xref: /linux/tools/testing/selftests/bpf/prog_tests/map_in_map.c (revision d7b4e3287ca3a7baf66efd9158498e551a9550da)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2023. Huawei Technologies Co., Ltd */
3 #define _GNU_SOURCE
4 #include <unistd.h>
5 #include <sys/syscall.h>
6 #include <test_progs.h>
7 #include <bpf/btf.h>
8 #include "access_map_in_map.skel.h"
9 
10 struct thread_ctx {
11 	pthread_barrier_t barrier;
12 	int outer_map_fd;
13 	int start, abort;
14 	int loop, err;
15 };
16 
17 static int wait_for_start_or_abort(struct thread_ctx *ctx)
18 {
19 	while (!ctx->start && !ctx->abort)
20 		usleep(1);
21 	return ctx->abort ? -1 : 0;
22 }
23 
24 static void *update_map_fn(void *data)
25 {
26 	struct thread_ctx *ctx = data;
27 	int loop = ctx->loop, err = 0;
28 
29 	if (wait_for_start_or_abort(ctx) < 0)
30 		return NULL;
31 	pthread_barrier_wait(&ctx->barrier);
32 
33 	while (loop-- > 0) {
34 		int fd, zero = 0;
35 
36 		fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, 4, 4, 1, NULL);
37 		if (fd < 0) {
38 			err |= 1;
39 			pthread_barrier_wait(&ctx->barrier);
40 			continue;
41 		}
42 
43 		/* Remove the old inner map */
44 		if (bpf_map_update_elem(ctx->outer_map_fd, &zero, &fd, 0) < 0)
45 			err |= 2;
46 		close(fd);
47 		pthread_barrier_wait(&ctx->barrier);
48 	}
49 
50 	ctx->err = err;
51 
52 	return NULL;
53 }
54 
55 static void *access_map_fn(void *data)
56 {
57 	struct thread_ctx *ctx = data;
58 	int loop = ctx->loop;
59 
60 	if (wait_for_start_or_abort(ctx) < 0)
61 		return NULL;
62 	pthread_barrier_wait(&ctx->barrier);
63 
64 	while (loop-- > 0) {
65 		/* Access the old inner map */
66 		syscall(SYS_getpgid);
67 		pthread_barrier_wait(&ctx->barrier);
68 	}
69 
70 	return NULL;
71 }
72 
73 static void test_map_in_map_access(const char *prog_name, const char *map_name)
74 {
75 	struct access_map_in_map *skel;
76 	struct bpf_map *outer_map;
77 	struct bpf_program *prog;
78 	struct thread_ctx ctx;
79 	pthread_t tid[2];
80 	int err;
81 
82 	skel = access_map_in_map__open();
83 	if (!ASSERT_OK_PTR(skel, "access_map_in_map open"))
84 		return;
85 
86 	prog = bpf_object__find_program_by_name(skel->obj, prog_name);
87 	if (!ASSERT_OK_PTR(prog, "find program"))
88 		goto out;
89 	bpf_program__set_autoload(prog, true);
90 
91 	outer_map = bpf_object__find_map_by_name(skel->obj, map_name);
92 	if (!ASSERT_OK_PTR(outer_map, "find map"))
93 		goto out;
94 
95 	err = access_map_in_map__load(skel);
96 	if (!ASSERT_OK(err, "access_map_in_map load"))
97 		goto out;
98 
99 	err = access_map_in_map__attach(skel);
100 	if (!ASSERT_OK(err, "access_map_in_map attach"))
101 		goto out;
102 
103 	skel->bss->tgid = getpid();
104 
105 	memset(&ctx, 0, sizeof(ctx));
106 	pthread_barrier_init(&ctx.barrier, NULL, 2);
107 	ctx.outer_map_fd = bpf_map__fd(outer_map);
108 	ctx.loop = 4;
109 
110 	err = pthread_create(&tid[0], NULL, update_map_fn, &ctx);
111 	if (!ASSERT_OK(err, "close_thread"))
112 		goto out;
113 
114 	err = pthread_create(&tid[1], NULL, access_map_fn, &ctx);
115 	if (!ASSERT_OK(err, "read_thread")) {
116 		ctx.abort = 1;
117 		pthread_join(tid[0], NULL);
118 		goto out;
119 	}
120 
121 	ctx.start = 1;
122 	pthread_join(tid[0], NULL);
123 	pthread_join(tid[1], NULL);
124 
125 	ASSERT_OK(ctx.err, "err");
126 out:
127 	access_map_in_map__destroy(skel);
128 }
129 
130 void test_map_in_map(void)
131 {
132 	if (test__start_subtest("acc_map_in_array"))
133 		test_map_in_map_access("access_map_in_array", "outer_array_map");
134 	if (test__start_subtest("sleepable_acc_map_in_array"))
135 		test_map_in_map_access("sleepable_access_map_in_array", "outer_array_map");
136 	if (test__start_subtest("acc_map_in_htab"))
137 		test_map_in_map_access("access_map_in_htab", "outer_htab_map");
138 	if (test__start_subtest("sleepable_acc_map_in_htab"))
139 		test_map_in_map_access("sleepable_access_map_in_htab", "outer_htab_map");
140 }
141 
142