glibc/nptl/tst-cleanup2.c
Siddhesh Poyarekar 6c8bbad927 Mark success return value as volatile to work around rescheduling
Resolves #15921

The test case nptl/tst-cleanup2 fails on s390x and power6 due to
instruction sheduling in gcc.  This was reported in gcc:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58034

but it was concluded that gcc is allowed to assume that the first
argument to sprintf is a character array - NULL not being a valid
character array.
2013-09-03 09:29:01 +05:30

69 lines
1.9 KiB
C

/* Copyright (C) 2003-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Bao Duong <bduong@progress.com>, 2003.
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
<http://www.gnu.org/licenses/>. */
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
static sigjmp_buf jmpbuf;
static void
sig_handler (int signo)
{
siglongjmp (jmpbuf, 1);
}
static int
do_test (void)
{
char *p = NULL;
/* gcc can overwrite the success written value by scheduling instructions
around sprintf. It is allowed to do this since according to C99 the first
argument of sprintf is a character array and NULL is not a valid character
array. Mark the return value as volatile so that it gets reloaded on
return. */
volatile int ret = 0;
struct sigaction sa;
sa.sa_handler = sig_handler;
sigemptyset (&sa.sa_mask);
sa.sa_flags = SA_SIGINFO;
if (sigaction (SIGSEGV, &sa, 0))
{
perror ("installing SIGSEGV handler\n");
exit (1);
}
puts ("Attempting to sprintf to null ptr");
if (setjmp (jmpbuf))
{
puts ("Exiting main...");
return ret;
}
sprintf (p, "This should segv\n");
return 1;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"