1 /* Test of sigaltstack wrappers.
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/xsignal.h>
20 #include <support/support.h>
21 #include <support/xunistd.h>
22 #include <support/check.h>
23 
24 #include <stdint.h>
25 #include <stdio.h>
26 
27 static volatile uintptr_t handler_stackaddr;
28 
29 static void
handler(int unused)30 handler (int unused)
31 {
32   int var;
33   handler_stackaddr = (uintptr_t) &var;
34 }
35 
36 int
do_test(void)37 do_test (void)
38 {
39   void *sstk = xalloc_sigstack (0);
40 
41   unsigned char *sp;
42   size_t size;
43   xget_sigstack_location (sstk, &sp, &size);
44   printf ("signal stack installed: sp=%p size=%zu\n", sp, size);
45 
46   struct sigaction sa;
47   sa.sa_handler = handler;
48   sa.sa_flags   = SA_RESTART | SA_ONSTACK;
49   sigfillset (&sa.sa_mask);
50   if (sigaction (SIGUSR1, &sa, 0))
51     FAIL_RET ("sigaction (SIGUSR1, handler): %m\n");
52 
53   raise (SIGUSR1);
54 
55   uintptr_t haddr = handler_stackaddr;
56   printf ("address of handler local variable: %p\n", (void *)haddr);
57   TEST_VERIFY ((uintptr_t)sp < haddr);
58   TEST_VERIFY (haddr < (uintptr_t)sp + size);
59 
60   xfree_sigstack (sstk);
61   return 0;
62 }
63 
64 #include <support/test-driver.c>
65