1 /* Support functions handling ptrace_scope.
2    Copyright (C) 2019-2022 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
support_ptrace_scope(void)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 }
44