Blame sysdeps/unix/sysv/linux/pthread_kill.c

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/* Copyright (C) 2002-2018 Free Software Foundation, Inc.
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   This file is part of the GNU C Library.
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   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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   The GNU C Library is free software; you can redistribute it and/or
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   modify it under the terms of the GNU Lesser General Public
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   License as published by the Free Software Foundation; either
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   version 2.1 of the License, or (at your option) any later version.
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   The GNU C Library is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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   Lesser General Public License for more details.
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   You should have received a copy of the GNU Lesser General Public
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   License along with the GNU C Library; if not, see
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   <http://www.gnu.org/licenses/>.  */
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#include <errno.h>
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#include <signal.h>
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#include <pthreadP.h>
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#include <tls.h>
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#include <sysdep.h>
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#include <unistd.h>
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int
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__pthread_kill (pthread_t threadid, int signo)
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{
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  struct pthread *pd = (struct pthread *) threadid;
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  /* Make sure the descriptor is valid.  */
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  if (DEBUGGING_P && INVALID_TD_P (pd))
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    /* Not a valid thread handle.  */
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    return ESRCH;
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  /* Force load of pd->tid into local variable or register.  Otherwise
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     if a thread exits between ESRCH test and tgkill, we might return
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     EINVAL, because pd->tid would be cleared by the kernel.  */
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  pid_t tid = atomic_forced_read (pd->tid);
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  if (__glibc_unlikely (tid <= 0))
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    /* Not a valid thread handle.  */
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    return ESRCH;
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  /* Disallow sending the signal we use for cancellation, timers,
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     for the setxid implementation.  */
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  if (signo == SIGCANCEL || signo == SIGTIMER || signo == SIGSETXID)
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    return EINVAL;
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  /* We have a special syscall to do the work.  */
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  INTERNAL_SYSCALL_DECL (err);
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  pid_t pid = __getpid ();
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  int val = INTERNAL_SYSCALL_CALL (tgkill, err, pid, tid, signo);
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  return (INTERNAL_SYSCALL_ERROR_P (val, err)
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	  ? INTERNAL_SYSCALL_ERRNO (val, err) : 0);
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}
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strong_alias (__pthread_kill, pthread_kill)