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  1// SPDX-License-Identifier: GPL-2.0
  2/* Copyright (c) 2021 Facebook */
  3
  4#include <test_progs.h>
  5#include <bpf/btf.h>
  6
  7#include "test_log_buf.skel.h"
  8#include "bpf_util.h"
  9
 10static size_t libbpf_log_pos;
 11static char libbpf_log_buf[1024 * 1024];
 12static bool libbpf_log_error;
 13
 14static int libbpf_print_cb(enum libbpf_print_level level, const char *fmt, va_list args)
 15{
 16	int emitted_cnt;
 17	size_t left_cnt;
 18
 19	left_cnt = sizeof(libbpf_log_buf) - libbpf_log_pos;
 20	emitted_cnt = vsnprintf(libbpf_log_buf + libbpf_log_pos, left_cnt, fmt, args);
 21
 22	if (emitted_cnt < 0 || emitted_cnt + 1 > left_cnt) {
 23		libbpf_log_error = true;
 24		return 0;
 25	}
 26
 27	libbpf_log_pos += emitted_cnt;
 28	return 0;
 29}
 30
 31static void obj_load_log_buf(void)
 32{
 33	libbpf_print_fn_t old_print_cb = libbpf_set_print(libbpf_print_cb);
 34	LIBBPF_OPTS(bpf_object_open_opts, opts);
 35	const size_t log_buf_sz = 1024 * 1024;
 36	struct test_log_buf* skel;
 37	char *obj_log_buf, *good_log_buf, *bad_log_buf;
 38	int err;
 39
 40	obj_log_buf = malloc(3 * log_buf_sz);
 41	if (!ASSERT_OK_PTR(obj_log_buf, "obj_log_buf"))
 42		return;
 43
 44	good_log_buf = obj_log_buf + log_buf_sz;
 45	bad_log_buf = obj_log_buf + 2 * log_buf_sz;
 46	obj_log_buf[0] = good_log_buf[0] = bad_log_buf[0] = '\0';
 47
 48	opts.kernel_log_buf = obj_log_buf;
 49	opts.kernel_log_size = log_buf_sz;
 50	opts.kernel_log_level = 4; /* for BTF this will turn into 1 */
 51
 52	/* In the first round every prog has its own log_buf, so libbpf logs
 53	 * don't have program failure logs
 54	 */
 55	skel = test_log_buf__open_opts(&opts);
 56	if (!ASSERT_OK_PTR(skel, "skel_open"))
 57		goto cleanup;
 58
 59	/* set very verbose level for good_prog so we always get detailed logs */
 60	bpf_program__set_log_buf(skel->progs.good_prog, good_log_buf, log_buf_sz);
 61	bpf_program__set_log_level(skel->progs.good_prog, 2);
 62
 63	bpf_program__set_log_buf(skel->progs.bad_prog, bad_log_buf, log_buf_sz);
 64	/* log_level 0 with custom log_buf means that verbose logs are not
 65	 * requested if program load is successful, but libbpf should retry
 66	 * with log_level 1 on error and put program's verbose load log into
 67	 * custom log_buf
 68	 */
 69	bpf_program__set_log_level(skel->progs.bad_prog, 0);
 70
 71	err = test_log_buf__load(skel);
 72	if (!ASSERT_ERR(err, "unexpected_load_success"))
 73		goto cleanup;
 74
 75	ASSERT_FALSE(libbpf_log_error, "libbpf_log_error");
 76
 77	/* there should be no prog loading log because we specified per-prog log buf */
 78	ASSERT_NULL(strstr(libbpf_log_buf, "-- BEGIN PROG LOAD LOG --"), "unexp_libbpf_log");
 79	ASSERT_OK_PTR(strstr(libbpf_log_buf, "prog 'bad_prog': BPF program load failed"),
 80		      "libbpf_log_not_empty");
 81	ASSERT_OK_PTR(strstr(obj_log_buf, "DATASEC license"), "obj_log_not_empty");
 82	ASSERT_OK_PTR(strstr(good_log_buf, "0: R1=ctx() R10=fp0"),
 83		      "good_log_verbose");
 84	ASSERT_OK_PTR(strstr(bad_log_buf, "invalid access to map value, value_size=16 off=16000 size=4"),
 85		      "bad_log_not_empty");
 86
 87	if (env.verbosity > VERBOSE_NONE) {
 88		printf("LIBBPF LOG:   \n=================\n%s=================\n", libbpf_log_buf);
 89		printf("OBJ LOG:      \n=================\n%s=================\n", obj_log_buf);
 90		printf("GOOD_PROG LOG:\n=================\n%s=================\n", good_log_buf);
 91		printf("BAD_PROG  LOG:\n=================\n%s=================\n", bad_log_buf);
 92	}
 93
 94	/* reset everything */
 95	test_log_buf__destroy(skel);
 96	obj_log_buf[0] = good_log_buf[0] = bad_log_buf[0] = '\0';
 97	libbpf_log_buf[0] = '\0';
 98	libbpf_log_pos = 0;
 99	libbpf_log_error = false;
100
101	/* In the second round we let bad_prog's failure be logged through print callback */
102	opts.kernel_log_buf = NULL; /* let everything through into print callback */
103	opts.kernel_log_size = 0;
104	opts.kernel_log_level = 1;
105
106	skel = test_log_buf__open_opts(&opts);
107	if (!ASSERT_OK_PTR(skel, "skel_open"))
108		goto cleanup;
109
110	/* set normal verbose level for good_prog to check log_level is taken into account */
111	bpf_program__set_log_buf(skel->progs.good_prog, good_log_buf, log_buf_sz);
112	bpf_program__set_log_level(skel->progs.good_prog, 1);
113
114	err = test_log_buf__load(skel);
115	if (!ASSERT_ERR(err, "unexpected_load_success"))
116		goto cleanup;
117
118	ASSERT_FALSE(libbpf_log_error, "libbpf_log_error");
119
120	/* this time prog loading error should be logged through print callback */
121	ASSERT_OK_PTR(strstr(libbpf_log_buf, "libbpf: prog 'bad_prog': -- BEGIN PROG LOAD LOG --"),
122		      "libbpf_log_correct");
123	ASSERT_STREQ(obj_log_buf, "", "obj_log__empty");
124	ASSERT_STREQ(good_log_buf, "processed 4 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0\n",
125		     "good_log_ok");
126	ASSERT_STREQ(bad_log_buf, "", "bad_log_empty");
127
128	if (env.verbosity > VERBOSE_NONE) {
129		printf("LIBBPF LOG:   \n=================\n%s=================\n", libbpf_log_buf);
130		printf("OBJ LOG:      \n=================\n%s=================\n", obj_log_buf);
131		printf("GOOD_PROG LOG:\n=================\n%s=================\n", good_log_buf);
132		printf("BAD_PROG  LOG:\n=================\n%s=================\n", bad_log_buf);
133	}
134
135cleanup:
136	free(obj_log_buf);
137	test_log_buf__destroy(skel);
138	libbpf_set_print(old_print_cb);
139}
140
141static void bpf_prog_load_log_buf(void)
142{
143	const struct bpf_insn good_prog_insns[] = {
144		BPF_MOV64_IMM(BPF_REG_0, 0),
145		BPF_EXIT_INSN(),
146	};
147	const size_t good_prog_insn_cnt = ARRAY_SIZE(good_prog_insns);
148	const struct bpf_insn bad_prog_insns[] = {
149		BPF_EXIT_INSN(),
150	};
151	size_t bad_prog_insn_cnt = ARRAY_SIZE(bad_prog_insns);
152	LIBBPF_OPTS(bpf_prog_load_opts, opts);
153	const size_t log_buf_sz = 1024 * 1024;
154	char *log_buf;
155	int fd = -1;
156
157	log_buf = malloc(log_buf_sz);
158	if (!ASSERT_OK_PTR(log_buf, "log_buf_alloc"))
159		return;
160	opts.log_buf = log_buf;
161	opts.log_size = log_buf_sz;
162
163	/* with log_level == 0 log_buf should stay empty for good prog */
164	log_buf[0] = '\0';
165	opts.log_level = 0;
166	fd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, "good_prog", "GPL",
167			   good_prog_insns, good_prog_insn_cnt, &opts);
168	ASSERT_STREQ(log_buf, "", "good_log_0");
169	ASSERT_GE(fd, 0, "good_fd1");
170	if (fd >= 0)
171		close(fd);
172
173	/* log_level == 2 should always fill log_buf, even for good prog */
174	log_buf[0] = '\0';
175	opts.log_level = 2;
176	fd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, "good_prog", "GPL",
177			   good_prog_insns, good_prog_insn_cnt, &opts);
178	ASSERT_OK_PTR(strstr(log_buf, "0: R1=ctx() R10=fp0"), "good_log_2");
179	ASSERT_GE(fd, 0, "good_fd2");
180	if (fd >= 0)
181		close(fd);
182
183	/* log_level == 0 should fill log_buf for bad prog */
184	log_buf[0] = '\0';
185	opts.log_level = 0;
186	fd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, "bad_prog", "GPL",
187			   bad_prog_insns, bad_prog_insn_cnt, &opts);
188	ASSERT_OK_PTR(strstr(log_buf, "R0 !read_ok"), "bad_log_0");
189	ASSERT_LT(fd, 0, "bad_fd");
190	if (fd >= 0)
191		close(fd);
192
193	free(log_buf);
194}
195
196static void bpf_btf_load_log_buf(void)
197{
198	LIBBPF_OPTS(bpf_btf_load_opts, opts);
199	const size_t log_buf_sz = 1024 * 1024;
200	const void *raw_btf_data;
201	__u32 raw_btf_size;
202	struct btf *btf;
203	char *log_buf = NULL;
204	int fd = -1;
205
206	btf = btf__new_empty();
207	if (!ASSERT_OK_PTR(btf, "empty_btf"))
208		return;
209
210	ASSERT_GT(btf__add_int(btf, "int", 4, 0), 0, "int_type");
211
212	raw_btf_data = btf__raw_data(btf, &raw_btf_size);
213	if (!ASSERT_OK_PTR(raw_btf_data, "raw_btf_data_good"))
214		goto cleanup;
215
216	log_buf = malloc(log_buf_sz);
217	if (!ASSERT_OK_PTR(log_buf, "log_buf_alloc"))
218		goto cleanup;
219	opts.log_buf = log_buf;
220	opts.log_size = log_buf_sz;
221
222	/* with log_level == 0 log_buf should stay empty for good BTF */
223	log_buf[0] = '\0';
224	opts.log_level = 0;
225	fd = bpf_btf_load(raw_btf_data, raw_btf_size, &opts);
226	ASSERT_STREQ(log_buf, "", "good_log_0");
227	ASSERT_GE(fd, 0, "good_fd1");
228	if (fd >= 0)
229		close(fd);
230	fd = -1;
231
232	/* log_level == 2 should always fill log_buf, even for good BTF */
233	log_buf[0] = '\0';
234	opts.log_level = 2;
235	fd = bpf_btf_load(raw_btf_data, raw_btf_size, &opts);
236	printf("LOG_BUF: %s\n", log_buf);
237	ASSERT_OK_PTR(strstr(log_buf, "magic: 0xeb9f"), "good_log_2");
238	ASSERT_GE(fd, 0, "good_fd2");
239	if (fd >= 0)
240		close(fd);
241	fd = -1;
242
243	/* make BTF bad, add pointer pointing to non-existing type */
244	ASSERT_GT(btf__add_ptr(btf, 100), 0, "bad_ptr_type");
245
246	raw_btf_data = btf__raw_data(btf, &raw_btf_size);
247	if (!ASSERT_OK_PTR(raw_btf_data, "raw_btf_data_bad"))
248		goto cleanup;
249
250	/* log_level == 0 should fill log_buf for bad BTF */
251	log_buf[0] = '\0';
252	opts.log_level = 0;
253	fd = bpf_btf_load(raw_btf_data, raw_btf_size, &opts);
254	printf("LOG_BUF: %s\n", log_buf);
255	ASSERT_OK_PTR(strstr(log_buf, "[2] PTR (anon) type_id=100 Invalid type_id"), "bad_log_0");
256	ASSERT_LT(fd, 0, "bad_fd");
257	if (fd >= 0)
258		close(fd);
259	fd = -1;
260
261cleanup:
262	free(log_buf);
263	btf__free(btf);
264}
265
266void test_log_buf(void)
267{
268	if (test__start_subtest("obj_load_log_buf"))
269		obj_load_log_buf();
270	if (test__start_subtest("bpf_prog_load_log_buf"))
271		bpf_prog_load_log_buf();
272	if (test__start_subtest("bpf_btf_load_log_buf"))
273		bpf_btf_load_log_buf();
274}