in = &args;
171 		topts.ctx_size_in = sizeof(args);
172 		/* fallthrough */
173 	case syscall_null_ctx_test:
174 		break;
175 	case tc_test:
176 		topts.data_in = &pkt_v4;
177 		topts.data_size_in = sizeof(pkt_v4);
178 		topts.repeat = 1;
179 		break;
180 	}
181 
182 	skel = kfunc_call_fail__open_opts(&opts);
183 	if (!ASSERT_OK_PTR(skel, "kfunc_call_fail__open_opts"))
184 		goto cleanup;
185 
186 	prog = bpf_object__find_program_by_name(skel->obj, param->prog_name);
187 	if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
188 		goto cleanup;
189 
190 	bpf_program__set_autoload(prog, true);
191 
192 	err = kfunc_call_fail__load(skel);
193 	if (!param->retval) {
194 		/* the verifier is supposed to complain and refuses to load */
195 		if (!ASSERT_ERR(err, "unexpected load success"))
196 			goto out_err;
197 
198 	} else {
199 		/* the program is loaded but must dynamically fail */
200 		if (!ASSERT_OK(err, "unexpected load error"))
201 			goto out_err;
202 
203 		prog_fd = bpf_program__fd(prog);
204 		err = bpf_prog_test_run_opts(prog_fd, &topts);
205 		if (!ASSERT_EQ(err, param->retval, param->prog_name))
206 			goto out_err;
207 	}
208 
209 out_err:
210 	if (!ASSERT_OK_PTR(strstr(obj_log_buf, param->expected_err_msg), "expected_err_msg")) {
211 		fprintf(stderr, "Expected err_msg: %s\n", param->expected_err_msg);
212 		fprintf(stderr, "Verifier output: %s\n", obj_log_buf);
213 	}
214 
215 cleanup:
216 	kfunc_call_fail__destroy(skel);
217 }
218 
test_main(void)219 static void test_main(void)
220 {
221 	int i;
222 
223 	for (i = 0; i < ARRAY_SIZE(kfunc_tests); i++) {
224 		if (!test__start_subtest(kfunc_tests[i].prog_name))
225 			continue;
226 
227 		if (!kfunc_tests[i].expected_err_msg)
228 			verify_success(&kfunc_tests[i]);
229 		else
230 			verify_fail(&kfunc_tests[i]);
231 	}
232 }
233 
test_subprog(void)234 static void test_subprog(void)
235 {
236 	struct kfunc_call_test_subprog *skel;
237 	int prog_fd, err;
238 	LIBBPF_OPTS(bpf_test_run_opts, topts,
239 		.data_in = &pkt_v4,
240 		.data_size_in = sizeof(pkt_v4),
241 		.repeat = 1,
242 	);
243 
244 	skel = kfunc_call_test_subprog__open_and_load();
245 	if (!ASSERT_OK_PTR(skel, "skel"))
246 		return;
247 
248 	prog_fd = bpf_program__fd(skel->progs.kfunc_call_test1);
249 	err = bpf_prog_test_run_opts(prog_fd, &topts);
250 	ASSERT_OK(err, "bpf_prog_test_run(test1)");
251 	ASSERT_EQ(topts.retval, 10, "test1-retval");
252 	ASSERT_NEQ(skel->data->active_res, -1, "active_res");
253 	ASSERT_EQ(skel->data->sk_state_res, BPF_TCP_CLOSE, "sk_state_res");
254 
255 	kfunc_call_test_subprog__destroy(skel);
256 }
257 
test_subprog_lskel(void)258 static void test_subprog_lskel(void)
259 {
260 	struct kfunc_call_test_subprog_lskel *skel;
261 	int prog_fd, err;
262 	LIBBPF_OPTS(bpf_test_run_opts, topts,
263 		.data_in = &pkt_v4,
264 		.data_size_in = sizeof(pkt_v4),
265 		.repeat = 1,
266 	);
267 
268 	skel = kfunc_call_test_subprog_lskel__open_and_load();
269 	if (!ASSERT_OK_PTR(skel, "skel"))
270 		return;
271 
272 	prog_fd = skel->progs.kfunc_call_test1.prog_fd;
273 	err = bpf_prog_test_run_opts(prog_fd, &topts);
274 	ASSERT_OK(err, "bpf_prog_test_run(test1)");
275 	ASSERT_EQ(topts.retval, 10, "test1-retval");
276 	ASSERT_NEQ(skel->data->active_res, -1, "active_res");
277 	ASSERT_EQ(skel->data->sk_state_res, BPF_TCP_CLOSE, "sk_state_res");
278 
279 	kfunc_call_test_subprog_lskel__destroy(skel);
280 }
281 
test_destructive_open_and_load(void)282 static int test_destructive_open_and_load(void)
283 {
284 	struct kfunc_call_destructive *skel;
285 	int err;
286 
287 	skel = kfunc_call_destructive__open();
288 	if (!ASSERT_OK_PTR(skel, "prog_open"))
289 		return -1;
290 
291 	err = kfunc_call_destructive__load(skel);
292 
293 	kfunc_call_destructive__destroy(skel);
294 
295 	return err;
296 }
297 
test_destructive(void)298 static void test_destructive(void)
299 {
300 	__u64 save_caps = 0;
301 
302 	ASSERT_OK(test_destructive_open_and_load(), "successful_load");
303 
304 	if (!ASSERT_OK(cap_disable_effective(1ULL << CAP_SYS_BOOT, &save_caps), "drop_caps"))
305 		return;
306 
307 	ASSERT_EQ(test_destructive_open_and_load(), -13, "no_caps_failure");
308 
309 	cap_enable_effective(save_caps, NULL);
310 }
311 
test_kfunc_call(void)312 void test_kfunc_call(void)
313 {
314 	test_main();
315 
316 	if (test__start_subtest("subprog"))
317 		test_subprog();
318 
319 	if (test__start_subtest("subprog_lskel"))
320 		test_subprog_lskel();
321 
322 	if (test__start_subtest("destructive"))
323 		test_destructive();
324 }
325