glibc/elf/tst-startup-errno.c
Aaron Merey 83fd4149ff Test that errno is set to 0 at program startup
Add new testcase elf/tst-startup-errno.c which tests that errno is set
to 0 at first ELF constructor execution and at the start of the
program's main function.

Tested for x86_64

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-09-20 15:49:36 -04:00

59 lines
1.4 KiB
C

/* Test the value of errno at program startup.
Copyright (C) 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/>. */
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
/* Verify that errno is 0 at first ELF constructor execution and at
the start of main. */
static void set_ctor_errno (void) __attribute__((constructor));
static int ctor_errno = -1;
static void
set_ctor_errno (void)
{
ctor_errno = errno;
}
static int
get_ctor_errno (void)
{
return ctor_errno;
}
int
main (void)
{
if (errno != 0)
{
printf ("At start of main errno set to %d != 0\n", errno);
exit (1);
}
if (get_ctor_errno () != 0)
{
printf ("At ctor exec errno set to %d != 0\n", get_ctor_errno ());
exit (1);
}
return 0;
}