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/* Check longjmp from user context to main context.
Copyright (C) 2023-2024 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/>. */
/* When _FORTIFY_SOURCE is defined to 2, ____longjmp_chk is called,
instead of longjmp. ____longjmp_chk compares the relative stack
values to decide if it is called from a stack frame which called
setjmp. If not, ____longjmp_chk assumes that an alternate signal
stack is used. Since comparing the relative stack values isn't
reliable with user context, when there is no signal, ____longjmp_chk
will fail. Undefine _FORTIFY_SOURCE to avoid ____longjmp_chk. */
#undef _FORTIFY_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <setjmp.h>
#include <ucontext.h>
#include <unistd.h>
static jmp_buf jmpbuf;
static ucontext_t ctx;
static void f2 (void);
static void
__attribute__ ((noinline, noclone))
f1 (void)
{
printf ("start f1\n");
f2 ();
}
static void
__attribute__ ((noinline, noclone))
f2 (void)
{
printf ("start f2\n");
if (setcontext (&ctx) != 0)
{
printf ("%s: setcontext: %m\n", __FUNCTION__);
exit (EXIT_FAILURE);
}
}
static void
f3 (void)
{
printf ("start f3\n");
longjmp (jmpbuf, 1);
}
static int
__attribute__ ((noinline, noclone))
do_test_1 (void)
{
char st1[32768];
if (setjmp (jmpbuf) != 0)
return 0;
puts ("making contexts");
if (getcontext (&ctx) != 0)
{
printf ("%s: getcontext: %m\n", __FUNCTION__);
exit (EXIT_FAILURE);
}
ctx.uc_stack.ss_sp = st1;
ctx.uc_stack.ss_size = sizeof st1;
ctx.uc_link = NULL;
makecontext (&ctx, (void (*) (void)) f3, 0);
f1 ();
puts ("FAIL: returned from f1 ()");
exit (EXIT_FAILURE);
}
static int
do_test (void)
{
return do_test_1 ();
}
#include <support/test-driver.c>
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