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

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include <linux/ptrace.h>
   4 #include <linux/bpf.h>
   5
   6 #include <netinet/in.h>
   7
   8 #include <bpf/bpf_helpers.h>
   9 #include <bpf/bpf_tracing.h>
  10 #include "bpf_trace_helpers.h"
  11
  12 static struct sockaddr_in old;
  13
  14 SEC("kprobe/__sys_connect")
  15 int BPF_KPROBE(handle_sys_connect)
  16 {
  17         void *ptr = (void *)PT_REGS_PARM2(ctx);
  18         struct sockaddr_in new;
  19
  20         bpf_probe_read_user(&old, sizeof(old), ptr);
  21         __builtin_memset(&new, 0xab, sizeof(new));
  22         bpf_probe_write_user(ptr, &new, sizeof(new));
  23
  24         return 0;
  25 }
  26
  27 char _license[] SEC("license") = "GPL";