tools/testing/selftests/bpf/progs/bpf_iter_test_kern6.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2020 Facebook */
   3 #include <vmlinux.h>
   4 #include <bpf/bpf_helpers.h>
   5
   6 char _license[] SEC("license") = "GPL";
   7
   8 __u32 value_sum = 0;
   9
  10 SEC("iter/bpf_map_elem")
  11 int dump_bpf_hash_map(struct bpf_iter__bpf_map_elem *ctx)
  12 {
  13         void *value = ctx->value;
  14
  15         if (value == (void *)0)
  16                 return 0;
  17
  18         /* negative offset, verifier failure. */
  19         value_sum += *(__u32 *)(value - 4);
  20         return 0;
  21 }