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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2020 Facebook */
   3
   4 #include <test_progs.h>
   5
   6 struct callback_head {
   7         struct callback_head *next;
   8         void (*func)(struct callback_head *head);
   9 };
  10
  11 /* ___shuffled flavor is just an illusion for BPF code, it doesn't really
  12  * exist and user-space needs to provide data in the memory layout that
  13  * matches callback_head. We just defined ___shuffled flavor to make it easier
  14  * to work with the skeleton
  15  */
  16 struct callback_head___shuffled {
  17         struct callback_head___shuffled *next;
  18         void (*func)(struct callback_head *head);
  19 };
  20
  21 #include "test_core_read_macros.skel.h"
  22
  23 void test_core_read_macros(void)
  24 {
  25         int duration = 0, err;
  26         struct test_core_read_macros* skel;
  27         struct test_core_read_macros__bss *bss;
  28         struct callback_head u_probe_in;
  29         struct callback_head___shuffled u_core_in;
  30
  31         skel = test_core_read_macros__open_and_load();
  32         if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
  33                 return;
  34         bss = skel->bss;
  35         bss->my_pid = getpid();
  36
  37         /* next pointers have to be set from the kernel side */
  38         bss->k_probe_in.func = (void *)(long)0x1234;
  39         bss->k_core_in.func = (void *)(long)0xabcd;
  40
  41         u_probe_in.next = &u_probe_in;
  42         u_probe_in.func = (void *)(long)0x5678;
  43         bss->u_probe_in = &u_probe_in;
  44
  45         u_core_in.next = &u_core_in;
  46         u_core_in.func = (void *)(long)0xdbca;
  47         bss->u_core_in = &u_core_in;
  48
  49         err = test_core_read_macros__attach(skel);
  50         if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
  51                 goto cleanup;
  52
  53         /* trigger tracepoint */
  54         usleep(1);
  55
  56         ASSERT_EQ(bss->k_probe_out, 0x1234, "k_probe_out");
  57         ASSERT_EQ(bss->k_core_out, 0xabcd, "k_core_out");
  58
  59         ASSERT_EQ(bss->u_probe_out, 0x5678, "u_probe_out");
  60         ASSERT_EQ(bss->u_core_out, 0xdbca, "u_core_out");
  61
  62 cleanup:
  63         test_core_read_macros__destroy(skel);
  64 }