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/* ISO C raise function for libpthread.
Copyright (C) 2002-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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 <errno.h>
#include <pthread.h>
#include <signal.h>
#include <internal-signals.h>
/* Raise the signal SIG. POSIX requires raise to be async-signal-safe,
but also requires it to be equivalent to pthread_kill (pthread_self (), sig),
and that construct is *not* async-signal safe. In particular, an
async signal handler that calls fork (which is also async-signal-safe)
could invalidate the handle returned by pthread_self, and/or cause
pthread_kill to be called twice. So we must block signals around
the operation. See bug 15368 for more detail.
Also, raise sets errno on failure, whereas pthread_kill returns the
error code. (It is not possible for pthread_self to fail.) */
int
__libc_raise (int sig)
{
/* Disallow sending the signals we use for cancellation, timers,
setxid, etc. This check is also performed in pthread_kill, but
if we do it now we can avoid blocking and then unblocking signals
unnecessarily. */
if (__glibc_unlikely (__is_internal_signal (sig)))
{
__set_errno (EINVAL);
return -1;
}
/* We can safely assume that __libc_signal_block_app and
__libc_signal_restore_set will not fail, because
sigprocmask can only fail under three circumstances:
1. sigsetsize != sizeof (sigset_t) (EINVAL)
2. a failure in copy from/to user space (EFAULT)
3. an invalid 'how' operation (EINVAL)
Getting any of these would indicate a bug in either the
definition of sigset_t or the implementations of the
wrappers. */
sigset_t omask;
__libc_signal_block_app (&omask);
int ret = __pthread_kill (__pthread_self (), sig);
__libc_signal_restore_set (&omask);
if (__glibc_unlikely (ret))
{
__set_errno (ret);
return -1;
}
return 0;
}
strong_alias (__libc_raise, raise)
libc_hidden_def (raise)
weak_alias (__libc_raise, gsignal)
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