xref: /linux/tools/testing/selftests/bpf/prog_tests/kfunc_call.c (revision 2af3aa702c05ecd05850db9d9e110be9ffa3cf47)
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_test5, 0),
78 	TC_TEST(kfunc_call_test5_asm, 0),
79 	TC_TEST(kfunc_call_test_ref_btf_id, 0),
80 	TC_TEST(kfunc_call_test_get_mem, 42),
81 	SYSCALL_TEST(kfunc_syscall_test, 0),
82 	SYSCALL_NULL_CTX_TEST(kfunc_syscall_test_null, 0),
83 	TC_TEST(kfunc_call_test_static_unused_arg, 0),
84 	TC_TEST(kfunc_call_ctx, 0),
85 };
86 
87 struct syscall_test_args {
88 	__u8 data[16];
89 	size_t size;
90 };
91 
92 static void verify_success(struct kfunc_test_params *param)
93 {
94 	struct kfunc_call_test_lskel *lskel = NULL;
95 	LIBBPF_OPTS(bpf_test_run_opts, topts);
96 	struct bpf_prog_desc *lskel_prog;
97 	struct kfunc_call_test *skel;
98 	struct bpf_program *prog;
99 	int prog_fd, err;
100 	struct syscall_test_args args = {
101 		.size = 10,
102 	};
103 
104 	switch (param->test_type) {
105 	case syscall_test:
106 		topts.ctx_in = &args;
107 		topts.ctx_size_in = sizeof(args);
108 		/* fallthrough */
109 	case syscall_null_ctx_test:
110 		break;
111 	case tc_test:
112 		topts.data_in = &pkt_v4;
113 		topts.data_size_in = sizeof(pkt_v4);
114 		topts.repeat = 1;
115 		break;
116 	}
117 
118 	/* first test with normal libbpf */
119 	skel = kfunc_call_test__open_and_load();
120 	if (!ASSERT_OK_PTR(skel, "skel"))
121 		return;
122 
123 	prog = bpf_object__find_program_by_name(skel->obj, param->prog_name);
124 	if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
125 		goto cleanup;
126 
127 	prog_fd = bpf_program__fd(prog);
128 	err = bpf_prog_test_run_opts(prog_fd, &topts);
129 	if (!ASSERT_OK(err, param->prog_name))
130 		goto cleanup;
131 
132 	if (!ASSERT_EQ(topts.retval, param->retval, "retval"))
133 		goto cleanup;
134 
135 	/* second test with light skeletons */
136 	lskel = kfunc_call_test_lskel__open_and_load();
137 	if (!ASSERT_OK_PTR(lskel, "lskel"))
138 		goto cleanup;
139 
140 	lskel_prog = (struct bpf_prog_desc *)((char *)lskel + param->lskel_prog_desc_offset);
141 
142 	prog_fd = lskel_prog->prog_fd;
143 	err = bpf_prog_test_run_opts(prog_fd, &topts);
144 	if (!ASSERT_OK(err, param->prog_name))
145 		goto cleanup;
146 
147 	ASSERT_EQ(topts.retval, param->retval, "retval");
148 
149 cleanup:
150 	kfunc_call_test__destroy(skel);
151 	if (lskel)
152 		kfunc_call_test_lskel__destroy(lskel);
153 }
154 
155 static void verify_fail(struct kfunc_test_params *param)
156 {
157 	LIBBPF_OPTS(bpf_object_open_opts, opts);
158 	LIBBPF_OPTS(bpf_test_run_opts, topts);
159 	struct bpf_program *prog;
160 	struct kfunc_call_fail *skel;
161 	int prog_fd, err;
162 	struct syscall_test_args args = {
163 		.size = 10,
164 	};
165 
166 	opts.kernel_log_buf = obj_log_buf;
167 	opts.kernel_log_size = log_buf_sz;
168 	opts.kernel_log_level = 1;
169 
170 	switch (param->test_type) {
171 	case syscall_test:
172 		topts.ctx_in = &args;
173 		topts.ctx_size_in = sizeof(args);
174 		/* fallthrough */
175 	case syscall_null_ctx_test:
176 		break;
177 	case tc_test:
178 		topts.data_in = &pkt_v4;
179 		topts.data_size_in = sizeof(pkt_v4);
180 		topts.repeat = 1;
181 		break;
182 	}
183 
184 	skel = kfunc_call_fail__open_opts(&opts);
185 	if (!ASSERT_OK_PTR(skel, "kfunc_call_fail__open_opts"))
186 		goto cleanup;
187 
188 	prog = bpf_object__find_program_by_name(skel->obj, param->prog_name);
189 	if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
190 		goto cleanup;
191 
192 	bpf_program__set_autoload(prog, true);
193 
194 	err = kfunc_call_fail__load(skel);
195 	if (!param->retval) {
196 		/* the verifier is supposed to complain and refuses to load */
197 		if (!ASSERT_ERR(err, "unexpected load success"))
198 			goto out_err;
199 
200 	} else {
201 		/* the program is loaded but must dynamically fail */
202 		if (!ASSERT_OK(err, "unexpected load error"))
203 			goto out_err;
204 
205 		prog_fd = bpf_program__fd(prog);
206 		err = bpf_prog_test_run_opts(prog_fd, &topts);
207 		if (!ASSERT_EQ(err, param->retval, param->prog_name))
208 			goto out_err;
209 	}
210 
211 out_err:
212 	if (!ASSERT_OK_PTR(strstr(obj_log_buf, param->expected_err_msg), "expected_err_msg")) {
213 		fprintf(stderr, "Expected err_msg: %s\n", param->expected_err_msg);
214 		fprintf(stderr, "Verifier output: %s\n", obj_log_buf);
215 	}
216 
217 cleanup:
218 	kfunc_call_fail__destroy(skel);
219 }
220 
221 static void test_main(void)
222 {
223 	int i;
224 
225 	for (i = 0; i < ARRAY_SIZE(kfunc_tests); i++) {
226 		if (!test__start_subtest(kfunc_tests[i].prog_name))
227 			continue;
228 
229 		if (!kfunc_tests[i].expected_err_msg)
230 			verify_success(&kfunc_tests[i]);
231 		else
232 			verify_fail(&kfunc_tests[i]);
233 	}
234 }
235 
236 static void test_subprog(void)
237 {
238 	struct kfunc_call_test_subprog *skel;
239 	int prog_fd, err;
240 	LIBBPF_OPTS(bpf_test_run_opts, topts,
241 		.data_in = &pkt_v4,
242 		.data_size_in = sizeof(pkt_v4),
243 		.repeat = 1,
244 	);
245 
246 	skel = kfunc_call_test_subprog__open_and_load();
247 	if (!ASSERT_OK_PTR(skel, "skel"))
248 		return;
249 
250 	prog_fd = bpf_program__fd(skel->progs.kfunc_call_test1);
251 	err = bpf_prog_test_run_opts(prog_fd, &topts);
252 	ASSERT_OK(err, "bpf_prog_test_run(test1)");
253 	ASSERT_EQ(topts.retval, 10, "test1-retval");
254 	ASSERT_NEQ(skel->data->active_res, -1, "active_res");
255 	ASSERT_EQ(skel->data->sk_state_res, BPF_TCP_CLOSE, "sk_state_res");
256 
257 	kfunc_call_test_subprog__destroy(skel);
258 }
259 
260 static void test_subprog_lskel(void)
261 {
262 	struct kfunc_call_test_subprog_lskel *skel;
263 	int prog_fd, err;
264 	LIBBPF_OPTS(bpf_test_run_opts, topts,
265 		.data_in = &pkt_v4,
266 		.data_size_in = sizeof(pkt_v4),
267 		.repeat = 1,
268 	);
269 
270 	skel = kfunc_call_test_subprog_lskel__open_and_load();
271 	if (!ASSERT_OK_PTR(skel, "skel"))
272 		return;
273 
274 	prog_fd = skel->progs.kfunc_call_test1.prog_fd;
275 	err = bpf_prog_test_run_opts(prog_fd, &topts);
276 	ASSERT_OK(err, "bpf_prog_test_run(test1)");
277 	ASSERT_EQ(topts.retval, 10, "test1-retval");
278 	ASSERT_NEQ(skel->data->active_res, -1, "active_res");
279 	ASSERT_EQ(skel->data->sk_state_res, BPF_TCP_CLOSE, "sk_state_res");
280 
281 	kfunc_call_test_subprog_lskel__destroy(skel);
282 }
283 
284 static int test_destructive_open_and_load(void)
285 {
286 	struct kfunc_call_destructive *skel;
287 	int err;
288 
289 	skel = kfunc_call_destructive__open();
290 	if (!ASSERT_OK_PTR(skel, "prog_open"))
291 		return -1;
292 
293 	err = kfunc_call_destructive__load(skel);
294 
295 	kfunc_call_destructive__destroy(skel);
296 
297 	return err;
298 }
299 
300 static void test_destructive(void)
301 {
302 	__u64 save_caps = 0;
303 
304 	ASSERT_OK(test_destructive_open_and_load(), "successful_load");
305 
306 	if (!ASSERT_OK(cap_disable_effective(1ULL << CAP_SYS_BOOT, &save_caps), "drop_caps"))
307 		return;
308 
309 	ASSERT_EQ(test_destructive_open_and_load(), -13, "no_caps_failure");
310 
311 	cap_enable_effective(save_caps, NULL);
312 }
313 
314 void test_kfunc_call(void)
315 {
316 	test_main();
317 
318 	if (test__start_subtest("subprog"))
319 		test_subprog();
320 
321 	if (test__start_subtest("subprog_lskel"))
322 		test_subprog_lskel();
323 
324 	if (test__start_subtest("destructive"))
325 		test_destructive();
326 }
327