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/* Make sure longjmp fortification catches bad signal stacks.
Copyright (C) 2013-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <setjmp.h>
#include <signal.h>
#include <string.h>
static int do_test (void);
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"
static char buf[SIGSTKSZ * 4];
static jmp_buf jb;
static void
handler (int sig)
{
if (sig == SIGUSR1)
{
if (setjmp (jb) != 0)
{
puts ("setjmp should not have been called");
kill (getpid (), SIGTERM);
}
}
else if (sig == SIGABRT)
{
/* Yeah it worked. */
_exit (0);
}
}
static int
do_test (void)
{
stack_t ss;
set_fortify_handler (handler);
/* Create a valid signal stack and enable it. */
ss.ss_sp = buf;
ss.ss_size = sizeof (buf);
ss.ss_flags = 0;
if (sigaltstack (&ss, NULL) < 0)
{
printf ("first sigaltstack failed: %m\n");
return 1;
}
/* Trigger the signal handler which will create a jmpbuf that points to the
end of the signal stack. */
signal (SIGUSR1, handler);
kill (getpid (), SIGUSR1);
/* Shrink the signal stack so the jmpbuf is now invalid.
We adjust the start & end to handle stacks that grow up & down. */
ss.ss_sp = buf + sizeof (buf) / 2;
ss.ss_size = sizeof (buf) / 4;
if (sigaltstack (&ss, NULL) < 0)
{
printf ("second sigaltstack failed: %m\n");
return 1;
}
/* This should fail. */
longjmp (jb, 1);
puts ("longjmp returned and shouldn't");
return 1;
}
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