1  /* Support functions handling ptrace_scope.
       2     Copyright (C) 2019-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <support/check.h>
      20  #include <support/xstdio.h>
      21  #include <support/xptrace.h>
      22  
      23  int
      24  support_ptrace_scope (void)
      25  {
      26    int ptrace_scope = -1;
      27  
      28  #ifdef __linux__
      29    /* YAMA may be not enabled.  Otherwise it contains a value from 0 to 3:
      30       - 0 classic ptrace permissions
      31       - 1 restricted ptrace
      32       - 2 admin-only attach
      33       - 3 no attach  */
      34    FILE *f = fopen ("/proc/sys/kernel/yama/ptrace_scope", "r");
      35    if (f != NULL)
      36      {
      37        TEST_COMPARE (fscanf (f, "%d", &ptrace_scope), 1);
      38        xfclose (f);
      39      }
      40  #endif
      41  
      42    return ptrace_scope;
      43  }