1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2022. Huawei Technologies Co., Ltd */
3 #define _GNU_SOURCE
4 #include <sched.h>
5 #include <stdbool.h>
6 #include <test_progs.h>
7 #include "htab_update.skel.h"
8
9 struct htab_update_ctx {
10 int fd;
11 int loop;
12 bool stop;
13 };
14
15 static void test_reenter_update(void)
16 {
17 struct htab_update *skel;
18 unsigned int key, value;
19 int err;
20
21 skel = htab_update__open();
22 if (!ASSERT_OK_PTR(skel, "htab_update__open"))
23 return;
24
25 /* lookup_elem_raw() may be inlined and find_kernel_btf_id() will return -ESRCH */
26 bpf_program__set_autoload(skel->progs.lookup_elem_raw, true);
27 err = htab_update__load(skel);
28 if (!ASSERT_TRUE(!err || err == -ESRCH, "htab_update__load") || err)
29 goto out;
30
31 skel->bss->pid = getpid();
32 err = htab_update__attach(skel);
33 if (!ASSERT_OK(err, "htab_update__attach"))
34 goto out;
35
36 /* Will trigger the reentrancy of bpf_map_update_elem() */
37 key = 0;
38 value = 0;
39 err = bpf_map_update_elem(bpf_map__fd(skel->maps.htab), &key, &value, 0);
40 if (!ASSERT_OK(err, "add element"))
41 goto out;
42
43 ASSERT_EQ(skel->bss->update_err, -EBUSY, "no reentrancy");
44 out:
45 htab_update__destroy(skel);
46 }
47
48 static void *htab_update_thread(void *arg)
49 {
50 struct htab_update_ctx *ctx = arg;
51 cpu_set_t cpus;
52 int i;
53
54 /* Pinned on CPU 0 */
55 CPU_ZERO(&cpus);
56 CPU_SET(0, &cpus);
57 pthread_setaffinity_np(pthread_self(), sizeof(cpus), &cpus);
58
59 i = 0;
60 while (i++ < ctx->loop && !ctx->stop) {
61 unsigned int key = 0, value = 0;
62 int err;
63
64 err = bpf_map_update_elem(ctx->fd, &key, &value, 0);
65 if (err) {
66 ctx->stop = true;
67 return (void *)(long)err;
68 }
69 }
70
71 return NULL;
72 }
73
74 static void test_concurrent_update(void)
75 {
76 struct htab_update_ctx ctx;
77 struct htab_update *skel;
78 unsigned int i, nr;
79 pthread_t *tids;
80 int err;
81
82 skel = htab_update__open_and_load();
83 if (!ASSERT_OK_PTR(skel, "htab_update__open_and_load"))
84 return;
85
86 ctx.fd = bpf_map__fd(skel->maps.htab);
87 ctx.loop = 1000;
88 ctx.stop = false;
89
90 nr = 4;
91 tids = calloc(nr, sizeof(*tids));
92 if (!ASSERT_NEQ(tids, NULL, "no mem"))
93 goto out;
94
95 for (i = 0; i < nr; i++) {
96 err = pthread_create(&tids[i], NULL, htab_update_thread, &ctx);
97 if (!ASSERT_OK(err, "pthread_create")) {
98 unsigned int j;
99
100 ctx.stop = true;
101 for (j = 0; j < i; j++)
102 pthread_join(tids[j], NULL);
103 goto out;
104 }
105 }
106
107 for (i = 0; i < nr; i++) {
108 void *thread_err = NULL;
109
110 pthread_join(tids[i], &thread_err);
111 ASSERT_EQ(thread_err, NULL, "update error");
112 }
113
114 out:
115 if (tids)
116 free(tids);
117 htab_update__destroy(skel);
118 }
119
120 void test_htab_update(void)
121 {
122 if (test__start_subtest("reenter_update"))
123 test_reenter_update();
124 if (test__start_subtest("concurrent_update"))
125 test_concurrent_update();
126 }
127
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