1/* Copyright (C) 2009-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2009.
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 <string.h>
22#include <unistd.h>
23#include <pthreadP.h>
24#include <tls.h>
25#include <sysdep.h>
26#include <shlib-compat.h>
27
28int
29__pthread_sigqueue (pthread_t threadid, int signo, const union sigval value)
30{
31#ifdef __NR_rt_tgsigqueueinfo
32 struct pthread *pd = (struct pthread *) threadid;
33
34 /* Force load of pd->tid into local variable or register. Otherwise
35 if a thread exits between ESRCH test and tgkill, we might return
36 EINVAL, because pd->tid would be cleared by the kernel. */
37 pid_t tid = atomic_forced_read (pd->tid);
38 if (__glibc_unlikely (tid <= 0))
39 /* Not a valid thread handle. */
40 return ESRCH;
41
42 /* Disallow sending the signal we use for cancellation, timers,
43 for the setxid implementation. */
44 if (signo == SIGCANCEL || signo == SIGTIMER || signo == SIGSETXID)
45 return EINVAL;
46
47 pid_t pid = getpid ();
48
49 /* Set up the siginfo_t structure. */
50 siginfo_t info;
51 memset (&info, '\0', sizeof (siginfo_t));
52 info.si_signo = signo;
53 info.si_code = SI_QUEUE;
54 info.si_pid = pid;
55 info.si_uid = __getuid ();
56 info.si_value = value;
57
58 /* We have a special syscall to do the work. */
59 int val = INTERNAL_SYSCALL_CALL (rt_tgsigqueueinfo, pid, tid, signo,
60 &info);
61 return (INTERNAL_SYSCALL_ERROR_P (val)
62 ? INTERNAL_SYSCALL_ERRNO (val) : 0);
63#else
64 return ENOSYS;
65#endif
66}
67versioned_symbol (libc, __pthread_sigqueue, pthread_sigqueue, GLIBC_2_34);
68
69#if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_11, GLIBC_2_34)
70compat_symbol (libpthread, __pthread_sigqueue, pthread_sigqueue, GLIBC_2_11);
71#endif
72