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/* Procedure definition for FE_MASK_ENV for Linux/ppc.
Copyright (C) 2007 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <fenv.h>
#include <errno.h>
#include <signal.h>
#include <unistd.h>
#include <sysdep.h>
#include <sys/prctl.h>
#include <kernel-features.h>
#if __ASSUME_NEW_PRCTL_SYSCALL == 0
/* This is rather fiddly under Linux. We don't have direct access,
and there is no system call, but we can change the bits
in a signal handler's context... */
static struct sigaction oact;
static void
fe_mask_handler (int signum, struct sigcontext *sc)
{
sc->regs->msr &= ~0x900ul; /* FE0 | FE1 */
sigaction (SIGUSR1, &oact, NULL);
}
#endif
const fenv_t *
__fe_mask_env (void)
{
#if __ASSUME_NEW_PRCTL_SYSCALL == 0
# if defined PR_SET_FPEXC && defined PR_FP_EXC_DISABLED
int result = INLINE_SYSCALL (prctl, 2, PR_SET_FPEXC, PR_FP_EXC_DISABLED);
if (result == -1 && errno == EINVAL)
# endif
{
struct sigaction act;
act.sa_handler = (sighandler_t) fe_mask_handler;
sigemptyset (&act.sa_mask);
act.sa_flags = 0;
sigaction (SIGUSR1, &act, &oact);
raise (SIGUSR1);
}
#else
INTERNAL_SYSCALL_DECL (err);
INTERNAL_SYSCALL (prctl, err, 2, PR_SET_FPEXC, PR_FP_EXC_DISABLED);
#endif
return FE_DFL_ENV;
}
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