1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2020 Tessares SA <http://www.tessares.net> */
3 
4 #include <test_progs.h>
5 #include "test_map_init.skel.h"
6 
7 #define TEST_VALUE 0x1234
8 #define FILL_VALUE 0xdeadbeef
9 
10 static int nr_cpus;
11 static int duration;
12 
13 typedef unsigned long long map_key_t;
14 typedef unsigned long long map_value_t;
15 typedef struct {
16 	map_value_t v; /* padding */
17 } __bpf_percpu_val_align pcpu_map_value_t;
18 
19 
map_populate(int map_fd,int num)20 static int map_populate(int map_fd, int num)
21 {
22 	pcpu_map_value_t value[nr_cpus];
23 	int i, err;
24 	map_key_t key;
25 
26 	for (i = 0; i < nr_cpus; i++)
27 		bpf_percpu(value, i) = FILL_VALUE;
28 
29 	for (key = 1; key <= num; key++) {
30 		err = bpf_map_update_elem(map_fd, &key, value, BPF_NOEXIST);
31 		if (!ASSERT_OK(err, "bpf_map_update_elem"))
32 			return -1;
33 	}
34 
35 	return 0;
36 }
37 
setup(enum bpf_map_type map_type,int map_sz,int * map_fd,int populate)38 static struct test_map_init *setup(enum bpf_map_type map_type, int map_sz,
39 			    int *map_fd, int populate)
40 {
41 	struct test_map_init *skel;
42 	int err;
43 
44 	skel = test_map_init__open();
45 	if (!ASSERT_OK_PTR(skel, "skel_open"))
46 		return NULL;
47 
48 	err = bpf_map__set_type(skel->maps.hashmap1, map_type);
49 	if (!ASSERT_OK(err, "bpf_map__set_type"))
50 		goto error;
51 
52 	err = bpf_map__set_max_entries(skel->maps.hashmap1, map_sz);
53 	if (!ASSERT_OK(err, "bpf_map__set_max_entries"))
54 		goto error;
55 
56 	err = test_map_init__load(skel);
57 	if (!ASSERT_OK(err, "skel_load"))
58 		goto error;
59 
60 	*map_fd = bpf_map__fd(skel->maps.hashmap1);
61 	if (CHECK(*map_fd < 0, "bpf_map__fd", "failed\n"))
62 		goto error;
63 
64 	err = map_populate(*map_fd, populate);
65 	if (!ASSERT_OK(err, "map_populate"))
66 		goto error_map;
67 
68 	return skel;
69 
70 error_map:
71 	close(*map_fd);
72 error:
73 	test_map_init__destroy(skel);
74 	return NULL;
75 }
76 
77 /* executes bpf program that updates map with key, value */
prog_run_insert_elem(struct test_map_init * skel,map_key_t key,map_value_t value)78 static int prog_run_insert_elem(struct test_map_init *skel, map_key_t key,
79 				map_value_t value)
80 {
81 	struct test_map_init__bss *bss;
82 
83 	bss = skel->bss;
84 
85 	bss->inKey = key;
86 	bss->inValue = value;
87 	bss->inPid = getpid();
88 
89 	if (!ASSERT_OK(test_map_init__attach(skel), "skel_attach"))
90 		return -1;
91 
92 	/* Let tracepoint trigger */
93 	syscall(__NR_getpgid);
94 
95 	test_map_init__detach(skel);
96 
97 	return 0;
98 }
99 
check_values_one_cpu(pcpu_map_value_t * value,map_value_t expected)100 static int check_values_one_cpu(pcpu_map_value_t *value, map_value_t expected)
101 {
102 	int i, nzCnt = 0;
103 	map_value_t val;
104 
105 	for (i = 0; i < nr_cpus; i++) {
106 		val = bpf_percpu(value, i);
107 		if (val) {
108 			if (CHECK(val != expected, "map value",
109 				  "unexpected for cpu %d: 0x%llx\n", i, val))
110 				return -1;
111 			nzCnt++;
112 		}
113 	}
114 
115 	if (CHECK(nzCnt != 1, "map value", "set for %d CPUs instead of 1!\n",
116 		  nzCnt))
117 		return -1;
118 
119 	return 0;
120 }
121 
122 /* Add key=1 elem with values set for all CPUs
123  * Delete elem key=1
124  * Run bpf prog that inserts new key=1 elem with value=0x1234
125  *   (bpf prog can only set value for current CPU)
126  * Lookup Key=1 and check value is as expected for all CPUs:
127  *   value set by bpf prog for one CPU, 0 for all others
128  */
test_pcpu_map_init(void)129 static void test_pcpu_map_init(void)
130 {
131 	pcpu_map_value_t value[nr_cpus];
132 	struct test_map_init *skel;
133 	int map_fd, err;
134 	map_key_t key;
135 
136 	/* max 1 elem in map so insertion is forced to reuse freed entry */
137 	skel = setup(BPF_MAP_TYPE_PERCPU_HASH, 1, &map_fd, 1);
138 	if (!ASSERT_OK_PTR(skel, "prog_setup"))
139 		return;
140 
141 	/* delete element so the entry can be re-used*/
142 	key = 1;
143 	err = bpf_map_delete_elem(map_fd, &key);
144 	if (!ASSERT_OK(err, "bpf_map_delete_elem"))
145 		goto cleanup;
146 
147 	/* run bpf prog that inserts new elem, re-using the slot just freed */
148 	err = prog_run_insert_elem(skel, key, TEST_VALUE);
149 	if (!ASSERT_OK(err, "prog_run_insert_elem"))
150 		goto cleanup;
151 
152 	/* check that key=1 was re-created by bpf prog */
153 	err = bpf_map_lookup_elem(map_fd, &key, value);
154 	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
155 		goto cleanup;
156 
157 	/* and has expected values */
158 	check_values_one_cpu(value, TEST_VALUE);
159 
160 cleanup:
161 	test_map_init__destroy(skel);
162 }
163 
164 /* Add key=1 and key=2 elems with values set for all CPUs
165  * Run bpf prog that inserts new key=3 elem
166  *   (only for current cpu; other cpus should have initial value = 0)
167  * Lookup Key=1 and check value is as expected for all CPUs
168  */
test_pcpu_lru_map_init(void)169 static void test_pcpu_lru_map_init(void)
170 {
171 	pcpu_map_value_t value[nr_cpus];
172 	struct test_map_init *skel;
173 	int map_fd, err;
174 	map_key_t key;
175 
176 	/* Set up LRU map with 2 elements, values filled for all CPUs.
177 	 * With these 2 elements, the LRU map is full
178 	 */
179 	skel = setup(BPF_MAP_TYPE_LRU_PERCPU_HASH, 2, &map_fd, 2);
180 	if (!ASSERT_OK_PTR(skel, "prog_setup"))
181 		return;
182 
183 	/* run bpf prog that inserts new key=3 element, re-using LRU slot */
184 	key = 3;
185 	err = prog_run_insert_elem(skel, key, TEST_VALUE);
186 	if (!ASSERT_OK(err, "prog_run_insert_elem"))
187 		goto cleanup;
188 
189 	/* check that key=3 replaced one of earlier elements */
190 	err = bpf_map_lookup_elem(map_fd, &key, value);
191 	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
192 		goto cleanup;
193 
194 	/* and has expected values */
195 	check_values_one_cpu(value, TEST_VALUE);
196 
197 cleanup:
198 	test_map_init__destroy(skel);
199 }
200 
test_map_init(void)201 void test_map_init(void)
202 {
203 	nr_cpus = bpf_num_possible_cpus();
204 	if (nr_cpus <= 1) {
205 		printf("%s:SKIP: >1 cpu needed for this test\n", __func__);
206 		test__skip();
207 		return;
208 	}
209 
210 	if (test__start_subtest("pcpu_map_init"))
211 		test_pcpu_map_init();
212 	if (test__start_subtest("pcpu_lru_map_init"))
213 		test_pcpu_lru_map_init();
214 }
215