1/* Copyright (C) 2002-2020 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include <signal.h>
21#include <pthreadP.h>
22#include <tls.h>
23#include <sysdep.h>
24#include <unistd.h>
25
26
27int
28__pthread_kill (pthread_t threadid, int signo)
29{
30 struct pthread *pd = (struct pthread *) threadid;
31
32 /* Make sure the descriptor is valid. */
33 if (DEBUGGING_P && INVALID_TD_P (pd))
34 /* Not a valid thread handle. */
35 return ESRCH;
36
37 /* Force load of pd->tid into local variable or register. Otherwise
38 if a thread exits between ESRCH test and tgkill, we might return
39 EINVAL, because pd->tid would be cleared by the kernel. */
40 pid_t tid = atomic_forced_read (pd->tid);
41 if (__glibc_unlikely (tid <= 0))
42 /* Not a valid thread handle. */
43 return ESRCH;
44
45 /* Disallow sending the signal we use for cancellation, timers,
46 for the setxid implementation. */
47 if (signo == SIGCANCEL || signo == SIGTIMER || signo == SIGSETXID)
48 return EINVAL;
49
50 /* We have a special syscall to do the work. */
51 pid_t pid = __getpid ();
52
53 int val = INTERNAL_SYSCALL_CALL (tgkill, pid, tid, signo);
54 return (INTERNAL_SYSCALL_ERROR_P (val)
55 ? INTERNAL_SYSCALL_ERRNO (val) : 0);
56}
57strong_alias (__pthread_kill, pthread_kill)
58