glibc/sysdeps/unix/sysv/linux/sigsetops.h
Adhemerval Zanella f26d456b98 linux: Fix __NSIG_WORDS and add __NSIG_BYTES
The __NSIG_WORDS value is based on minimum number of words to hold
the maximum number of signals supported by the architecture.

This patch also adds __NSIG_BYTES, which is the number of bytes
required to represent the supported number of signals.  It is used in
syscalls which takes a sigset_t.

Checked on x86_64-linux-gnu and i686-linux-gnu.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-07 14:10:58 -03:00

116 lines
3.2 KiB
C

/* __sigset_t manipulators. Linux version.
Copyright (C) 1991-2020 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/>. */
#ifndef _SIGSETOPS_H
#define _SIGSETOPS_H 1
#include <signal.h>
#include <limits.h>
#include <libc-pointer-arith.h>
/* Return a mask that includes the bit for SIG only. */
#define __sigmask(sig) \
(1UL << (((sig) - 1) % ULONG_WIDTH))
/* Return the word index for SIG. */
static inline unsigned long int
__sigword (int sig)
{
return (sig - 1) / ULONG_WIDTH;
}
/* Linux sig* functions only handle up to __NSIG_WORDS words instead of
full _SIGSET_NWORDS sigset size. The signal numbers are 1-based, and
bit 0 of a signal mask is for signal 1. */
#define __NSIG_WORDS (ALIGN_UP ((_NSIG - 1), ULONG_WIDTH) / ULONG_WIDTH)
_Static_assert (__NSIG_WORDS <= _SIGSET_NWORDS,
"__NSIG_WORDS > _SIGSET_WORDS");
/* This macro is used on syscall that takes a sigset_t to specify the expected
size in bytes. As for glibc, kernel sigset is implemented as an array of
unsigned long. */
#define __NSIG_BYTES (__NSIG_WORDS * (ULONG_WIDTH / UCHAR_WIDTH))
static inline void
__sigemptyset (sigset_t *set)
{
int cnt = __NSIG_WORDS;
while (--cnt >= 0)
set->__val[cnt] = 0;
}
static inline void
__sigfillset (sigset_t *set)
{
int cnt = __NSIG_WORDS;
while (--cnt >= 0)
set->__val[cnt] = ~0UL;
}
static inline int
__sigisemptyset (const sigset_t *set)
{
int cnt = __NSIG_WORDS;
int ret = set->__val[--cnt];
while (ret == 0 && --cnt >= 0)
ret = set->__val[cnt];
return ret == 0;
}
static inline void
__sigandset (sigset_t *dest, const sigset_t *left, const sigset_t *right)
{
int cnt = __NSIG_WORDS;
while (--cnt >= 0)
dest->__val[cnt] = left->__val[cnt] & right->__val[cnt];
}
static inline void
__sigorset (sigset_t *dest, const sigset_t *left, const sigset_t *right)
{
int cnt = __NSIG_WORDS;
while (--cnt >= 0)
dest->__val[cnt] = left->__val[cnt] | right->__val[cnt];
}
static inline int
__sigismember (const sigset_t *set, int sig)
{
unsigned long int mask = __sigmask (sig);
unsigned long int word = __sigword (sig);
return set->__val[word] & mask ? 1 : 0;
}
static inline void
__sigaddset (sigset_t *set, int sig)
{
unsigned long int mask = __sigmask (sig);
unsigned long int word = __sigword (sig);
set->__val[word] |= mask;
}
static inline void
__sigdelset (sigset_t *set, int sig)
{
unsigned long int mask = __sigmask (sig);
unsigned long int word = __sigword (sig);
set->__val[word] &= ~mask;
}
#endif /* bits/sigsetops.h */