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/* ABI compatibility for obsolete sigvec function from 4.2BSD.
Copyright (C) 1991-2024 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 <shlib-compat.h>
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_21)
# include <signal.h>
# include <errno.h>
# include <stddef.h>
/* These are the struct sigvec and SV_* bit definitions that
used to be in <signal.h>. The whole interface now exists
solely for ABI compatibility, so it can just be here. */
struct sigvec
{
__sighandler_t sv_handler; /* Signal handler. */
int sv_mask; /* Mask of signals to be blocked. */
int sv_flags; /* Flags (see below). */
};
# define SV_ONSTACK (1 << 0)/* Take the signal on the signal stack. */
# define SV_INTERRUPT (1 << 1)/* Do not restart system calls. */
# define SV_RESETHAND (1 << 2)/* Reset handler to SIG_DFL on receipt. */
/* Include macros to convert between `sigset_t' and old-style mask. */
# include <sigset-cvt-mask.h>
# ifndef SA_RESETHAND
/* When sigaction lacks the extension bit for it,
we use a wrapper handler to support SV_RESETHAND. */
struct sigvec_wrapper_data
{
__sighandler_t sw_handler;
unsigned int sw_mask;
};
static void sigvec_wrapper_handler (int sig) __THROW;
static struct sigvec_wrapper_data sigvec_wrapper_data[NSIG];
# endif
/* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
of VEC. The signals in `sv_mask' will be blocked while the handler runs.
If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
reset to SIG_DFL before `sv_handler' is entered. If OVEC is non-NULL,
it is filled in with the old information for SIG. */
int
__sigvec (int sig,
const struct sigvec *vec,
struct sigvec *ovec)
{
struct sigaction old;
# ifndef SA_RESETHAND
if (vec == NULL || !(vec->sv_flags & SV_RESETHAND))
# endif
{
struct sigaction new, *n;
if (vec == NULL)
n = NULL;
else
{
__sighandler_t handler;
unsigned int mask;
unsigned int sv_flags;
unsigned int sa_flags;
handler = vec->sv_handler;
mask = vec->sv_mask;
sv_flags = vec->sv_flags;
sa_flags = 0;
if (sv_flags & SV_ONSTACK)
{
# ifdef SA_ONSTACK
sa_flags |= SA_ONSTACK;
# else
__set_errno (ENOSYS);
return -1;
# endif
}
# ifdef SA_RESTART
if (!(sv_flags & SV_INTERRUPT))
sa_flags |= SA_RESTART;
# endif
# ifdef SA_RESETHAND
if (sv_flags & SV_RESETHAND)
sa_flags |= SA_RESETHAND;
# endif
n = &new;
new.sa_handler = handler;
if (sigset_set_old_mask (&new.sa_mask, mask) < 0)
return -1;
new.sa_flags = sa_flags;
}
if (__sigaction (sig, n, &old) < 0)
return -1;
}
# ifndef SA_RESETHAND
else
{
__sighandler_t handler;
unsigned int mask;
struct sigvec_wrapper_data *data;
struct sigaction wrapper;
handler = vec->sv_handler;
mask = (unsigned int)vec->sv_mask;
data = &sigvec_wrapper_data[sig];
wrapper.sa_handler = sigvec_wrapper_handler;
/* FIXME: should we set wrapper.sa_mask, wrapper.sa_flags?? */
data->sw_handler = handler;
data->sw_mask = mask;
if (__sigaction (sig, &wrapper, &old) < 0)
return -1;
}
# endif
if (ovec != NULL)
{
__sighandler_t handler;
unsigned int sv_flags;
unsigned int sa_flags;
unsigned int mask;
handler = old.sa_handler;
sv_flags = 0;
sa_flags = old.sa_flags;
# ifndef SA_RESETHAND
if (handler == sigvec_wrapper_handler)
{
handler = sigvec_wrapper_data[sig].sw_handler;
/* should we use data->sw_mask?? */
sv_flags |= SV_RESETHAND;
}
# else
if (sa_flags & SA_RESETHAND)
sv_flags |= SV_RESETHAND;
# endif
mask = sigset_get_old_mask (&old.sa_mask);
# ifdef SA_ONSTACK
if (sa_flags & SA_ONSTACK)
sv_flags |= SV_ONSTACK;
# endif
# ifdef SA_RESTART
if (!(sa_flags & SA_RESTART))
# endif
sv_flags |= SV_INTERRUPT;
ovec->sv_handler = handler;
ovec->sv_mask = (int)mask;
ovec->sv_flags = (int)sv_flags;
}
return 0;
}
compat_symbol (libc, __sigvec, sigvec, GLIBC_2_0);
# ifndef SA_RESETHAND
static void
sigvec_wrapper_handler (int sig)
{
struct sigvec_wrapper_data *data;
struct sigaction act;
int save;
__sighandler_t handler;
data = &sigvec_wrapper_data[sig];
act.sa_handler = SIG_DFL;
act.sa_flags = 0;
sigset_set_old_mask (&act.sa_mask, data->sw_mask);
handler = data->sw_handler;
save = errno;
(void) __sigaction (sig, &act, (struct sigaction *) NULL);
__set_errno (save);
(*handler) (sig);
}
# endif /* No SA_RESETHAND. */
#endif /* SHLIB_COMPAT */
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