xref: /linux/tools/testing/selftests/bpf/prog_tests/kfunc_call.c (revision 5763790965eb3414148720f030b20fd5ccc438ca)
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_zero_size, 0, "min value is outside of the allowed memory range"),
70 	TC_FAIL(kfunc_call_test_get_mem_fail_oversized, 0, "allocation size exceeds u32 max"),
71 	TC_FAIL(kfunc_call_test_get_mem_fail_not_const, 0, "is not a const"),
72 	TC_FAIL(kfunc_call_test_mem_acquire_fail, 0, "acquire kernel function does not return PTR_TO_BTF_ID"),
73 	TC_FAIL(kfunc_call_test_pointer_arg_type_mismatch, 0, "R1 expected pointer to ctx, but got scalar"),
74 
75 	/* success cases */
76 	TC_TEST(kfunc_call_test1, 12),
77 	TC_TEST(kfunc_call_test2, 3),
78 	TC_TEST(kfunc_call_test4, -1234),
79 	TC_TEST(kfunc_call_test5, 0),
80 	TC_TEST(kfunc_call_test5_asm, 0),
81 	TC_TEST(kfunc_call_test_ref_btf_id, 0),
82 	TC_TEST(kfunc_call_test_get_mem, 42),
83 	SYSCALL_TEST(kfunc_syscall_test, 0),
84 	SYSCALL_NULL_CTX_TEST(kfunc_syscall_test_null, 0),
85 	TC_TEST(kfunc_call_test_static_unused_arg, 0),
86 	TC_TEST(kfunc_call_ctx, 0),
87 };
88 
89 struct syscall_test_args {
90 	__u8 data[16];
91 	size_t size;
92 };
93 
94 static void verify_success(struct kfunc_test_params *param)
95 {
96 	struct kfunc_call_test_lskel *lskel = NULL;
97 	LIBBPF_OPTS(bpf_test_run_opts, topts);
98 	struct bpf_prog_desc *lskel_prog;
99 	struct kfunc_call_test *skel;
100 	struct bpf_program *prog;
101 	int prog_fd, err;
102 	struct syscall_test_args args = {
103 		.size = 10,
104 	};
105 
106 	switch (param->test_type) {
107 	case syscall_test:
108 		topts.ctx_in = &args;
109 		topts.ctx_size_in = sizeof(args);
110 		/* fallthrough */
111 	case syscall_null_ctx_test:
112 		break;
113 	case tc_test:
114 		topts.data_in = &pkt_v4;
115 		topts.data_size_in = sizeof(pkt_v4);
116 		topts.repeat = 1;
117 		break;
118 	}
119 
120 	/* first test with normal libbpf */
121 	skel = kfunc_call_test__open_and_load();
122 	if (!ASSERT_OK_PTR(skel, "skel"))
123 		return;
124 
125 	prog = bpf_object__find_program_by_name(skel->obj, param->prog_name);
126 	if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
127 		goto cleanup;
128 
129 	prog_fd = bpf_program__fd(prog);
130 	err = bpf_prog_test_run_opts(prog_fd, &topts);
131 	if (!ASSERT_OK(err, param->prog_name))
132 		goto cleanup;
133 
134 	if (!ASSERT_EQ(topts.retval, param->retval, "retval"))
135 		goto cleanup;
136 
137 	/* second test with light skeletons */
138 	lskel = kfunc_call_test_lskel__open_and_load();
139 	if (!ASSERT_OK_PTR(lskel, "lskel"))
140 		goto cleanup;
141 
142 	lskel_prog = (struct bpf_prog_desc *)((char *)lskel + param->lskel_prog_desc_offset);
143 
144 	prog_fd = lskel_prog->prog_fd;
145 	err = bpf_prog_test_run_opts(prog_fd, &topts);
146 	if (!ASSERT_OK(err, param->prog_name))
147 		goto cleanup;
148 
149 	ASSERT_EQ(topts.retval, param->retval, "retval");
150 
151 cleanup:
152 	kfunc_call_test__destroy(skel);
153 	if (lskel)
154 		kfunc_call_test_lskel__destroy(lskel);
155 }
156 
157 static void verify_fail(struct kfunc_test_params *param)
158 {
159 	LIBBPF_OPTS(bpf_object_open_opts, opts);
160 	LIBBPF_OPTS(bpf_test_run_opts, topts);
161 	struct bpf_program *prog;
162 	struct kfunc_call_fail *skel;
163 	int prog_fd, err;
164 	struct syscall_test_args args = {
165 		.size = 10,
166 	};
167 
168 	opts.kernel_log_buf = obj_log_buf;
169 	opts.kernel_log_size = log_buf_sz;
170 	opts.kernel_log_level = 1;
171 
172 	switch (param->test_type) {
173 	case syscall_test:
174 		topts.ctx_in = &args;
175 		topts.ctx_size_in = sizeof(args);
176 		/* fallthrough */
177 	case syscall_null_ctx_test:
178 		break;
179 	case tc_test:
180 		topts.data_in = &pkt_v4;
181 		topts.data_size_in = sizeof(pkt_v4);
182 		topts.repeat = 1;
183 		break;
184 	}
185 
186 	skel = kfunc_call_fail__open_opts(&opts);
187 	if (!ASSERT_OK_PTR(skel, "kfunc_call_fail__open_opts"))
188 		goto cleanup;
189 
190 	prog = bpf_object__find_program_by_name(skel->obj, param->prog_name);
191 	if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
192 		goto cleanup;
193 
194 	bpf_program__set_autoload(prog, true);
195 
196 	err = kfunc_call_fail__load(skel);
197 	if (!param->retval) {
198 		/* the verifier is supposed to complain and refuses to load */
199 		if (!ASSERT_ERR(err, "unexpected load success"))
200 			goto out_err;
201 
202 	} else {
203 		/* the program is loaded but must dynamically fail */
204 		if (!ASSERT_OK(err, "unexpected load error"))
205 			goto out_err;
206 
207 		prog_fd = bpf_program__fd(prog);
208 		err = bpf_prog_test_run_opts(prog_fd, &topts);
209 		if (!ASSERT_EQ(err, param->retval, param->prog_name))
210 			goto out_err;
211 	}
212 
213 out_err:
214 	if (!ASSERT_OK_PTR(strstr(obj_log_buf, param->expected_err_msg), "expected_err_msg")) {
215 		fprintf(stderr, "Expected err_msg: %s\n", param->expected_err_msg);
216 		fprintf(stderr, "Verifier output: %s\n", obj_log_buf);
217 	}
218 
219 cleanup:
220 	kfunc_call_fail__destroy(skel);
221 }
222 
223 static void test_main(void)
224 {
225 	int i;
226 
227 	for (i = 0; i < ARRAY_SIZE(kfunc_tests); i++) {
228 		if (!test__start_subtest(kfunc_tests[i].prog_name))
229 			continue;
230 
231 		if (!kfunc_tests[i].expected_err_msg)
232 			verify_success(&kfunc_tests[i]);
233 		else
234 			verify_fail(&kfunc_tests[i]);
235 	}
236 }
237 
238 static void test_subprog(void)
239 {
240 	struct kfunc_call_test_subprog *skel;
241 	int prog_fd, err;
242 	LIBBPF_OPTS(bpf_test_run_opts, topts,
243 		.data_in = &pkt_v4,
244 		.data_size_in = sizeof(pkt_v4),
245 		.repeat = 1,
246 	);
247 
248 	skel = kfunc_call_test_subprog__open_and_load();
249 	if (!ASSERT_OK_PTR(skel, "skel"))
250 		return;
251 
252 	prog_fd = bpf_program__fd(skel->progs.kfunc_call_test1);
253 	err = bpf_prog_test_run_opts(prog_fd, &topts);
254 	ASSERT_OK(err, "bpf_prog_test_run(test1)");
255 	ASSERT_EQ(topts.retval, 10, "test1-retval");
256 	ASSERT_NEQ(skel->data->active_res, -1, "active_res");
257 	ASSERT_EQ(skel->data->sk_state_res, BPF_TCP_CLOSE, "sk_state_res");
258 
259 	kfunc_call_test_subprog__destroy(skel);
260 }
261 
262 static void test_subprog_lskel(void)
263 {
264 	struct kfunc_call_test_subprog_lskel *skel;
265 	int prog_fd, err;
266 	LIBBPF_OPTS(bpf_test_run_opts, topts,
267 		.data_in = &pkt_v4,
268 		.data_size_in = sizeof(pkt_v4),
269 		.repeat = 1,
270 	);
271 
272 	skel = kfunc_call_test_subprog_lskel__open_and_load();
273 	if (!ASSERT_OK_PTR(skel, "skel"))
274 		return;
275 
276 	prog_fd = skel->progs.kfunc_call_test1.prog_fd;
277 	err = bpf_prog_test_run_opts(prog_fd, &topts);
278 	ASSERT_OK(err, "bpf_prog_test_run(test1)");
279 	ASSERT_EQ(topts.retval, 10, "test1-retval");
280 	ASSERT_NEQ(skel->data->active_res, -1, "active_res");
281 	ASSERT_EQ(skel->data->sk_state_res, BPF_TCP_CLOSE, "sk_state_res");
282 
283 	kfunc_call_test_subprog_lskel__destroy(skel);
284 }
285 
286 static int test_destructive_open_and_load(void)
287 {
288 	struct kfunc_call_destructive *skel;
289 	int err;
290 
291 	skel = kfunc_call_destructive__open();
292 	if (!ASSERT_OK_PTR(skel, "prog_open"))
293 		return -1;
294 
295 	err = kfunc_call_destructive__load(skel);
296 
297 	kfunc_call_destructive__destroy(skel);
298 
299 	return err;
300 }
301 
302 static void test_destructive(void)
303 {
304 	__u64 save_caps = 0;
305 
306 	ASSERT_OK(test_destructive_open_and_load(), "successful_load");
307 
308 	if (!ASSERT_OK(cap_disable_effective(1ULL << CAP_SYS_BOOT, &save_caps), "drop_caps"))
309 		return;
310 
311 	ASSERT_EQ(test_destructive_open_and_load(), -13, "no_caps_failure");
312 
313 	cap_enable_effective(save_caps, NULL);
314 }
315 
316 void test_kfunc_call(void)
317 {
318 	test_main();
319 
320 	if (test__start_subtest("subprog"))
321 		test_subprog();
322 
323 	if (test__start_subtest("subprog_lskel"))
324 		test_subprog_lskel();
325 
326 	if (test__start_subtest("destructive"))
327 		test_destructive();
328 }
329