LXR linux/tools/testing/selftests/bpf/progs/test_core_reloc

   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright (c) 2019 Facebook
   3
   4#include <linux/bpf.h>
   5#include <stdint.h>
   6#include <bpf/bpf_helpers.h>
   7#include <bpf/bpf_core_read.h>
   8
   9char _license[] SEC("license") = "GPL";
  10
  11struct {
  12        char in[256];
  13        char out[256];
  14} data = {};
  15
  16struct core_reloc_flavors {
  17        int a;
  18        int b;
  19        int c;
  20};
  21
  22/* local flavor with reversed layout */
  23struct core_reloc_flavors___reversed {
  24        int c;
  25        int b;
  26        int a;
  27};
  28
  29/* local flavor with nested/overlapping layout */
  30struct core_reloc_flavors___weird {
  31        struct {
  32                int b;
  33        };
  34        /* a and c overlap in local flavor, but this should still work
  35         * correctly with target original flavor
  36         */
  37        union {
  38                int a;
  39                int c;
  40        };
  41};
  42
  43#define CORE_READ(dst, src) bpf_core_read(dst, sizeof(*(dst)), src)
  44
  45SEC("raw_tracepoint/sys_enter")
  46int test_core_flavors(void *ctx)
  47{
  48        struct core_reloc_flavors *in_orig = (void *)&data.in;
  49        struct core_reloc_flavors___reversed *in_rev = (void *)&data.in;
  50        struct core_reloc_flavors___weird *in_weird = (void *)&data.in;
  51        struct core_reloc_flavors *out = (void *)&data.out;
  52
  53        /* read a using weird layout */
  54        if (CORE_READ(&out->a, &in_weird->a))
  55                return 1;
  56        /* read b using reversed layout */
  57        if (CORE_READ(&out->b, &in_rev->b))
  58                return 1;
  59        /* read c using original layout */
  60        if (CORE_READ(&out->c, &in_orig->c))
  61                return 1;
  62
  63        return 0;
  64}
  65
  66