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

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /*
   4  * Copyright 2020 Google LLC.
   5  */
   6
   7 #include "vmlinux.h"
   8 #include <bpf/bpf_helpers.h>
   9 #include <bpf/bpf_tracing.h>
  10 #include  <errno.h>
  11
  12 char _license[] SEC("license") = "GPL";
  13
  14 int monitored_pid = 0;
  15 int mprotect_count = 0;
  16 int bprm_count = 0;
  17
  18 SEC("lsm/file_mprotect")
  19 int BPF_PROG(test_int_hook, struct vm_area_struct *vma,
  20              unsigned long reqprot, unsigned long prot, int ret)
  21 {
  22         if (ret != 0)
  23                 return ret;
  24
  25         __u32 pid = bpf_get_current_pid_tgid() >> 32;
  26         int is_stack = 0;
  27
  28         is_stack = (vma->vm_start <= vma->vm_mm->start_stack &&
  29                     vma->vm_end >= vma->vm_mm->start_stack);
  30
  31         if (is_stack && monitored_pid == pid) {
  32                 mprotect_count++;
  33                 ret = -EPERM;
  34         }
  35
  36         return ret;
  37 }
  38
  39 SEC("lsm/bprm_committed_creds")
  40 int BPF_PROG(test_void_hook, struct linux_binprm *bprm)
  41 {
  42         __u32 pid = bpf_get_current_pid_tgid() >> 32;
  43
  44         if (monitored_pid == pid)
  45                 bprm_count++;
  46
  47         return 0;
  48 }