tools/testing/selftests/bpf/prog_tests/map_in_map.c

   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